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Species diversity is the number of different species in a particular area and their relative abundance. The area in question could be a habitat, a biome, or the entire biosphere. Areas with low species diversity, such as the glaciers of Antarctica, still contain a wide variety of living organisms, whereas the diversity of tropical rainforests is so great that it cannot be accurately assessed. Species richness, the number of species living in a habitat or other unit, is one component of biodiversity. Species evenness is a component of species diversity based on relative abundance (the number individuals in a species relative to the total number of individuals in all species within a system). Foundation species (see Ecosystem Types and Dynamics) often have the highest relative abundance of species. Two locations with the same richness do not necessarily have the same species evenness. For example, both communities in figure \(\PageIndex{b}\) have three different trees species and thus a species richness of three. However, there is a dominant species (represented by six individuals) in community #1. In community #2, there are three of individuals of each species. Therefore, community #2 has a greater species evenness and greater species diversity overall.
The Number of Species on Earth
Despite considerable effort, knowledge of the species that inhabit the planet is limited. About 1.5 million species have been described, but many more species are yet to be identified. Estimates of the total number of species on Earth range from 3 million to 100 million, with more recent estimates commonly ranging from 8 to 11 million species. A 2011 study suggests that only 13% of eukaryotic species (such as plants, animals, fungi, and algae) have been named (Table \(\PageIndex{a}\) . Estimates of numbers of prokaryotic species (such as bacteria) are largely guesses, but biologists agree that science has only just begun to catalog their diversity. In fact, a 2017 study by Brendan Larsen and colleagues estimated that there are actually 1-6 billion species on Earth with at least 70% of them being bacteria. Given that Earth is losing species at an accelerating pace, science knows little about what is being lost.
Table \(\PageIndex{a}\): The estimated number of species by taxonomic group—including both described (named and studied) and predicted (yet to be named) species.
Type of Organism Mora et al. 2011 Described Mora et al. 2011 Predicted Chapman 2009 Described Chapman 2009 Predicted Groombridge and Jenkins 2002 Described Groombridge and Jenkins 2002 Predicted
Animals 1,124,516 9,920,000 1,424,153 6,836,330 1,225,500 10,820,000
Photosynthetic protists (such as algae) 17,892 34,900 25,044 200,500 No data No data
Fungi 44,368 616,320 98,998 1,500,000 72,000 1,500,000
Plants 224,244 314,600 310,129 390,800 270,000 320,000
Non-photosynthetic protists 16,236 72,800 28,871 1,000,000 80,000 600,000
Prokaryotes No data No data 10,307 1,000,000 10,175 No data
Total 1,438,769 10,960,000 1,897,502 10,897,630 1,657,675 13,240,000
There are various initiatives to catalog described species in accessible and more organized ways, and the internet is facilitating that effort. Nevertheless, at the current rate of species description, which according to the State of Observed Species reports is 17,000–20,000 new species a year, it would take close to 500 years to describe all of the species currently in existence. The task, however, is becoming increasingly impossible over time as extinction removes species from Earth faster than they can be described.
Naming and counting species may seem an unimportant pursuit given the other needs of humanity, but it is not simply an accounting. Describing species is a complex process by which biologists determine an organism’s unique characteristics and whether or not that organism belongs to any other described species. It allows biologists to find and recognize the species after the initial discovery to follow up on questions about its biology. That subsequent research will produce the discoveries that make the species valuable to humans and to our ecosystems. Without a name and description, a species cannot be studied in depth and in a coordinated way by multiple scientists.
DNA Barcoding
The technology of molecular genetics and data processing and storage are maturing to the point where cataloging the planet’s species in an accessible way is close to feasible. DNA barcoding is one molecular genetic method, which takes advantage of a specialized structures inside of some cells called mitochondria (figure \(\PageIndex{a}\)). Mitochondria contain DNA that is separate from the rest of the cell, and one of the genes in mitochondrial DNA changes more quickly through the process of evolution than regular DNA. While plants contain mitochondria, DNA from their chloroplasts, the specialized structures in which photosynthesis occurs, are more often barcoded. Rapid DNA sequencing technology make the molecular genetics portion of the work relatively inexpensive and quick. Computer resources store and make available the large volumes of data. Projects are currently underway to use DNA barcoding to catalog museum specimens, which have already been named and studied, as well as testing the method on less studied groups. As of mid 2012, close to 150,000 named species had been barcoded. Early studies suggest there are significant numbers of undescribed species that looked too much like sibling species to previously be recognized as different. These now can be identified with DNA barcoding.
Importance of Species Diversity
Healthy ecosystems contain a diversity of species, and each species plays a role in ecosystem function; therefore, species diversity as well as ecosystem diversity are essential to maintaining ecosystem services. For example, many medications are derived from natural chemicals made by a diverse group of organisms. For example, many plants produce compounds meant to protect the plant from insects and other animals that eat them. Some of these compounds also work as human medicines. Contemporary societies that live close to the land often have a broad knowledge of the medicinal uses of plants growing in their area. For centuries in Europe, older knowledge about the medical uses of plants was compiled in herbals—books that identified the plants and their uses. Humans are not the only animals to use plants for medicinal reasons. The other great apes, orangutans, chimpanzees, bonobos, and gorillas have all been observed self-medicating with plants.
Modern pharmaceutical science also recognizes the importance of these plant compounds. Examples of significant medicines derived from plant compounds include aspirin, codeine, digoxin, atropine, and vincristine (figure \(\PageIndex{c}\)). Many medications were once derived from plant extracts but are now synthesized. It is estimated that, at one time, 25 percent of modern drugs contained at least one plant extract. That number has probably decreased to about 10 percent as natural plant ingredients are replaced by synthetic versions of the plant compounds. Antibiotics, which are responsible for extraordinary improvements in health and lifespans in developed countries, are compounds largely derived from fungi and bacteria.
In recent years, animal venoms and poisons have excited intense research for their medicinal potential. By 2007, the FDA had approved five drugs based on animal toxins to treat diseases such as hypertension, chronic pain, and diabetes. Another five drugs are undergoing clinical trials and at least six drugs are being used in other countries. Other toxins under investigation come from mammals, snakes, lizards, various amphibians, fish, snails, octopuses, and scorpions.
Aside from representing billions of dollars in profits, these medications improve people’s lives. Pharmaceutical companies are actively looking for new natural compounds that can function as medicines. It is estimated that one third of pharmaceutical research and development is spent on natural compounds and that about 35 percent of new drugs brought to market between 1981 and 2002 were from natural compounds.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.01%3A_The_Value_of_Biodiversity/3.1.02%3A_Species_Diversity.txt |
In contrast to ecosystem and species diversity, genetic diversity is a measure of the variability among individuals within a single species. Genetic diversity is represented by the variety of alleles present within a population. A gene represents the fundamental physical unit of heredity, and alleles are specific versions of these genes. For example, there is a gene for flower colors in peas, one allele for that gene carries information for white flowers while another allele carries information for purple flowers. Alleles are passed from parent to offspring. Mutations, changes in the DNA sequences that usually result from errors during DNA replication, are the original source of new alleles.
As a result of sexual reproduction, individuals can have different allele combinations for each gene. Genetic diversity provides the raw material for evolutionary adaptation, the process by which the genetic composition of populations change over time in a way that makes it more suited to the environment.
Loss of genetic diversity makes a species less able to reproduce successfully and less adaptable to a changing environment or to a new disease. Small populations of species are especially susceptible to loss of genetic diversity. When a species loses too many individuals, it becomes genetically uniform. Some of the causes for the loss in genetic diversity include: inbreeding among closely related individuals and genetic drift, the process by which the genetic composition of a population fluctuates randomly over time.
Low genetic diversity makes the Tasmanian devil (figure \(\PageIndex{a}\)) especially vulnerable to Devil Facial Tumor Disease (DFTD), a cancer that threatens it with extinction. Contagious cancers are typically spread by viruses, which can transmit cancer-causing genes; however, in the case of DFTD, the cancerous cells themselves are spread among individuals. Usually, the immune system can recognize cancerous cells, infected cells, and foreign cells, but DFTD cells evade the immune system. If Tasmanian devils had high genetic diversity, it is likely that some individuals would have alleles that made them resistant to DFTD. These individuals would survive and reproduce more frequently than others, and the resistant alleles would become more common in the population (evolutionary adaptation would occur). Because Tasmanian devils have low genetic diversity, there is less opportunity for such evolutionary adaptation.
Genetic diversity is important to agriculture. Since the beginning of human agriculture more than 10,000 years ago, human groups have been breeding and selecting crop varieties. This crop diversity matched the cultural diversity of highly subdivided populations of humans. For example, potatoes were domesticated beginning around 7,000 years ago in the central Andes of Peru and Bolivia. The people in this region traditionally lived in relatively isolated settlements separated by mountains. The potatoes grown in that region belong to seven species and the number of varieties likely is in the thousands. Each variety has been bred to thrive at particular elevations and soil and climate conditions. The diversity is driven by the diverse demands of the dramatic elevation changes, the limited movement of people, and the demands created by crop rotation for different varieties that will do well in different fields.
The potato demonstrates a well-known example of the risks of low crop diversity: during the tragic Irish potato famine (1845–1852 AD), the single potato variety grown in Ireland became susceptible to a potato blight—wiping out the crop (figure \(\PageIndex{b}\)). The loss of the crop led to famine, death, and mass emigration. Resistance to disease is a chief benefit to maintaining crop biodiversity and lack of diversity in contemporary crop species carries similar risks. Seed companies, which are the source of most crop varieties in developed countries, must continually breed new varieties to keep up with evolving pest organisms. These same seed companies, however, have participated in the decline of the number of varieties available as they focus on selling fewer varieties in more areas of the world replacing traditional local varieties.
Potatoes are only one example of agricultural diversity. Every plant, animal, and fungus that has been cultivated by humans has been bred from original wild ancestor species into diverse varieties arising from the demands for food value, adaptation to growing conditions, and resistance to pests. The ability to create new crop varieties relies on the diversity of varieties available and the availability of wild forms related to the crop plant. These wild forms are often the source of new gene variants that can be bred with existing varieties to create varieties with new attributes. Loss of wild species related to a crop will mean the loss of potential in crop improvement. Maintaining the genetic diversity of wild species related to domesticated species ensures our continued supply of food.
Since the 1920s, government agriculture departments have maintained seed banks of crop varieties as a way to maintain crop diversity. This system has flaws because over time seed varieties are lost through accidents and there is no way to replace them. In 2008, the Svalbard Global seed Vault, located on Spitsbergen island, Norway, (figure \(\PageIndex{c}\)) began storing seeds from around the world as a backup system to the regional seed banks. If a regional seed bank stores varieties in Svalbard, losses can be replaced from Svalbard should something happen to the regional seeds. The Svalbard seed vault is deep into the rock of the arctic island. Conditions within the vault are maintained at ideal temperature and humidity for seed survival, but the deep underground location of the vault in the arctic means that failure of the vault’s systems will not compromise the climatic conditions inside the vault.
Supplemental Reading
Dunlap, Garrett. 2018. Facing Facts: Why a transmissible facial cancer is decimating Tasmanian devil populations. SITN Blog. The Graduate School of Arts and Sciences. Harvard University.
Attributions
Modified by Melissa Ha from the following sources:
• Biological from AP Environmental Science by University of California College Prep, University of California (licensed under CC-BY). Download for free at CNX.
• Importance of Biodiversity from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.01%3A_The_Value_of_Biodiversity/3.1.03%3A_Genetic_Diversity.txt |
Biodiversity is not evenly distributed on the planet. For example, Lake Victoria in Africa (figure \(\PageIndex{a}\)) contained almost 500 species from a family of fishes called cichlids before the introduction of the invasive Nile Perch in the 1980s and 1990s caused a mass extinction. (Note that this number does not include species of other fish families.) Lake Huron, the second largest of North America's Great Lakes, contains about 79 species of fish, all of which are found in many other lakes in North America. What accounts for the difference in diversity between Lake Victoria and Lake Huron? Lake Victoria is a tropical lake, while Lake Huron is a temperate lake. Lake Huron in its present form is only about 7,000 years old, while Lake Victoria in its present form is about 15,000 years old. These two factors, latitude and age, are two of several hypotheses biogeographers have suggested to explain biodiversity patterns on Earth.
Biogeography is the study of the distribution of the world’s species both in the past and in the present. The work of biogeographers is critical to understanding our physical environment, how the environment affects species, and how changes in environment impact the distribution of a species. There are three main subfields of biogeography: ecological biogeography, historical biogeography (called paleobiogeography), and conservation biogeography. Ecological biogeography studies the current factors affecting the distribution of plants and animals. Historical biogeography, as the name implies, studies the past distribution of species. Conservation biogeography, on the other hand, is focused on the protection and restoration of species based upon the known historical and current ecological information.
The Tropics Have High Biodiversity
One of the oldest observed patterns in ecology is that biodiversity typically increases as latitude declines. In other words, the greatest species richness occurs near the equator and the lowest richness occurs near the poles (figure \(\PageIndex{b}\)).
It is not yet clear why biodiversity increases closer to the equator, but hypotheses include the greater age of the ecosystems in the tropics versus temperate regions, which were largely devoid of life or drastically impoverished during the last ice age. The greater age provides more time for speciation, the evolutionary process of creating new species. Another possible explanation is the greater energy the tropics receive from the sun, but scientists have not been able to explain how greater energy input could translate into more species. The complexity of tropical ecosystems may promote speciation by increasing the habitat complexity, thus providing more ecological niches (see Communities chapter). Lastly, the tropics have been perceived as being more stable than temperate regions, which have a pronounced climate and day-length seasonality. The stability of tropical ecosystems might promote speciation. Regardless of the mechanisms, it is certainly true that biodiversity is greatest in the tropics. There are also high numbers of endemic species.
Biodiversity Hotspots
In 1988, British environmentalist Norman Myers developed a conservation concept to identify geographical areas rich in species and at significant risk for species loss: biodiversity hotspots. The original criteria for a hotspot included the presence of 1500 or more endemic plant species and 70 percent of the area disturbed by human activity. Endemic species are found in only one location. For example, all of cichlid species found in Lake Victoria only occurred there. The blue jay is endemic to North America, while the Barton Springs salamander is endemic to the mouth of one spring in Austin, Texas. Endemic species with highly restricted distributions, like the Barton Springs salamander, are particularly vulnerable to extinction. If a population of a widespread species declines in one region, individuals from another region may be able to recolonize the first location, but this is not possible for endemic species. Endemic species are particularly common in isolated regions, such as mountaintops or islands. Endemism is especially likely on islands that are large and far from the mainland. Identifying biodiversity hotspots aids with conservation efforts, a kind of conservation triage. By protecting hotspots, governments are able to protect a larger number of species. There are now 34 biodiversity hotspots (figure \(\PageIndex{c}\)) containing large numbers of endemic species, which include half of Earth’s endemic plants.
Biodiversity Hotspots in South Africa
A rich species diversity is found in South Africa. With a land surface of approximately 148,000 km2 (about 57,000 square miles), representing approximately 1% of the Earth's total surface, South Africa contains 10% of the world's total known bird, fish and plant species, and 6% of the world's mammal and reptile species.
This natural wealth is threatened by the expansion of the human population and the increasing demand this places on the environment. The Karoo (figure \(\PageIndex{d}\)) and the Cape are biodiversity hotspots in South Africa. South Africa has a wide range of climatic conditions and many variations in landscape, creating a variety of ecological niches, which can promote species diversity. These various landscapes give rise to the biomes which allow a wide variety of life to survive.
More than 20,300 species of flowering plants occur in South Africa (figure \(\PageIndex{e}\)). One of the six most important areas of plant growth in the world is in the Western Cape. Most of the 2,000 threatened species of plants are found in the fynbos in South-West Cape (figure \(\PageIndex{f}\)).
South Africa is home to 243 mammal species. Among the 17 threatened species in South Africa are the black rhino, pangolin, and giant golden mole. The blue antelope and quagga (figure \(\PageIndex{g}\)) have become extinct. Of more than 800 bird species, 26 are threatened, including the penguin, Cape vulture, martial eagle (figure \(\PageIndex{h}\)), and Cape parrot. In total 370 reptiles and amphibians occur in the region of which 21 are threatened. Six of these are endangered. Of the 220 freshwater fishes in South Africa, 21 are threatened. There are more than 2,000 marine fish species. While many insect species remain unidentified, 80,000 insects are known to occur.
Modified by Melissa Ha from Biodiversity and Biomes from Life Sciences Grade 10 by Siyavula (CC-BY)
Spatial and Temporal Heterogeneity Promote Biodiversity
Environmental heterogeneity refers to the lack of uniformity in an area. Regions that are spatially heterogeneous are composed of smaller areas with contrasting vegetation, water and nutrient availability, soils and rocks, or other features. In regions that are temporally heterogeneous, conditions fluctuate over time. Heterogeneity promotes species richness by increasing the number of ecological niches, and heterogenous regions are thus priorities with respect to conserving biodiversity. Some regions are more hetergeneous than others. For example, a wetland consists of many microhabitats that differ in soil type and water availability, and water levels change over the seasons. Other regions, like the temperate grasslands in the midwestern United States, are relatively homogenous (uniform). Just as biodiversity can be assessed at a variety of scales, heterogeneity can be measured at large scales (such as within an entire biome) or small scales (such as within a single meadow).
Attributions
Modified by Melissa Ha from the following sources:
3.1.05: Data Dive- Biodiversity and Drugs
Overview
Global biodiversity continues to contribute significantly to the production of drugs. A 2016 paper reviewed drug sources for both synthetic and natural categories from 1981 to 2014. The figure below below displays the categories used in the analysis and a graph breaking down their results:
• “B”: Biological macromolecule
• “N”: Unaltered natural product, however, could have been semi- or totally synthetic
• “NB”: Natural product “botanical drug”
• “ND”: Natural product derivative
• “S”: Synthetic drug
• “S*”: Synthetic drug (NP pharmacophore)
• “V”: Vaccine
• “S-VM”: Natural product mimic of “S”
• “S*-VM”: Natural product mimic of “S*”
Questions
1. What question(s) are the authors trying to answer with this graph?
2. What are the top three largest approved drug categories?
3. After reading over the categories outlined, provide your impression/reflection for all the categories that were identified.
4. What reason could you provide as to why the N and NB categories are so small compared to ND?
5. Do you think the results of this graph can be used as a defense of saving/conserving biodiversity now and into the future? Why?
Raw Data From Above Graph(s)
Table \(\PageIndex{a}\): Raw data for percent of drugs approved between 1981 and 2004 with either a synthetic or natural sub-classification. Graph by Rachel Schleiger (CC-BY-NC) modified from data in Newman DJ and Cragg GM 2016.
3.1.06: Review
Summary
After completing this chapter you should be able to...
• Define biodiversity.
• Distinguish among ecosystem, species, and genetic diversity, explaining the value of each.
• Define and provide examples of ecosystem services.
• Distinguish between species richness and species evenness.
• Provide an approximate estimate of the number of species on Earth as well as the percentage of species that have been identified.
• Explain the criteria for biodiversity hotspots and their role in conservation.
• Identify the characteristics of endemic species.
• Summarize hypotheses explaining high biodiversity near the equator.
Biodiversity exists at multiple levels of organization and is measured in different ways depending on the goals of those taking the measurements. These measurements include ecosystem diversity, species diversity, and genetic diversity. The number of described species is estimated to be 1.5 million with about 17,000 new species being described each year. Estimates for the total number of species on Earth vary but are on the order of 10 million. Biodiversity is negatively correlated with latitude for most taxa, meaning that biodiversity is higher in the tropics. The mechanism for this pattern is not known with certainty, but several plausible hypotheses have been advanced.
Attributions
Modified by Melissa Ha from Conservation & Biodiversity from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.01%3A_The_Value_of_Biodiversity/3.1.04%3A_Patterns_of_Biodiversity.txt |
Chapter Hook
The northern spotted owl (Strix occidentalis caurina) is a western North American owl species that prefers large swaths of pristine old growth forests (that typically take 150-200 years to mature) for nesting. Unfortunately, most western forests have been regularly harvested for timber since around the establishment of the Forest Service in 1905. Thus, this species preferred habitat has been largely destroyed and their populations have plummeted. Habitat destruction is the number one cause for species extinction globally. For some species that are very habitat specific, like the northern spotted owl, there are not as many conservation actions to choose from that can help reverse declining population trends.
Figure \(\PageIndex{a}\) Northern spotted owl perched in a tree. Image by USFS (licensed under CC-BY 2.0)
Biodiversity loss refers to the reduction of biodiversity due to displacement or extinction of species. The loss of a particular individual species may seem unimportant to some, especially if it is not a charismatic species like the Bengal tiger or the bottlenose dolphin. However, biologists estimate that species extinctions are currently many times higher the normal, or background, rate seen previously in Earth’s history. This translates to the loss of tens of thousands of species within our lifetimes. This is likely to have dramatic effects on human welfare through the collapse of ecosystems. Loss of biodiversity may have reverberating consequences on ecosystems because of the complex interrelations among species. For example, the extinction of one species may cause the extinction of another. To measure biodiversity loss, scientists assess which species are at risk of extinction as well as survey ecosystem decline.
The core threat to biodiversity on the planet is the combination of human population growth and the resources used by that population. The human population requires resources to survive and grow, and many of those resources are being removed unsustainably from the environment. The five main threats to biodiversity are habitat loss, pollution, overexploitation, invasive species, and climate change. Increased mobility and trade has resulted in the introduction of invasive species while the other threats are direct results of human population growth and resource use.
Attribution
Modified by Rachel Schleiger and Melissa Ha from Threats to Biodiversity and Importance of Biodiversity from Environmental Biology by Matthew R. Fisher (licensed under CC-BY)
3.02: Threats to Biodiversity
Speciation and Extinction
The number of species on the planet, or in any geographical area, is the result of an equilibrium of two evolutionary processes that are ongoing: speciation and extinction. Speciation occurs when new species evolve, and extinction is the global loss of a species. When speciation rates begin to outstrip extinction rates, the number of species will increase; likewise, the number of species will decrease when extinction rates begin to overtake speciation rates. Throughout Earth’s history, these two processes have fluctuated—sometimes leading to dramatic changes in the number of species on Earth as reflected in the fossil record (Figure \(\PageIndex{a}\)).
Mass Extinctions
Paleontologists have identified five events in geological history of sudden and dramatic losses in biodiversity, with more than half of all extant species disappearing from the fossil record. Extant species are those that are surviving (not extinct) at a point in time. These five events are called mass extinctions. There are many lesser, yet still dramatic, extinction events, but the five mass extinctions have attracted the most research. An argument can be made that the five mass extinctions are only the five most extreme events in a continuous series of large extinction events that have occurred since 542 million years ago.
The fossil record of the mass extinctions was the basis for defining periods of geological history, so they typically occur at the transition point between geological periods. The transition in fossils from one period to another reflects the dramatic loss of species and the gradual origin of new species. These transitions can be seen in the rock layers. Table \(\PageIndex{a}\) provides the names and dates of the five mass extinctions.
In most cases, the hypothesized causes are still controversial; however, the causes of the most recent event, the end-Cretaceous extinction, are best understood (table \(\PageIndex{a}\)). It was during this extinction event that the dinosaurs, the dominant vertebrate group for millions of years, disappeared from the planet (with the exception of a theropod clade that gave rise to birds). Indeed, every land animal that weighed more then 25 kg (55 lbs) became extinct. The cause of this extinction is now understood to be the result of a cataclysmic impact of a large meteorite, or asteroid, off the coast of what is now the Yucatán Peninsula. Biodiversity recovery times after mass extinctions vary, but have been up to 30 million years.
Table \(\PageIndex{a}\): Summary of the five mass extinctions, including the name, dates, percent of biodiversity lost, and hypothesized causes.
Geological Period Mass Extinction Name Time (millions of years ago) Loss in Biodiversity Hypothesized Cause(s)
Ordovician–Silurian end-Ordovician O–S 450–440 85% of marine species Global cooling and then warming, gamma-ray burst from supernova removed ozone layer
Late Devonian end-Devonian 375–360 79-87% of all species Unknown
Permian–Triassic end-Permian 251 96% of marine species and 70% of terrestrial (land) species Volcanic activity, decrease on dissolved oxygen in the oceans
Triassic–Jurassic end-Triassic 205 76% of all species Climate change, asteroid impact, volcanic eruptions
Cretaceous–Paleogene end-Cretaceous K–Pg (K–T) 65.5 50% of animals and plants Asteroid impact
The Pleistocene Extinction is one of the lesser extinctions, and a recent one. It is well known that the North American, and to some degree Eurasian megafauna, or large animals, disappeared toward the end of the last glaciation (cooling) period. The extinction appears to have happened in a relatively restricted time period of 10,000–12,000 years ago. In North America, the losses were quite dramatic and included the woolly mammoths (last dated about 4,000 years ago in an isolated population), mastodon, giant beavers, giant ground sloths, saber-toothed cats, and the North American camel, just to name a few. The possibility that the rapid extinction of these large animals was caused by overhunting, a type of overexploitation, was first suggested in the 1900s. Research into this hypothesis continues today. It seems likely that overhunting caused many pre-written history extinctions in many regions of the world.
The Sixth Mass Extinction
The sixth, or Holocene, mass extinction appears to have begun earlier than previously believed and has mostly to do with the activities of Homo sapiens. Since the beginning of the Holocene period, there are numerous recent extinctions of individual species that are recorded in human writings. Most of these are coincident with the expansion of the European colonies since the 1500s.
One of the earlier and popularly known examples is the dodo bird. The dodo bird lived in the forests of Mauritius, an island in the Indian Ocean. The dodo bird became extinct around 1662 (figure \(\PageIndex{b}\)). It was hunted for its meat by sailors and was easy prey because the dodo, which did not evolve with humans, would approach people without fear. Introduced pigs, rats, and dogs brought to the island by European ships also killed dodo young and eggs.
Steller's sea cow became extinct in 1768; it was related to the manatee and probably once lived along the northwest coast of North America. Steller's sea cow was first discovered by Europeans in 1741 and was hunted for meat and oil. The last sea cow was killed in 1768. That amounts to 27 years between the sea cow’s first contact with Europeans and extinction of the species.
In 1914, the last living passenger pigeon died in a zoo in Cincinnati, Ohio. This species had once darkened the skies of North America during its migrations, but it was hunted and suffered from habitat loss through the clearing of forests for farmland. In 1918, the last living Carolina parakeet died in captivity. This species was once common in the eastern United States, but it suffered from habitat loss. The species was also hunted because it ate orchard fruit when its native foods were destroyed to make way for farmland. The Japanese sea lion, which inhabited a broad area around Japan and the coast of Korea, became extinct in the 1950s due to fishermen. The Caribbean monk seal was distributed throughout the Caribbean Sea but was driven to extinction via hunting by 1952.
As described in the next section, the current high rates of extinction will cause a large and rapid decline in the biodiversity of the planet. According to a 2019 United Nations report, 1 million species are at risk of extinction. Considering there are estimated to be 8-11 million species total (see The Number of Species on Earth), that means up to 12.5% of species could go extinct, and many of them within our lifetimes.
Estimates of Present-Time Extinction Rates
The background extinction rate is estimated to be about 1 extinction per million species each year (E/MSY). For example, if there are 8-11 million species in existence, then we would expect 8-11 of those species to become extinct in a year.
Estimates of extinction rates are hampered by the fact that most extinctions are probably happening without observation. One contemporary extinction-rate estimate uses the extinctions in the written record since the year 1500. For birds alone, this method yields an estimate of 26 E/MSY, almost three times the background rate. However, this value may be underestimated for three reasons. First, many existing species would not have been described until much later in the time period and so their loss would have gone unnoticed. Second, we know the number is higher than the written record suggests because now extinct species are being described from skeletal remains that were never mentioned in written history. And third, some species are probably already extinct even though conservationists are reluctant to name them as such. Taking these factors into account raises the estimated extinction rate to nearer 100 E/MSY. The predicted rate by the end of the century is 1500 E/MSY.
A second approach to estimating present-time extinction rates is to correlate species loss with habitat loss, and it is based on measuring forest-area loss and understanding species–area relationships. The species-area relationship is the rate at which new species are seen when the area surveyed is increased (figure \(\PageIndex{c}\)). Likewise, if the habitat area is reduced, the number of species seen will also decline. This kind of relationship is also seen in the relationship between an island’s area and the number of species present on the island: as one increases, so does the other, though not in a straight line. Estimates of extinction rates based on habitat loss and species–area relationships have suggested that with about 90 percent of habitat loss an expected 50 percent of species would become extinct. Species–area estimates have led to estimates of present-day species extinction rates of about 1000 E/MSY and higher.
Many extinctions will affect species that biologists have not yet discovered. Most of these “invisible” species that will become extinct currently live in tropical rainforests (figure \(\PageIndex{d}\)). These rainforests are the most diverse ecosystems on the planet and are being destroyed rapidly by deforestation to provide timber and space for agriculture.
Extirpation
The elimination of species at a local level–known as extirpation – also poses threats to the integrity and sustainability of ecosystems. Widespread extirpation can obviously lead to extinction, but absence of species, even at a local scale, can affect ecosystem function. For example, by the mid-1920s wolves had been extirpated from Yellowstone National Park, although they continued to thrive elsewhere. When wolves were reintroduced to the park in the mid-1990s, they regulated elk populations, benefiting the vegetation and plant communities (see Ecosystem Restoration). What mattered for ecosystem function in Yellowstone was whether wolves were present there, not just whether the species survived somewhere.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.01%3A_Extinction.txt |
The Red List
The International Union for the Conservation of Nature (IUCN) coordinates efforts to catalog and preserve biodiversity worldwide. One way scientists gauge trends in biodiversity is by monitoring the fate of individual species. Since 1964, the IUCN has compiled information in the Red List of Threatened Species, which includes plants, animals, fungi, and selected brown algae species. Updates to the Red List are released every four years.
Species can be classified into nine Red List categories based on their extinction risk. Firstly, there are species that are already extinct and those that are extinct in the wild, meaning that the remaining individuals are only found in captivity. Species at risk of extinction are called threatened. Species that are at risk of becoming threatened are called near threatened. The Emperor Penguin (Aptenodytes forsteri) is an example a near threatened species, mainly due to habitat loss and climate change (figure \(\PageIndex{a}\)). Those with little risk of extinction are designated least concern. Note that only a fraction of the 8-11 million species on Earth are identified (see The Number of Species on Earth). For many of the species that are identified, data still needs to be gathered before they can be assigned to a Red List category (data deficient). Less than 10% of the approximately 1.5 million identified species have been assessed for the Red List at all. Species that have not been assessed are deemed not evaluated
There are three categories of threatened species: vulnerable, endangered, and critically endangered. Of these, critically endangered species have the greatest risk while vulnerable species are at the least risk out of the threatened categories. The African elephant (Loxodonta africana) is listed vulnerable species due to poaching and habitat loss (figure \(\PageIndex{b}\)). Interestingly, the forest subspecies (L. africana cylotis) is at much greater risk than the savanna subspecies (L. africana africana), but the Red List category is assigned at the species level in this case. The blue whale (Balaenoptera musculus) is endangered due to pollution, climate change, and poaching (figure \(\PageIndex{c}\)). Fortunately, blue whale population size is increasing. Several species of pitcher plants, which trap insects as a source of nitrogen, are critically endangered due to overexploitation and habitat loss (figure \(\PageIndex{d}\)).
Extinct and Threatened Animals
Scientists know much more about the state of vertebrates—especially mammals, birds, and amphibians—than they do about other forms of animal life. Of 6,594 described mammal species, 96 species have become extinct during the last 500 years (Mammal Diversity Database). According to the Red List, approximately 26% of mammal species worldwide are known to be threatened. A smaller percentage (about 14%) of the world's 10,721 identified bird species (Birds of the World) are threatened (figure \(\PageIndex{e}\)).
Among the well-studied vertebrates, amphibians are faring especially poorly. Of the more than 6,000 known species of amphibians, 35 have become extinct worldwide since 1500 (figure \(\PageIndex{f}\)), and two others are extinct in the wild (Red List). Overall, 41% of the world's amphibian species are known to be threatened (Red List). Only small proportions of the world's species of reptiles and fish have been evaluated for purposes of the Red List. Among those, 34% of selected reptiles and 8% of selected bony fishes are threatented (Red List).
Invertebrates comprise the vast majority of animals, an estimated 97% of animal species. They include everything from insects and arachnids, to mollusks, crustaceans, corals, and more. Few of these groups have been assessed in a comprehensive way, but assessments within some groups call attention to disturbing, large-scale trends. For example, 33% of the world's reef-building corals are already considered threatened (Red List), and many more of them are experiencing rates of decline that move them toward threatened status (figure \(\PageIndex{g}\)). The demise of reef-building corals has magnified ecological impacts, since so much other marine life depends on them.
Ecosystem Loss and Alteration
Another way of gauging biodiversity involves assessment on the scale of ecosystems. The causes of wholesale losses of ecosystems are much the same as those driving extinction or endangerment of species, with habitat destruction and fragmentation being the primary agent. Worldwide, for example, the conversion of land to agriculture and cultivation have led to significant losses in grassland ecosystems. In North America, nearly 70% of the tallgrass prairie ecosystem (which once covered 142 million acres) has been converted to agriculture, and losses from other causes, such as urban development, have brought the total to about 90%. Current estimates indicate that agricultural activity and cultivation systems now cover nearly 25% of the Earth's surface
According to the United Nations Millennium Ecosystem Assessment, by the beginning of the 21st century, 15 of the world’s 24 ecosystems, from rainforests to aquifers to fisheries, were rated in serious decline. For example, tropical rainforests, which are the habitats for nearly half of the world's plant and animal species, covered about 4 billion acres in past centuries, but only 2.5 billion acres remain and nearly 1% is being lost annually. Losses have been especially severe in the tropics of Africa and Southeast Asia. Current estimates indicate that about 50% of the world's wetland habitat has been lost. (Note that wetlands are a broad collection of many different ecosytem types.) The former extent of wetland habitats worldwide (fresh, brackish and salt) is difficult to determine but certainly exceeded a billion acres.
Attribution
Modified by Melissa Ha from Biodiversity, Species Loss, and Ecosystem Function and The Industrialization of Nature: A Modern History (1500 to the present) from Sustainability: A Comprehensive Foundation by Tom Theis and Jonathan Tomkin, Editors. Download for free at CNX. (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.02%3A_Measures_of_Biodiversity_Loss.txt |
Humans rely on technology to modify their environment and make it habitable. Other species cannot do this. Elimination of their habitat—whether it is a forest, coral reef, grassland, or flowing river—will kill the individuals in the species. Remove the entire habitat, and the species will become extinct, unless they are among the few species that do well in human-built environments. Habitat loss includes habitat destruction and habitat fragmentation.
Habitat Destruction
Habitat destruction occurs when the physical environment required by a species is altered so that the species can no longer live there. Human destruction of habitats accelerated in the latter half of the twentieth century. Consider the exceptional biodiversity of Sumatra: it is home to one species of orangutan, a species of critically endangered elephant, and the Sumatran tiger, but half of Sumatra’s forest is now gone. The neighboring island of Borneo, home to the other species of orangutan, has lost a similar area of forest. Forest loss continues in protected areas of Borneo. The orangutan in Borneo is listed as endangered by the International Union for Conservation of Nature (IUCN), but it is simply the most visible of thousands of species that will not survive the disappearance of the forests of Borneo. The forests are removed for timber and to plant palm oil plantations (figure \(\PageIndex{a}\)). Palm oil is used in many products including food products, cosmetics, and biodiesel in Europe. According to Global Forest Watch, 9.7% of tree cover was lost globally from 2002 to 2019, and 9% of that occurred in Indonesia and Malaysia (where Sumatra and Borneo are located). Figure \(\PageIndex{b}\) shows the average annual change in forest area around the world from 1990 to 2015.
Preventing Habitat Destruction with Wise Wood Choices
Most consumers do not imagine that the home improvement products they buy might be contributing to habitat loss and species extinctions. Yet the market for illegally harvested tropical timber is huge, and the wood products often find themselves in building supply stores in the United States. One estimate is that up to 10% of the imported timber in the United States, which is the world’s largest consumer of wood products, is illegally logged. A 2012 United Nations and Interpol report estimated that the illegal timber trade is worth \$30-100 billion each year. Most of the illegal products are imported from countries that act as intermediaries and are not the originators of the wood.
How is it possible to determine if a wood product, such as flooring, was harvested sustainably or even legally? The Forest Stewardship Council (FSC) certifies sustainably harvested forest products (figure \(\PageIndex{c}\)). Looking for their certification on flooring and other hardwood products is one way to ensure that the wood has not been taken illegally from a tropical forest. There are certifications other than the FSC, but these are run by timber companies, thus creating a conflict of interest. Another approach is to buy domestic wood species. While it would be great if there was a list of legal versus illegal woods, it is not that simple. Logging and forest management laws vary from country to country; what is illegal in one country may be legal in another. Where and how a product is harvested and whether the forest from which it comes is being sustainably maintained all factor into whether a wood product will be certified by the FSC. It is always a good idea to ask questions about where a wood product came from and how the supplier knows that it was harvested legally.
Habitat Destruction of Rivers and Streams
Habitat destruction can affect ecosystems other than forests. Rivers and streams are important ecosystems and are frequently the target of habitat modification. Damming of rivers affects flow and access to habitat. Altering a flow regime can reduce or eliminate populations that are adapted to seasonal changes in flow. For example, an estimated 91% of riverways in the United States have been modified with damming or stream bank modification. Many fish species in the United States, especially rare species or species with restricted distributions, have seen declines caused by river damming and habitat loss. Research has confirmed that species of amphibians that must carry out parts of their life cycles in both aquatic and terrestrial habitats are at greater risk of population declines and extinction because of the increased likelihood that one of their habitats or access between them will be lost. This is of particular concern because amphibians have been declining in numbers and going extinct more rapidly than many other groups for a variety of possible reasons.
Habitat Fragmentation
Habitat fragmentation occurs when the living space of a species is divided into discontinuous patches. For example, a mountain highway could divide a forest habitat into separate patches. This is especially problematic for consumers at the top of the food chain, which require large ranges to find adequate prey. Additionally, habitat fragmentation separates individuals from potential mates. Wildlife corridors mitigate the damage of habitat fragmentation by connecting patches with suitable habitat. For example, the bridge over a highway could allow animals to move between habitat patches (figure \(\PageIndex{d}\)). Riparian areas, areas of land adjacent to bodies of water, such as streams, can serve as natural wildlife corridors when left intact. | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.03%3A_Habitat_Loss.txt |
Overexploitation (overharvesting) involves hunting, fishing, or otherwise collecting organisms at a faster rate than they can be replenished.
Terrestrial Animals
Terrestrial animals may be overexploited as sources of food, garments, jewelry, medicine, or pets. For example, the poaching of elephants for their valuable ivory and rhinos for their horns, which are used in traditional medicine, is a major threat to these species. There are also concerns about the effect of the pet trade on some terrestrial species such as turtles, amphibians, birds, plants, and even the orangutans. Harvesting of pangolins for their scales and meat, and as curiosities, has led to a drastic decline in population size (figure \(\PageIndex{a}\)).
Bush meat is the generic term used for wild animals killed for food. Hunting is practiced throughout the world, but hunting practices, particularly in equatorial Africa and parts of Asia, are believed to threaten several species with extinction. Traditionally, bush meat in Africa was hunted to feed families directly. However, recent commercialization of the practice now has bush meat available in grocery stores, which has increased harvest rates to the level of unsustainability. Additionally, human population growth has increased the need for protein foods that are not being met from agriculture. Species threatened by the bush meat trade are mostly mammals including many monkeys and the great apes living in the Congo basin.
Aquatic Animals
Aquatic species are particularly vulnerable to overexploitation, which is more specifically called overfishing in this case. For about one billion people, aquatic resources provide the main source of animal protein (figure \(\PageIndex{b}\)), but since 1990, production from global fisheries (areas for catching wild or farmed fish or other aquatic animals) has declined. Figure \(\PageIndex{c}\) illustrates the extent of overfishing in the U.S. Despite considerable effort, few fisheries are managed sustainability. For example, the western Atlantic cod fishery was a hugely productive fishery for 400 years, but the introduction of modern fishing vessels in the 1980s and the pressure on the fishery led to it becoming unsustainable. Bluefin tuna are in danger of extinction. The once-abundant Mediterranean swordfish fishery have been depleted to commercial and biological exhaustion.
Most fisheries are managed as a common resource, available to anyone willing to fish, even when the fishing territory lies within a country’s territorial waters. Common resources are subject to an economic pressure known as the tragedy of the commons, in which fishers have little motivation to exercise restraint in harvesting a fishery when they do not own the fishery. This results on overexploitation. In a few fisheries, the biological growth of the resource is less than the potential growth of the profits made from fishing if that time and money were invested elsewhere. In these cases—whales are an example—economic forces will drive toward fishing the population to extinction.
Overfishing can result in a radical restructuring of the marine ecosystem in which a dominant species is so overexploited that it no longer serves its ecological function. For example, overfishing a tertiary consumer could causes populations of secondary consumers to increase. Secondary consumers would then feed on primary consumes (like zooplankton), decreasing their population size. With fewer zooplankton, populations of primary producers (phytoplankton, or photosynthetic microorganisms) would be unregulated (see Food Chains). The collapse of fisheries has dramatic and long-lasting effects on local human populations that work in the fishery. In addition, the loss of an inexpensive protein source to populations that cannot afford to replace it will increase the cost of living and limit societies in other ways. In general, the fish taken from fisheries have shifted to smaller species, and the larger species are overfished. The ultimate outcome could clearly be the loss of aquatic systems as food sources.
A related consequence of fishing practices is "bycatch," animals that fishers sometimes catch and discard because they do not want them, cannot sell them, or are not allowed to keep them. Bycatch can be fish, but also includes other animals such as dolphins, whales, sea turtles, and seabirds that become hooked or entangled in fishing gear.
Coral reefs are extremely diverse marine ecosystems that face peril from several processes. Reefs are home to 1/3 of the world’s marine fish species—about 4,000 species—despite making up only one percent of marine habitat. Most home marine aquaria house coral reef species that are wild-caught organisms—not cultured organisms. Although no marine species is known to have been driven extinct by the pet trade, there are studies showing that populations of some species have declined in response to harvesting, indicating that the harvest is not sustainable at those levels.
Plants and Fungi
Some plant and fungal species are also overexploited, particularly if they are slow-growing. For example, stocks of wild ginseng, which is valued for its health benefits, are dwindling. Peyote cactus, which causes hallucinations and is used in sacred ceremonies, is also declining. Yarsagumba, dead moth larvae that were infected by fungal parasites (caterpillar fungus, Ophiocordyceps sinensis), is overexploited because it is highly valued in traditional medicine and used as an aphrodisiac (figure \(\PageIndex{d}\)).
Attributions
Modified by Melissa Ha from the following sources:
3.2.05: Pollution
Pollution occurs when chemicals, particles, or other materials are released into the environment, harming the organisms there. For many thousands of years, ever since they built the first campfire, human activity has generated air, water, and soil pollution. For most of human history, however, these contaminants had relatively little environmental impact. But over the last few centuries, pollution levels skyrocketed as a result of population growth and the Industrial Revolution. As a result, regulations have been enacted to control emissions. Even where these are effective in curbing current pollution sources, high levels of contamination may exist from past activity. And new contamination can occur through industrial accidents or other inadvertent releases of toxic substances.
Pollution has contributed to the decline of many threatened species. For example, a 2007 study by Kingsford and colleagues found that pollution was a major pressure on 30% of threatened Red List species in Australia and surrounding regions.
Power plants, factories, and vehicles are common sources of air pollution. In some cases, the pollutants are directly toxic (for example, lead), but in other cases the pollutants indirectly cause ecological harm when they are present in unnaturally large quantities (for example, carbon dioxide emissions leading to climate change). Not only can air pollutants directly harm animals by causing respiratory issues and cancer as well as damage vegetation, but some interact with the atmosphere to form acid deposition (commonly called acid rain). Acid deposition disrupts aquatic ecosystems as well as soil communities and plant growth.
Heavy metals, plastics, pesticides, herbicides, fertilizers, and sediments are examples of water pollution. Heavy metals (including copper, lead, mercury, and zinc) can leach into soil and water from mines. Furthermore, acid mine drainage is caused by reaction of mine wastes, such as sulfides, with rainfall or groundwater to produce acids, like sulfuric acid. The Environmental Protection Agency estimates that 40% of the watersheds in the western United States are contaminated by mine run-off. Plastics harm shorebirds, turtles and aquatic invertebrates that ingest and accumulate them. Nutrients, such as nitrate and phosphates, are healthy in bodies of water to an extent, but when fertilizer pollution adds too many of these nutrients at one time, algal blooms can result. This has cascading effects that can ultimately shade and kill aquatic plants and deplete oxygen needed by fish and other animals (eutrophication). A particularly concerning water pollution problem is micropollutants. For examples, some chemical residues affect growth, cause birth defects, and have other toxic effects on humans and other organisms even at very low concentrations.
Figure \(\PageIndex{a}\) summarizes the effects of air and water pollution on biodiversity, and the chapters about Solid Waste Management, Water Pollution, and Air Pollution explain these threats in more detail.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.04%3A_Overexploitation.txt |
Invasive species are non-native organisms that, when introduced to an area out of its native range, disrupt the community they invade. Non-native (exotic) refers to species occurring outside of their historic distribution. Invasive species have been intentionally or unintentionally introduced by humans into an ecosystem in which they did not evolve. Human transportation of people and goods, including the intentional transport of organisms for trade, has dramatically increased the introduction of species into new ecosystems. These new introductions are sometimes at distances that are well beyond the capacity of the species to ever travel itself and outside the range of the species’ natural predators. Invasive species can cause ecological and economic damage. They threaten other species through competition for resources, predation, or disease.
In the United States, invasive species like the purple loosestrife (Lythrum salicaria) and the zebra mussel (Dreissena polymorpha) have drastically altered the ecosystems they invaded. Some well-known invasive animals include the emerald ash borer (Agrilus planipennis) and the European starling (Sturnus vulgaris; figure \(\PageIndex{a}\)). Whether enjoying a forest hike, taking a summer boat trip, or simply walking down an urban street, you have likely encountered an invasive species.
Asian Carp
One of the many recent proliferations of an invasive species concerns the Asian carp in the United States. Asian carp were introduced to the United States in the 1970s by fisheries (commercial catfish ponds) and by sewage treatment facilities that used the fish’s excellent filter feeding abilities to clean their ponds of excess plankton. Some of the fish escaped, and by the 1980s they had colonized many waterways of the Mississippi River basin, including the Illinois and Missouri Rivers.
Voracious feeders and rapid reproducers, Asian carp may outcompete native species for food and could lead to their extinction. One species, the grass carp, feeds on phytoplankton and aquatic plants. It competes with native species (those that historically occurred in the area and are adapted to the local ecosystem) for these resources and alters habitats for other fish by removing aquatic plants. In some parts of the Illinois River, Asian carp constitute 95 percent of the community’s biomass. Although edible, the fish is bony and not desired in the United States.
The Great Lakes and their prized salmon and lake trout fisheries are being threatened by Asian carp. The carp are not yet present in the Great Lakes, and attempts are being made to prevent its access to the lakes through the Chicago Ship and Sanitary Canal, which is the only connection between the Mississippi River and Great Lakes basins. To prevent the Asian carp from leaving the canal, a series of electric barriers have been used to discourage their migration; however, the threat is significant enough that several states and Canada have sued to have the Chicago channel permanently cut off from Lake Michigan. Local and national politicians have weighed in on how to solve the problem. In general, governments have been ineffective in preventing or slowing the introduction of invasive species.
Effect on Endemic Species
Lakes and islands are particularly vulnerable to extinction threats from introduced species. In Lake Victoria, the intentional introduction of the Nile perch was largely responsible for the extinction of about 200 species of cichlids (see Patterns of Biodiversity). The accidental introduction of the brown tree snake via aircraft (figure \(\PageIndex{b}\)) from the Solomon Islands to Guam in 1950 has led to the extinction of three species of birds and three to five species of reptiles endemic to the island. Several other species are still threatened. The brown tree snake is adept at exploiting human transportation as a means to migrate; one was even found on an aircraft arriving in Corpus Christi, Texas. Constant vigilance on the part of airport, military, and commercial aircraft personnel is required to prevent the snake from moving from Guam to other islands in the Pacific, especially Hawaii. Islands do not make up a large area of land on the globe, but they do contain a disproportionate number of endemic species because of their isolation from mainland ancestors.
Introduction by Ballast Water
Many introductions of aquatic species, both marine and freshwater, have occurred when ships have dumped ballast water taken on at a port of origin into waters at a destination port. Water from the port of origin is pumped into tanks on a ship empty of cargo to increase stability. The water is drawn from the ocean or estuary of the port and typically contains living organisms such as plant parts, microorganisms, eggs, larvae, or aquatic animals. The water is then pumped out before the ship takes on cargo at the destination port, which may be on a different continent. The zebra mussel was introduced to the Great Lakes from Europe prior to 1988 in ballast water. The zebra mussels in the Great Lakes have created millions of dollars in clean-up costs to maintain water intakes and other facilities. The mussels have also altered the ecology of the lakes dramatically. They threaten native mollusk populations, but have also benefited some species, such as smallmouth bass. The mussels are filter feeders and have dramatically improved water clarity, which in turn has allowed aquatic plants to grow along shorelines, providing shelter for young fish where it did not exist before. The European green crab, Carcinus maenas, was introduced to San Francisco Bay in the late 1990s, likely in ship ballast water, and has spread north along the coast to Washington. The crabs have been found to dramatically reduce the abundance of native clams and crabs with resulting increases in the prey species of those native crabs.
Invasive Species as Diseases
Invading exotic species can also be disease organisms. It now appears that the global decline in amphibian species recognized in the 1990s is, in some part, caused by the fungus Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis (figure \(\PageIndex{c}\)). There is evidence that the fungus is native to Africa and may have been spread throughout the world by transport of a commonly used laboratory and pet species: the African clawed frog, Xenopus laevis. It may well be that biologists themselves are responsible for spreading this disease worldwide. The North American bullfrog, Rana catesbeiana, which has also been widely introduced as a food animal but which easily escapes captivity, survives most infections of B. dendrobatidis and can act as a disease reservoir by storing the infectious fungus.
Early evidence suggests that another fungal pathogen, Geomyces destructans, introduced from Europe is responsible for white-nose syndrome, which infects cave-hibernating bats in eastern North America and has spread from a point of origin in western New York State (figure \(\PageIndex{d}\)). The disease has decimated bat populations and threatens extinction of species already listed as endangered: the Indiana bat, Myotis sodalis, and potentially the Virginia big-eared bat, Corynorhinus townsendii virginianus. How the fungus was introduced is unknown, but one logical presumption would be that recreational cavers unintentionally brought the fungus on clothes or equipment from Europe.
Biological Control of Invasive Species
One reason why invasive species proliferate dramatically outside of their native range is due to release from predators. This means that parasites, predators, or herbivores that usually regulate their populations are not present, allowing them to outcompete or overpredate native species, which are still regulated. Based on this principle, organisms that regulate the invasive species populations have been introduced to the newly colonized areas in some cases. The release of organisms (or viruses) to limit population size is called biological control. As described in the examples below, biological control of invasive species has had varying success, exacerbating the problem in some cases and solving it in others.
Prickly-pear Cactus (Opuntia)
Introduced into Australia, this cactus soon spread over millions of hectares of range land driving out forage plants. In 1924, the cactus moth, Cactoblastis cactorum, was introduced (from Argentina) into Australia. The caterpillars of the moth are voracious feeders on prickly-pear cactus, and within a few years, the caterpillars had reclaimed the range land without harming a single native species. However, its introduction into the Caribbean in 1957 did not produce such happy results. By 1989, the cactus moth had reached Florida, and now threatens five species of native cacti there.
Purple Loosestrife
The leaf beetle (Galerucella calmariensis) has been introduced to suppress purple loosestrife, a noxious weed (figure \(\PageIndex{e}\)). A combination of four biological controls, including the leaf beetle were released in Minnesota since 1992. While it has not eradicated populations of this invasive species, biological control largely removed leaves from 20% of the purple loosestrive populations where it was released, which could reduce competition for native species. The biological controls established populations in most locations where they were released and even spread to new patches of purple loosestrife.
Klamath Weed
In 1946 two species of Chrysolina beetles were introduced into California to control the Klamath weed (St. Johnswort) that was ruining millions of acres of range land in California and the Pacific Northwest. Before their release, the beetles were carefully tested to make certain that they would not turn to valuable plants once they had eaten all the Klamath weed they could find. The beetles succeeded beautifully, restoring about 99% of the endangered range land and earning them a commemorative plaque at the Agricultural Center Building in Eureka, California.
European Rabbit
In 1859, the European rabbit was introduced into Australia for sport. With no important predator there, it multiplied explosively (figure \(\PageIndex{f}\)). The raising of sheep (another imported species) suffered badly as the rabbits competed with them for forage.
In 1950, the myxoma virus was brought from Brazil and released. The epidemic that followed killed off millions of rabbits (more than 99% of the population). Green grass returned, and sheep raising once again became profitable. Rabbit populations gradually increased, however, because the rabbits evolved to be more resistant to the virus, and the myxoma virus evolved to cause less damage. (Parasites, like viruses, benefit from multiplying inside the host and spreading to other individuals. If they kill their hosts too soon, they typically limit opportunities to multiply and spread.) More recently, the rabbit hemorrhagic disease virus has been used as biological control.
Strategies for Effective Biological Control
To summarize the lessons learned from biological control successes and failures, only candidates that have a very narrow target preference (eat only a sharply-limited range of hosts) should be chosen. Each candidate should be carefully tested to be sure that once it has cleaned up the intended target, it does not turn to desirable species. Biological controls must not be used against native species. Finally, introduction of non-native species into the environment should be avoided because they could themselves be invasive.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.06%3A_Invasive_Species.txt |
Global climate change is also a consequence of human population needs for energy, and the use of fossil fuels to meet those needs. Essentially, burning fossil fuels, including as oil, natural gas, and coal, increases carbon dioxide concentrations in the atmosphere. Carbon dioxide traps heat energy from the sun, resulting not only in an average increase in global temperature but also in changing precipitation patterns and increased frequency and severity of extreme weather events, such as hurricanes. Scientists overwhelmingly agree the present warming trend is caused by humans. See the Climate Change chapter for a detailed description its cause and impacts. A few examples of how climate change impacts biodiversity are described in the paragraphs below.
Climate change is recognized as a major extinction threat, particularly when combined with other threats such as habitat loss. Scientists disagree about the likely magnitude of the effects, with extinction rate estimates ranging from 15 percent to 40 percent of species committed to extinction by 2050. By altering regional climates, it makes habitats less hospitable to the species living in them. The warming trend will shift colder climates toward the north and south poles, forcing species to move (if possible) with their adapted climate norms. For example, one study indicates that European bird species ranges have moved 91 kilometers (56.5 miles) northward, on average. The same study suggested that the optimal shift based on warming trends was double that distance, suggesting that the populations are not moving quickly enough. Range shifts have also been observed in plants, butterflies, other insects, freshwater fishes, reptiles, amphibians, and mammals.
The shifting ranges will impose new competitive regimes on species as they find themselves in contact with other species not present in their historic range. One such unexpected species contact is between polar bears and grizzly bears (figure \(\PageIndex{a}\)). Previously, these two species had separate ranges. Now, their ranges are overlapping and there are documented cases of these two species mating and producing viable offspring.
Climate gradients will also move up mountains, eventually crowding species higher in altitude and eliminating the habitat for those species adapted to the highest elevations. Some climates will completely disappear. The rate of warming appears to be accelerated in the arctic, which is recognized as a serious threat to polar bear populations that require sea ice to hunt seals during the winter months. Seals are a critical source of protein for polar bears. A trend to decreasing sea ice coverage has occurred since observations began in the mid-twentieth century. The rate of decline observed in recent years is far greater than previously predicted by climate models.
Changing climates also throw off the delicate timing adaptations that species have to seasonal food resources and breeding times. Scientists have already documented many contemporary mismatches to shifts in resource availability and timing. For example, pollinating insects typically emerge in the spring based on temperature cues. In contrast, many plant species flower based on daylength cues. With warmer temperatures occurring earlier in the year, but daylength remaining the same, pollinators ahead of peak flowering. As a result, there is less food (nectar and pollen) available for the insects and less opportunity for plants to have their pollen dispersed. For migrating birds, timing is everything – they must arrive at their summer breeding grounds when food supplies are at their peak, so that they can rebuild their body fat and reproduce successfully. In some areas, birds are showing up early, before flowers open or insects hatch, and finding very little to eat.
Ocean levels rise in response to climate change due to meltwater from glaciers and the greater volume occupied by warmer water. Shorelines will be inundated, reducing island size, which will have an effect on some species, and a number of islands will disappear entirely. Additionally, the gradual melting and subsequent refreezing of the poles, glaciers, and higher elevation mountains—a cycle that has provided freshwater to environments for centuries—will be altered. This could result in an overabundance of salt water and a shortage of freshwater.
Finally, increased carbon dioxide levels in the atmosphere react with ocean water to form carbonic acid, a phenomenon called ocean acidification. In combination with warmer temperatures, ocean acidification is responsible for coral bleaching, the process by which coral expel the algae that typically conduct photosynthesis within the corals. Ocean acidification can also dissolve the calcium carbonate skeletons formed by the coral. Overall, climate change plays a major role in the loss of nearly one third of coral reefs.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.07%3A_Climate_Change.txt |
Overview
Starting in 1998, the World Wildlife Federation (WWF) began publishing the Living Planet Report. This report analyzes the health of the plant relative to the impact humanity has on it, and is updated every two years. This report continually urges humanity, especially world leaders, to work together to build a more sustainable, resilient, and healthy future for people and nature. In the 2018 update, there was an overview of the major threats to biodiversity for several animal families of concern. See the graph of their results below:
Questions
1. What is the independent (explanatory) variable and the dependent (response) variable?
2. What animal category above is most affected by habitat destruction? What about exploitation?
3. What category above has the largest impact (on average) on all species?
4. What is different for the fish data patterns compared to the other animal categories? Why?
5. How can the results of this graph to inform future conservation efforts?
6. Based on what you have learned in the chapter, list two other categories of life that you think should be added to the graph. Provide at least one reason for each as to why you think it should be added.
Raw Data From Above Graph(s)
Table \(\PageIndex{a}\): Raw data for percent of biodiversity threats to various animal groups. Graph by Rachel Schleiger (CC-BY-NC) modified from data in Living Planet Report 2018 Aiming Higher.
Animal Group Habitat Degradation Exploitation Invasive Species And Disease Pollution Climate Change
Birds 49 18 10 11 12
Reptiles/Amphibians 47 23 12 11 7
Mammals 45 38 9 5 3
Fish 28 55 5 4 8
Attribution
Rachel Schleiger (CC-BY-NC)
3.2.09: Review
Summary
After completing this chapter you should be able to...
• Describe biodiversity as the equilibrium of naturally fluctuating rates of extinction and speciation.
• Summarize potential causes of mass extinctions and the associated biodiversity loss.
• Compare the present rate of extinction to the background extinction rate.
• Describe the causes and consequences of the sixth mass extinction.
• Describe how the loss of biodiversity is measured.
• Distinguish among the Red List categories.
• Name, define, and provide examples of the five major threats to biodiversity.
• Provide examples of the successes and failures of biological control in regulating invasive species.
Five mass extinctions with losses of more than 50 percent of extant species are observable in the fossil record. The sixth mass extinction is currently in progress with present-day extinction rates much greater than the background extinction rate.
The core threats to biodiversity are human population growth and unsustainable resource use. These are habitat loss, overexploitation, pollution, invasive species, and climate change. Habitat loss occurs through deforestation, damming of rivers, and other activities. Water and air pollution introduce toxic substances into the environment that harm plants and animals. Overexploitation is a threat particularly to aquatic species, but the poaching of terrestrial animals and overcollection of plants and fungi also puts species at risk. Invasive species have been the cause of a number of extinctions and are especially damaging to islands and lakes. Climate change is forcing range changes that can lead to extinction. It is also affecting adaptations to the timing of resource availability that negatively affects species in seasonal environments. Climate change will also raise sea levels, eliminating some islands and reducing the area of all others.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.02%3A_Threats_to_Biodiversity/3.2.08%3A_Data_Dive-_Threats_to_Biodiversity.txt |
Chapter Hook
As of 2020, there were 41,415 species on the International Union for Conservation of Nature (IUCN) Red List, 16,306 of them being endangered and threatened with extinction. This is up from 16,118 from 2019. The Island Fox (Urocyon littoralis) is only found on six of the California Channel Islands off the coast of southern California. In the mid-1990’s four island fox subspecies experienced drastic population declines. Soon after, they were listed as critically endangered on the IUCN red list and endangered on the U.S Endangered Species Act. However, due to uncompromising recovery efforts (through supported funding from its endangered status), all four subspecies have almost completely recovered their populations. Regrettably, not all species that end up on the IUCN red list or endangered species list have trajectories that later hold such hope.
The field of conservation focuses on preserving biodiversity. Effective conservation depends on ecological knowledge. Today, the main efforts to preserve biodiversity involve legislative approaches to regulate human and corporate behavior, setting aside protected areas, and ecosystem restoration.
Attribution
Modified by Rachel Schleiger and Melissa Ha from Preserving Biodiversity from Environmental Biology by Matthew R. Fisher (licensed under CC-BY)
• 11.1: Policies
National laws, such as the Endangered Species Act, and state laws, such as the California Endangered Species Act, strive to protect biodiversity. International agreements, including the Convention on International Trade in Endangered Species of Wild Fauna and Flora and the Migratory Bird Treaty Act, facilitate collaboration among different countries in conservation efforts.
• 11.2: Non-profit Organizations
Non-profit organizations fund conservation research and actions.
• 11.3: Species-level Conservation
Species-level conservation focuses on increasing the population size of just one (often charismatic) species. Depending on the species, conservation strategies may include captive breeding and reintroduction, vaccination, and habitat restoration.
• 11.4: Protected Areas
Protected areas are those set aside to preserve biodiversity. Different types of protected areas offer different degrees of protection and vary in which human activities are permitted. Examples include wilderness areas, national and state parks, national forests, and wildlife refuges.
• 11.5: Ecosystem Restoration
Ecosystem restoration focuses on returning an area to its natural state following disturbance by humans to promote native species and ecosystem services.
• 11.6: Economic Influences on Conservation
Debt-for-nature swaps and ecotourism add economic incentive to conservation efforts and thus promote their success.
• 11.7: Individual Choices
Individuals can assist with conservation efforts by purchasing sustainable products, conserving resources, and engaging in citizen science.
• 11.8: Data Dive- Island Fox Populations
• 11.9: Review
3.03: Protecting Biodiveristy
National and State Laws
Within many countries there are laws that protect endangered species and regulate hunting and fishing. For example, the Endangered Species Act (ESA) was enacted in 1973 in the United States. The ESA does not automatically protect species categorized as threatened on the Red List. Instead, the U.S. Fish and Wildlife Service (FWS), which enforces the ESA, assesses candidates for protected status as threatened or endangered (figure \(\PageIndex{a}\)). Consideration of candidate species can be initiated by the FWS itself or at the request of the public. Through the Species Status Assessment Framework, the FWS compiles biological data, such as habitat and population information and current threats to the species. This biological data is used to inform decisions.
Once a species is listed, the FWS is required by law to develop a management plan to protect the species and bring it back to sustainable numbers. The ESA, and others like it in other countries, is a useful tool, but it suffers because it is often difficult to get a species listed or to get an effective management plan in place once a species is listed.
The 1972 Marine Mammals Protection Act prohibits the “take” of marine mammals—including harassment, hunting, capturing, collecting, or killing—in U.S. waters and by U.S. citizens on the high seas. The act also makes it illegal to import marine mammals and marine mammal products into the United States without a permit.
State laws can also aid in conservation. Through California Endangered Species Act (CESA), originally passed in 1970 and subsequently amended, the California Fish and Game Commission assesses species to be listed as threatened or endangered by the state. A listed species, or any part or product of the plant or animal, may not be imported into the state, exported out of the state, “taken” (killed), possessed, purchased, or sold without proper authorization.
Note that endangered is a subcategory of threatened on the Red List, but for ESA and CESA, threatened and endangered are separate categories, with the latter representing at the greater risk of extinction.
International Agreements
The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) treaty came into force in 1975. The treaty, and the national legislation that supports it, provides a legal framework for preventing listed species from being transported across nations’ borders, thus protecting them from being caught or killed when the purpose involves international trade.
Species can be listed in one of three CITES appendices. Trade is banned for Appendix I species, which are threatened with extinction. For example the trade of ivory is banned by CITES. Trade is regulated for Appendix II species, such as the meat and shells of the queen conch or big-leaf mahogany (figure \(\PageIndex{b}\)). Appendix III species are protected in at least one country, and the local government needs a coordinated response through CITES. For example, several species of red and pink corals have been added to Appendix III at the request of China.
Approximately 35,800 species are protected by the CITES. The treaty is limited in its reach because it only deals with international movement of organisms or their parts. It is also limited by various countries’ ability or willingness to enforce the treaty and supporting legislation.
The Migratory Bird Treaty Act (MBTA) is an agreement between the United States and Canada that was signed into law in 1918 in response to declines in North American bird species caused by hunting. The Act now lists over 800 protected species. It makes it illegal to disturb or kill the protected species or distribute their parts (much of the hunting of birds in the past was for their feathers). Examples of protected species include northern cardinals, the Red-tailed Hawk, and the American Black Vulture.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.01%3A_Policies.txt |
The private non-profit sector plays a large role in the conservation effort both in North America and around the world. For example, the World Wildlife Fund raised over \$300 million in the 2017-2018 fiscal year to protect endangered animals, their habitats, and natural resources. Some non-profit organizations are species specific, like the Orangutan Foundation, and others are broadly focused, such as the IUCN and Trade Records Analysis of Flora and Fauna in Commerce (TRAFFIC). Illegal wildlife trade is monitored by TRAFFIC. The Nature Conservancy (figure \(\PageIndex{a}\)) takes a novel approach. It purchases land and protects it in an attempt to set up preserves for ecosystems.
Attributions
Modified by Melissa Ha from the following sources:
3.3.03: Species-level Conservation
Some conservation efforts center around a single species. Often this is a charismatic species that elicits public interest, such as tigers, sea otters, or the California Condor. The specific approach depends on specific threats based by the species of focus. When California Condor population size plummeted, leaving only 23 individuals, they were relocated into a controlled environment and provided with optimal conditions for reproduction. This is called captive breeding. Individuals have since been reintroduced into the environment. One threat to the species was lead from bullets that were entering the food chain and ultimately poisoning the California Condor. Public education and providing lead-free bullets was thus another component of their conservation plan. By 2016, the population size increased to 446 individuals, with 276 of those living in the wild.
When disease puts species at risk, vaccination may be part of the conservation plan. For example, the black-footed ferret of the Great Plains is threatened by sylvatic plague as well as habitat loss. In response, peanut buttered-flavored oral vaccines were distributed over their habitats. Conservation efforts also focused on captive breeding and reintroduction. Once thought to be extinct, there are now several hundred black-footed ferrets in captivity and similar numbers in the wild (figure \(\PageIndex{a}\)).
Protecting or restoring habitat is another component of species-level conservation. For example, the Northern Spotted Owl lives in old-growth forests. Protecting intact old-growth forests and restoring forest habitat is thus critical to their success. This is accompanied by removal of the Barred Owl, an invasive that competes with the Northern Spotted Owl. Similarly, removal of the invasive iceplant Carpobrotus edulis from California coasts, restores conditions for endangered dune vegetation (figure \(\PageIndex{b}\)-d). In other cases, habitat restoration involves promoting populations of native species that support those at risk, such as promoting vegetation that provides food and shelter for waterfowl.
Seemingly unimpressive species can still serve vital ecological roles. For example, the delta smelt is an important food source for larger fish species. Additionally, it serves as an indicator species because the health of its populations reflect overall ecosystem health. While the delta smelt has been a focus of species-level conservation, non-charismatic species are often overlooked. In fact, a 2007 study by Colléony and colleagues found that people more often donated to conservation efforts for species that were more similar to humans rather than choosing those that were at greatest risk of extinction. Broad approaches such as establishing protected areas and ecosystem restoration benefit charismatic and non-charismatic species alike. Additionally, broad approaches protect unidentified and species that have not been assessed.
Attribution
Melissa Ha (CC-BY-NC) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.02%3A_Non-profit_Organizations.txt |
It is important to protect natural areas for several reasons. Some people feel a cultural or spiritual connection to the wilderness. Every year, millions of people visit recreational lands such as parks and wilderness areas to experience attractions of the great outdoors: hiking among the giant sequoias in California, traveling on a photo safari in Kenya or just picnicking at a local county park. Besides providing people with obvious health benefits and aesthetic pleasures, recreational lands also generate considerable tourist money for government and local economies. Outdoor recreation activities such as hiking and camping benefit tourist industries and manufacturers of outdoor clothes and equipment.
Establishment of preserves is one of the key tools in conservation efforts. A preserve is an area of land set aside with varying degrees of protection for the organisms that exist within the boundaries of the preserve (figure \(\PageIndex{a}\)). Governments or private organizations establish nature preserves. In 2016, the IUCN estimated that 14.7 percent of Earth’s land surface was covered by preserves of various kinds. This area is large, but only 20% of the key biodiversity areas identified by the IUCN were sufficiently protected.
There has been extensive research into optimal preserve designs for maintaining biodiversity. Preserves can be seen as “islands” of habitat within “an ocean” of non-habitat. In general, large preserves are better because they support more species, including species with large home ranges; they have more core area of optimal habitat for individual species; they have more niches to support more species; and they attract more species because they can be found and reached more easily. One large preserve is better than the same area of several smaller preserves because there is more core habitat unaffected by less hospitable ecosystems outside the preserve boundary. For this same reason, preserves in the shape of a square or circle will be better than a preserve with many thin “arms.” If preserves must be smaller, then providing wildlife corridors between two preserves is important so that species and their genes can move between them. All of these factors are taken into consideration when planning the nature of a preserve before the land is set aside. In addition to the physical specifications of a preserve, there are a variety of regulations related to the use of a preserve. These can include anything from timber extraction, mineral extraction, regulated hunting, human habitation, and nondestructive human recreation.
The public lands described below differ in their level of protection. For example, national parks and forests allow camping whereas wildlife refuges place more limitations on human activities.
Wilderness Areas
Wilderness areas, comprise ecosystems in which human activity has not significantly affected the plant and animal populations or their environment. Natural processes predominate. According to the "Wilderness Act of 1964," wilderness areas are defined as being those areas where the nearest road is at least five miles away and where no permanent buildings stand. Activities that could disrupt native species, such as the use of motorized vehicles is prohibited. More than 100 million acres of land are now preserved as wilderness under this act. Sparsely populated Alaska contains the largest chunk of wilderness areas, over half of it. Although wilderness areas are scattered among most of the lower 48 states, the largest percentage is found in the western states. Few undesignated areas in the contiguous states remain that would qualify as wilderness.
National parks and forests and wildlife refuges can contain wilderness areas. California contains significant wilderness areas, with over 4 million acres of National Forest Wilderness areas, and 1.5 million acres of mostly desert wilderness in the Mojave Desert National Preserve (figure \(\PageIndex{b}\)).
Wilderness areas provide an essential habitat for a wide array of fish, wildlife, and plants, and are particularly important in protecting endangered species. For scientists, wilderness areas serve as natural laboratories, where studies can be performed that would not be possible in developed areas.
National and State Parks
The United States has set aside more land for public recreational use than any other country. The National Park System manages more than 380 parks, recreation areas, seashores, trails, monuments, memorials, battlefields, and other historic sites. It consists of more than 80 million acres nationwide (figure \(\PageIndex{c}\)). The largest national park is Wrangell–St. Elias National Park and Preserve in Alaska with over 13 million acres. California has eight national parks: Channel Islands, Death Valley, Joshua Tree, Lassen, Redwood, Sequoia, Kings Canyon, and Yosemite. Many national parks such as Yosemite, Yellowstone and the Grand Canyon are such popular recreation destinations that the ecosystems of those parks are being severely tested by human activities.
Every state has also set aside significant amounts of land for recreational use. The California State Park System manages more than one million acres of parklands including: coastal wetlands, estuaries, scenic coastlines, lakes, mountains and desert areas. California's largest state park is Anza-Borrego Desert State Park, which is the largest state park in the United States with 600,000 acres. The stated mission of the California State Park System is "to provide for the health, inspiration and education of the people of California by helping to preserve the state's extraordinary biological diversity, protecting its most valued natural and cultural resources and creating opportunities for high-quality outdoor recreation".
National Forests
The National Forest System, managed by the U.S. Forest Service (part of the United States Department of Agriculture), consists of more than 170 forestlands and grasslands, which are available for activities such as camping, fishing, hiking and hunting. These are managed as multiple use lands, which balance the needs for recreation, grazing, timber, watershed protection, wildlife and fish, and wilderness.
Some examples of national forests are the Sierra National Forest in California and the White Mountain National Forest in New Hampshire. The Coronado National Forest in Arizona is famous for "sky islands", or steep mountain ranges surrounded by low-lying areas. The dramatic increase in elevation is associated with changes in the flora and fauna (figure \(\PageIndex{d}\)). Explore national forests using this interactive map
Wildlife Refuges
The U.S. Fish and Wildlife Service manage more than 500 national wildlife refuges (figure \(\PageIndex{e}\)), which not only protect animal habitats and breeding areas but also provide recreational facilities. Find a Refuge is an interactive map for locating wildlife refuges.
Supplemental Reading
America's Public Lands Explained. 2016. U.S. Department of the Interior.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.04%3A_Protected_Areas.txt |
Ecosystem restoration is the process of bringing an area back to its natural state, before it was impacted through destructive human activities. It holds considerable promise as a mechanism for maintaining or restoring biodiversity and reinstating ecosystem services. It requires a broad interdisciplinary approach involving many different scientific fields of study (for example, biology, ecology, hydrology and geology). Reintroducing wolves, a top predator, to Yellowstone National Park in 1995 led to dramatic changes in the ecosystem that increased biodiversity. The wolves (figure \(\PageIndex{a}\)) function to suppress elk and coyote populations and provide more abundant resources to the detritivores. Reducing elk populations has allowed revegetation of riparian areas (those along the banks of a stream or river), which has increased the diversity of species in that ecosystem. Reduction of coyote populations by wolves has increased the prey species previously suppressed by coyotes. In this ecosystem, the wolf is a keystone species, meaning a species that is instrumental in maintaining diversity within an ecosystem. Removing a keystone species from an ecological community causes a collapse in diversity. The results from the Yellowstone experiment suggest that restoring a keystone species effectively can have the effect of restoring biodiversity in the community. Ecologists have argued for the identification of keystone species where possible and for focusing protection efforts on these species. It makes sense to return the keystone species to the ecosystems where they have been removed.
Other large-scale restoration experiments underway involve dam removal. In the United States, since the mid-1980s, many aging dams are being considered for removal rather than replacement because of shifting beliefs about the ecological value of free-flowing rivers. The measured benefits of dam removal include restoration of naturally fluctuating water levels (often the purpose of dams is to reduce variation in river flows), which leads to increased fish diversity and improved water quality (see Dams and Reservoirs for more about the impact of dams). In the Pacific Northwest of the United States, dam removal projects are expected to increase populations of salmon, which is considered a keystone species because it transports nutrients to inland ecosystems during its annual spawning migrations. In other regions, such as the Atlantic coast, dam removal has allowed the return of other spawning anadromous fish species (species that are born in fresh water, live most of their lives in salt water, and return to fresh water to spawn). Some of the largest dam removal projects have occurred recently, such as Elwha Dam on the Olympic Peninsula of Washington State. The large-scale ecological experiments that these removal projects constitute will provide valuable data for other dam projects slated either for removal or construction.
Besides physical processes, socioeconomic factors must also be considered in a restoration project. Actions of humans have historically been important in shaping ecosystems, and are important in determining the success of restoration efforts. Because the cost to restore an individual site can involve millions of dollars, government support is a necessity.
Environmental Remediation
Danger to human health from both historic and modern pollution requires that cleanup measures be implemented. Remediation is aimed at neutralization, containment, and/or removal of the polluting chemicals. The goal is to prevent the spread of the pollution, or to reduce it to levels that will not appreciably risk human health. Many times, it is physically impossible or financially unfeasible to completely clear all contamination. Often, experts and the public disagree on how clean is clean enough.
Many communities are struggling to find the funds and technological expertise needed to clean up polluted areas. Some settings, such as brownfields, can be remediated fairly easily. Brownfields are abandoned industrial or commercial facilities or blighted urban areas that need to be cleansed of contamination before they can be redeveloped. Other areas, because of their size or the extreme toxicity of their contaminants, require very expensive, complex, and long-term remediation. Many of these have been designated as Superfund sites.
Superfund sites are areas with the most toxic contamination in the United States. The contamination may not only make the site itself too dangerous to inhabit, but often leaks toxic levels of pollutants into the surrounding soil, water, or air. An example of a Superfund site is Love Canal in Niagara Falls, New York (figure \(\PageIndex{b}\)). The canal was a chemical waste dump for many years, then in the 1950’s was covered with soil and sold to the city. Over time, many homes and a school were built over the former dump. In the 1970’s, heavy rains raised the water table and carried contaminants back to the surface. Residents noticed foul smells, and gardens and trees turned black and died. Soon after, rates of birth defects, cancer, and other illnesses began to rise sharply. In 1977, the State of New York and the federal government began remediation work. Buildings were removed, and all residents were bought out and relocated, contaminated deposits and soils were excavated, and remaining soils and groundwater were treated and sealed off to prevent further spread of the contamination. Remediation activities have now been completed at this site.
The type of pollution and the medium affected (air, water, or soil) determine remediation methods. Methods include incineration, absorption onto carbon, chemical methods, or bioremediation. Bioremediation is the use of plants, bacteria, or fungus to “digest” the contaminant to a non-toxic or less toxic form. All of these methods tend to be expensive and time-consuming.
Reclamation and Mitigation
Reclamation involves salvaging some features of a degraded habitat, but it may not restore the ecosystem fully (figure \(\PageIndex{c}\)). For example, instead of abandoning a mined area once resources have been collected, it can be reclaimed by planting vegetation, reshaping the landscape, and redirecting water flow. However the reclaimed land still lacks many features of the original ecosystem, such as complex topography, vegetation that took tens or hundreds of years to grow, soil quality, and an intricate network of streams.
Sometimes, actions can be taken to avoid, reduce or compensate for the effects of environmental damage. Such mitigation efforts have been taken by the Army Corps of Engineers during construction projects. The native plants are removed from a site before construction begins and transplanted at a special holding site. After the construction project is completed, the native plants are replanted using those from the holding site. Another example of mitigation might involve the creation or enhancement of wetlands in one area, in order to compensate for permitted wetland losses in another area. Mitigation often goes hand-in-hand with restoration. Texaco, in conjunction with environmental groups and the United States Fish and Wildlife Service, restored 500 acres of agricultural lands in the lower Mississippi Delta to bottomland hardwoods. Texaco received environmental credits for the mitigating effects of the new woodlands on air quality.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.05%3A_Ecosystem_Restoration.txt |
Economics greatly impacts conservation success. Short-term profits can incentivize individuals, companies, or governments to harvesting resources at an unsustainable rate and at the expense of ecosystem health. In impoverished regions, compromising habitat to grow high-value crops, such as coffee or oil palms, or poaching endangered species may seem like the only source of income. One solution is debt-for-nature swaps through which one country forgives the debt of another if the latter agrees to protect natural areas. These conservation efforts can provide a new source of income for residents near the protected areas. For example, the United States forgave \$20 million in debt from Costa Rica. In exchange, Costa Rica invested in expanding its protected areas and developing the ecotourism industry, which provides jobs to many of its residents (figure \(\PageIndex{a}\)). Ecotourism involves visiting and enjoying natural areas while minimizing ecological damage. Ecotourism can benefit local economies and alleviate poverty especially if the earnings from it are reinvested into the communities living near tourist destinations. It generates jobs such as park operators, sellers of local crafts, and tour guides.
Attribution
Modified by Melissa Ha from Ecotourism from Life Sciences Grade 10 by Siyavula (licensed under CC-BY)
3.3.07: Individual Choices
Many of the strategies for preserving biodiversity operate at the level of whole governments or large organizations; however, your choices as an individual also play a role in conservation.
Consumer Choices
The products you purchase have differing impacts on biodiversity. Educating yourself on the origin of products and food that you purchase and choosing the sustainable options can help preserve biodiveristy. For example, arabica coffee can be grown in the shade, meaning there is no need to fully clear rainforest vegetation when growing this species (figure \(\PageIndex{a}\)). However, robusta coffee requires full sun, and cultivating it has a greater impact or rainforest biodiversity. Monterey Bay Aquarium provides a sustainable seafood guide, which identifies seafood choices that have a lower environmental impact. Choosing local products reduces the amount of fossil fuels that were burned to transport them to you, thus reducing carbon emissions that contribute to climate change.
Some products have special certifications that indicate their impact on biodiversity. For example, certified organic products must be cultivated without the use of synthetic pesticides, herbicides, and fertilizers, which pollute the surrounding areas. Additionally, they cannot contain genetically modified organisms (GMOs), which have both positive and negative environmental implications. If you cannot afford to buy all organic produce, see the Environmental Working Group's lists of the Clean Fifteen™ (for which pesticide use is already limited) and Dirty Dozen™ (which are high priority to purchase organic or avoid due to high pesticide residues). The Roundtable on Sustainable Palm Oil (RSPO) certifies oil palm plantations that follow standards such as avoiding deforestation and using fire to clear land. Additionally, RSPO-certified business must follow guidelines to compensate their employees sufficiently. Fair Trade Certified™ goods must meet social and environmental standards that support the United Nation's Sustainable Development Goals.
Resource Conservation
Resource conservation is individual choice that can promote biodiversity. In this case, conservation refers to limiting one's use of resources, such as water, electricity, and gasoline. Landscaping with drought-tolerant plants to limit the need for irrigation or using a low-flow shower head are examples of water conservation. Because much electricity is generated from burning fossil fuels, such as coal and natural gas, conserving electricity reduces carbon emissions associated with climate change. Turning off lights and appliances when not in use and insulating one's home to reduce electricity spent on heating and cooling save money and benefit the environment. Similarly, transportation choices such as carpooling, biking, or taking public transportation can limit carbon emissions. Reusing items or not purchasing unnecessary ones also conserves the energy needed to produce and transport these goods and reduces plastic waste, which is particularly harmful to aquatic ecosystems. See chapters about Water Resources, Renewable Energy, and Solid Waste Management for more about resource conservation.
Guide to Planting a Pollinator Garden
Whether you have a few feet on your apartment balcony or several acres, you can promote populations of native bees, butterflies, and other pollinators by building a pollinator garden (figure \(\PageIndex{b}\)). The first step is to choose a location. While flowering plants can grow in both shady and sunny locations, consider your audience. Butterflies and other pollinators like to bask in the sun and some of their favorite wildflowers grow best in full or partial sun with some protection from the wind. The next step is to identify your soil type. Take a look at your soil - is it sandy and well-drained or more clay-like and wet? You can turn over a test patch or check out a soil mapper to learn more. Your soil type and the amount of sunlight it gets will help determine the kinds of plants you can grow.
Next, research which varieties of milkweed and wildflowers are native to your area and do well in your soil and sunlight conditions. Native plants, those that have historically occurred in the area, are the ideal choice, because they require less maintenance and tend to be heartier. Find a nursery that specializes in native plants near you - they’ll be familiar with plants that are meant to thrive in your region. Some examples of pollinator-friendly plants native to California, include the California poppy, California lilac, milkweed, and foothill penstemon. The California Native Plant Society and UC Berkeley Urban Bee Lab have additional plant suggestions. It’s essential to choose plants that have not been treated with pesticides. Choosing perennials will ensure your plants come back each year, reducing the need for maintenance.
Remember to think about more than just the summer growing season. Pollinators need nectar early in the spring, throughout the summer and even into the fall. Choosing plants that bloom at different times will help you create a bright and colorful garden that both you and pollinators will love for months!
Some native bee species use bare soil for nesting. While applying mulch can help control weeds, leaves some bare soil if possible. Some native pollinators also nest in tiny cavities, which may already occur naturally in or near your garden or can be provided with bee boxes.
Make sure to weed and water your garden to keep it healthy. It may take some time, but you will eventually see butterflies and other pollinators enjoying your garden.
Modified by Melissa Ha from the U.S. Fish and Wildlife Service (public domain).
Citizen Science
Finally, citizen science provides the opportunity to be directly involved in biological conservation efforts. For some opportunities like Globe at Night, which assess light pollution, or the Lost Ladybug Project, data can be collected independently and submitted online. Others, like bird banding, are scheduled events in which experts train a group of volunteers to complete fieldwork (figure \(\PageIndex{c}\)). The federal government's citizen science database lists many such opportunities.
Attribution
Melissa Ha (CC-BY-NC) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.06%3A_Economic_Influences_on_Conservation.txt |
Overview
The Island Fox Conservation Working Group and Friends of the Island Fox nonprofit organization work hard to continually fund research and conservation projects to ensure the continued survival of the island fox. In addition, they also have educational outreach programs about the island fox as an endangered species to get public support. Every June the Island Fox Conservation Working Group meets to go over updates and plan for the future. In the 2019 meeting they discussed population trends across the six island fox subspecies and determine what those populations mean for the subspecies trajectory moving into the future. The results of this meeting can be seen in the graph and table below:
Table \(\PageIndex{a}\): The 2019 designated statuses for the subspecies of island fox based on fox population and island size. Graph by Rachel Schleiger (CC-BY-NC) modified from data in 2019 Island Fox Status Update.
Island Island Size Fox Population Status
San Miguel Small 171 Concerned
San Nicolas Small 400 Improved
Santa Rosa Large 1862 Stable
Santa Cruz Large 2462 Stable
Santa Catalina Large 1571 Stable
San Clemento Small 778 Stable
Questions
1. What is the independent (explanatory) variable and the dependent (response) variable?
2. What question(s) are the authors trying to answer with this graph and table?
3. Which subspecies of island fox do you think is the most stable? Why?
4. Which year(s) were bad (meaning population estimates were very low) for most of the island fox subspecies?
5. As noted in the graph, populations are estimated for each subspecies annually. Why do you think an annual estimation was chosen in the conservation plan instead of a longer time interval?
Raw Data From Above Graph(s)
Table \(\PageIndex{b}\): Raw data for population trends for subspecies of island fox (solid lines = large island subspecies, dashed lines = small island subspecies). Graph by Rachel Schleiger (CC-BY-NC) modified from data in 2019 Island Fox Status Update.
Year San Clemento San Nicolas San Miguel Santa Rosa Santa Cruz Santa Catalina
1994 1000 520 450 1800 1500 1300
1996 810 550 100 400 1100 800
1998 650 550 40 100 800 300
2000 800 450 20 50 100 200
2002 450 500 25 60 90 350
2004 450 500 50 70 200 375
2006 400 506 100 80 300 650
2008 400 725 260 100 750 900
2010 900 500 500 350 1050 1000
2012 850 640 525 700 1800 1500
2014 1200 263 510 900 2750 1750
2016 860 329 329 1600 2400 1400
2017 775 255 255 1800 3150 2050
2018 790 400 200 1800 2500 1600
Attribution
Rachel Schleiger (CC-BY-NC)
3.3.09: Review
Summary
After completing this chapter you should be able to...
• Describe the legislative framework for conservation, providing and describing examples of national and state laws and international agreements.
• Summarize the role of non-profit organizations in conservation.
• Discuss species-level conservation in terms of its success and shortcomings.
• Provide specific examples of species-level conservation, including the name of the species and the strategies used.
• Explain the importance of protected areas and distinguish between different types of protected areas.
• Describe principles of preserve design.
• Identify examples of the effects of ecosystem restoration, remediation, reclamation, and mitigation.
• Explain how economic factors influence conservation efforts.
• Identify actions that individuals can take to preserve biodiversity.
There is a legislative framework for biodiversity protection. In the United States, the Endangered Species Act protects listed species but is hampered by procedural difficulties and a focus on individual species. International treaties such as CITES regulate the transportation of endangered species across international borders. The non-profit sector is also very active in funding and organizing conservation efforts.
Conservation involves a variety of approaches, and many factors influence the success of conservation efforts. Species-level conservation may include captive breeding and reintroduction, vaccinations, and habitat restoration. Presently, 14.7 percent of Earth’s land surface is protected in some way. Preserves are a major tool in conservation efforts, and large, interconnected preserves favor biodiversity. The U.S. government maintains wilderness areas, national and state parks, national forests, and wildlife refuges, which differ in their levels of protection. Ecosystem restoration promotes biodiversity, improves conditions for native species, and reinstates ecosystem services. Debt-for-nature swaps and ecotourism assist conservation efforts economically. Through choosing products that minimize environmental harm and resource conservation, individuals play an important role in preserving biodiversity.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/03%3A_Conservation/3.03%3A_Protecting_Biodiveristy/3.3.08%3A_Data_Dive-_Island_Fox_Populations.txt |
The objective for this unit is to set the stage for understanding how humans have altered the trajectory of Earths abiotic and biotic systems. Specifically this unit will dive into the history of humans on this Earth, how we became successful, how we utilize/acquire basic necessities (water, food), and the how increasing population densities have influenced environmental health. This unit will also addresses the past and present of how the above variables changed as our population changed.
Figure \(1\): Chart of human evolution compared to other extinct species of the Homo genus. Image by Reed DL, Smith VS, Hammond SL, Rogers AR (licensed under CC-BY 2.5)
Attribution
Rachel Schleiger (CC-BY-NC)
• 12: The Human Population
Concepts of animal population dynamics can be applied to human population growth. Earth’s human population and their use of resources are growing rapidly, to the extent that some worry about the ability of Earth’s environment to sustain its human population. Long-term exponential growth carries with it the potential risks of famine, disease, and large-scale death, as well as social consequences of crowding.
• 13: Water Resources
Humans depend on freshwater resources, which are relatively limited compared to the abundance of water on Earth (mostly in the oceans and trapped in glaciers). Water availability is driven by the water cycle. Globally, agriculture is the biggest consumer of freshwater. Solutions to water shortages include dams and reservoirs, desalination, and water conservation.
• 14: Agriculture
Food insecurity is driven by poverty. Production the world's food has relied largely on industrial agriculture, but sustainable agriculture offers an alternative approach. A large percentage of soy, corn, and cotton grown in the U.S. are genetically modified, meaning that their genes have been directly altered by scientists.
• 15: Environmental Health
The field of environmental health is concerned with how natural and human-built surroundings affect health and well-being. Humans face biological, chemical, and physical hazards. Biological hazards result in infectious disease, and epidemiologists study patterns of disease outbreaks. Environmental toxicologists study the effects of chemical hazards. Public health organizations focus on environmental hazard reduction.
Thumbnail image - "Human ecological footprint" is in the Public Domain
04: Humans and the Environment
Chapter Hook
Why is the human species (Homo sapiens) so successful? We have the unique ability to not just occupy, but thrive, in diverse environments, even some of the most extreme. Through our social cooperation (despite large groups with no kin), language, art, and ingenuity (especially with tools and fire), our species became unstoppable. Modern humans have permanent settlements on all but one continent (Antarctica) and have exponentially increased our population. We have changed the world! However, this transformation has consequences for all species (including our own), necessitating updated survival strategies across the board.
Concepts of population ecology can be applied to human population growth. Demography is the study how human populations grow, shrink, and change in terms of age and gender compositions. Demographers also compare populations in different countries or regions. The human population has increased dramatically in the last few centuries and continues to grow (figure \(\PageIndex{a}\)). Overpopulation risks human well-being and compromises ecosystem functioning.
Attributions
Modified by Rachel Schleiger and Melissa Ha from the following sources:
• 12.1: History of Human Population Growth
Human population size has increased dramatically since the Industrial Revolution, from 1 to 7.8 billion people. While the human population continues to grow, the global population growth rate has declined. Nevertheless, the large world population as well as resource use threatens ecosystems with collapse and causes global environmental issues, such as climate change.
• 12.2: The Rate of Human Population Growth
Demographic transition is the shift from high to low birth and death rates. The future population size of different countries depends on total fertility rate, the average number of children per woman, and the age structure of the population.
• 12.3: Looking Ahead
The human population continues to grow, and according to some experts, we have already passed our carrying capacity. Carrying capacity depends on resource use per person; countries with large ecological footprints disproportionately impact the environment. China's One-Child Policy was a controversial attempt to regulate human population growth, but more ethical population regulation focuses on improving access to healthcare and education.
• 12.4: Data Dive- World Population Densities
• 12.5: Review
4.01: The Human Population
The human population is growing rapidly. For most of human history, there were fewer than 1 billion people on the planet. During the time of the Agricultural Revolution, 10,000 B.C., there were only 5-10 million people on Earth - which is basically the population of New York City today. In 1800, when the Industrial Revolution began, there were approximately 1 billion people on Earth. Continued agricultural expansion and extraction of fossil fuels and minerals led to rapid global economic growth and, in turn, population growth in the 19th century. We’ve added over 6 billion people to the human population in just a little over 200 years (figure \(\PageIndex{a}\)). As of August 2020, the global human population is around 7.8 billion people.
Although global population size continues to increase, the rate of human population growth has decreased. This means that the population size is not increasing as quickly as it did in the past (figure \(\PageIndex{a}\)).
The fundamental cause of the acceleration of growth rate for humans in the past 200 years has been the reduced death rate due to changes in public health and sanitation. Clean drinking water and proper disposal sewage has drastically improved health in developed nations. Also, medical innovations such as the use of antibiotics and vaccines have decreased the ability of infectious disease to limit human population growth. In the past, diseases such as the bubonic plaque of the fourteenth century killed between 30 and 60 percent of Europe’s population and reduced the overall world population by as many as one hundred million people. Naturally, infectious disease continues to have an impact on human population growth, especially in poorer nations. For example, life expectancy in sub-Saharan Africa, which was increasing from 1950 to 1990, began to decline after 1985 largely as a result of HIV/AIDS mortality. According to a 2016 study by Marcus et al., The reduction in life expectancy caused by HIV/AIDS was estimated to be 8 years for 2016.
Human technology and particularly our harnessing of the energy contained in fossil fuels have caused unprecedented changes to Earth’s environment, altering ecosystems to the point where some may be in danger of collapse. Changes on a global scale including depletion of the ozone layer, desertification and topsoil loss, and global climate change are caused by human activities.
Reference
Marcus, J. L., Chao, C. R., Leyden, W. A., Xu, L., Quesenberry, C. P., Jr, Klein, D. B., Towner, W. J., Horberg, M. A., & Silverberg, M. J. (2016). Narrowing the Gap in Life Expectancy Between HIV-Infected and HIV-Uninfected Individuals With Access to CareJournal of acquired immune deficiency syndromes (1999)73(1), 39–46.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.01%3A_The_Human_Population/4.1.01%3A_History_of_Human_Population_Growth.txt |
Demographic Transition
Recall from the Populations chapter that the population growth rate (r) equals the birth rate minus the death rate. Slowly declining birth rates following an earlier sharp decline in death rates are today characteristic of most of the less-developed regions of the world. The shift from high birth and death rates to low birth as well as death rates is called the demographic transition.
Prior to World War II, advances in public health were largely limited to affluent, industrialized countries. But since then, many more countries have enjoyed improvements in public health - always with dramatic effect on death rates. For example, in 1945, the death rate in Sri Lanka (then called Ceylon) was 0.022 (2.2%). In 1946, a large-scale program to control mosquitos, which transmit malaria, was started. By eliminating the mosquito, the incidence of malaria dropped sharply. After 9 years, the death rate dropped to 0.010 (1%), and by 2012 was 0.006 (0.6%). However, a compensating decline in birth rates has come more slowly; the birth rate was 0.018 (1.8% in 2012). With birth rates higher than death rates, the population was increasing at an annual rate of 0.012 (1.2%) per year, with a doubling time of 57.5 years (t = 0.69/0.012).
Predicting Future Population Size
Doubling time is based on a constant population growth rate, but this rate can change depending on a number of factors, including total fertility rate (TFR) and the age structure of the population.
Total Fertility Rate
The total fertility rate (TFR) is the average number of children that each woman will have during her lifetime. The TFR is an average because, of course, some women will have more, some fewer, and some no children at all. Theoretically, when the TFR = 2, each pair of parents just replaces itself. Actually it takes a TFR of 2.1 or 2.2 to replace each generation - this number is called the replacement fertility rate - because some children will die before they grow up to have their own two children. In countries with low life expectancies, the replacement rate is even higher (2.2–3). Figure \(\PageIndex{a}\) compares he total fertility rate in different countries.
Age Structure
The age structure of a population, the proportion of a population in different age classes, is an important factor in population dynamics. The relationship between TFR and the population growth rate (r) depends on age structure. For example, if at one period a population has an unusually large number of children, they will — as they pass through their childbearing years — increase the r of the population even if their TFR goes no higher than 2. Most people have children between the ages of 15 and 49. So if a population has a large number of young people just entering their reproductive years, the rate of growth of that population is sure to rise.
Models that incorporate age structure allow better prediction of population growth, plus the ability to associate this growth with the level of economic development in a region. Countries with rapid growth associated with high birth rates have a pyramidal shape in their age structure diagrams, showing a preponderance of younger individuals, many of whom are of reproductive age (figure \(\PageIndex{b}\)).
The age structure of a population also reflects the recent pattern of mortality. In countries where injuries, starvation, and disease, etc. take a heavy toll throughout life, the age structure diagram has a broad base. In countries where almost everyone survives until old age, the bases is narrower.
Rapid growth is most often observed in underdeveloped countries where individuals do not live to old age because of less-than-optimal living conditions, and there is a high birth rate. Age structures of areas with slow growth, including developed countries such as the United States, still have a pyramidal structure, but with many fewer young and reproductive-aged individuals and a greater proportion of older individuals compared to underdeveloped countries. Other developed countries, such as Italy, have zero population growth. The age structure of these populations is more conical, with an even greater percentage of middle-aged and older individuals.The actual growth rates in different countries are shown in figure \(\PageIndex{c}\), with the highest rates tending to be in the less economically developed countries of Africa and Asia.
The U.S. Baby Boom
The TFR in the United States declined from more than 4 late in the nineteenth century to less than replacement in the early 1930s. However, when the small numbers of children born in the depression years reached adulthood, they went on a childbearing spree that produced the baby-boom generation (figure \(\PageIndex{d}\)). In 1957, more children were born in the United States than ever before (or since).
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.01%3A_The_Human_Population/4.1.02%3A_The_Rate_of_Human_Population_Growth.txt |
Population Projections
A consequence of exponential human population growth is that is takes less time to add a particular number of humans to our Earth. Figure \(\PageIndex{a}\) shows that 123 years were necessary to add 1 billion humans in 1930, but it only took 24 years to add two billion people between 1975 and 1999. As already discussed, at some point it would appear that our ability to increase our carrying capacity indefinitely on a finite world is uncertain. Without new technological advances, the human growth rate has been predicted to continue to slow in the coming decades. However, the population will still be increasing and the threat of overpopulation remains.
Exponential growth cannot continue indefinitely. If the current world value for r (1.075% in 2019) remains unchanged, the global population would grow from its current 7.8 billion (August 2020) to 9.7 billion by 2050. Experts predict that the global population will continue to grow until 2100, reaching a peak of almost 11 billion. So this begs the question(s)... What is the carrying capacity for humans on Earth? How long until we reach it, or have we already surpassed it? Then finally, what are the consequences of our current and projected populations?
Long-term Consequences
Humans are not unique in their ability to alter their environment. For example, beaver dams alter the stream environment where they are built. Humans, however, have the ability to alter their environment to increase its carrying capacity, sometimes to the detriment of other species. Earth’s human population and their use of resources are growing rapidly, to the extent that some demographers say that humans have already exceeded our carrying capacity. This would mean that the Earth cannot indefinitely support our current population size. Long-term exponential growth carries with it the potential risks of famine, disease, and large-scale death, as well as social consequences of crowding such as increased crime.
The impact of humans on our environment depends not only on population size but also on resource use. The ecological footprint is a measure of the area of land needed to support an individual or country. This includes agricultural lands used to provide food, other lands used to provide goods (such as forests to provide timber) and fuels (such as oil fields to provide fossil fuels), and the land needed to dispose of wastes.
Countries differ in the average ecological footprint per person, and these differences are associated with region (figure \(\PageIndex{b}\)). For example, in 2017, the ecological footprint per person in the United States was 8.1 global hectares compared to only 1.2 global hectares in India. (Visit footprintnetwork.org to see ecological footprints and related metrics for all countries.) Many factors affect the size of an ecological footprint from economic development to resource conservation to individual product choice. Reducing our ecological footprints can increase our carrying capacity and decrease environmental impact. So maybe we should update the question of, "What the Earths carrying capacity for humans," to, "What is the carrying capacity of people on Earth at which we can provide a fair and decent life for all humans while causing the minimum impact on the environment?
Are you wondering about the size of your ecological footprint? You can estimate it here.
Regulation
Reducing the population growth rate will limit the consequences of overpopulation; however, regulation of the human population is a complex issue that presents ethical considerations.
Efforts to moderate population control led to the 1979 One-Child Policy in China, which imposed fines on urban couples who had more than one child (figure \(\PageIndex{c}\)). Additionally, only a couple's first child was granted educational and health care benefits. The effectiveness of the policy in limiting overall population growth is controversial, as was the policy itself. Tragically, this policy combined with the desire of many couples to have a male heir led to female infanticide. Furthermore, enforcement of the policy led to human rights abuses including forced sterilizations and forced abortions. Over the years, some restrictions associated with the One-Child Policy were lifted. For example, in 2013, an adult who was an only child was allowed to have two children. The policy ended in 2016, and as of May 2021, each couple is now permitted to have up to three children.
Zero population growth occurs when the birth rate equals the death rate such that the rate of population growth is zero. Logically, this would occur when total fertility rate equals replacement fertility rate, but as described in the previous section, this depends on the age structure of a population.
All else being equal, reductions in total fertility rate will slow human population growth. Total fertility rate is negatively correlated with improved standard of living, access to health care, and gender equality. As countries develop economically, individuals become increasingly dependent on urban jobs rather than the family farm for income and provisions. While a large family would be needed to tend the family farm, supporting many children in an urban area is expensive. As a result, economic development is associated with couples choosing to have fewer children.
Access to healthcare decreases childhood mortality and provides the option of birth control. While decreased infant and childhood mortality alone would increase the population growth rate, people tend to have fewer children when they can be confident that all of their children are likely to survive; thus, as childhood mortality declines, total fertility rate also declines, lowering the population growth rate.
The education of women and girls is also associated with a decreased total fertility rate. Furthermore, family planning education programs have had highly positive effects in some countries on limiting population growth rates and increasing standards of living. When women have knowledge of family planning, power to make decisions about their family size, and a variety of career options, fertility rate declines. In regions that have made recent strides in educating girls, families more often choose to have a small number of children so that they can afford to pay for their education regardless of gender.
Attributions
Modified by Melissa Ha from the following sources:
4.1.04: Data Dive- World Population Densities
Overview
The Socioeconomic Data and Applications Center (SEDAC), is one of the Distributed Active Archive Centers (DAACs) in the Earth Observing System Data and Information System (EOSDIS) of the U.S. National Aeronautics and Space Administration (NASA). Its main objective is to investigate human interactions in the environment and to develop and operate applications that support the integration of socioeconomic and earth science data and to serve as an "Information Gateway" between earth sciences and social sciences. One of the projects it continually updates is creating global population density maps. Their 2020 map can be observed below:
Questions
1. The data on the above graph is overlaid onto a world map. Why do you think this is a powerful way to display data?
2. What question(s) are the authors trying to answer with this graph and table?
3. Which areas of the globe have the highest density levels (darkest density shading)?
4. Are there any areas of the globe that surprise you (either high or low) with their density? Why?
5. How can policy makers/world leaders/health organizations use this information? Provide at least 3 ideas.
6. What is missing from this map? Hint: It’s very large!
Attribution
Rachel Schleiger (CC-BY-NC)
4.1.05: Review
Summary
After completing this chapter you should be able to...
• Discuss the history of human population growth.
• Define demographic transition.
• Explain how total fertility rate and age structure affect current and future population growth rate.
• Interpret age structure diagrams.
• Discuss the long-term implications of unchecked human population growth with respect to carrying capacity and ecological footprints.
• Describe efforts to regulate human population size.
The world’s human population is growing at an exponential rate. Humans have increased the world’s carrying capacity through migration, agriculture, medical advances, and communication. The age structure of a population allows us to predict population growth. Unchecked human population growth could have dire long-term effects on our environment.
Attribution
Modified by Melissa Ha from Human Population Growth from General Biology by OpenStax (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.01%3A_The_Human_Population/4.1.03%3A_Looking_Ahead.txt |
Chapter Hook
The aqueducts of Rome are a huge feat of ancient achievement and ingenuity. Not only did they provide water for drinking and bathing but contributed to agriculture, hygiene (through sewers and plumbing), culture, and industry. These stone waterways took about 500 years to complete (312 BC to 226 AD) and contributed significantly to the success of Rome. Water is essential for survival, so other ancient civilizations found ways to move water as well; however, none even came close to being as successful or magnificent.
• 13.1: Fresh Water Supply and the Water Cycle
Despite the abundance of water on Earth, only about 0.01% is available for human use. Most of Earth's water is in the oceans, and much of the freshwater is trapped in ice caps and glaciers. The water cycle describes the movement of water among bodies of water, the atmosphere, organisms, and the ground. This drives the availability of water resources, including precipitation, surface water, and groundwater.
• 13.2: Water Usage
In the United States, 281 billion gallons of water are withdrawn each day, of which 82 billion gallons are groundwater. The state of California accounts for 9% of national groundwater withdrawals. A typical person in the U.S. directly uses 80-100 gallons of water each day.
• 13.3: Water Scarcity and Solutions
Many people still lack access to sufficient and clean water, resulting in the water crisis. Water shortages (scarcity) may be physical or economic. Solutions to water scarcity involve dams and reservoirs, rainwater harvesting, aqueducts, desalination, water reuse, and water conservation.
• 13.4: Data Dive- Aqueducts of Rome
• 13.5: Review
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
4.02: Water Resources
Water, air, and food are the most important natural resources to people. Humans can live only a few minutes without oxygen, less than a week without water, and about a month without food. Water also is essential for our oxygen and food supply. Plants breakdown water and use it to create oxygen during the process of photosynthesis.
Human babies are approximately 75% water, and adults are 60% water. Our brain is about 85% water, blood and kidneys are 83% water, muscles are 76% water, and even bones are 22% water. We constantly lose water by perspiration. In temperate climates we should drink about two quarts of water per day, and people in hot desert climates should drink up to 10 quarts of water per day. Loss of 15% of body-water usually causes death.
Water Reservoirs
Water is the only common substance that occurs naturally on Earth in three forms: solid, liquid and gas. The hydrosphere is the area of Earth where water movement and water storage occurs. Water reservoirs are the locations where water is stored. (Note that this term can also refer to artificial lakes created by dams.) Water is found as a liquid on the surface (rivers, lakes, oceans) and beneath the surface (groundwater), as ice (polar ice caps and glaciers), and as water vapor in the atmosphere. Figure \(\PageIndex{a}\) illustrates the average time that an individual water molecule may spend in the Earth’s major water reservoirs. Residence time is a measure of the average time an individual water molecule stays in a particular reservoir.
Earth is truly the Water Planet. The abundance of liquid water on Earth’s surface distinguishes us from other bodies in the solar system. About 71% of Earth’s surface is covered by water, and approximately half of Earth’s surface is obscured by clouds (also made of water) at any time. There is a very large volume of water on our planet, about 1.4 billion cubic kilometers (km3) = 330 million cubic miles, or about 53 billion gallons per person on Earth. All of Earth’s water could cover the United States to a depth of 145 km (90 mi).
Despite the vast volumes of water on Earth, only 2.5% is freshwater (figure \(\PageIndex{b}\)), and only 0.01% is available for humans to use. If all of world’s water was shrunk to the size of 1 gallon, then the total amount of fresh water would be about 1/3 cup, and the amount of readily usable freshwater would be 2-3 tablespoons. Much of Earth's freshwater is trapped in glaciers and polar ice caps (figure \(\PageIndex{c}\)), and this water is inconveniently located, mostly in Antarctica and Greenland. Shallow groundwater (water located below the Earth's surface) is the largest reservoir of usable fresh water. Many organisms are dependent on surface waters, such as lakes and rivers, which comprise a small fraction of freshwater on Earth. A lack of these surface waters can have negative effects on ecosystems.
The Water Cycle
The water cycle (hydrologic cycle) shows the movement of water through different reservoirs, which include oceans, atmosphere, glaciers, groundwater, lakes, rivers, and organisms (figure \(\PageIndex{d}\)). Solar energy, which warms the oceans and other surface waters, and gravity drive the motion of water in the water cycle. This leads to evaporation (liquid water to water vapor) of liquid surface water, sublimation (ice to water vapor) of frozen water, and transpiration (the loss of water from plants to the atmosphere). When water in the soil is taken up by plant roots, it moves through tubes in the plant (the vascular system), evaporates within the space of the leaf, and transpires through the stomata (small microscope openings) of the leaves. Ecologists combine transpiration and evaporation into a single term that describes water returned to the atmosphere: evapotranspiration. Thus, large amounts of water move into the atmosphere as water vapor.
Water vapor in the atmosphere can migrate long-distances from ocean to over land by way of prevailing winds. Over the ocean or land, the air can cool and cause the water to condense back into liquid water. This usually happens in the form of very small water droplets that form around a microscopic piece of dust or salt called condensation nuclei. These small water droplets are visible as a cloud. Clouds build and once the water droplets are big enough, they fall to earth as precipitation (rain, snow, hail, or sleet), which returns water to Earth’s surface.
Precipitation that reaches land can immediately return to the atmosphere, add to groundwater, or form surface runoff. In most natural terrestrial environments, rain encounters vegetation before it reaches the soil surface. A significant percentage of water evaporates immediately from the surfaces of plants or directly from the soil surface. Groundwater is replenished when water infiltrates into the soil and finally fills the pore spaces between particles in dirt, sand, and gravel or in the fissures in rocks. Groundwater slowly moves through rock and unconsolidated materials and some of it eventually reaches the surface again, where it discharges as springs and into streams, lakes, and the ocean. Many streams flow not because they are replenished from rainwater directly but because they receive a constant inflow from the groundwater below. Also, surface water in streams and lakes can infiltrate again to recharge groundwater. Therefore, the surface water and groundwater systems are connected. Groundwater can also ultimately flow into the ocean through subsurface groundwater flow, but some groundwater is found very deep in the bedrock and can persist there for millennia. Surface runoff is the flow of freshwater over land either from rain or melting ice. Runoff can make its way through streams and lakes to the oceans. Surface runoff will occur only if the soil becomes saturated with water in a heavy rainfall.
The steps of the water cycle are explained in the video below.
Salinity and the Water Cycle
An important part of the water cycle is how water varies in salinity, which is the abundance of dissolved ions in water. The saltwater in the oceans is highly saline, with about 35,000 mg of dissolved ions per liter of seawater. Evaporation is a distillation process that produces nearly pure water with almost no dissolved ions. As water vaporizes, it leaves the dissolved ions in the original liquid phase. Eventually, condensation forms clouds and sometimes precipitation. After rainwater falls onto land, it dissolves minerals in rock and soil, which increases its salinity. Rain and surface runoff are major ways in which minerals, including phosphorus and sulfur, are cycled from land to water. The environmental effects of runoff were discussed in Biogeochemical Cycles. Freshwater (such as lakes, rivers, and near-surface groundwater) has a relatively low salinity.
Human Interactions with The Water Cycle
Humans alter the water cycle by extracting large amounts of freshwater from surface waters as well as groundwater (see Water Usage). Additionally, changes in land use, such as deforestation, agriculture, and urbanization, reduce vegetation cover, which reduces infiltration and increases surface runoff. (Vegetation naturally traps precipitation as it falls, slows the flow surface runoff, and increases the infiltration rate.) This intensifies flooding and exacerbates erosion, lowering soil quality and causing sediment pollution in water. Additionally, humans redirect the flow of water by building dams and aqueducts (figure \(\PageIndex{e}\)). So much water is removed or redirected from the Colorado River in the western United States that, despite its considerable size, in some years it is dry before reaching the sea in Mexico. In an extreme example, the Aral Sea in Central Asia has decreased to only 10% of its initial size after water was diverted for agriculture (see this case study for more details).
Water Resources
Freshwater resources are ultimately replenished by precipitation. This water can then be obtained from surface water, such as rivers and lakes, and from aquifers, which store groundwater.
Primary Freshwater Resources: Precipitation
Precipitation levels are unevenly distributed around the globe, affecting fresh water availability (figure \(\PageIndex{f}\)). In general, due the uneven heating of the Earth and global air circulation cells resulting from the Earth's rotation, air rises near the equator and near 60° north and south latitude and sinks at the poles and 30° north and south latitude. As discussed in Climate Effects on Biomes, the intense sunlight at the equator heats air, causing it to rise and cool, which decreases the ability of the air mass to hold water vapor and results in frequent rainstorms. Around 30 degrees north and south latitude, descending air conditions produce warmer air, which increases its ability to hold water vapor and results in dry conditions. Both the dry air conditions and the warm temperatures of these latitude belts favor evaporation.
The size of continents, mountains, prevailing winds, ocean circulation patterns, and even the proximity of bodies of water can affect local climate patterns. For example, when cold winds blow across the relatively warm Great Salt Lake, the air warms, which causes it to pick up moisture. This local increase in the moisture content of the air may eventually fall as snow or rain on nearby mountains, a phenomenon known as “lake-effect precipitation”.
In the United States, the 100th Meridian roughly marks the boundary between the humid and arid parts of the country (figure \(\PageIndex{g}\)). Irrigation is required to grow crops west of the 100th Meridian. In the West, surface water is stored in reservoirs (artificial lakes) and mountain snowpacks and strategically released through a system of canals during times of high use.
Surface Water: Rivers and Lakes
Rivers are an important water resource for irrigation of cropland and drinking water for many cities around the world. Flowing water from rain and melted snow on land enters river channels by surface runoff (figure \(\PageIndex{h}\)) and seepage from surrounding land. The geographic area drained by a river and its tributaries is called a watershed. The Mississippi River watershed includes approximately 40% of the U.S., a measure that includes the smaller watersheds, such as the Ohio River and Missouri River that help to comprise it. Rivers that have had international disputes over water supply include the Colorado (Mexico, southwest U.S.), Nile (Egypt, Ethiopia, Sudan), Euphrates (Iraq, Syria, Turkey), Ganges (Bangladesh, India), and Jordan (Israel, Jordan, Syria).
In addition to rivers, lakes can also be an excellent source of freshwater for human use. They usually receive water from surface runoff and groundwater. By building dams, people create artificial lakes (reservoirs).
Groundwater Resources
Although most people in the world use surface water, groundwater is a much larger reservoir of usable freshwater, containing more than 30 times more water than rivers and lakes combined. A large area of subsurface, porous rock unit or sediment that holds extractable groundwater is an aquifer. The saturated zone of an aquifer is where groundwater completely fills pore spaces in earth materials. The water table is the uppermost level at which the pores are fully saturated with water (figure \(\PageIndex{i}\)).
A combination of a place to put water (porosity) and the ability to move water (permeability) makes a good aquifer. Porosity is a measure of the open space in rocks –expressed as the percentage of open space that makes up the total volume of the rock or sediment material. Permeability is a measure of the interconnectedness of pores in a rock or sediment. The connections between pores allows for that material to transmit water. Porosity and permeability are functions of soil particle composition. For example, clays generally have very high porosity, but the pores are poorly connected, thereby causing low permeability.
Aquifers are commonly drilled, and wells installed, to provide water for agriculture and personal use. In many cases aquifers are being depleted faster than they are being replenished by water infiltrating down from above. Groundwater is a particularly important resource in arid climates, where surface water may be scarce. In addition, groundwater is the primary water source for rural homeowners, providing 98% of that water demand in the U.S.
As groundwater is pumped from water wells, there usually is a localized drop in the water table around the well called a cone of depression (figure \(\PageIndex{j}\)). When there are a large number of wells that have been pumping water for a long time, the regional water table can drop significantly. This is called groundwater mining, which can force the drilling of deeper, more expensive wells that commonly encounter more saline groundwater. Rivers, lakes, and artificial lakes (reservoirs) can also be depleted due to overuse. Some large rivers, such as the Colorado in the U.S. and Yellow in China, run dry in some years.
Another water resource problem associated with groundwater mining is saltwater intrusion, where overpumping of fresh water aquifers near ocean coastlines causes saltwater to enter freshwater zones. The drop of the water table around a cone of depression in an aquifer can change the direction of regional groundwater flow, which could send nearby pollution toward the pumping well instead of away from it. Finally, problems of subsidence (gradual sinking of the land surface over a large area) and sinkholes (rapid sinking of the land surface over a small area) can develop due to a drop in the water table. Because the pores in the aquifer collapse as subsidence occurs, this permanently reduces the capacity of the aquifer to hold water in the future.
Groundwater is replenished through infiltration, seepage from surface water (lakes, rivers, reservoirs, and swamps), surface water deliberately pumped into the ground, irrigation, and underground wastewater treatment systems (septic tanks). Recharge areas are locations where surface water infiltrates the ground rather than running into rivers or evaporating (figure \(\PageIndex{k}\)). Recharge areas are generally the topographically highest location of an aquifer. They are characterized by streams that lie below the water table and sediment or rock that allows infiltration into the subsurface. Wetlands, for example, are excellent recharge areas. Recharge areas mark the beginning of groundwater flow paths.
Recharge can be induced through the aquifer management practice of aquifer storage and recovery. Injection wells allow for humans to increase the rate of recharge into an aquifer system by pumping water into an aquifer (figure \(\PageIndex{k}\)). Injection wells are regulated by state and federal governments to ensure that the injected water is not negatively impacting the quality or supply of the existing groundwater in the aquifer. Some aquifers are capable of storing significant quantities of water, allowing water managers to use the aquifer system like a surface reservoir. Water is stored in the aquifer during periods of low water demand and high water supply and later extracted during times of high water demand and low water supply. | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.02%3A_Water_Resources/4.2.01%3A_Fresh_Water_Supply_and_the_Water_Cycle.txt |
Freshwater supply is one of the most important ecosystem services. In 2014, global water consumption was 3999 km3 per year (over 1,000 trillion gallons!). The greatest use of this water is for irrigation in agriculture, but significant quantities of water are also extracted for public and municipal use, as well as industrial applications and power generation (figure \(\PageIndex{a}\)).
Humans require only about 1 gallon per day to survive, but a typical person in a U.S. household uses approximately 80-100 gallons per day, which includes cooking, washing dishes and clothes, flushing the toilet, and bathing. Additionally, we rely on the food, energy, and mineral resources, which all require water to produce. For example, approximately three gallons are needed to produce a tomato, 150 gallons for a loaf of bread, and 1,600 for a pound of beef. (You can learn more about the water footprint of different foods using this interactive website.) Twenty-one gallons are needed to produce one kilowatt-hour (kWh) of electricity from a traditional power plant (about 1 kWh is needed to heat an oven for 30 minutes), and one ton of steel consumes about 63,000 gallons of water. The water demand of an area is a function of the population and other uses of water.
In the United States, 281 billion gallons of water were withdrawn per day in 2015, of which 82 billion gallons are fresh groundwater (figure \(\PageIndex{b}\)). The state of California accounts for 9% of national water withdrawal (figure \(\PageIndex{c}\)).
Attributions
Modified by Melissa Ha from the following sources
4.2.03: Water Scarcity and Solutions
One of the most important environmental goals is to provide clean water to all people. Fortunately, water is a renewable resource and is difficult to destroy. Evaporation and precipitation combine to replenish our fresh water supply constantly; however, water availability is complicated by its uneven distribution over the Earth.
Water Scarcity
The water crisis refers to a global situation where people in many areas lack access to sufficient water, clean water, or both. Arid climate and densely populated areas have combined in many parts of the world to create water shortages, which are projected to worsen in the coming years due to population growth, water overuse, water pollution, and climate change. Specifically, climate change shifts precipitation patterns and causes the snow pack that recharges rivers to melt earlier in the year. Furthermore, rising sea levels associated with climate change worsen saltwater intrusion.
Water scarcity refers to water shortages, which can be physical or economic (figure \(\PageIndex{a}\)). Physical water scarcity is the lack of sufficient water resources in an area; that is, water is depleted more quickly than it is replenished. Unpredictable precipitation patterns associated with climate change, which increase the risk of flooding and drought, exacerbates physical water scarcity. Economic water scarcity occurs when people cannot afford access to water. The United Nations estimates that over half of the global population faces water scarcity for one or more months of the year (see The Sustainable Development Goals Report 2019). According to the World Health Organization and UNICEF, 785 million people lack access to even a basic drinking water service (see Drinking Water) and two billion people lack access to improved sanitation as simple as a pit latrine (see Sanitation), and three billion people lack a facility to wash their hands (see Hand Hygiene for All). As a result, nearly 829,000 people die every year from diarrheal diseases, and 297,000 of those deaths occur among children under the age of five (see Drinking Water).
Solutions for Addressing Water Shortages
While some human activities have exacerbated the water crisis, humans have also developed technologies to better acquire or conserve freshwater. Solutions to addressing water shortages include dams and reservoirs, rainwater harvesting, aqueducts, desalination, water reuse, and water conservation.
Dams and Reservoirs
Reservoirs (artificial lakes) that form behind dams in rivers can collect water during wet times and store it for use during dry spells (figure \(\PageIndex{b}\)). They also can be used for urban water supplies. Other benefits of dams and reservoirs are hydroelectricity, flood control, and recreation. Some of the drawbacks are evaporative loss of water in arid climates and downstream river channel erosion. Additionally, dams reduce water flow downstream, which could lead to political conflicts when rivers span states or countries.
The negative ecosystem impacts of dams are another major drawback. For example, dams change a river to a lake habitat and interfere with migration and spawning of fish. Furthermore, warming of the surface water in the reservior influences the temperature of the water downstream, impacting the fish and aquatic invertebrates that are adapted to colder water. Dams also trap sediments that would otherwise continue to flow down the river, creating habitat and supplying nutrietns downstream.
Rainwater Harvesting
Rainwater harvesting involves catching and storing rainwater before it reaches the ground. Figure \(\PageIndex{c}\) shows a complex rainwater harvesting system (rain water capture system) proposed for federal buildings, but smaller, simpler systems (sometimes called rain barrels) can be used by individual homeowners (figure \(\PageIndex{d}\)).
Aqueducts
Aqueducts can move water from where it is plentiful to where it is needed. Aqueducts can be controversial and politically difficult especially if the water transfer distances are large. One drawback is the water diversion can cause drought in the area from where the water is drawn. For example, Owens Lake and Mono Lake in central California began to disappear after their river flow was diverted to the Los Angeles aqueduct (figure \(\PageIndex{e}\)). Without water supply, Owens Lake dried and became a major source of particulate matter, polluting the air during dust storms (see Air Pollution). Owens Lake remains almost completely dry, but Mono Lake has recovered more significantly due to legal intervention. Learn more about the Los Angeles Aqueduct here.
Desalination
One method that can actually increase the amount of freshwater on Earth is desalination, which involves removing dissolved salt and minerals from seawater or saline groundwater (figure \(\PageIndex{f}\)). An advantage of this approach is that there is a virtually unlimited supply of saltwater. There are several ways to desalinate seawater including boiling, filtration, electrodialysis (applying an electric current to removed the ions which comprise salts), and reverse osmosis (figure \(\PageIndex{g}\)). All of these procedures are moderately to very expensive and require considerable energy input, making the water produced much more expensive than freshwater from conventional sources. In addition, the process creates highly saline wastewater, which must be disposed of and creates significant environmental impact. Desalination is most common in the Middle East, where energy from oil is abundant but water is scarce.
Water Reuse (Water Recycling)
Water recycling refers to reusing water for appropriate purposes such as agriculture, municipal water supply, industrial processes, and environmental restoration (figure \(\PageIndex{h}\)). This could occur at the scale of a single household, for example, installing plumbing that reroutes water drained from the sink to flush the toilet. Water recycling can also occur at large scales. For example, wastewater from the sewage system is regularly treated to an extent, but it can be treated further to produce potable water (which is safe to drink) and then pumped into depleted aquifers. This approach limits saltwater intrusion of aquifers near the coast and reduces dependence on precipitation and subsequent infiltration to recharge aquifers. Orange County Water District in California employed this system following an information campaign to explain the purification process and ensure public confidence in the safety of the treated wastewater.
Water Conservation
Water conservation refers to using less water and using it more efficiently. Around the home, conservation can involve both water-saving technologies and behavioral decisions. Examples of water-saving technologies include high-efficiency clothes washers and low-flow showers and toilets. Water-conserving behaviors include turning off the water while you brush your teeth, taking shorter showers and showers instead of baths, and fixing leaky faucets. A dishwasher uses less water than washing dishes by hand, particularly the dishwasher is only run when it is full. Similarly, running fewer, larger loads of laundry conserves water relative to more frequent, smaller loads. Choosing foods with a low water footprint (like eggs) over those with a high water footprint (like beef) can also conserve water.
Gardening offers several water-saving opportunities. If you live in a dry climate, consider growing only native, drought-tolerant vegetation, which requires little irrigation (figure \(\PageIndex{h}\)). When you do irrigate your garden, do so only as needed and early in the morning, when less water will be lost to evaporation. Drip systems assist in delivering only the needed amount of water in a way that minimizes evaporation. These strategies can also be applied at large scales in agriculture, which is extremely important considering the high agricultural demands on our water supply relative to municipal use. Water conservation strategies in agriculture include growing crops in areas where the natural rainfall can support them, more efficient irrigation systems such as drip systems, and no-till farming, which reduces evaporative losses by covering the soil.
Bottled water is not a sustainable solution to the water crisis. Bottled water is not necessarily any safer than the U.S. public water supply, it costs on average about 700 times more than U.S. tap water, and every year it uses approximately 200 billion plastic and glass bottles that have a relatively low rate of recycling. Compared to tap water, it uses much more energy, mainly in bottle manufacturing and long-distance transportation. (Purchasing a water filter is a more sustainable solution than bottled water if you do not like the taste of tap water.)
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.02%3A_Water_Resources/4.2.02%3A_Water_Usage.txt |
Overview
All drinking water sources are subject to contamination that require appropriate treatment to eliminate disease-causing pathogens. Sources of water contamination can originate from naturally occurring chemicals and minerals (arsenic, radon, uranium), local land use practices (fertilizers, pesticides), manufacturing processes, and sewage. If left untreated, the presence of contaminants in water can lead to adverse health effects, both acute and chronic. This is why the achievement of the aqueducts of Rome are so astounding! Not only did they water to the residents of Rome, but somehow the Romans were able to identify the cleanest water sources for drinking without the most basic testing equipment. In 1995 Peter Aicher published a book titled, “Guide to the aqueducts of ancient Rome.” The book discusses a lot of the history surrounding the 11 aqueducts while also integrating a more modern analysis of the quality of the water based on where it was sourced. The table below provides a brief overview of the aqueducts along with several notes about their use:
Table \(\PageIndex{a}\): Aqueduct characteristics and notes about water volume, source, quality and use. Table by Rachel Schleiger (CC-BY-NC) modified from data in Aicher PJ 1995.
Aqueduct Construction Complete Volume (units) Water Source Water Quality Notes
Appia 312 BC 31 Springs Good
All underground except inside walls
70% for civic/imperial uses
Anio Vetus 272-269 BC 74 River Poor Used for baths, gardens, and industry
Marcia 144-240 BC 78 Springs Best
Pure/cold/hard water
Supplied baths
Tepula 126-125 BC 7 Streams Good Warm water (60F)
Julia 33 BC 20 Springs Good N/A
Virgo 22-19 BC 41 Marsh Good
Almost all underground, some along channel
Supplied baths
Alsietina 2 BC 7 Lake Poor Build to supply basin for mock sea battles
Claudia 38-52 AD 76 Springs Good Built several branches in the city
Anio Novus 38-52 AD 78 River Okay Quality was poor until later improved
Traiana 109 AD 47 Springs Good N/A
Alexandria 226 AD 9 Springs Good Served baths
Questions
1. How many of the 11 aqueducts do you think have drinkable water?
2. Does the above answer surprise you? Why/why not?
3. How many of the aqueducts with drinkable water come from a higher volume aqueduct?
4. Based on what you can observe in the notes, what did the Romans do when water wasn’t drinkable?
5. What is the most surprising thing to you about the data presented in the above table? Why?
Attribution
Rachel Schleiger (CC-BY-NC)
4.2.05: Review
Summary
After completing this chapter you should be able to...
• Describe the different water reservoirs and identify which of these reservoirs are accessible to humans.
• Diagram the water cycle and explain how humans interact with the water cycle.
• Explain how groundwater is acquired from aquifers and how aquifers are recharged.
• Identify the main water-consuming sectors and their relative contributions to water usage.
• Compare physical and economic water scarcity.
• Outline strategies for addressing water shortages.
• Provide examples of water conserving technologies and behaviors.
Water is stored in water reservoirs. Although there is much water on Earth, only a fraction of this is freshwater that is accessible to humans. The water cycle describes the movement of water through each reservoir and involves sublimination and evapotranspiration, condensation, precipitation, infiltration, and surface runoff. Humans alter the water cycle through land use and diverting water flow. Precipitation—a major control of fresh water availability—is unevenly distributed around the globe. More precipitation falls near the equator, and landmasses there are characterized by a tropical rainforest climate. Less precipitation tends to fall near 30 degrees latitude, where the world’s largest deserts are located. Surface waters, including lakes are rivers, are an important source of freshwater. Additionally, groundwater can be extracted from aquifers. Agriculture is the greatest consumer of water, followed by industry and municipal use.
The water crisis refers to a global situation where people in many areas lack access to sufficient water or clean water or both. Physical water scarcity occurs when water resources are insufficient, but people face economic water scarcity when they cannot afford access to water. Partial solutions to the water crisis include dams and reservoirs, rainwater harvesting, aqueducts, desalination, water reuse, and water conservation.
Attribution
Modified by Melissa Ha from Water Availability and Use from Environmental Biology by Matthew R. Fisher (licensed under CC BY-NC-SA) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.02%3A_Water_Resources/4.2.04%3A_Data_Dive-_Aqueducts_of_Rome.txt |
Chapter Hook
Steep mountain landscapes aren’t an ideal place for farming. Yet, for thousands of years farmers in mountainous regions all over the world have grown crops, even on some of the steepest slopes. To accomplish this effectively, farmers needed to carve gigantic steps across mountainous contours, forming terraces. These terraces create enchanting ripple like patterns across the landscape and make one almost forget that these farms are meant to help feed local and global communities.
Since the transition to agriculture 10,000 years ago, human communities have struggled against the reality that soil suffers nutrient depletion through constant plowing and harvesting (mostly nitrogen loss). The specter of a significant die-off in human population owing to stagnant crop yields was averted in the 1970s by the Green Revolution, which, through the engineering of new crop varieties, large-scale irrigation projects, and the massive application of petroleum-based fertilizers to supplement nitrogen, increased staple crop production with such success that the numbers suffering malnutrition actually declined worldwide in the last two decades of the 20th century, from 1.9 to 1.4 billion, even as the world’s population increased at 100 times background rates. The prospects for expanding those gains in the new century are nevertheless threatened by the success of industrial agriculture itself. Soil depletion, declining water resources, and the diminishing returns of fertilizer technology—all the products of a half-century of industrial agriculture—have seen increases in crop yields level off.
Thumbnail image - Women farmers planting a rice field in West Sumatra.
Attribution
Modified by Melissa Ha and Rachel Schleiger from The Industrialization of Nature: A Modern History (1500 to the present) from Sustainability: A Comprehensive Foundation by Tom Theis and Jonathan Tomkin, Editors. Download for free at CNX. (licensed under CC-BY)
• 14.1: Food Security
Poverty—not food availability—is the major driver of food insecurity. In 2019, 8.9% of the world population were undernourished (lacked sufficient calories). Food security is dependent on availability, access, and utilization. Undernourishment, malnutrition (lack of essential vitamins and minerals), and obesity, all threaten global health.
• 14.2: Industrial Agriculture
Industrial agriculture employs heavy machinery, synthetic pesticides, and synthetic fertilizers. It relies on monocultures of high yield crop varieties. While industrial agriculture has delivered tremendous gains in productivity and efficiency, it has also caused serious ecological damage.
• 14.3: Selective Breeding and Genetic Engineering
The development of a new crop variety is an example of agricultural biotechnology: a range of tools that include both traditional breeding techniques and more modern lab-based methods. Traditional selective breeding dates back thousands of years, whereas biotechnology uses the tools of genetic engineering developed over the last few decades. Through genetic engineering, scientists can more quickly and directly alter an organisms DNA, producing a genetically modified organism (GMOs).
• 14.4: Sustainable Agriculture
Sustainable agriculture means an integrated system of plant and animal production practices that can be continued indefinitely because they do not degrade the environment or deplete natural resources. It incorporates integrated pest management and sustainable methods for promoting soil fertility. Organic agriculture abstains from using synthetic pesticides and fertilizers, genetically modified organisms, hormones, and antibiotics. Consumer choices can promote sustainable agriculture.
• 14.5: Data Dive- Landslides and Ag Terraces
• 14.6: Review
4.03: Agriculture
Progress continues in the fight against hunger, yet an unacceptably large number of people lack the food they need for an active and healthy life. In 2019, 690 million people in the world (8.9%) were undernourished (lacked sufficient calories; see The State of Food Security...), and 8.2% of the global population lived in poverty (see Goal 1...). Poverty is internationally defined as living on less than \$1.90 per day. Poverty—not food availability—is the major driver of food insecurity. Improvements in agricultural productivity are necessary to increase rural household incomes and access to available food but are insufficient to ensure food security. Evidence indicates that poverty reduction and food security do not necessarily move in tandem. The main problem is lack of economic (social and physical) access to food at national and household levels and inadequate nutrition. Food security not only requires an adequate supply of food but also entails availability, access, and utilization by all—people of all ages, gender, ethnicity, religion, and socioeconomic levels.
From Agriculture to Food Security
Agriculture and food security are inextricably linked. The agricultural sector in each country is dependent on the available natural resources, as well as the politics that govern those resources. Staple food crops are the main source of dietary energy in the human diet and include things such as rice, wheat, sweet potatoes, maize (corn), and cassava (figure \(\PageIndex{a}\)).
Food Security
An individual must have access to food in ample quantity and of sufficient nutritional quality at all times to be food secure. Those who never have sufficient quality food are chronically food insecure. Food security is determined by availability, access, and utilization.
Food availability refers to whether enough food is produced globally to feed the world's population. In fact, enough food is produced globally, but it is not accessible to everyone who needs it. Food access refers to the ability to obtain food in ample quantity and of nutritional quality. In the United States, residents of food deserts face limited access to nutritious foods, particularly fresh produce (figure \(\PageIndex{b}\)). This problem is compounded when residents do not own a vehicle or have access to public transportation to obtain foods from surrounding areas or lack the funds to do so.
Food utilization essentially translates the food available to a household into nutritional security for its members. One aspect of utilization is analyzed in terms of distribution according to need. Nutritional standards exist for the actual nutritional needs, which differ by gender, age, and life phase (for example, pregnancy), but these “needs” are often socially constructed based on culture. For example, in South Asia evidence shows that women eat after everyone else has eaten and are less likely than men in the same household to consume preferred foods such as meats and fish.
Food insecurity can result in undernourishment and malnutrition (a lack of essential nutrients; figure \(\PageIndex{c}\)). The economic costs of undernourishment and malnutrition are substantial, potentially costing individuals 10% of their lifetime earnings and costing nations 2-3% of gross domestic product (GDP) in the worst-affected countries (Alderman 2005). This in part due to the reduced ability of under- and malnourished individuals to work. Additionally, without proper nutrition, children can develop disabilities that make it more difficult for them to join to workforce as adults. The economic costs reported here do not even account for the healthcare costs associated with under- and malnutrition.
Obesity
Obesity means having excess body fat resulting in a body mass index (BMI) of 30 or higher, and overweight individuals have a BMI of 25 or higher (figure \(\PageIndex{d}\)). BMI is a common metric for obesity because it is determined based on weight and height; however, an individual with a big bone structure and/or high muscle mass could have a high BMI without facing the health risks associated with obesity. Likewise, an individual with excess body fat but little muscle mass might have a "healthy" BMI, but their excess body fat could still compromise their health. For these reasons, some experts rely on other metrics, such as relative fat mass (RFM). Relative fat mass is equal to height divided by waist circumference multiplied by 76 for females or 64 for males. An RFM of 32% or higher for females and 25% or higher for males is considered obese. Harvard Chan School of Public Health provides a thorough discussion of the advantages and disadvantages of various obesity metrics.
Obesity has become a significant global health challenge, yet is preventable and reversible. Since the 1970s, obesity rates have rapidly increased, resulting in a global obesity epidemic. Thirty-nine percent of the world's adults, or 1.9 billion people, are overweight in 2016. Of these, 650 million are obese (Obesity and Overweight). Obesity was linked to 4.7 million premature deaths in 2017 (about 8% of all deaths that year; Hannah/Our World in Data). The economic cost of obesity has been estimated at \$2 trillion (Tremmel et al.).
Initially centered in developed countries, the obesity epidemic now affects countries of all economic statuses. In low-income countries, this results in a triple burden of undernourishment, malnutrition, and obesity. There is significant variation by region; some have very high rates of undernourishment and low rates of obesity, while in other regions the opposite is true (figure \(\PageIndex{e}\)).
Obesity accounts for a growing level and share of worldwide noncommunicable diseases, including diabetes, heart disease, and certain cancers that can reduce quality of life and increase public health costs of already under-resourced developing countries. Driven primarily by increasing availability of processed, affordable, and effectively marketed food, the global food system is falling short with rising obesity and related poor health outcomes. Due to established health implications and rapid increase in prevalence, obesity is now a recognized major global health challenge.
Attribution
Modified by Melissa Ha from Food Security from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.03%3A_Agriculture/4.3.01%3A_Food_Security.txt |
Also known as conventional agriculture, industrial agriculture is a method of farming that involves use of synthetic fertilizer, synthetic pesticides, and machinery. Industrial agriculture is dependent on large investments in mechanized equipment powered mostly by fossil fuels. In the case of livestock, most production comes from systems where animals are highly concentrated and confined.
Synthetic Pesticides
Pests are organisms that occur where they are not wanted or that cause damage to crops or humans or other animals (figure \(\PageIndex{a}\)). Thus, the term “pest” is a highly subjective term. A pesticide is a term for any substance intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides (weed killers), fungicides, and various other substances used to control pests. Chemical pesticides can be effective, fast acting, adaptable to all crops and situations. When first applied, pesticides can result in impressive production gains of crops. However, despite these initial gains, excessive use of pesticides can be ecologically unsound (see Disadvantages of Industrial Agriculture). By their very nature, most pesticides create some risk of harm—pesticides can cause harm to humans, animals, and/or the environment because they are designed to kill or otherwise adversely affect living things. At the same time, pesticides are useful to society because they can kill potential disease-causing organisms and control insects, weeds, worms, and fungi.
Monoculture Farming
Industrial agriculture employs monoculture farming, which involves growing only one species of crop in a large area (figure \(\PageIndex{b}\)). The plants in a monoculture are evenly spaced and have the same planting, irrigation, fertilizer, harvesting, etc. requirements, and this uniformity results in efficient use of farming machinery. Often, the crop is a high yield variety (high yielding variety; HYV), which is produced through selectively breeding individual plants with desirable characteristics. Compared to traditional crops, HYVs can produce more per unit area of land. Monoculture farming compromises genetic and species diversity in agriculture, however, promoting the spread of pests and risking that all the plants for hundreds of acres could be susceptible to the same disease (see Genetic Diversity).
Advantages of Industrial Agriculture
Industrial agriculture has delivered tremendous gains in productivity and efficiency. Food production worldwide has overall risen since the 1940s (figure \(\PageIndex{c}\)); the World Bank estimates that between 70 percent and 90 percent of the recent increases in food production are the result of industrial agriculture rather than greater acreage under cultivation (figure \(\PageIndex{d}\)). United States consumers have come to expect abundant and inexpensive food. Additionally, the use of synthetic pesticides ensures that produce is relatively free of blemishes (figure \(\PageIndex{e}\)).
Figure \(\PageIndex{d}\): The arable (farmable) land required to produce a fixed amount of a crop has decreased over time due to improved agricultural efficiency. Image by Hannah Ritchie and Max Roser/Our World in Data (CC-BY)
Industrial agriculture expands where crops can be cultivated. Applying synthetic fertilizers to poor soils can make them fertile. Additionally, irrigation systems promote high agricultural productivity in regions and during seasons that would otherwise only support the most drought-tolerant species. For example, about 25% of the food consumed in the United States is produced in California's Central Valley, which receives little rain in the summer months (figure \(\PageIndex{f}\)).
Disadvantages of Industrial Agriculture
Economically, the U.S. agricultural sector includes a history of increasingly large federal expenditures. Also observed is a widening disparity among the income of farmers and the escalating concentration of agribusiness—industries involved with manufacture, processing, and distribution of farm products—into fewer and fewer hands. Market competition is limited and farmers have little control over prices of their goods, and they continue to receive a smaller and smaller portion of consumer dollars spent on agricultural products.
Economic pressures have led to a tremendous loss to the number of farms, particularly small farms, and farmers during the past few decades. More than 155,000 farms were lost from 1987 to 1997. Economically, it is very difficult for potential farmers to enter the business today because of the high cost of doing business. Farming equipment is expensive, and the industrial agricultural system favors large corporate farms, which can more easily invest in this equipment. While this equipment promotes efficiency, it also reduces the number of jobs in agriculture (figure \(\PageIndex{g}\)).
The mechanical farming equipment required for industrial agriculture relies on fossil fuels. Burning fossil fuels releases air pollution, including greenhouse gases, which cause climate change. Additionally, the synthetic fertilizers and pesticides used in industrial agriculture are produced from fossil fuels. Furthermore, agriculture areas rarely contain as much biomass (organic matter that comprises living things) as biodiverse, intact ecosystems. Biomass is an important carbon sink because its organic molecules store carbon that could otherwise be in the atmosphere as carbon dioxide or methane, both greenhouse gases. Soils with a substantial organic component are also carbon sinks. Industrial agricultural practices that deplete these soils (see below) contribute to climate change, but alternative practices can promote this benefit of healthy soils (see Sustainable Agriculture).
While synthetic fertilizers provide crops with the necessary nutrients for high productivity, excess nutrients from fertilizers can enter bodies of water through runoff. This can lead to a bloom of algae or photosynthetic bacteria in lakes, rivers, and bays in a process called eutrophication. These photosynthetic microorganisms sometimes produce toxins that kill aquatic animals and can even harm the humans who consume these animals. Furthermore, they block aquatic plants from accessing light. Eventual decomposition of algal blooms requires oxygen, which results in hypoxia (low levels of dissolved oxygen), further harming aquatic species. Additionally, industrial agriculture pollutes water with pesticides and sediments. Pesticides are not only widespread in surface waters, but pesticides from every chemical class have been detected in groundwater.
Industrial agricultural practices often deplete soil quality. For example, wind and water erosion of exposed topsoil removes particles and nutrients from the soil (which also contributes to eutrophication and sediment pollution). Tilling (mixing the soil) and overgrazing of livestock exacerbates erosion. When livestock remove too much vegetation from an area, plant roots no longer anchor the soil in place, and erosion ensues. Farming equipment compacts the soil. This limits infiltration of water into the soil (decreases soil permeability), makes it more difficult for roots to penetrate the soil, and hinders gas exchange in roots. In extreme cases, soil has eroded and lost its ability to retain water that once arable (farmable) land becomes a desert-like (desertification; see Soil Degradation; figure \(\PageIndex{h}\)).
Irrigation can lead to salinization (increased salinity). While the water itself eventually evaporates, is transpired, or drains from the soil, the minerals dissolved in the water may remain in the soil. Over time, these minerals can accumulate to levels that are toxic for most plants. As discussed in Water Usage, irrigation for agriculture accounts for 69% of global water usage. Withdrawal of sufficient water for irrigation contributes to water shortages and diverts water from ecosystems (see Aqueducts).
Repeated pesticide application exerts selective pressure on insects, fungi, and other crop pests to evolve pesticide resistance. By chance, some individuals in a pest population may carry gene versions that confer pesticide resistance. When these populations are exposed to pesticides, individuals with these gene versions are the most likely to survive and reproduce. They then pass these genes to their offspring, and pesticide resistance becomes more and more common in the population over time (figure \(\PageIndex{i}\)). At this point, pesticides may need to be applied at greater concentrations or more frequently to achieve the same effect. If pesticide that was initially used is no longer effective at all, the farmer would be forced to find a different pesticide. Over 400 insects and mite pests and more than 70 fungal pathogens have become resistant to one or more pesticides.
The human health and environmental costs of pesticide use have been unevenly distributed. Despite the fact that the lion’s share of chemical pesticides are applied in developed countries, 99 percent of all pesticide poisoning cases occur in developing countries where regulatory, health and education systems are weakest. Many farmers in developing countries overuse pesticides and do not take proper safety precautions because they do not understand the risks and fear smaller harvests. Making matters worse, developing countries seldom have strong regulatory systems for dangerous chemicals; pesticides banned or restricted in industrialized countries are used widely in developing countries. Farmers’ perceptions of appropriate pesticide use vary by setting and culture. Prolonged exposure to pesticides has been associated with several chronic and acute health effects like non-Hodgkin’s lymphoma, leukemia, as well as cardiopulmonary disorders, neurological and hematological symptoms, and skin diseases.
Pesticides have also placed stresses on pollinators and other beneficial insect species. They can lead to the destruction of natural enemies, which would regulate pest populations in an intact ecosystem. For example, once apple growers began controlling pests with the pesticide dichlorodiphenyltrichloroethane (DDT), which has since been banned, they quickly found their orchards being attacked by scale insects and mites. The reason: DDT had killed off their natural enemies. More generally, pollution from industrial agriculture along with habitat loss due to converting healthy ecosystems into agricultural fields is a major threat to biodiversity. As mentioned previously, monoculture farming limits biodiversity in crops.
With respect to animal agriculture, keeping livestock are kept in close quarters increases the risk of disease spread among them. For these reason, food animals are commonly given antibiotics, either preventatively or to treat existing infections. As discussed in the Infectious Diseases section, the overuse of antibiotics (whether in humans or farm animals) increases selection for the evolution of antibiotic-resistant strains of bacteria or other disease-causing organisms. Infections by antibiotic-resistant strains are more difficult to treat.
As with many industrial practices, potential health hazards are often tied to farming practices. Under research and investigation currently is the sub-therapeutic use of antibiotics in animal production, and pesticide and nitrate contamination of water and food. Farm worker health is also a consideration in all farming practices.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.03%3A_Agriculture/4.3.02%3A_Industrial_Agriculture.txt |
The development of a new crop variety is an example of agricultural biotechnology, a range of tools that include both traditional breeding techniques and more modern lab-based methods. Traditional methods date back thousands of years, whereas biotechnology uses the tools of genetic engineering developed over the last few decades.
Selective Breeding (Artificial Selection)
Nearly all the fruits and vegetables found in your local market would not occur naturally. In fact, they exist only because of human intervention that began thousands of years ago. Humans created the vast majority of crop species by using traditional breeding practices on naturally-occurring, wild plants. These practices rely upon selective breeding (artificial selection), human-facilitated reproduction of individuals with desirable traits. For example, high yield varieties were produced through selective breeding. Traditional breeding practices, although low-tech and simple to perform, have the practical outcome of modifying an organism’s genetic information, thus producing new traits.
Selective breeding is limited, however, by the life cycle of the plant and the genetic variants that are naturally present. For example, even the fastest flowering corn variety has a generation time of 60 days (the time required for a seed to germinate, produce a mature plant, get pollinated, and ultimately produce more seeds) in perfect conditions. Each generation provides an opportunity to selectively breed individual plants and generate seeds that are slightly closer to the desired outcome (for example, producing bigger, juicier kernels). Furthermore, if no individuals happen to possess gene variants that result in bigger, juicier kernels, it is not possible to artificially select this trait. Finally, traditional breeding shuffles all of the genes between the two individuals being bred, which can number into the tens of thousands (maize, for example, has 32,000 genes). When mixing such a large number of genes, the results can be unpredictable.
An interesting example is maize (corn). Biologists have discovered that maize was developed from a wild plant called teosinte. Through traditional breeding practices, humans living thousands of years ago in what is now Southern Mexico began selecting for desirable traits until they were able to transform the plant into what is now known as maize (figure \(\PageIndex{a}\)). In doing so, they permanently (and unknowingly) altered its genetic instructions.
This history of genetic modification is common to nearly all crop species. For example, cabbage, broccoli, Brussel sprouts, cauliflower, and kale were all developed from a single species of wild mustard plant (figure \(\PageIndex{b}\)). Wild nightshade was the source of tomatoes, eggplant, tobacco, and potatoes, the latter developed by humans 7,000 – 10,000 years ago in South America.
Genetic Engineering
Genetic engineering is the process of directly altering an organism's DNA to produce the desired crops more rapidly than selective breeding. Because genes can be obtained from other species or even synthesized in the lab, scientists are not limited by existing genetic variation within a crop species (or closely related species with which they can be crossed). This broadens the possible traits that can be added to crops. Modern genetic engineering is more precise than selective breeding in the sense that biologists can modify just a single gene. Also, genetic engineering can introduce a gene between two distantly-related species, such as inserting a bacterial gene into a plant (figure \(\PageIndex{c}\)).
Genetically modified organisms (GMOs) are those that have had their DNA altered through genetic engineering. Genetically modified crops are sometimes called genetically engineered (GE) crops. Transgenic organisms are a type of genetically modified organism that contains genes from a different species. Because they contain unique combinations of genes and are not restricted to the laboratory, transgenic plants and other GMOs are closely monitored by government agencies to ensure that they are fit for human consumption and do not endanger other plant and animal life. Because these foreign genes (transgenes) can spread to other species in the environment, particularly in the pollen and seeds of plants, extensive testing is required to ensure ecological stability.
How to Genetically Modify Plant Cells
DNA can be inserted into plant cells through various techniques. For example, a gene gun propels DNA bound to gold particles into plant cells. (DNA is negatively charge and clings to positively charged gold.) A more traditional approach employs the plant pathogen Agrobacterium tumefaciens (figure \(\PageIndex{d}\)). Ordinarily, this bacterium causes crown gall disease in plants by inserting a circular piece of DNA, called the Ti plasmid, into plant cells. This DNA incorporates into plant chromosomes, giving them genes to produce the gall (figure \(\PageIndex{e}\)), which provides a home for the bacterial pathogen.
Scientists alters the process by which Agrobacterium infects and genetically alter plant cells to produce genetically modified plants with agriculturally beneficial traits as follows (figure \(\PageIndex{f}\)):
1. T-DNA, which codes for the crown gall is removed from the Ti plasmid, and genes for desired traits are added.
2. The modified plasmid is then added back to Agrobacterium.
3. Agrobacterium infects undifferentiated plant cells (stem cells that can develop into any part of the plant; figure \(\PageIndex{g}\)).
4. The modified plant cells are given hormones to produce the entire plant.
Examples of Genetically Modified Crops
Many genetically modified crops have been approved in the U.S. and produce our foods. The first genetically modified organism approved by the U.S. Food and Drug Administration (FDA) in 1994 was Flavr Savr™ tomatoes, which have a longer shelf life (delayed rotting) because a gene responsible for breaking down cells in inhibited. Flavr Savr tomatoes are genetically modified (because their DNA has been altered) but not trasgenic (because they do not contain genes from another species). The Flavr Savr tomato did not successfully stay in the market because of problems maintaining and shipping the crop. Golden rice produces β-carotene, a precursor to vitamin A (figure \(\PageIndex{h}\); β-carotene is also in high concentrations in carrots, sweet potatoes, and cantaloupe, giving them their orange color.) Roundup Ready® corn, cotton, and soybeans are resistant to this common herbicide, making it easier to uniformly spray it in a field to kill the weeds without harming the crops (figure \(\PageIndex{i}\)).
Crops have also been engineered to produce insecticides. Bacillus thuringiensis (Bt) is a bacterium that produces protein crystals that are toxic to many insect species that feed on plants. Insects that have eaten Bt toxin stop feeding on the plants within a few hours. After the toxin is activated in the intestines of the insects, death occurs within a couple of days. The gene to produce Bt toxin has been added to many crops including corn (figure \(\PageIndex{j}\)), potatoes, and cotton, providing plants with defense against insects.
Genetically modified foods are widespread in the United States. For example, 94% of soy crops were genetically modified for herbicide resistance in 2020. Likewise, 8% of cotton and 10% of corn crops were modified for herbicide resistance in addition to the 83% of cotton and 79% of corn crops that were genetically modified in multiple ways.
Genetically modified animals have recently entered the market as well. AquaAdvantage® salmon are modified to grow more rapidly and were approved in November of 2015. However, as of March 2021, they have still not been sold due to legal challenges. In 2020, the FDA approved GalSafe™ pigs for medicine and food production. These pigs lack a molecule on the outside of their cells that cause allergies in some people.
Advantages of Genetically Modified Crops
Advances in biotechnology may provide consumers with foods that are nutritionally-enriched, longer-lasting, or that contain lower levels of certain naturally occurring toxins present in some food plants. For example, researchers are using biotechnology to try to reduce saturated fats in cooking oils and reduce allergens in foods. Whether these benefits will reach the people who need them most remains to be seen. While cultivating golden rice could address vitamin A deficiency in millions of people, it has not historically been accessible to these people because it is patented and expensive. Similarly, genetically modified seeds could increase the income of impoverished farmers if they were available at low or no cost, but this is not always the case.
Rainbow and SunUp papayas are a success story of how genetically modified crops can benefit small farmers and the economy in general. In the early 1990s, an emerging disease was destroying Hawaii’s production of papaya and threatening to decimate the \$11-million industry (figure \(\PageIndex{k}\)). Fortunately, a man named Dennis Gonsalves (figure \(\PageIndex{l}\)), who was raised on a sugar plantation and then became a plant physiologist at Cornell University, would develop papaya plants genetically engineered to resist the deadly virus. By the end of the decade, the Hawaiian papaya industry and the livelihoods of many farmers were saved thanks to the free distribution of Dr. Gonsalves's seeds.
The effect of genetically modified crops on the environment depends on the specific genetic modification and which agricultural practices it promotes. For example, Bt crops produce their own insecticides such that external application of these chemicals is unnecessary, reducing the negative impacts of industrial agriculture. Ongoing research is exploring whether crops can be engineered to fix nitrogen in the atmosphere (as some bacteria do) rather than relying on ammonium, nitrites, and nitrates in the soil. If these crops were successfully engineered, they could reduce synthetic fertilizer application and minimize nutrient runoff that leads to eutrophication.
Genetically modified crops may have the potential to conserve natural resources, enable animals to more effectively use nutrients present in feed, and help meet the increasing world food and land demands. In practice, however, countries that use genetically modified crops compared to those that do not only enjoy a slight (or nonexistent) increase in yield.
Disadvantages of Genetically Modified Crops
Social Concerns
Intellectual property rights are one of the important factors in the current debate on genetically modified crops. Genetically modified crops can be patented by agribusinesses, which can lead to them controlling and potentially exploiting agricultural markets. Some accuse companies, such as Monsanto, of allegedly controlling seed production and pricing, much to the detriment of farmers (figure \(\PageIndex{m}\)).
Environmental Concerns
Genetically modified crops present several environmental concerns. Monoculture farming already reduces biodiversity, and cultivating genetically modified crops, for which individual plants are quite similar genetically, exacerbates this. The use of Roundup Ready® crops naturally encourages widespread herbicide use, which could unintentionally kill nearby native plants. This practice would also increase herbicide residues on produce. While Bt crops are beneficial in the sense that they do not require external insecticide application, but Bt toxin is spread in their pollen. An early study found that Bt corn pollen may be harmful to monarch caterpillars (figure \(\PageIndex{n}\)), but only at concentrations that are seldom reached in nature. Follow-up studies found that most of Bt corn grown did not harm monarchs; however, the one strain of Bt corn did was consequently removed from the market.
Through interbreeding, or hybridization, genetically modified crops might share their transgenes with wild relatives. This could affect the genetics of those wild relatives and have unforeseen consequences on their populations and could even have implications for the larger ecosystem. For example, if a gene engineered to confer herbicide resistance were to pass from a genetically modified crop to a wild relative, it might transform the wild species into a super weed – a species that could not be controlled by herbicide. Its rampant growth could then displace other wild species and the wildlife that depends on it, thus inflecting ecological harm.
Not only could escaped genes alter weedy species, but they could also enter populations of native species. This could make some native species better competitors than they were previously, disrupting ecosystem dynamics. (They could potentially outcompete other native species with which they would otherwise coexist.)
While there is evidence of genetic transfer between genetically modified crops and wild relatives, there is not yet evidence of ecological harm from that transfer. Clearly, continued monitoring, especially for newly-developed crops, is warranted.
The escape of genetically modified animals has potential to disrupt ecosystems as well. For example, if AquaAdvantage salmon were to escape into natural ecosystem, as farmed fish often do, they could outcompete native salmon, including endangered species. Their genetic modification, which facilitates rapid growth, could result in a competitive advantage.
Health Concerns
In addition to environmental risks, some people are concerned about potential health risks of genetically modified crops because they feel that genetic modification alters the intrinsic properties, or essence, of an organism. As discussed above, however, it is known that both traditional breeding practices and modern genetic engineering produce permanent genetic changes. Furthermore, selective breeding actually has a larger and more unpredictable impact on a species’s genetics because of its comparably crude nature.
To address these concerns (and others), the US National Academies of Sciences, Engineering, and Medicine (NASEM) published a comprehensive, 500-page report in 2016 that summarized the current scientific knowledge regarding genetically modified crops. The report, titled Genetically Engineered Crops: Experiences and Prospects, reviewed more than 900 research articles, in addition to public comments and expert testimony. NASEM’s GE Crop Report found “no substantiated evidence of a difference in risks to human health between current commercially available genetically engineered (GE) crops and conventionally bred crops, nor did it find conclusive cause-and-effect evidence of environmental problems from the GE crops.” Additionally, the UN’s Food and Agriculture Organization has concluded that risks to human and animal health from the use of GMOs are negligible. The scientific consensus on genetically modified crops is quite clear: they are safe for human consumption.
The potential of genetically modified crops to be allergenic is one of the potential adverse health effects, and it should continue to be studied, especially because some scientific evidence indicates that animals fed genetically modified crops have been harmed. NASEM’s GE Crop Report concluded that when developing new crops, it is the product that should be studied for potential health and environmental risks, not the process that achieved that product. What this means is, because both traditional breeding practices and modern genetic engineering produce new traits through genetic modification, they both present potential risks. Thus, for the safety of the environment and human health, both should be adequately studied.
Are Genetically Modified Crops the Solution We Need?
Significant resources, both financial and intellectual, have been allocated to answering the question: are genetically modified crops safe for human consumption? After many hundreds of scientific studies, the answer is yes. But a significant question still remains: are they necessary? Certainly, such as in instances like Hawaii’s papaya, which were threatened with eradication due to an aggressive disease, genetic engineering was a quick and effective solution that would have been extremely difficult, if not impossible, to solve using traditional breeding practices.
However, in many cases, the early promises of genetically engineered crops – that they would improve nutritional quality of foods, confer disease resistance, and provide unparalleled advances in crop yields – have largely failed to come to fruition. NASEM’s GE Crop Report states that while genetically modified crops have resulted in the reduction of agricultural loss from pests, reduced pesticide use, and reduced rates of injury from insecticides for farm workers, they have not increased the rate at which crop yields are advancing when compared to non-GE crops. Additionally, while there are some notable exceptions like golden rice or virus-resistant papayas, very few genetically engineered crops have been produced to increase nutritional capacity or to prevent plant disease that can devastate a farmer’s income and reduce food security. The vast majority of genetically modified crops are developed for only two purposes: to introduce herbicide resistance or pest resistance. Genetically modified crops are concentrated in developed countries, and their availability in developing countries, where they are perhaps most needed, is limited (figure \(\PageIndex{o}\)).
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.03%3A_Agriculture/4.3.03%3A_Selective_Breeding_and_Genetic_Engineering.txt |
Sustainable agriculture is a method of farming that does not deplete natural resources or degrade the environment and can therefore be continued indefinitely. Sustainable farms often rely on components of local ecosystems. For example, they might promote conditions for natural decomposition of wastes or employ natural enemies to control pests through predation or competition. More specifically, the 1977 and 1990 “Farm Bills” describe sustainable agriculture as "an integrated system of plant and animal production practices having a site-specific application that will, over the long term:
• satisfy human food and fiber needs;
• enhance environmental quality and the natural resource base upon which the agricultural economy depends;
• make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls;
• sustain the economic viability of farm operations;
• enhance the quality of life for farmers and society as a whole."
Promoting biodiversity is key to sustainable agriculture, and high biodiversity results intact ecosystem services such as nutrient cycling and regulation of pest populations. This is consistent with the goal of sustainable agriculture: to mimic the processes found in natural ecosystems. In contrast to the monocultures of industrial agriculture, polyculture farming is a common practice in sustainable agriculture. This assists with regulating pests and maintaining soil fertility (see below). Seed banks, locations at which many different types of seeds are stored, are key to conserving the genetic diversity of crops. These storage sites are cold enough to keep seeds frozen naturally (figure \(\PageIndex{a}\)).
Integrated Pest Management
Integrated Pest Management (IPM) refers to a mix of farmer-driven, ecologically-based pest control practices that seek to reduce reliance on synthetic chemical pesticides. It uses several methods simultaneously to control pest populations. The steps of integrated pest management are to (1) identify true pests, (2) set thresholds and monitor (figure \(\PageIndex{b}\)), and (3) develop an action plan. As many insects, microbes, and other organisms found in an agricultural area have a neutral or beneficial effect, it is not necessary to remove them. True pests are those that are causing economic harm, and they are managed (kept below economically damaging levels) rather than eradicated.
An IPM Action Plan draws on four types of control: cultural, mechanical, biological, and chemical. These methods are listed in order of least to most environmental impact and are thus applied in this order. For example, cultural control is attempted first. If that is not effective, mechanical control is added to the plan, and so on. Chemical control is used as a last resort and is deemphasized in an IPM plan. When pesticides must be used, they are selected and applied in a way that minimizes adverse effects on beneficial organisms, humans, and the environment. It is commonly understood that applying an IPM approach does not necessarily mean eliminating pesticide use, although this is often the case because pesticides are often over-used for a variety of reasons.
An Alternative to Spraying: Bollworm Control in Shandong
Farmers in Shandong (China) have been using innovative methods to control bollworm infestation in cotton when this insect became resistant to most pesticides. Among the control measures implemented were:
1. The use of pest resistant cultivars and interplanting of cotton with wheat or maize.
2. Use of lamps and poplar twigs to trap and kill adults to lessen the number of adults.
3. If pesticides were used, they were applied on parts of the cotton plant’s stem rather than by spraying the whole field (to protect natural enemies of the bollworm).
These and some additional biological control tools have been effective in controlling insect populations and insect resistance, protecting surroundings and lowering costs.
Cultural Control
Cultural control refers to minimizing the conditions that allow pests to thrive and spread. Examples include alternating which crops are planted each year (crop rotation), planting multiple types of crops near each other (intercropping; figure \(\PageIndex{c}\)), selecting pest-resistant varieties, and planting pest-free rootstock (underground plant parts). Crop rotation prevents pests that are specialized to a particular type of crop from continuing year after year because their host plants are only available in certain years. Similarly, intercropping spatially limits the spread of pests. Strip cropping is a type of intercropping that involves growing different types of crops in alternating rows. Pests may infest one (or several) rows of their host species, but they would have to move past multiple rows of non-hosts to access additional host plants. Additionally, cultural control can involve optimizing irrigation and fertilizer application to promote plant defense and limit disease spread. Cultural control methods can be very effective and cost-efficient and present little to no risk to people or the environment.
Mechanical Control
Mechanical control refers to physically removing pests or excluding them with barriers (figure \(\PageIndex{d}\)). Mechanical controls that remove pests include sticky insect traps, mole traps, and removing weeds by hand. Netting to exclude birds, deer fencing, and weed cloth, plastic weed barriers (figure \(\PageIndex{c}\)) or mulch are additional examples of mechanical control.
Biological Control
Biological control is the use of organisms to reduce pest populations (also see Invasive Species). One biological control strategy involves releasing natural enemies, such as predators, parasites, or parasitoids of the pest organisms (parasitoids are similar to parasites, but they consistently kill their hosts). Home gardeners can also rely on natural enemies by purchasing preying mantises, ladybugs (ladybird beetles), or lacewings for release (figure \(\PageIndex{e}\)). Successful examples include ladybird beetles to depress aphid populations, parasitoid wasps to control whiteflies, and fungi, such as Trichoderma, to suppress fungal-caused plant diseases.
If not used carefully, chemical control can have unintended negative consequences for biological control. In 1887, the cottony cushion scale (native to Australia) was devastating the citrus groves of California. A U.S. entomologist went to Australia to find a natural enemy and came back with the vedalia beetle, a species of ladybird beetle. Released in California, the beetle quickly brought the scale under control, at least until 1946. In that year, the pest made a dramatic comeback. This coincided with the first use of the now-banned pesticide dichlorodiphenyltrichloroethane (DDT) in the groves. Not only did DDT kill the target pest insects, but it killed the vedalia beetle as well. Only by altering spray procedures and reintroducing the beetle was the scale insect again controlled.
Another strategy for biological control involves releasing sterile males, which compete with fertile males for mates, ultimately decreasing pest population size. This technique was first applied against the screwworm fly, a serious pest of cattle (figure \(\PageIndex{f}\)). The female flies lay their eggs in sores or other open wounds on the animals. After hatching, the larvae eat the tissues of their host. As they do so, they expose a still larger area to egg laying, often finally killing the host.
Prior to its eradication from the southeastern United States, the screwworm was causing huge annual livestock losses. The sterile male technique involves releasing factory-reared and sterilized flies into the natural population. Sterilization is done by exposing the factory flies to just enough gamma radiation to make them sterile but not enough to reduce their general vigor.
Starting in early 1958, up to 50 million sterilized flies were released each week from aircraft flying over Florida and parts of the adjoining states. Each time a fertile female in the natural population mated with a sterile male, the female layed sterile eggs. Since the females mate only once, her reproductive career was at an end. By early 1959, the pest was totally eliminated east of the Mississippi River. The problem in southwestern states was more challenging because the fly winters in Mexico and could move across the border with each new season. Even so, by expanding the program to include Mexico as well, the screwworm fly was finally eliminated from Mexico in 1991.
The sterile male technique also successfully controlled the Mediterranean fruit fly ("medfly"), a destructive fruit fly of citrus, peaches, pears, and apples in California.
Chemical Control
Chemical control refers to the use of pesticides. If chemical control is needed, IPM favors highly targeted chemicals, such as pheromones to disrupt pest mating. Pheromones are chemical signals released by animals to communicate with other members of their species. Humans and many insect species alike release pheromones that function in attracting mates. Releasing the pheremones of insect pests can confuse males seeking mates and ultimately hinder them from reproducing (figure \(\PageIndex{g}\)). This "male confusion" has been successful against the pink bollworm that infests cotton and reduced the need for conventional chemical insecticides by 90%. Pheromones have also been successful against pests that attack tomatoes, grapes, and peaches. If targeted chemicals are not effective, IPM may employ conventional pesticides, ideally only applying them to the spots that they are needed and at the lowest effective concentration. Broadcast spraying of non-specific pesticides is a last resort.
Sustainable Practices to Maintain Soil Fertility
A variety of sustainable practices can maintain soil quality. Many of these strategies have additional benefits such as regulating pests, limiting climate change, and preventing water pollution. These methods enrich the soil with nutrients, ensure proper water holding capacity (ability of the soil to retain water), and limit soil-degrading processes such as erosion and compaction.
Crop Rotation
As previously mentioned, crop rotations are planned sequences of different crops over time on the same field (figure \(\PageIndex{h}\)). Rotating crops provides productivity benefits by improving soil nutrient levels and breaking crop pest cycles. Farmers may also choose to rotate crops in order to reduce their production risk through diversification or to manage scarce resources, such as labor, during planting and harvesting. This strategy reduces the pesticide costs by naturally breaking the cycle of weeds, insects and diseases. Also, grass and legumes in a rotation protect water quality by preventing excess nutrients or chemicals from entering water supplies.
Intercropping
Intercropping means growing two or more crops in close proximity to each other during part or all of their life cycles to promote soil improvement, biodiversity, and pest management. Incorporating intercropping principles into an agricultural operation increases diversity and interaction between plants, arthropods, mammals, birds and microorganisms resulting in a more stable crop-ecosystem and a more efficient use of space, water, sunlight, and nutrients (figure \(\PageIndex{i}\)). This collaborative type of crop management mimics nature and is subject to fewer pest outbreaks, improved nutrient cycling and crop nutrient uptake, and increased water infiltration and moisture retention. Soil quality, water quality and wildlife habitat all benefit.
A common example of strip cropping (a type of intercropping; see above) involves alternating a row crop such as corn with a ground-covering crop such as alfalfa. The ground-covering crop helps reduce water runoff and traps soil eroded from the row crop. If this ground-covering crop is a member of the legume family such as alfalfa or soybeans and is associated with nitrogen-fixing bacteria, then alternating the strips from one planting to the next can also help maintain topsoil fertility.
Cover Crops
Cover crops are those that are planted in the off-season to avoid leaving the soil bare. They can prevent soil and wind erosion, improve soil’s physical and biological properties, supply nutrients, suppress weeds, improve the availability of soil water, and break pest cycles along with various other benefits. Cover crops are often members of the legume family and help enrich the soil with usable nitrogen. A single species or mix of cover crop species may be planted (figure \(\PageIndex{j}\)).
Agroforestry
Agroforestry is the process of planting rows of trees interspersed with a cash crop (figure \(\PageIndex{k-l}\)). Besides helping to prevent wind and water erosion of the soil, the trees provide shade which helps promote soil moisture retention. Decaying tree litter also provides some nutrients for the interplanted crops. The trees themselves may provide a cash crop. For example, fruit or nut trees may be planted with a grain crop. You can learn more about agroforestry using this interactive site by the United States Department of Agriculture and Forest Service.
Contour and Terrace Farming
Contour farming involves plowing and planting crop rows along the natural contours of gently sloping land (figure \(\PageIndex{l}\)). The lines of crop rows perpendicular to the slope help to slow water runoff, inhibit the formation of channels of water, and limit soil erosion (and the resultant loss of nutrients). Terracing is a common technique used to control water erosion on more steeply sloped hills and mountains (figure \(\PageIndex{l}\)). Broad, level terraces are constructed along the contours of the slopes, and these act as dams trapping water for crops, reducing runoff, and limiting erosion.
Minimal Tillage and No-till Agriculture
In modern agricultural practices, heavy machinery is used to prepare the seedbed for planting, to control weeds, and to harvest the crop. The use of heavy equipment has many advantages in saving time and labor, but can cause compaction of soil and disruption of the natural soil organisms. The problem with soil compaction is that increased soil density limits root penetration depth and may inhibit proper plant growth. Another aspect of soil tillage (mixing the soil) is that it may lead to more rapid decomposition of organic matter due to greater soil aeration. Over large areas of farmland, this has the unintended consequence of releasing more carbon and nitrous oxides (greenhouse gases) into the atmosphere, thereby contributing to climate change.
One of the easiest ways to prevent these problems is to minimize the amount of tillage, or turning over of the soil. In minimal tillage (conservation tillage) or no-till agriculture, the land is disturbed as little as possible by leaving crop residue in the fields (figure \(\PageIndex{m}\)). Special seed drills inject new seeds and fertilizer into the unplowed soil. Tillage of fields does help to break up clods that were previously compacted, so best practices may vary at sites with different soil textures and composition. With proper planning, minimal tillage and no-till agriculture can simultaneously limit soil erosion and compaction, protect soil organisms, reduce costs (if performed correctly), and promote water infiltration. Furthermore, carbon can actually become sequestered into the soil with these methods, thus mitigating climate change. Minimal or no-till agriculture have proved a major success in Latin America and are being used in South Asia and Africa. However, a drawback of this method is that the crop residue can serve as a good habitat for insect pests and plant diseases.
Windbreaks
Creating windbreaks by planting tall trees along the perimeter of farm fields can help control the effects of wind erosion of soil (figure \(\PageIndex{n}\)). Windbreaks reduce wind speed at ground level, an important factor in wind erosion. They also help trap snow in the winter months, leaving soil less exposed. As a side benefit, windbreaks also provide a habitat for birds and animals. One drawback is that windbreaks can be costly to farmers because they reduce the amount of available cropland.
Organic Agriculture
Organic agriculture is often incorporated into sustainable agriculture (figure \(\PageIndex{o}\)). To be certified as organic, farms must avoid using synthetic pesticides, synthetic fertilizers, and genetically modified organisms (figure \(\PageIndex{p}\)). Organic meat, poultry, eggs, and dairy products come from animals that are given no antibiotics or growth hormones. Pests may instead be controlled by natural enemies or naturally produced substances such as neem oil or diatomaceous earth. Some organic alternatives to synthetic pesticides have relatively low environmental impact (such as salt spray), but there are many naturally produced compounds that are still toxic to people or cause ecological harm when widely used. Interestingly, external application of Bt toxin is approved for organic farming, but use of genetically engineered Bt crops is not. The latter results in lower concentrations of Bt toxin in the environment because it is locally produced directly by the plants themselves. In summary, although many practices of organic agriculture benefit the environment and meet sustainability goals, some organic farms are not sustainable and some sustainable farms are not organic.
Consumer Choices that Support Sustainable Agriculture
Even if you're not a farmer or lawmaker, you have the power to promote sustainable agriculture as a consumer. As discussed in Food Chains and Food Webs, it generally requires more land and more energy to produce meat compared to plant-based foods due to the inefficient transfer of energy from one trophic level to the next. For this reason, plant-based diets tend to be more sustainable, but this depends on the types of foods consumed and how they were produced.
Local food is not only fresher, but it requires fewer food miles (figure \(\PageIndex{q}\)). In some ways, organic food causes less environmental degradation, but note that organic does not necessarily mean sustainable (see above). Because it limits machinery, synthetic pesticides, and synthetic fertilizers, it has a smaller carbon footprint (meaning it minimizes contribution to climate change). The Clean 15 is a list of produce that is low in pesticide residues. If you can't afford all organic foods, these are the best items to purchase non-organic. Examples include avocados, sweet corn, and pineapple. The Dirty Dozen lists produce that has the most pesticide residues. If you can only afford a few organic items, these are best to purchase organic. Examples include strawberries, spinach, and nectarines. Finally, some foods, such as beef, have higher carbon footprint and water footprint than others.
The Future of the Sustainable Agriculture Concept
Many in the agricultural community have adopted the sense of urgency and direction pointed to by the sustainable agriculture concept (figure \(\PageIndex{r}\)). Sustainability has become an integral component of many government, commercial, and non-profit agriculture research efforts, and it is beginning to be woven into agricultural policy. Increasing numbers of farmers and ranchers have embarked on their own paths to sustainability, incorporating integrated and innovative approaches into their own enterprises.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.03%3A_Agriculture/4.3.04%3A_Sustainable_Agriculture.txt |
Overview
The beauty of terraced agriculture almost makes the observer forget that it is still a form of habitat destruction and landscape modification. A 2019 study investigated the risk to terraced landscapes with varying states of upkeep after severe rainfall events, which increase chances of serious damage due to landslide events. The authors compared three classes of upkeep:
• Succession on terrace: Which includes all terraced areas in which cultivation activities ceased, and is currently substituted by both wood and shrub cover.
• Cultivated terrace: Which includes all areas which are still under any kind of cultivation, from olive groves, to vineyards, to other crops
• Vegetated natural slopes: Which refer to those areas covered by spontaneous vegetation which have never been terraced.
Landslide mapping was used to estimate the size of damage after a landslide event took place. Below is a graph for some of the published results:
Questions
1. What is the independent (explanatory) variable and the dependent (response) variable?
2. What question(s) are the authors trying to answer with this graph?
3. Do the authors use any control category/variable to help clarify the patterns observed? If so, what?
4. Which status has the most consistent increased landslide frequency?
5. What landslide frequency patterns can you observe across the three size?
6. How can the results of this graph to inform future projects/restoration efforts when a terrace is abandoned?
Raw Data For Above Graph(s)
Table \(\PageIndex{a}\): Raw data for percent breakdown of landslide frequency and size by terrace status. Graph by Rachel Schleiger (CC-BY-NC) modified from data in Agnoletti M, Errico A, Santoro A, Dani A, Preti F 2019.
Terrace Status 100-300 300-500 Over 500
Succession On Terrace 50 84 72
Cultivated Terrace 35 8 14
Vegetated Natural Slope 15 8 14
Attribution
Rachel Schleiger (CC-BY-NC)
4.3.06: Review
Summary
After completing this chapter you should be able to...
• Describe the global state of food security.
• Compare industrial agriculture, sustainable agriculture, and organic agriculture.
• Define pests and pesticides.
• Detail the advantages and disadvantages of industrial agriculture.
• Compare selective breeding with genetic engineering.
• Explain how plants are genetically modified.
• Detail the advantages and disadvantages of using genetically modified crops.
• Explain the steps of integrated pest management and provide examples of cultural, mechanical, biological, and chemical control.
• Describe each sustainable practice that maintains soil quality and explain the additional benefits of these practices.
Progress continues in the fight against hunger, yet an unacceptably large number of people still lack the food they need for an active and healthy life. Food security is dependent on availability, access, and utilization.
Industrial agriculture is the prevailing agricultural system that relies on heavy machinery, synthetic pesticides, and synthetic herbicides. It has led to tremendous gains in productivity and efficiency worldwide. On the other hand, industrial agriculture has put small farms at a disadvantage and caused several ecological issues. It has exacerbated climate change, caused water pollution, degraded soil quality, harmed beneficial native organisms, and led to the evolution of pesticide resistance.
Both selective breeding and genetic engineering are processes of agricultural biotechnology. Selective breeding occurs when humans assist individual organisms with favorable traits in reproduction generation after generation. Genetic engineering refers to lab methods that directly alter an organism's DNA. Advocates say that application of genetic engineering in agriculture has resulted in benefits to farmers, producers, and consumers. While genetically modified organisms (GMOs) have potential to address malnutrition, reduce pesticide application, and combat crop disease, the companies who patent them now have greater control over agriculture. Furthermore, escaped transgenes can create herbicide-resistant superweeds. While members of the public have raised concerns about health impacts of GMOs, the National Academies of Sciences, Engineering, and Medicine's assessment of over 900 studies found that GMOs do not threaten human health.
Sustainable agriculture is an alternative to industrial agriculture that focuses on preserving natural resources and protecting the environment. It can thus be continued indefinitely. Sustainable agriculture employs integrated pest management (IPM), which relies on a variety of approaches to keep populations of true pests below economically harmful levels. Approaches with the lowest environmental impact are prioritized under IPM. A variety of sustainable practices such as crop rotation, intercropping, terrace farming, and minimal tillage can maintain soil fertility. Many of these methods additionally help regulate pest populations, preserve water quality, and combat climate change. Organic agriculture avoids using synthetic pesticides, synthetic fertilizers, GMOs, hormones, and antibiotics. Organic and sustainable farming practices often overlap. Consumers can promote sustainable agriculture by purchasing local, organic foods and choosing foods with low carbon and water footprints.
Attribution
Modified by Melissa Ha from Conventional and Sustainable Agriculture and Food and Hunger from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.03%3A_Agriculture/4.3.05%3A_Data_Dive-_Landslides_and_Ag_Terraces.txt |
Chapter Hook
In 1854 England, a cholera epidemic started wiping out people within a day of symptoms starting. Only one physician, Dr John Snow, thought that it connected with contaminated water sources. Over the course of a month, Dr Snow was able to provide evidence that one particular well was connected with almost all of the deaths. Later, it was discovered that the contaminant in the water was a bacterium, named for the disease it caused, Vibrio cholerae. Unfortunately, cholera is not a disease of the past. The World Health Organization calculates an average of 1.3-4 million cases where an estimated 21-143,000 of these cases result in death. In some places, there is enough preventative testing to stop the spread of the disease before people get sick. However, in others, the contamination is unfortunately addressed only after an epidemic occurs.
• 15.1: Types of Environmental Hazards
Environmental health focuses on how natural and human-built surroundings affect health and well-being. This field assesses three interrelated types of environmental hazards: biological, chemical, and physical.
• 15.2: Epidemiology
The field of epidemiology is concerned with the geographical distribution and timing of infectious disease occurrences and how they are transmitted and maintained in nature, with the goal of recognizing and controlling outbreaks. The science of epidemiology includes etiology (the study of the causes of disease) and investigation of disease transmission (mechanisms by which a disease is spread).
• 15.3: Infectious Diseases
Infectious diseases remain a leading cause of death worldwide. Emerging diseases are those that have increased in prevalence in the last 20 years. Key infectious diseases of global concern are COVID-19, Ebola virus disease, HIV/AIDS, malaria, and tuberculosis. Many diseases have been eradicated with the help of vaccinations, but some diseases for which vaccines exist remain a threat. Antibiotics are effective in treating infectious diseases, but widespread use causes antibiotic resistance.
• 15.4: Environmental Toxicology
Environmental toxicology is the scientific study of the health effects associated with exposure to toxic chemicals. Potency, persistence, solubility, bioaccumulation, and biomagnification can all impact the safety of a chemical. The dose-response curve can determine the lethal dose-50%, a measure of toxicity.
• 15.5: Environmental Hazard Reduction
The World Heath Organization works with the CDC in the U.S. and equivalent agencies in other nations to promote global public health. Key strategies for reducing environmental hazards include providing access to clean water, improving sanitation and hygiene, and limiting exposure to disease vectors. The public serves an important role by engaging in behaviors that limit disease spread or exposure to toxins and supporting policies that limit environmental hazards.
• 15.6: Data Dive- Cholera Cases Worldwide
• 15.7: Review
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
4.04: Environmental Health
Environmental health is a field that focuses on how the natural and human-built surroundings as well as behaviors affect human well-being. The field is concerned with preventing disease, death, and disability by reducing exposure to environmental hazards and promoting behavioral change. Environmental hazards are threats to human health and well-being (table \(\PageIndex{a}\)).
Table \(\PageIndex{a}\): Typical Environmental Health Issues: Determinants and Health Consequences.
Underlying Determinants Possible Adverse Health and Safety Consequences
Inadequate water (quantity and quality), sanitation and solid waste disposal, improper hygein (handwashing) Diarrhea and vector-related diseases (for example, malaria, schistosomiasis, and dengue)
Improper water resource managment, uncluding poor drainage Vector-related diseases
Crowded housing and poor ventialtion of smoke Acute and chronic respiratory disease, including lung cancer from coal and tobacco inhalation
Exposures to vehicular and industrial air pollution Respiratory diseases, some cancers, and loss of IQ in children
Population movement and encroachment and construction, which affect feeding and breeding grounds of vectors, such as mosquitoes
Vector-related diseases
May also spread other infectious diseases (for example, HIV/AIDS, Ebola)
Exposure to naturally ocurring toxic substances Poising from substances such as arsenic, manganese, and fluorides
Natural resources degradation (for example, landslides, poor drainage, erosion) Injury and death from landslides and flooding
Climate change, partly from combustion of fossil fuel and release of greenhouse gases in transportation, industry, and poor energy conservation in housing, fuel, commerce, and industry
Injury/death from extreeme heat/cold, sotres, floods, and fires
Indirect effects spread of vectorbrone diseases, aggravation of respriatory diseases, population dislocation, water pollution from sea level rise, etc.
Ozone depletion from industrial and commercial actvitiy
Skin cancer, cataracts
Indirect effect: compromised food production
Table based on Lvovsky/World Bank (CC-BY)
Traditional versus Modern Environmental Hazards
Environmental hazards can be classified as traditional or modern. Traditional hazards are related to poverty and mostly affect low-income people and those in developing countries. Modern hazards, caused by technological development, prevail in industrialized countries where exposure to traditional hazards is low.
The impact of traditional hazards exceeds that of modern hazards by 10 times in Africa, five times in Asian countries (except for China), and 2.5 times in Latin America and the Middle East (figure \(\PageIndex{a}\)). Water-related diseases caused by inadequate water supply and sanitation impose an especially large health burden in Africa, Asia, and the Pacific region. In India alone, 90,000 children under five died diarrhea in 2017. Globally, 409,000 people died of malaria in 2019 with 94% of these deaths occurring in African countries. In 2016, approximately one third of the world’s households used unprocessed solid fuels, particularly biomass (crop residues, wood, and dung) for cooking and heating in inefficient stoves without proper ventilation. This exposes people—mainly low-income women and children—to high levels of indoor air pollution, the cause of about 1.6 million deaths in each year (figure \(\PageIndex{b}\)).
The contribution of modern environmental risks to the disease burden in most developing countries is similar to – and in quite a few countries, greater than – that in rich countries (figure \(\PageIndex{a}\)). Urban air pollution, for example, is highest in parts of China, India, and some cities in Asia and Latin America. Low-income people increasingly experience a “double burden” of traditional and modern environmental health risks. In rich countries, they experience twice the burden of illness and death from all causes and 10 times greater disease burden from environmental risks.
Biological, Chemical, and Physical Environmental Hazards
Environmental hazards can also be classified into three interrelated categories (biological, chemical, and physical) based on the properties of their causes. These categories are not mutually exclusive with traditional versus modern hazards. For example, indoor air pollution is both a traditional and chemical hazard. Different hazards can interact and exacerbate one another. For example, a flood is primarily a physical hazard, but it can lead to the spread of waterborne disease (a biological hazard). Similarly, air pollution (a chemical hazard) can damage respiratory tissue, making the body more vulnerable to a respiratory infection (a biological hazard). Infectious diseases (biological hazards) can also weaken the immune system, making an individual more vulnerable to chemical hazards.
Biological Hazards
For most of human history, biological hazards were the most significant factor in health. Biological hazards are infectious (communicable) diseases caused by pathogens (disease-causing organisms or infectious particles) such as bacteria, fungi, parasitic worms, protozoa, viruses, and prions. Bacteria are single-celled organisms with small, simple cells. Examples of bacterial diseases include tuberculosis, cholera, bacterial pneumonia, and dysentery. Fungi may have one or multiple cells and have a more complex cell type than bacteria. Fungal diseases include minor infections like candidiasis (yeast infection) or athlete's foot, but they can also causes severe respiratory infections (histoplasmosis, coccidioidomycosis, etc.) particularly in individuals with compromised immune systems. Parasitic worms are animals from several phyla (groups) that siphon nutrients from their hosts. Examples include tapeworms, commonly acquired through consuming undercooked meat, and blood flukes (Schistosoma). Like fungi, protozoa have larger, more complex cells than bacteria, but they are single celled and lack the rigid cell wall that surrounds fungal cells. Malaria (figure \(\PageIndex{c}\)), African trypanosomiasis (sleeping sickness), and giardiasis are caused by protozoa. Viruses are infectious particles with genetic information surrounded by a protein coat, but they are not technically considered organisms in part because they do not consist fo cells. COVID-19, influenza, measles, the common cold, ebola viral disease (Ebola hemorrhagic fever), and human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) are all caused by viruses. Prions (proteinaceous infectious particles) are even simpler than viruses because they lack genetic material and only contain protein.
While the proportion of deaths caused by in infectious diseases has overall decreased (with a higher proportion of deaths caused by noncommunicable diseases such as cancer and cardiovascular disease), infectious diseases still caused about one in five deaths in 2017. These deaths occurred at the highest rates in developing countries and many were in children. Malnutrition, unclean water, poor sanitary conditions and lack of proper medical care all play roles in transmission and high death rates from infectious diseases Compounding the problems of infectious diseases are factors such as antibiotic-resistant pathogens, pesticide-resistant disease vectors, and overpopulation.
Chemical Hazards
Chemical hazards are toxic substances, which cause damage to living organisms. Air pollutants (such as secondhand smoke or carbon monoxide), heavy metals, and pesticides are a few examples. We can be exposed to these contaminants from a variety of residential, commercial, and industrial sources. Sometimes harmful environmental contaminants occur biologically, such as those from mold or a toxic algae bloom. Toxins can be classified based on their origin, purpose, chemical structure and properties, or effects. Table \(\PageIndex{b}\) describes a few categories of toxins based on their effects and provides examples. A few of these examples are discussed more specifically below.
Table \(\PageIndex{b}\): Classification of Environmental Contaminants
Contaminant Definition
Carcinogen An agent which may produce cancer (uncontrolled cell growth), either by itself or in conjunction with another substance. Examples include formaldehyde, asbestos, radon, vinyl chloride, and tobacco.
Teratogen
A substance which can cause physical defects in a developing embryo. Examples include alcohol and cigarette smoke.
Mutagen A material that induces genetic changes (mutations) in the DNA. Examples include radioactive substances (such as radon and nuclear fuel and waste) and nitrous acid. Some forms of radiation (see Physical Hazards) are also mutagens.
Neurotoxin
A substance that can cause an adverse effect on the chemistry, structure or function of the nervous system. Examples include lead and mercury.
Endocrine disruptor
A chemical that may interfere with the body’s endocrine (hormonal) system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife. A wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including pharmaceuticals, dioxin and dioxin-like compounds, arsenic, polychlorinated biphenyls (PCBs), DDT and other pesticides, per- and polyfluoroalkyl substances (PFAS), pthalates, and plasticizers such as bisphenol A (BPA).
Formaldehyde
Formaldehyde is a colorless, flammable gas or liquid that has a pungent, suffocating odor. It is a volatile organic compound, which is a compound containing carbon and hydrogen that easily becomes a vapor or gas. It is also naturally produced in small, harmless amounts in the human body. The primary way we can be exposed to formaldehyde is by breathing air containing it. Formaldehyde is released into the air by industries using or manufacturing formaldehyde, wood products (such as particle-board, plywood, and furniture), automobile exhaust, cigarette smoke, paints and varnishes, and carpets and permanent press fabrics. Nail polish and commercially applied floor finish emit formaldehyde (figure \(\PageIndex{d}\)).
In general, indoor environments consistently have higher concentrations than outdoor environments because many building materials, consumer products, and fabrics emit formaldehyde. Levels of formaldehyde measured in indoor air range from 0.02–4 parts per million (ppm). Formaldehyde levels in outdoor air range from 0.001 to 0.02 ppm in urban areas.
Heavy Metals
Heavy metals are chemical elements of high density that form a special type of bond (called metallic bonds, in which electrons are shared but in a less constricted way than in covalent bonds). Arsenic, mercury, lead, and cadmium are examples of heavy metals.
Arsenic (As) is a naturally occurring element that is normally present throughout our environment in water, soil, dust, air, and food. Levels of arsenic can regionally vary due to farming and industrial activity as well as natural geological processes. The arsenic from farming and smelting tends to bind strongly to soil and is expected to remain near the surface of the land for hundreds of years as a long-term source of exposure. Wood that has been treated with chromated copper arsenate (CCA) is commonly found in decks and railings in existing homes and outdoor structures such as playground equipment. Some underground aquifers are located in rock or soil that has naturally high arsenic content.
Most arsenic gets into the body through ingestion of food or water. Arsenic in drinking water is a problem in many countries around the world, including Bangladesh, Chile, China, Vietnam, Taiwan, India, and the United States. Arsenic may also be found in foods, including rice and some fish, where it is present due to uptake from soil and water. It can also enter the body by breathing dust containing arsenic.
Arsenic poisoning causes a variety of symptoms and serious health conditions (figure \(\PageIndex{e}\)). Researchers are finding that arsenic, even at low levels, can interfere with the body’s endocrine system. Arsenic is also a known human carcinogen associated with skin, lung, bladder, kidney, and liver cancer.
Mercury (Hg) is a naturally occurring metal, a useful chemical in some products, and a potential health risk. Mercury exists in several forms; the types people are usually exposed to are methylmercury and elemental mercury. Elemental mercury at room temperature is a shiny, silver-white liquid which can produce a harmful odorless vapor. Methylmercury, an organic compound, can build up in the bodies of long-living, predatory fish (Biomagnification). Although fish and shellfish have many nutritional benefits, consuming large quantities of fish increases a person’s exposure to mercury. Pregnant women who eat fish high in mercury on a regular basis run the risk of permanently damaging their developing fetuses. Children born to these mothers may exhibit motor difficulties, sensory problems and cognitive deficits. The United States Environmental Protection Agency thus recommends that pregnant women and young children should not consume any swordfish, shark, king mackerel, or tilefish because of their high mercury content. These individuals are advised to eat fish low in mercury such as salmon, shrimp, pollock, and catfish (figure \(\PageIndex{f}\)). To keep mercury out of the fish we eat and the air we breathe, it’s important to take mercury-containing products to a hazardous waste facility for disposal. Common products sold today that contain small amounts of mercury include fluorescent lights and button-cell batteries (figure \(\PageIndex{g}\)).
Lead (Pb) is a metal that occurs naturally in the rocks and soil of the Earth’s crust. It is also released from mining, manufacturing, and the combustion (burning) fossil fuels such as coal, oil, gasoline, and natural gas. Lead has no distinctive taste or smell. Lead is used to produce batteries, pipes, roofing, scientific electronic equipment, military tracking systems, medical devices, and products to shield X-rays and nuclear radiation. It is used in ceramic glazes and crystal glassware. Because of health concerns, lead and lead compounds were banned from house paint in 1978; from solder used on water pipes in 1986; from gasoline in 1995; from solder used on food cans in 1996; and from tin-coated foil on wine bottles in 1996. The U.S. Food and Drug Administration has set a limit on the amount of lead that can be used in ceramics.
Lead and lead compounds are listed as “reasonably anticipated to be a human carcinogen”. It can affect almost every organ and system in your body. It can be equally harmful if breathed or swallowed. The part of the body most sensitive to lead exposure is the central nervous system, especially in children, who are more vulnerable to lead poisoning than adults. A child who swallows large amounts of lead can develop brain damage that can cause convulsions and death; the child can also develop blood anemia, kidney damage, colic, and muscle weakness. Repeated low levels of exposure to lead can alter a child’s normal mental and physical growth and result in learning or behavioral problems. Exposure to high levels of lead for pregnant women can cause miscarriage, premature births, and smaller babies. Repeated or chronic exposure can cause lead to accumulate in your body, leading to lead poisoning.
The video below explains how Flint, Michigan's water supply was polluted with lead in 2014 and the problematic government response that followed. This video was made in 2016. As of 2020, Flint has a clean water source, and the city of Flint is in the process of compensating affected residents for the damages. (Click here to read a 2020 update.)
Asbestos
Asbestos is a mineral fiber that occurs in rock and soil. Because of its fiber strength and heat resistance asbestos has been used in a variety of building construction materials for insulation and as a fire retardant. Asbestos has also been used in a wide range of manufactured goods, mostly in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings. Exposure to asbestos is associated with cancers (lung cancer and mesothelioma) and another lung disease called asbestosis. In the United States, certain uses of asbestos, including in corrugated paper, flooring, and building insulation, are banned under the Toxic Substances Control Act and Clean Air Act (figure \(\PageIndex{h}\)). In contrast, asbestos is fully banned in 67 countries as of 2019.
Per- and polyfluoroalkyl substances (PFAS)
Per- and polyfluoroalkyl substances (PFAS) are a group of manufactured organic chemicals used in a variety of industries (figure \(\PageIndex{i}\)). They can be found in food packaging, stain- and water-repellent fabrics, nonstick products (such as Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams.
Studies indicate that some PFAS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. More limited findings associate some PFAS with low infant birth weights, effects on the immune system, cancer, and thyroid hormone disruption in humans.
Eight major chemical manufacturers in the U.S. phased out the use certain PFAS (called perfluorooctanoic acid, PFOA, and perfluorooctane sulfonate, PFOS) and related chemicals in their products and as emissions from their facilities. However, these PFAS can still be imported and other PFAS are still manufactured in the U.S.
Polychlorinated Biphenyls (PCBs)
Polychlorinated biphenyls (PCBs) are a group of manufactured organic chemicals. They belong to a broad family of chemicals known as chlorinated hydrocarbons, which consisting of carbon, hydrogen and chlorine atoms (figure \(\PageIndex{j}\)). The number of chlorine atoms and their location in a PCB molecule determine many of its physical and chemical properties. PCBs have no known taste or smell, and range in consistency from an oil to a waxy solid.
Polychlorinated biphenyls have been shown to cause cancer, cause birth defects, and affect the immune, reproductive, nervous, and endocrine systems in animals. Studies in humans support evidence for potential carcinogenic and non-carcinogenic effects of PCBs. The different health effects of PCBs may be interrelated. Alterations in one system may have significant implications for the other systems of the body.
The manufacture of PCBs in the U.S. began in 1929 until it was banned in 1979 under the Toxic Substances Control Act. Due to their non-flammability, chemical stability, high boiling point and electrical insulating properties, PCBs were used in hundreds of industrial and commercial applications including in electrical equipment, coolants paints, plastics, rubber products, pigments, and dyes.
Bisphenol A (BPA)
Bisphenol A (BPA) is a chemical synthesized in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins. Polycarbonate plastics have many applications including use in some food and drink packaging such as water and infant bottles, impact-resistant safety equipment, and medical devices (figure \(\PageIndex{k}\)). Epoxy resins are used as lacquers to coat metal products such as food cans, bottle tops, and water supply pipes. Some dental sealants and composites may also contribute to BPA exposure. The primary source of exposure to BPA for most people is through the diet. Bisphenol A can leach into food from the protective internal epoxy resin coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water bottles, and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or bottle, than the age of the container. It has also be found in breast milk.
Some animal studies suggest that infants and children may be the most vulnerable to the effects of BPA. It disrupts signaling by estrogen, a naturally produced hormone, and the U.S. National Toxicology Program (NTP) documented concerns about its effects on the behavior, brain, and prostate in young children and developing fetuses.
The following personal choices can reduce exposure to BPA:
• Avoid microwaving polycarbonate plastic food containers. Polycarbonate is strong and durable, but over time it may break down from over use at high temperatures.
• Note recycle codes on the bottom of plastic containers. Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA.
• Reduce your use of canned foods.
• When possible, opt for glass, porcelain or stainless steel containers, particularly for hot food or liquids.
While BPA is not banned in the U.S., the Food and Drug Adminsitration banned its use in baby bottles and sippy cups in 2012 and its use in the coating of infant formula containers in 2013. However, similar compounds such as bisphenol S (BPS) are now used as replacements.
Phthalates
Phthalates are a group of synthetic chemicals used to soften and increase the flexibility of plastic and vinyl. Polyvinyl chloride is made softer and more flexible by the addition of phthalates. Phthalates are used in hundreds of consumer products. Phthalates are used in cosmetics and personal care products, including perfume, hair spray, soap, shampoo, nail polish, and skin moisturizers (figure \(\PageIndex{l}\)). They are used in consumer products such as flexible plastic and vinyl toys, shower curtains, wallpaper, vinyl miniblinds, food packaging, and plastic wrap. Exposure to low levels of phthalates may come from eating food packaged in plastic that contains phthalates or breathing dust in rooms with vinyl miniblinds, wallpaper, or recently installed flooring that contain phthalates. We can be exposed to phthalates by drinking water that contains phthalates.
Phthalates are suspected to be endocrine disruptors. Some types of phthalates have affected the reproductive system of laboratory animals. In 2017, The U.S. Consumer Product Safety Commission (CPSC) has banned several pthalates from being used at concentrations greater than 0.1% in toys and products designed to be used by children three years old or younger.
Radon
Radon is a radioactive gas that is naturally-occurring, colorless, and odorless (figure \(\PageIndex{m}\)). It comes from the natural decay of uranium or thorium found in nearly all soils. It typically moves up through the ground and into the home through cracks in floors, walls and foundations. It can also be released from building materials or from well water. Radon breaks down quickly, giving off radioactive particles. Long-term exposure to these particles can lead to lung cancer. Radon is the leading cause of lung cancer among nonsmokers, according to the U.S. Environmental Protection Agency, and the second leading cause behind smoking. To reduce the risk of radon exposure, the Department of Urban and Housing Development recommends testing your home for radon, avoiding smoking to reduce the risk of lung cancer, and ensuring proper ventilation in your home.
Dichlorodiphenyltrichloroethane (DDT)
Dichlorodiphenyltrichloroethane (DDT) was the first of a long line of chlorinated hydrocarbon insecticides (figure \(\PageIndex{n}\)). These compounds are chains of carbon and hydrogen with chlorine atoms replacing some of the hydrogen atoms. Introduced during World War II, DDT, along with penicillin and the sulfa drugs, was responsible for the fact that this was the first war in history where trauma killed more people - combatants and noncombatants alike - than infectious disease.
Dichlorodiphenyltrichloroethane is effective against many crop pests as well as vectors of human diseases such as the mosquitoes that spread malaria and yellow fever and fleas, which transmit the plague. Prior to the introduction of DDT, the number of cases of malaria in Ceylon (now Sri Lanka) was more than a million a year. By 1963 the disease had been practically eliminated from the island. However, growing concern about the hazards of DDT led to its abandonment there in the mid-1960s, and soon thereafter malaria became common once again. Because it remains in the environment and is resistant to breakdown, DDT was especially effective against malarial mosquitoes. One or two sprays a year on the walls of homes kept them free of mosquitoes. It was also inexpensive, further adding to its appeal, but DDT has several serious drawbacks.
Because DDT builds up in fatty tissues (bioaccumulation) and becomes more concentrated at the highest levels of the food chain (biomagnification), it is especially harmful to apex predators, such as Bald Eagles (figure \(\PageIndex{o}\)). Classical studies documenting these effects were described in the 1960s bestseller Silent Spring by Rachel Carson. It was discovered that DDT caused the eggshells of birds to become fragile and break, making reproduction impossible. As a result, the Bald Eagle was listed as an endangered species under U.S. law. After DDT was banned in the United States in 1972, affected bird populations made noticeable recoveries, including the iconic Bald Eagle.
Physical Hazards
Physical hazards are additional forces that can imperil humans. Physical hazards may arise naturally such as natural disasters (earthquakes, wildfires, landslides, etc.) or extreme weather (figure \(\PageIndex{p}\)). Others may arise from human structures or activities (traffic accident, building collapse, injury from mechanical equipment, strain on the body from repeated movements, etc.) Some physical hazards, such as explosions or radiation, can arise from natural or human sources.
Radiation is energy given off by matter in the form of rays or high-speed particles, and some types of radiation present a physical hazard. Some familiar forms of radiation are infrared radiation (heat), visible light, ultraviolet (UV) light, radio waves, and microwaves. We are exposed to radiation every day from natural sources. For example, the sun exposes us to UV radiation. We are also exposed to radiation from human-made sources like medical X-rays and smoke detectors. We’re even exposed to low levels of radiation on cross-country flights, from watching television, and even from some construction materials. Some types of radioactive materials are more dangerous than others. Specifically, ionizing radiation, like X rays and gamma rays (one of the forms of radiation emitted from nuclear fuel and waste), have enough energy to break molecular bonds and displace (or remove) electrons from atoms.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.01%3A_Types_of_Environmental_Hazards.txt |
The field of epidemiology concerns the geographical distribution and timing of infectious disease occurrences and how they are transmitted and maintained in nature, with the goal of recognizing and controlling outbreaks. The science of epidemiology includes etiology (the study of the causes of disease) and investigation of disease transmission (mechanisms by which a disease is spread). Epidemiologists are thus scientists who study the causes and patterns of human disease, which involves examining statistics to identify health threats and recommending strategies to reduce these threats.
The work of epidemiologist Alice Wang is highlighted in the video below. While many of the examples on this page focus on infectious disease (which result from biological hazards), epidemiologists can study noncommunicable diseases too (such as poisoning or obesity). The text at the end of the video says, "Are You CDC? For more information bout employment opportunities with CDC, please visit: jobs.cdc.gov".
History of Epidemiology
The studies of 19th century physicians and researchers such as John Snow, Florence Nightingale, Ignaz Semmelweis, Joseph Lister, Robert Koch, Louis Pasteur, and others sowed the seeds of modern epidemiology.
John Snow (figure \(\PageIndex{a}\)) was a British physician known as the father of epidemiology for determining the source of the 1854 Broad Street cholera epidemic in London. Based on observations he had made during an earlier cholera outbreak (1848–1849), Snow proposed that cholera was spread through a fecal-oral route of transmission and that a microbe was the infectious agent. He investigated the 1854 cholera epidemic in two ways. First, suspecting that contaminated water was the source of the epidemic, Snow identified the source of water for those infected. He found a high frequency of cholera cases among individuals who obtained their water from the River Thames downstream from London. This water contained the refuse and sewage from London and settlements upstream. He also noted that brewery workers did not contract cholera and on investigation found the owners provided the workers with beer to drink and stated that they likely did not drink water. Second, he also painstakingly mapped the incidence of cholera and found a high frequency among those individuals using a particular water pump located on Broad Street. In response to Snow’s advice, local officials removed the pump’s handle, resulting in the containment of the Broad Street cholera epidemic. John Snow’s own account of his work has additional links and information.
Snow’s work represents an early epidemiological study and it resulted in the first known public health response to an epidemic. Snow’s meticulous case-tracking methods are now common practice in studying disease outbreaks and in associating new diseases with their causes. His work further shed light on unsanitary sewage practices and the effects of waste dumping in the Thames. Additionally, his work supported the germ theory of disease, which argued disease could be transmitted through contaminated items, including water contaminated with fecal matter.
Florence Nightingale’s work is another example of an early epidemiological study. In 1854, Nightingale was part of a contingent of nurses dispatched by the British military to care for wounded soldiers during the Crimean War. Nightingale kept meticulous records regarding the causes of illness and death during the war. Her recordkeeping was a fundamental task of what would later become the science of epidemiology. Her analysis of the data she collected was published in 1858. In this book, she presented monthly frequency data on causes of death in a wedge chart histogram (figure \(\PageIndex{b}\)). This graphical presentation of data, unusual at the time, powerfully illustrated that the vast majority of casualties during the war occurred not due to wounds sustained in action but to what Nightingale deemed preventable infectious diseases. Often these diseases occurred because of poor sanitation and lack of access to hospital facilities. Nightingale’s findings led to many reforms in the British military’s system of medical care. Learn more about Nightingale’s wedge chart here.
Joseph Lister provided early epidemiological evidence leading to good public health practices in clinics and hospitals. Most physicians did not wash their hands between patient visits or clean and sterilize their surgical tools. Lister, however, discovered the disinfecting properties of carbolic acid, also known as phenol. He introduced several disinfection protocols that dramatically lowered post-surgical infection rates. He demanded that surgeons who worked for him use a 5% carbolic acid solution to clean their surgical tools between patients, and even went so far as to spray the solution onto bandages and over the surgical site during operations (figure \(\PageIndex{c}\)). He also took precautions not to introduce sources of infection from his skin or clothing by removing his coat, rolling up his sleeves, and washing his hands in a dilute solution of carbolic acid before and during the surgery.
Analyzing Disease in a Population
Epidemiological analyses are always carried out with reference to a population, which is the group of individuals that are at risk for the disease or condition. The population can be defined geographically, but if only a portion of the individuals in that area are susceptible, additional criteria may be required. Susceptible individuals may be defined by particular behaviors, such as intravenous drug use, owning particular pets, or membership in an institution, such as a college. Being able to define the population is important because most measures of interest in epidemiology are made with reference to the size of the population.
The state of being diseased is called morbidity. Morbidity in a population can be expressed in a few different ways. Morbidity, or total morbidity, is expressed in numbers of individuals without reference to the size of the population. The morbidity rate can be expressed as the number of diseased individuals out of a standard number of individuals in the population, such as 100,000, or as a percent of the population.
There are two aspects of morbidity that are relevant to an epidemiologist: a disease’s prevalence and its incidence. Prevalence is the number, or proportion, of individuals with a particular illness in a given population at a point in time. For example, the Centers for Disease Control and Prevention (CDC) estimated that about 1.2 million people in the United States lived with an active human immunodeficiency virus (HIV) infection in 2018. Expressed as a proportion, or rate, this is a prevalence of 367 infected persons per 100,000 in the population. On the other hand, incidence is the number or proportion of new cases in a period of time. For the same year, the CDC estimates that there were 36,400 newly diagnosed cases of HIV infection, which is an incidence of 11.1 new cases per 100,000 in the population. The relationship between incidence and prevalence can be seen in figure \(\PageIndex{d}\). For a chronic disease like HIV infection, prevalence will generally be higher than incidence because it represents the cumulative number of new cases over many years minus the number of cases that are no longer active (because the patient died or was cured).
In addition to morbidity rates, the incidence and prevalence of mortality (death) may also be reported. A mortality rate can be expressed as the percentage of the population that has died from a disease or as the number of deaths per 100,000 persons (or other suitable standard number).
Patterns of Incidence
Diseases that are seen only occasionally, and usually without geographic concentration, are called sporadic diseases. Examples of sporadic diseases include tetanus, rabies, and plague. In the United States, Clostridium tetani, the bacterium that causes tetanus, is ubiquitous in the soil environment, but incidences of infection occur only rarely and in scattered locations because most individuals are vaccinated, clean wounds appropriately, or are only rarely in a situation that would cause infection. Likewise in the United States there are a few scattered cases of plague each year, usually contracted from rodents in rural areas in the western states.
Diseases that are constantly present (often at a low level) in a population within a particular geographic region are called endemic diseases. For example, malaria is endemic to some regions of Brazil, but is not endemic to the United States.
Diseases for which a larger than expected number of cases occurs in a short time within a geographic region are called epidemic diseases. Influenza is a good example of a commonly epidemic disease. Incidence patterns of influenza tend to rise each winter in the northern hemisphere. These seasonal increases are expected, so it would not be accurate to say that influenza is epidemic every winter; however, some winters have an usually large number of seasonal influenza cases in particular regions, and such situations would qualify as epidemics (figures \(\PageIndex{e-f}\)).
An epidemic that occurs on a worldwide scale is called a pandemic disease. For example, HIV/AIDS (acquired immunodeficiency syndrome) and coronavirus disease 19 (COVID-19) are pandemic diseases, and novel influenza virus strains often become pandemic.
Etiology
When studying an epidemic, an epidemiologist’s first task is to determinate the cause of the disease, called the etiologic agent or causative agent. Connecting a disease to a specific pathogen can be challenging because of the extra effort typically required to demonstrate direct causation as opposed to a simple association. It is not enough to observe an association between a disease and a suspected pathogen; controlled experiments are needed to eliminate other possible causes. In addition, pathogens are typically difficult to detect when there is no immediate clue as to what is causing the outbreak. Signs and symptoms of disease are also commonly nonspecific, meaning that many different agents can give rise to the same set of signs and symptoms. This complicates diagnosis even when a causative agent is familiar to scientists.
Robert Koch was the first scientist to specifically demonstrate the causative agent of a disease (anthrax) in the late 1800s. Koch developed four criteria, now known as Koch’s postulates, which had to be met in order to positively link a disease with a pathogenic microbe (figure \(\PageIndex{g}\)). Between 1876 and 1905, many common diseases were linked with their etiologic agents, including cholera, diphtheria, gonorrhea, meningitis, plague, syphilis, tetanus, and tuberculosis. Today, we use the molecular Koch’s postulates, a variation of Koch’s original postulates. (You can read more about both here.)
How Diseases Spread
Understanding how infectious pathogens spread is critical to preventing infectious disease. For pathogens to persist over long periods of time they require reservoirs where they normally reside. Reservoirs can be living organisms (rats, bats, racoons, livestock, etc.)or nonliving sites. Nonliving reservoirs can include soil and water in the environment. These may naturally harbor the organism because it may grow in that environment. These environments may also become contaminated with pathogens in human feces, pathogens shed by intermediate hosts, or pathogens contained in the remains of intermediate hosts.
An individual capable of transmitting a pathogen without displaying symptoms is referred to as a carrier. A passive carrier is contaminated with the pathogen and can mechanically transmit it to another host; however, a passive carrier is not infected. By contrast, an active carrier is an infected individual who can transmit the disease to others. An active carrier may or may not exhibit signs or symptoms of infection.
Regardless of the reservoir, transmission must occur for an infection to spread. Contact transmission includes direct contact or indirect contact. Person-to-person transmission is a form of direct contact transmission. Here the agent is transmitted by physical contact between two individuals (figure \(\PageIndex{h}\)) through actions such as touching, kissing, sexual intercourse, or droplet sprays. Indirect contact transmission involves inanimate objects called fomites that become contaminated by pathogens from an infected individual or reservoir (figure \(\PageIndex{i}\)). For example, an individual with the common cold may sneeze, causing droplets to land on a fomite such as a tablecloth or carpet, or the individual may wipe her nose and then transfer mucus to a fomite such as a doorknob or towel.
Vehicle transmission refers to the transmission of pathogens through vehicles such as water, food, and air. Water contamination through poor sanitation methods leads to waterborne transmission of disease. Waterborne disease remains a serious problem in many regions throughout the world. The World Health Organization (WHO) estimates that contaminated drinking water is responsible for more than 500,000 deaths each year. Similarly, food contaminated through poor handling or storage can lead to foodborne transmission of disease. Dust and fine particles known as aerosols, which can float in the air, can carry pathogens and facilitate the airborne transmission of disease.
Diseases can also be transmitted by a mechanical or biological vector, an animal (typically an arthropod) that carries the disease from one host to another. Ticks, fleas, and mosquitos are examples of vectors (figure \(\PageIndex{j}\)). Mechanical transmission is facilitated by a mechanical vector, an animal that carries a pathogen from one host to another without being infected itself. Biological transmission occurs when the pathogen reproduces within a biological vector that transmits the pathogen from one host to another (figure \(\PageIndex{k}\)).
Ecosystem degradation can increase disease spread through several mechanisms. First, it can promote vector populations. For example, deforestation, dams, and urbanization increase the amount of standing water, increasing habitat for vectors, such as mosquitoes. Additionally, climate change may expand the range of disease vectors that are limited to tropical or subtropical regions. Second, disruptions in the water cycle can create conditions that favor pathogens. For example, fertilizer runoff from agriculture increases nutrient levels, making bodies of water more suitable for the bacterium that causes cholera. Increased flooding as a result of changes in land use and climate change also facilitates the spread of waterborne disease.
A third way that ecosystem degradation can increase disease spread is through decreasing biodiversity. For example, Lyme disease is caused by the bacterium Borrelia and is transmitted to humans from small mammals (the reservoirs) by ticks (figures \(\PageIndex{l-m}\)). Some reservoirs (squirrels and opossums) remove ticks, reducing infection, but field mice do not. Habitat fragmentation has increased field mice relative to squirrels and opossums and thus increased the reservoir for Lyme disease.
Individuals suspected or known to have been exposed to certain contagious pathogens may be quarantined, or isolated to prevent transmission of the disease to others. Hospitals and other health-care facilities generally set up special wards to isolate patients with particularly hazardous diseases such as tuberculosis or COVID-19 (figure \(\PageIndex{n}\)). Depending on the setting, these wards may be equipped with special air-handling methods, and personnel may implement special protocols to limit the risk of transmission, such as personal protective equipment or the use of chemical disinfectant sprays upon entry and exit of medical personnel.
Attribution
Modified by Melissa Ha from Disease and Epidemiology from Microbiology by OpenStax (licensed under CC-BY). Access for free at openstax.org. | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.02%3A_Epidemiology.txt |
Worldwide, infectious diseases (biological hazards) accounted for three of the 10 leading causes of death in 2020. In children under five leading causes of death include acute respiratory infections (from indoor air pollution); diarrheal diseases (mostly from poor water, sanitation, and hygiene); and other infectious diseases such as malaria. Children are especially susceptible to environmental factors that put them at risk of developing illness early in life. Malnutrition (the condition that occurs when body does not get enough nutrients) is an important contributor to child mortality—malnutrition and environmental infections are inextricably linked.
The World Health Organization (WHO) recently concluded that about 50% of the consequences of malnutrition are in fact caused by inadequate water and sanitation provision and poor hygienic practices. For example, intestinal worms, which thrive in poor sanitary conditions, infect close to 90 percent of children in the developing world and, depending on the severity of the infection may lead to malnutrition, anemia, or stunted growth. About 6 million people are blind from trachoma, a disease caused by the lack of clean water combined with poor hygiene practices.
An emerging infectious disease is either new to the human population or has shown an increase in prevalence in the previous twenty years. Examples include coronavirus disease 19 (COVID-19), Ebola virus disease, West Nile virus, Zika virus, sudden acute respiratory syndrome (SARS), H1N1 influenza; swine and avian influenza (swine, bird flu), human immunodeficiency virus (HIV)/acquired immunodeficiency disorder (AID, and a variety of other viral, bacterial, and protozoal diseases (table \(\PageIndex{a}\)). Whether the disease is new or conditions have changed to cause an increase in frequency, its status as emerging implies the need to apply resources to understand and control its growing impact. Emerging diseases may change their frequency gradually over time, or they may experience sudden widespread growth.
Table \(\PageIndex{a}\): Some Emerging and Reemerging Infectious Diseases
Disease Pathogen Year Discovered Affected Regions Transmission
AIDS HIV 1981 Worldwide Contact with infected body fluids
Chikungunya fever Chikungunya virus 1952 Africa, Asia, India; spreading to Europe and the Americas Mosquito-borne
Ebola virus disease Ebola virus 1976 Central and Western Africa Contact with infected body fluids
H1N1 Influenza (swine flu) H1N1 virus 2009 Worldwide Droplet transmission
Lyme disease Borrelia burgdorferi bacterium 1981 Northern hemisphere From mammal reservoirs to humans by tick vectors
West Nile virus disease West Nile virus 1937 Africa, Australia, Canada to Venezuela, Europe, Middle East, Western Asia Mosquito-borne
Emerging diseases are found in all countries, both developed and developing. Some nations are better equipped to deal with them. National and international public health agencies watch for epidemics in developing countries because those countries rarely have the health-care infrastructure and expertise to deal with large outbreaks effectively. In addition to the altruistic goal of saving lives and assisting nations lacking in resources, the global nature of transportation means that an outbreak anywhere can spread quickly to every corner of the planet. Managing an epidemic in one location—its source—is far easier than fighting it on many fronts.
In 2015, the WHO set priorities on several emerging diseases that had a high probability of causing epidemics and that were poorly understood (and thus urgently required research and development efforts).
reemerging infectious disease is a disease that is increasing in frequency after a previous period of decline. Its reemergence may be a result of changing conditions or old prevention regimes that are no longer working. Examples of such diseases are drug-resistant forms of tuberculosis, bacterial pneumonia, and malaria. Drug-resistant strains of the bacteria causing gonorrhea and syphilis are also becoming more widespread, raising concerns of untreatable infections.
A variety of environmental factors may contribute to re-emergence of a particular disease, including temperature, moisture, human food or animal feed sources, etc. Disease re-emergence may be caused by the coincidence of several of these environmental and/or social factors to allow optimal conditions for transmission of the disease.
It seems likely that a wide variety of infectious diseases have affected human populations for thousands of years emerging when the environmental, host, and agent conditions were favorable. Expanding human populations have increased the potential for transmission of infectious disease as a result of close human proximity and increased likelihood for humans to be in “the wrong place at the right time” for disease to occur (eg, natural disasters or political conflicts). Global travel increases the potential for a carrier of disease to transmit infection thousands of miles away in just a few hours, as evidenced by WHO precautions concerning international travel and health.
Selected Infectious Diseases
COVID-19
Coronavirus disease 19 (COVID-19) is a respiratory illness caused by a virus called novel species of coronavirus (SARS-CoV-2). Symptoms include fever or chills, cough, shortness or breath or difficulty breathing, fatigue, headache, and sore throat. The WHO declared coronavirus disease 19 (COVID-19) a public health emergency of international concern on January 30 and a pandemic on March 11, 2020. A seemingly limited cluster of cases of pneumonia linked to a sea food market in Wuhan, China has become one of the worst pandemics in human history with a staggering number of more than 90.2 million infections in 177 countries and 1.9 million deaths globally as of January 10, 2021 (figure \(\PageIndex{a}\)). This illustrates how locally emerging pathogens have the capacity to spread rapidly and cross borders and become an imminent public health threat to the entire world. You can view the the latest COVID-19 data here.
Studies indicate that SARS-CoV-2 might originate from bat coronaviruses and infects humans directly or through other animals as intermediaries. It primarily spreads between humans through the respiratory tract by involving droplets, aerosols, respiratory secretions, or saliva. It is most often spread by direct contact transmission, but it airborne transmission has been documented in certain situations, such as in an enclosed space (figure \(\PageIndex{b}\)). Researchers continue to investigate airborne transmission of the virus. This coronavirus is infectious during its incubation period, which is reported to be 3-7 days, at most 14 days, when no symptoms are shown in patients. Those infected may experience mild to moderate disease (80%), severe disease (15%), and critical illness (5%) with an overall case fatality rate of 0.5–2.8% with much higher rates (3.7–14.8%) in octogenarians. The severe and critical illness categories (about 20% of all infections) have overwhelmed health systems worldwide (figure \(\PageIndex{c}\)). The Centers for Disease Control and Prevention's COVID-19 page has the latest information about preventing transmission, vaccines, symptoms, and testing.
Ebola Virus Disease
Ebola virus disease, previously known as Ebola hemorrhagic fever, is a rare and deadly disease caused by infection with one of the Ebola virus strains (figure \(\PageIndex{d}\)). Ebola can cause disease in humans and nonhuman primates. Health experts had been aware of the Ebola virus since the 1970s, but outbreak at scale that had not yet been seen occurred in western Africa through 2014–2016. Previous human epidemics had been small, isolated, and contained. Indeed, the gorilla and chimpanzee populations of western Africa had suffered far worse from Ebola than the human population. The pattern of small isolated human epidemics changed in 2014. Its high transmission rate, coupled with cultural practices for treatment of the dead and perhaps its emergence in an urban setting, caused the disease to spread rapidly, and thousands of people died. The international public health community responded with a large emergency effort to treat patients and contain the epidemic.
The 2014-2016 Ebola epidemic was the largest in history (with 28,616 cases and 11,310 deaths), affecting multiple countries in West Africa. There were a small number of cases reported in Nigeria and Mali and a single case reported in Senegal; however, these cases were contained, with no further spread in these countries. Even with the support of international agencies, the systems in western Africa struggled to identify and care for the sick and control spread. Engaging local leaders in prevention programs and messaging, along with careful policy implementation at the national and global level, helped to eventually contain the spread of the virus and put an end to this outbreak. The U.S. Food and Drug Administration approved a vaccine for Ebola late in 2019.
HIV/AIDS
Human immunodeficiency virus (HIV) is a virus that attacks the body’s immune system. If HIV is not treated, it can lead to acquired immunodeficiency syndrome (AIDS). Those with AIDS have weakened immune systems and are thus more susceptible to cancers and other infections. First identified in 1981, the HIV/AIDS epidemic has spread with ferocious speed. In 2019, 38 million people were living HIV globally. Over 95 percent of people living with HIV are in low- and middle- income countries. There were 1.7 million new infections in 2019, and more than half of new infections are among young people below age 25. In 2019 alone, 690,000 million people died from AIDS and related illnesses. In 2016, HIV/AIDS is was the second leading cause of death in Africa. At its peak, the epidemic cut life expectancy by more than 10 years in several nations (figure \(\PageIndex{e}\)).
Malaria
Approximately 40% of the world’s people—mostly those living in the world’s poorest countries—are at risk from malaria. Malaria is an infectious disease spread by mosquitoes but caused by a single-celled protozoan parasite called Plasmodium. There were 229 million cases of malaria and 409,000 deaths in 2019 with most cases and deaths found in Sub-Saharan Africa (figure \(\PageIndex{f}\)). However, Asia, Latin America, the Middle East, and parts of Europe are also affected. Pregnant women are especially at high risk of malaria. Non-immune pregnant women risk both acute and severe clinical disease, resulting in fetal loss in up to 60% of such women and maternal deaths in more than 10%, including a 50% mortality rate for those with severe disease. Semi-immune pregnant women with malaria infection risk severe anemia (lack of sufficient red blood cells to deliver oxygen) and impaired fetal growth, even if they show no signs of acute clinical disease. An estimated 10,000 women and 200,000 infants die annually as a result of malaria infection during pregnancy.
Tuberculosis
The WHO estimates that 10.4 million new cases and 1.5 million deaths occur from tuberculosis (TB) each year. One-third of TB cases remain unknown to the health care system. For those accessing treatment, however, prevalence and mortality have declined significantly, and millions of lives have been saved.
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, which is transmitted between humans through the respiratory route and most commonly affects the lungs but can damage any tissue. When an infected individual coughs, exhales, speaks, etc., the bacterium is released in droplets that can remain suspended in the air for several hours. Only a minority (approximately 10 percent) of individuals infected with M. tuberculosis progress to active TB disease, while the remainder may maintain a latent infection that serves as a reservoir. TB has special challenges, including (a) a substantial number of patients with active disease are asymptomatic, capable of transmitting infection without knowing it; (b) patients must maintain compliance with treatment for six to nine months; and (c) the pathogen persists in many infected individuals in a latent state for many years but can be reactivated over a lifetime to cause disease and become transmissible.
This video by the CDC explains the basics of TB.
Disease Eradication
Many diseases have been eradicated or are nearly eradicated worldwide (Table \(\PageIndex{b}\)). Strategies to eradicate disease infectious diseases include vaccination, improved hygiene and sanitation, preventative medication, and public health education. Some of these strategies are discussed in Environmental Health Reduction, and vaccination is discussed below.
Table \(\PageIndex{b}\): Infectious diseases that have been eradicated and could be eradicated in the future.
Disease Burden of disease Cause Ways to eradicate Fatality
Smallpox Declared eradicated in 1980 Variola virus Eradicated using vaccination 30%
Rinderpest Declared eradicated in 2011 Rinderpest virus Sanitary measures and vaccination 100%
Poliomielitis 116 cases in 2017 Poliovirus Vaccination For paralytic polio 2-5% in children and increases to 15-30% in adults
Guinea worm disease 30 cases in 2017 Parasitic worm Dracunculus medinensis Hygiene, water decontamination and health education Not fatal but debilitating
Measles 173,457 reported cases to WHO in 2017 Measles morbillivirus Vaccination 15%
Mumps 560,622 reported cases to WHO in 2017 Mumps orthorubulavirus Vaccination 0.01% for mumps-caused encephalitis
Rubella 6,789 reported cases to WHO in 2017 Rubella virus Vaccination Not reported
Lymphatic filariasis No estimate available. In 2014, 68 million people were infected and 790 million people where at risk of infection Roundworms:
W. bancrofti,
B. malayi,
B. timori
Preventive chemotherapy Not fatal but highly debilitating
Cysticercosis 2.56–8.30 million cases estimated by the WHO Tapeworms:
T. solium,
T. saginata,
T. asiatica
Sanitation and health education. Vaccination of pigs Varies between countries <1-30%
Table modified from Max Roser, Sophie Ochmann, Hannah Behrens, Hannah Ritchie and Bernadeta Dadonaite (2014) - "Eradication of Diseases". Published online at OurWorldInData.org. (CC-BY).
Vaccination
Vaccines function in inducing a specific immune response that can immediately counter a pathogen if exposed. Vaccines lead to the production of specialized cells and antibodies, which can efficiently and effectively target pathogens. There are several types of vaccines. Some consists of dead or inactivated pathogens or parts of them. The Pfizer-BioNTech and Moderna COVID-19 vaccines, approved by the FDA in December of 2020 consist of a piece of the the virus's genetic material (called mRNA). When injected, the body uses this genetic information to synthesize the spike protein of the virus, which stimulates an immune responses without causing infection.
Development and approval of a vaccine does not automatically eradicate a disease (figure \(\PageIndex{g}\)), for the vaccine must be distributed to those who need it. Access is particularly challenging in developing countries, especially for low-income individuals there. In the case of tuberculosis, which remains widespread, a vaccine has been available for 100 years, but it is more effective in protecting severe forms of the disease in children than lung infections in adults. A new, more effective vaccine is likely needed to eradicate tuberculosis.
New vaccines must be rigorously tested before they are approved. Not only are vaccines safe, but we would face spikes in deadly infectious diseases without them. The antivax movement has unfortunately spread false information questioning the safety of vaccines, but you can educate yourself with reliable information about the development, testing, and safety of vaccines here.
Antibiotic Resistance
Antibiotics and similar drugs, together called antimicrobial agents, have been used for the last 70 years to treat patients who have infectious diseases. Technically, antibiotics are substances that are produced by certain microorganisms (such as the fungus, Penicillium, or the bacterium Streptomyces) that inhibit the growth of other microorganisms. However, any drugs used to treat bacterial infections are commonly referred to as antibiotics. Neither of these definitions includes substances used to treat viral infections, which are called antivirals. Since the 1940s, the use of antiobitics has greatly reduced illness and death from infectious diseases. However, these drugs have been used so widely and for so long that the infectious organisms the antibiotics are designed to kill have adapted to them, making the drugs less effective.
Overuse of antibiotics have allowed pathogens to evolve antibiotic resistance, which occurs when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections (figure \(\PageIndex{h}\)). Overuse takes many forms, such as the inclusion of antibiotics in household products or prescribing antibiotics to treat infections without first determining whether the infection is bacterial or viral (in which case, the antibiotic would not be effective). Similar to the evolution of pesticide resistance, widespread use of antibiotics favors individuals that happen to have gene versions conferring antibiotic resistance. These individuals have the best chance of surviving and reproducing, so much so, that an antibiotic-resistant strain evolves. The initial antibiotic is not longer effective against this strain, and it must be treated with alternative medications. For example, tuberculosis (TB) was nearly eliminated in most parts of the world, but drug-resistant strains have now reversed that trend.
A similar example of drug resistance has evolved in Plasmodium, the protozoa that cause malaria. The insecticide dichlorodiphenyltrichloroethane (DDT) was widely used to control malaria-carrying mosquito populations in tropical regions. However, after many years the mosquitoes developed a natural resistance to DDT and again spread the disease widely. Anti-malarial medicines were also over-prescribed, which allowed Plasmodium to become drug-resistant.
New forms of antibiotic resistance can cross international boundaries and spread between continents with ease. Many forms of resistance spread with remarkable speed. Each year in the United States, at least 2 million people acquire serious infections with bacteria that are resistant to one or more of the antibiotics designed to treat those infections. At least 23,000 people die each year in the US as a direct result of these antibiotic-resistant infections. Many more die from other conditions that were complicated by an antibiotic-resistant infection. The use of antibiotics is the single most important factor leading to antibiotic resistance around the world. Antibiotics are among the most commonly prescribed drugs used in human medicine, but up to 50% of all the antibiotics prescribed for people are not needed or are not optimally effective as prescribed.
The video below shows an experiment done at Harvard Medical school, where they show bacteria adapting very quickly to apparently deadly conditions.
During recent years, there has been growing concern over methicillin-resistant Staphylococcus aureus (MRSA), a bacterium that is resistant to many antibiotics. In the community, most MRSA infections are skin infections. In medical facilities, MRSA causes life-threatening bloodstream infections, pneumonia and surgical site infections.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.03%3A_Infectious_Diseases.txt |
Environmental toxicology is the scientific study of the properties of toxins, chemicals that may cause damage to living organisms, and the health effects associated exposure to them (table \(\PageIndex{a}\)). The field also involves managing these toxins and the protecting humans and ecosystems from them. Toxicologists are scientists who study the properties of toxins, and these damage-causing properties, are called toxicity. In other words, toxicologists evaluate chemical hazards.
Table \(\PageIndex{a}\): The 15 Highest Priority Toxins According to the Agency for Toxic Substances and Disease Registry (ATSDR) Substance Priority List in 2019. These substances are ranked based on their toxicity and chance of exposure at sites on the National Priorities List (NPL), where toxins have been spilled or otherwise released.
2019 Rank Substance Name
1 Arsenic
2 Lead
3 Mercury
4 Vinyl chloride
5 Polychlorinated biphenyls (PCBs)
6 Benzene
7 Cadmium
8 Benzo[a]pyrene
9 Polycyclic aromatic hydrocarbons
10
Benzo[b]fluoranthene
11 Chloroform
12
Aroclor 1260
13 p,p'-DDT
14 Aroclor 1254
15 Dibenz[a,h]anthracene
Table modified from ATSDR/CDC (public domain).
What Forms do Chemicals Take?
Chemical substances can take a variety of forms. They can be in the form of solids, liquids, dusts, vapors, gases, fibers, mists and fumes (figure \(\PageIndex{a}\)). The form a substance is in has a lot to do with how it gets into your body and what harm it can cause. A chemical can also change forms. For example, liquid solvents can evaporate and give off vapors that you can inhale. Sometimes chemicals are in a form that can’t be seen or smelled, so they can’t be easily detected.
Routes of Exposure to Chemicals
In order to cause health problems, chemicals must enter your body. Once chemicals have entered your body, some can move into your bloodstream and reach internal “target” organs, such as the lungs, liver, kidneys, or nervous system. There are three main routes of exposure, or ways a chemical can get into your body (figure \(\PageIndex{b}\)).
The first route is inhalation, which results from breathing in chemical gases, mists, or dusts that are in the air. Because the air sacs in the lungs are structure for gas exchange, consisting of only a single layer of thin cells, inhaled substances can rapidly pass from the air sacs into capillaries and enter the bloodstream. Inhaled toxins can also cause local damage to the mouth, airways, and lungs.
The second route is ingestion, swallowing that occurs chemicals have spilled or settled onto food, beverages, cigarettes, beards, or hands. Toxins can then cause local damage to the digestive tract and may be absorbed, most often through the intestines, into the blood stream.
The third route is skin or eye contact. When chemicals directly touch the skin or get in the eyes, they can cause localized damage or be absorbed through the skin into the bloodstream. Because the skin consists of many cell layers that are reinforced with protective compounds, it is more difficult for toxins to enter the body through the skin compared to inhalation and ingestion. However, toxins can easily enter through damaged skin, and some substances can be absorbed through intact skin. Because the eyes have a rich blood supply, toxins can ready enter the bloodstream through eye contact.
What Factors Impact a Chemical's Safety?
Why are some chemicals more harmful than other? Many factors are considered when evaluating a chemical's safety including potency, persistence, solubility, bioaccumulation and biomagnification. Potency refers to the amount of a chemical needed to cause harm. The more potent a toxin, the lower the concentration needed to cause harm. Persistence refers to how long a substance takes to break down. Persistent chemicals are of greater concern because they remain in the environment (or even in organisms) for long time periods. Solubility refers to whether the chemical dissolves in certain solvents, such as water or fat. Generally, fat-soluble (lipid-soluble) toxins are more dangerous because they can accumulate in fatty tissues (see below) whereas water-soluble toxins could be more easily flushed out of the body. Furthermore, fat-soluble toxins are more easily absorbed by the body.
Bioaccumulation
Bioaccumulation is the buildup of chemicals in an organism’s tissues over its lifetime. While bioaccumulated toxins are commonly fat soluble, such as DDT and PCBs, water-soluble toxins, such as inorganic forms of heavy metals can also bioaccumulate. For example, lead accumulates in the teeth and bone, and mercury can accumulate in the kidneys and brain.
Biomagnification
Biomagnification is the increasing concentration of toxins in organisms at each successive trophic level. When organisms with bioaccumulated toxins are consumed, the toxins are transferred to their predators (figure \(\PageIndex{d}\)). Biomagnification explains why some fish species high on the food chain contain high concentrations of mercury and cadmium, another heavy metal.
In addition to high persistence, fat solubility, and bioaccumulation, biomagnification explains why the now-banned insecticide dichlorodiphenyltrichloroethane (DDT) caused so much damage. Producers absorbed DDT and passed it on to successive levels of consumers at increasingly higher rates. For example, spraying a marsh to control mosquitoes will cause trace amounts of DDT to accumulate in the cells of microscopic aquatic organisms, the plankton, in the marsh. In feeding on the plankton, filter-feeders, like clams and some fish, harvest DDT as well as food. (Concentrations of DDT 10 times greater than those in the plankton have been measured in clams.) The process of concentration goes right on up the food chain from one trophic level to the next. Gulls, which feed on clams, may accumulate DDT to 40 or more times the concentration in their prey. This represents a 400-fold increase in concentration along the length of this short food chain. Ultimately, apex predators at the top of the food chain such as Bald Eagles, pelicans, falcons, and ospreys fed on contaminated fish, reaching dangerous DDT levels.
Another substances that biomagnifies is polychlorinated biphenyl (PCB). The National Atmospheric and Oceanic Administration (NOAA) studied biomagnification of PCB in the Saginaw Bay of Lake Huron of the North American Great Lakes (figure \(\PageIndex{d}\)). Concentrations of PCB increased from the producers of the ecosystem (phytoplankton) through the different trophic levels of fish species. The apex predator, the walleye, had more than four times the amount of PCBs compared to phytoplankton. Also, research found that birds that eat these fish may have PCB levels that are at least ten times higher than those found in the lake fish. This aquatic ecosystem offered an ideal opportunity to study biomagnification because PCB generally exists at low concentrations in this environment, but apex predators accumulated very high concentrations of the toxin.
Persistent Organic Pollutants (POPs)
Persistent organic pollutants (POPs) are a group of organic chemicals that pose risks to human health and ecosystems. Examples include the pesticide dichlorodiphenyltrichloroethane (DDT) and the industrial chemicals polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS). The contaminant in Agent Orange (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) is another POP (see The Scientific Method). Persistent organic pollutants have the following three characteristics:
• Persistent: POPs are chemicals that last a long time in the environment. Some may resist breakdown for years and even decades while others could potentially break down into other toxic substances.
• Bioaccumulative: POPs can accumulate in animals and humans, usually in fatty tissues and largely from the food they consume. As these compounds move up the food chain, they concentrate to levels that could be thousands of times higher than acceptable limits.
• Toxic: POPs can cause a wide range of health effects in humans, wildlife and fish. They have been linked to effects on the nervous system, reproductive and developmental problems, suppression of the immune system, cancer, and endocrine disruption. The deliberate production and use of most POPs has been banned around the world, with some exemptions made for human health considerations (for example, DDT for malaria control) and/or in very specific cases where alternative chemicals have not been identified. However, the unintended production and/or the current use of some POPs continue to be an issue of global concern. Even though most POPs have not been manufactured or used for decades, they continue to be present in the environment and thus potentially harmful. The same properties that originally made them so effective, particularly their stability, make them difficult to eradicate from the environment.
The relationship between exposure to environmental contaminants such as POPs and human health is complex. There is mounting evidence that these persistent, bioaccumulative and toxic chemicals (PBTs) cause long-term harm to human health and the environment. Drawing a direct link, however, between exposure to these chemicals and health effects is complicated, particularly since humans are exposed on a daily basis to many different environmental contaminants through the air they breathe, the water they drink, and the food they eat. Numerous studies link POPs with a number of adverse effects in humans. These include effects on the nervous system, problems related to reproduction and development, cancer, and genetic impacts. Moreover, there is mounting public concern over the environmental contaminants that mimic hormones in the human body (endocrine disruptors).
Through atmospheric processes, they are deposited onto land or into water ecosystems where they accumulate and potentially cause damage. From these ecosystems, they evaporate, again entering the atmosphere, typically traveling from warmer temperatures toward cooler regions. They condense out of the atmosphere whenever the temperature drops, eventually reaching highest concentrations in circumpolar countries. Through these processes, POPs can move thousands of kilometers from their original source of release in a cycle that may last decades.
As with humans, animals are exposed to POPs in the environment through air, water and food. POPs can remain in sediments for years, where bottom-dwelling creatures consume them and who are then eaten by larger fish. Because tissue concentrations can biomagnify at each level of the food chain, top predators, including whales, seals, polar bears, birds of prey, tuna, swordfish and bass may have a million times greater concentrations of POPs than the water itself. Once POPs are released into the environment, they may be transported within a specific region and across international boundaries transferring among air, water, and land.
While generally banned or restricted (figure \(\PageIndex{e}\)), POPs make their way into and throughout the environment on a daily basis through a cycle of long-range air transport and deposition called the “grasshopper effect.”The “grasshopper” processes begin with the release of POPs into the environment. When POPs enter the atmosphere, they can be carried with wind currents, sometimes for long distances.
What Are the Health Effects of Toxins?
A toxin's effect is determined by many factors. Firstly, the same toxin and the same concentration can affect individuals differently depending on age, overall health, genetics, gender, and other factors. For example, young children are especially susceptible to heavy metals and bisphenol A (BPA). Additionally, as many toxins are processed by the liver, and liver function decreases with age, elderly individuals are more susceptible to certain toxins. Similarly, an generally health individual is likely to withstand exposure toxins better than someone facing other health concerns. Regarding genetics, some individuals may have versions of genes that make them more susceptible or resistant to certain toxins. In addition to individual factors, the length of exposure, presence of other toxins, and concentration (dosage) all impact toxicity
Acute vs. Chronic Effects
An acute effect of a toxin is one that occurs rapidly after exposure to a large amount of that substance. A chronic effect of a contaminant results from exposure to small amounts of a substance over a long period of time. In such a case, the effect may not be immediately obvious. Chronic effects are difficult to measure, as the effects may not be seen for years. Long-term exposure to cigarette smoking, low-level radiation exposure, and moderate alcohol use are all thought to produce chronic effects.
Toxicological Interactions
Exposure to multiple chemicals simultaneously can result in a variety of effects, or chemical interactions (figure \(\PageIndex{f}\)). These can apply to any chemicals that affect the body, including drugs and toxins (in the latter case, they are called toxicological interactions.) If the effect of the two chemicals combined is the sum of their individual effects, the chemical interaction is called an additive effect. Suppose that drug A and drug B have the same effect on the body (for example, each increasing heart rate by five beats per minute). An additive effect would occur if taking both drugs together increased the heart rate by 10 beats per minute. For example, toluene and xylene, which are both found in solvents and paints have an additive effect. Each causes eye, nose, and throat irritation, dizziness, headaches, and confusion. A study found that their combined effects on memory, cognitive function, and coordination was roughly equal to the sum of their individual effects.
In contrast, if taking both drugs A and B simultaneously increased heart rate by less than 10 beats per minute (less than their sum), their interaction would be considered an antagonistic effect, indicating that they interfere with each other. For example, ethanol (found in alcoholic beverages) and methanol (wood alcohol) both have toxic effects, but methanol is more immediately damaging. When methanol is ingested, they body converts it to dangerous compounds that cannot be easily removed from the body. Ethanol can used to treat methanol poisoning because it blocks the enzymes that facilitate these reactions, providing the body an opportunity to eliminate the methanol.
If combining drugs A and B increased heart rate more than 10 beats per minute, their interaction would be a synergistic effect; that is, their combined effect was greater than the sum of their individual effects. For example, smoking combined with asbestos exposure have a synergistic effect in causing lung cancer.
The Dose-Response Curve
For centuries, scientists have known that just about any substance is toxic in sufficient quantities. It is a thus common saying among toxicologists that "the dose makes the poison". In fact, too high a dosage (amount) of an otherwise helpful drug can cause negative health effects or even death. Similarly, small amounts of selenium are required by living organisms for proper functioning, but large amounts may cause cancer.
The effect of a certain chemical on an individual depends on the dose of the chemical. This relationship is often illustrated by a dose-response curve, which shows the relationship between dose and the response of the individual. Lethal doses in humans have been determined for many substances from information gathered from records of homicides, accidental poisonings, testing on animals, and experiments on cell cultures. A dose that is lethal to 50% of a population of test animals is called the lethal dose-50%, or LD50 (Table \(\PageIndex{b}\)). Determination of the LD50 is required for new synthetic chemicals in order to give a measure of their toxicity. Because a single conventional LD50 test may kill as many as 100 animals, the United States and other members of the Organization for Economic Cooperation and Development agreed in December 2000 to phase out the LD50 test in favor of alternatives that greatly reduce (or even eliminate) deaths of the test animals.
Table \(\PageIndex{b}\): The LD50 values for some insecticides. In each case, the chemical was fed to laboratory rats. Note that the lower the LD50, the more toxic the chemical.
Chemical Category Oral LD50 in Rats
(mg/kg)
Aldicarb ("Temik") Carbamate 1
Carbaryl ("Sevin") Carbamate 307
DDT Chlorinated hydrocarbon 87
Dieldrin Chlorinated hydrocarbon 40
Diflubenzuron ("Dimilin") Chitin inhibitor 10,000
Malathion Organophosphate 885
Methoprene JH mimic 34,600
Methoxychlor Chlorinated hydrocarbon 5,000
Parathion Organophosphate 3
Piperonyl butoxide Synergist 7,500
Pyrethrins Plant extract 200
Rotenone Plant extract 60
A dose that causes 50% of a population to exhibit any significant response, whether therapeutic or harmful (hair loss, stunted development, etc.), is referred to as the effective dose-50%, or ED50 (figure \(\PageIndex{h}\)). Some toxins have a threshold dose below which there is no apparent effect on the exposed population, called the no-observed-adverse-effect level (NOAEL; figure \(\PageIndex{i}\)). The lowest dose at which any negative effect is apparent is called the lowest-observed-adverse-effect level (LOAEL). Between NOAEL and LOAEL, there may be a noticeable but harmless effect.
Human Health, Environmental, and Economic Effects of Pesticide Use in Potato Production in Ecuador
The International Potato Center (CIP) conducted an interdisciplinary and inter-institutional research intervention project dealing with pesticide impacts on agricultural production, human health, and the environment in Carchi, Ecuador. Carchi is the most important potato-growing area in Ecuador, where smallholder farmers dominate production. They use tremendous amounts of pesticides for the control of the Andean potato weevil and the late blight fungus. Virtually all farmers apply highly hazardous pesticides (classified by the World Health Organization as class Ib) using hand pump backpack sprayers (figure \(\PageIndex{g}\)). The LD50 for class Ib pesticides is 5-50 or 20-200 mg/kg for oral ingestion in solid or liquid form, respectively. For dermal (skin) exposure, the LD50 is 10-100 or 40-400 mg/kg for solids and liquids, respectively. The LD50 class III pesticides, which are considered only slightly hazardous, is at least 10 times greater that that for class Ib pesticides.
The study found that the health problems caused by pesticides are severe and are affecting a high percentage of the rural population. Despite the existence of technology and policy solutions, government policies continue to promote the use of pesticides. The study conclusions concurred with those by the pesticide industry, “that any company that could not ensure the safe use of highly toxic pesticides should remove them from the market and that it is almost impossible to achieve safe use of highly toxic pesticides among small farmers in developing countries.”
Source: Yanggen et al. 2003.
Precautionary Principle
Determining a safe dosage from a dose-response curve employs the precautionary principle, which put simply, embodies the phrase “It’s better safe than sorry.” Actions that follow the precautionary principle allow margin to ensure safety in the case that a toxin or drug is later found to have negative effect at a lower dosage than first detected. The safe dosage is often set to 1% or even 0.1% of the NOAEL.
The precautionary principle is sometimes applied to other components of environmental toxicology. For example in the European Union (EU), manufacturers must demonstrate the safety of their product before it is sold. While this is also required in the U.S. for chemicals that have not been used before, there is no such rule for existing products. It is instead the responsibility of Environmental Protection Agency to demonstrate that products already on the market are unsafe before banning them. In summary, the precautionary principle is applied to regulating potential toxins in products in both the EU and U.S.; however, the EU's applies the precautionary principle more broadly. The EU errors on the side of caution, potentially banning chemicals that are harmless until they are proven safe, but the U.S. risks exposure to potential toxins before their safety is determined.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.04%3A_Environmental_Toxicology.txt |
Public Health Organizations
A large number of international programs and agencies are involved in efforts to promote global public health. Among their goals are developing infrastructure in health care, public sanitation, and public health capacity; monitoring infectious disease occurrences around the world; coordinating communications between national public health agencies in various countries; and coordinating international responses to major health crises. In large part, these international efforts are necessary because disease-causing microorganisms know no national boundaries.
International public health issues are coordinated by the World Health Organization (WHO), an agency of the United Nations. Of its roughly \$4 billion budget for 2015–16, about \$1 billion was funded by member states and the remaining \$3 billion by voluntary contributions. In addition to monitoring and reporting on infectious disease, WHO also develops and implements strategies for their control and prevention. WHO has had a number of successful international public health campaigns. For example, its vaccination program against smallpox, begun in the mid-1960s, resulted in the global eradication of the disease by 1980. WHO continues to be involved in infectious disease control, primarily in the developing world, with programs targeting malaria, HIV/AIDS, and tuberculosis, among others. It also runs programs to reduce illness and mortality that occur as a result of violence, accidents, lifestyle-associated illnesses such as diabetes, and poor health-care infrastructure.
WHO maintains a global alert and response system that coordinates information from member nations. In the event of a public health emergency or epidemic, it provides logistical support and coordinates international response to the emergency. The United States contributes to this effort through the Centers for Disease Control and Prevention (CDC), an agency of the Department of Health and Human Services (figure \(\PageIndex{a}\)). The CDC carries out international monitoring and public health efforts, mainly in the service of protecting US public health in an increasingly connected world. Similarly, the European Union maintains a Health Security Committee that monitors disease outbreaks within its member countries and internationally, coordinating with WHO.
One way that the CDC carries out this mission is by overseeing the National Notifiable Disease Surveillance System (NNDSS) in cooperation with regional, state, and territorial public health departments. The NNDSS monitors diseases considered to be of public health importance on a national scale. Such diseases are called notifiable diseases or reportable diseases because all cases must be reported to the CDC. A physician treating a patient with a notifiable disease is legally required to submit a report on the case. Notifiable diseases include HIV infection, measles, West Nile virus infections, and many others. Some states have their own lists of notifiable diseases that include diseases beyond those on the CDC’s list.
Notifiable diseases are tracked by epidemiological studies and the data is used to inform health-care providers and the public about possible risks. The CDC publishes the Morbidity and Mortality Weekly Report (MMWR), which provides physicians and health-care workers with updates on public health issues and the latest data pertaining to notifiable diseases. Table \(\PageIndex{a}\) is an example of the kind of data contained in the MMWR.
Table \(\PageIndex{a}\): Incidence of Four Notifiable Diseases in the United States, Week Ending January 2, 2016
Disease Current Week (Jan 2, 2016) Median of Previous 52 Weeks Maximum of Previous 52 Weeks Cumulative Cases 2015
Campylobacteriosis 406 869 1,385 46,618
Chlamydia trachomatis infection 11,024 28,562 31,089 1,425,303
Giardiasis 115 230 335 11,870
Gonorrhea 3,207 7,155 8,283 369,926
The current Morbidity and Mortality Weekly Report is available online.
Strategies for Reducing Environmental Hazards
Providing access to clean water is an important strategy for reducing environmental hazards. Because lack of clean water is responsible for diarrheal and other infectious diseases, particular in developing countries, access to clean water limits disease spread (a biological hazard). Furthermore, clean water reduces exposure to toxins (chemical hazards). This can be achieved through digging wells and establishing water treatment facilities. Improving sanitation and hygiene (for example, by supplying latrines, [figure \(\PageIndex{b}\)] and handwashing stations) further reduces the spread of infectious disease.
In Sub-Saharan Africa and South Asia, the use of pipe filters helped eradicate Guinea worm disease, which is caused by a parasitic worm. People are infected by this disease when they drink water contaminated by small animals called copepods that house the larvae. Once in the body, the larvae mature in the abdomen, and adult worms eventually (and painfully) exit through the skin. If an infected person enters a body of water at this stage, adult worms release more larvae into the water, continuing their life cycle. Pipe filters are straw-like structures that contain openings small enough to allow the passage of water but not copepods, preventing infection.
Another strategy to limit exposure to biological hazards is to reduce exposure to disease vectors. Depending on the specific vector and disease this could involve removing standing water (which facilitates mosquito reproduction), application of pesticides, or use of netting (figure \(\PageIndex{c}\)). Biological control is also slowly emerging in vector control in public health and in areas that for a long time mainly focused on chemical vector control of the Anopheles mosquito (the vector of malaria) and the black fly (the vector of river blindness, caused by a parasitic worm). The release of sterile males has been used to control the tsetse fly, the vector of African sleeping sickness. Vaccinating animals that harbor diseases (reservoirs) can also limit the chance of infection.
Because air pollution exposes individuals to toxins, limiting air pollution is another means of reducing environmental hazards. This can involve energy conservation, using clean energy, such as solar or wind (rather than burning fossil fuels), enforcing air pollution standards on industry, and implementing pollution-reducing technologies, at an industry or household scale. A main source of indoor air pollution is cooking using a fire indoors. Solar ovens provide a pollution-free alternative for people who do not have access to electricity or gas for cooking (figure \(\PageIndex{d}\)).
The public have an important role in environmental hazard reduction. Firstly, the public must engage in behaviors to prevent disease spread and minimize contact with toxins, and public health education is critical to this. In the case of Guinea worm disease, individuals learned how to use pipe filters and shy they must avoid submerging wounds from the worms in bodies of water to limit disease spread. In the case of COVID-19, individuals are learning to reduce disease transmission by employing frequent handwashing, mask wearing, and social distancing (figure \(\PageIndex{e}\)).
The public can also support policies that reduce exposure to environmental hazards. For example, many states have laws that reduce exposure to secondhand smoke. The Toxic Substances Control Act (TSCA) bans or regulates harmful chemicals, such as asbestos and heavy metals (figure \(\PageIndex{f}\))..
Many strategies for reducing environmental health hazards directly align with the United Nations Sustainable Development Goals, particularly goals 3 (Good Health and Well-Being) and 6 (Clean Water and Sanitation).
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.05%3A_Environmental_Hazard_Reduction.txt |
Overview
The World Health Organization (WHO) seeks to promote health and safety for humanity, especially the most vulnerable. What this means is they do everything from basic primary care, to research, to data inventory, to health education, and to many other imperative health initiatives worldwide. When it comes to data, they keep up to date records for chronic and acute diseases, especially those that can cause global/local health emergencies. Generally, the WHO tracks the number of cases (infection rates) and case fatalities for each disease. However, there are many other statistics they can analyze depending on the level of accuracy and detail of the data they receive. They can also break up or group their statistics by country or by continent (as you see below). In addition, the WHO can be a great database for researchers around the globe. Below is a graph created by WHO data on cholera from a 2019 publication about cholera epidemiology:
Questions
1. What kind of graph is this?
2. What is the independent (explanatory) variable and the dependent (response) variable?
3. Which continent has the most consistent cholera cases?
4. Describe the patterns you see in cholera cases for the Americas and Asia from 1989 to 2017.
5. In what ways do you think the WHO uses data observed in the graph above to make choices into the future? Provide at least two ideas/examples.
Raw Data For Above Graph(s)
Raw data table link for above graph. (CC-BY4.0)
Attribution
Rachel Schleiger (CC-BY-NC)
4.4.07: Review
Summary
After completing this chapter you should be able to...
• Compare traditional and modern environmental hazards.
• Provide examples of biological, chemical, and physical hazards.
• Distinguish between morbidity and mortality.
• Distinguish between disease prevalence and incidence.
• Compare sporadic, endemic, epidemic, and pandemic patterns of incidence.
• Compare contact, vector, and vehicle modes of transmission and provide examples of how environmental degradation has increased transmission.
• Identify examples of emerging and reemerging infectious diseases.
• Briefly explain how vaccines work and their role in eradicating infectious diseases.
• Describe how antibiotic resistance evolves.
• Identify the three main routes of exposure to chemicals.
• Identify and define five factors that impact a chemical's safety.
• Compare additive, antagonistic, and synergistic toxicological interactions.
• Explain how the lethal dose-50% is determined from a dose-response curve.
• Provide examples of strategies for reducing environmental hazards.
Environmental health focuses on how the natural and human-built surroundings as well as behaviors affect human well-being. Traditional hazards are related to poverty and mostly affect low-income people and those in developing countries whereas modern hazards result from technological development and prevail in industrialized countries. Environmental health hazards are classified as biological (infectious diseases), chemical (exposure to toxins), or physical.
Epidemiology is the science underlying public health. Morbidity means being in a state of illness, whereas mortality refers to death; both morbidity rates and mortality rates are of interest to epidemiologists. Incidence is the number of new cases (morbidity or mortality), usually expressed as a proportion, during a specified time period; prevalence is the total number affected in the population, again usually expressed as a proportion. Sporadic diseases only occur rarely and largely without a geographic focus. Endemic diseases occur at a constant (and often low) level within a population. Epidemic diseases and pandemic diseases occur when an outbreak occurs on a significantly larger than expected level, either locally or globally, respectively. Diseases may be spread through contact transmission (direct physical interaction or indirect interaction through shared objects), vehicle transmission (through water, food, or air), or vector transmission (by an animal). Ecosystem degradation can exacerbate disease spread through creating conditions where vectors, pathogens, or reserviors thrive.
Emerging and reemerging diseases have been defined as infectious diseases of humans whose occurrence during the past two decades has substantially increased or threatens to increase in the near future relative to populations affected, geographic distribution, or magnitude of impacts. Vaccination has been used to successfully eradicate several infectious diseases by stimulating a specific immune response. For remaining diseases that are commonly treated with medications, antibiotic resistance continues to be a global problem. New forms of antibiotic resistance can cross international boundaries and spread between continents.
Environmental toxicology is the scientific study of the health effects associated with exposure to toxins. The three mains routes of exposure to toxins are inhalation, ingestion, and skin or eye contact. Potency, persistence, solubility, bioaccumulation, and biomagnification all affect a chemical's safety. Bioaccumulation refers to the buildup of a toxin over an individual's lifetime whereas biomagnification occurs to increasing concentrations of a toxin as it moves up the food chain. Toxins may interact with each other in an additive, antagonistic, or synergistic way. The potency of a toxin is measure by the lethal dose-50% (LD50), the concentration that is fatal to 50% of the test population. This is determined through a dose-response curve, which shows the percent of individuals affected as a function of concentration.
The World Health Organization (WHO) is an agency of the United Nations that collects and analyzes data on disease occurrence from member nations. WHO also coordinates public health programs and responses to international health emergencies. In the United States, the Centers for Disease Control and Prevention monitors notifiable diseases and publishes weekly updates in the Morbidity and Mortality Weekly Report. Strategies for reducing environmental hazards include providing access to clean water, improving sanitation and hygiene, and limiting exposure to disease vectors. The public serves an important role by engaging in behaviors that limit disease spread or exposure to toxins and supporting policies that limit environmental hazards.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/04%3A_Humans_and_the_Environment/4.04%3A_Environmental_Health/4.4.06%3A_Data_Dive-_Cholera_Cases_Worldwide.txt |
Energy for lighting, heating and cooling our buildings, manufacturing products, and powering our transportation systems comes from a variety of natural sources. Nonrenewable energy is finite and cannot be replenished within a human timescale. Examples include nuclear energy and fossil fuels. In contrast renewable resources are replenished on shorter time scales, and it is thus possible to use them indefinitely. All energy sources have and some environmental and health cost, and the distribution of energy is not equally distributed among all nations.
Attribution
Modified by Melissa Ha and Rachel Schleiger from Challenges and Impacts of Energy Use from Environmental Biology by Matthew R. Fisher (licensed under CC-BY)
• 16: Fossil Fuels
Fossil fuels are nonrenewable sources of energy that formed from ancient organisms. They include coal, oil, and natural gas. Coal is mined and then burned to produce heat to generate electricity. Oil and natural gas can be extracted through conventional wells or through unconventional methods, such as fracking. Fossil fuel use harms human health as well as the environment.
• 17: Nuclear Energy
Nuclear energy relies on radioactive isotopes, which are unstable. Nuclear reactions release heat, which can be harnessed into electricity. The use of nuclear energy is does not release greenhouse gases or significantly contribute to climate change. However, nuclear accidents, while rare, have severe and long-lasting impacts.
• 18: Renewable Energy
Renewable energy sources are replenished on short time scales and can thus be used indefinitely. Examples of renewable energy include wind, solar, geothermal, hydropower, and biofuels. The use of renewable energy, along with energy conservation, limits the environmental impact of energy use.
Thumbnail image - "Renewable energy on the grid" is in the Public Domain
05: Energy
Chapter Hook
Human use of coal dates back thousands of years, and archeologists have found evidence for its use and excavation across the globe. As such, it is impossible to know how coal’s utility was discovered. In the Americas, Aztecs used coal for fuels and decoration. In Europe, Romans were noted as early as the late 2nd century AD to be extracting coal and using it to smelt iron ore and heat their famous public baths. Coals earliest reference in writings was by a Greek scientist Theophrastus (c.371-267 BC) about its usage in metalworking. In Asia, the Chinese are known to have been mining and using coal as far back as 3490 BC. Overall, there is a deep history of human usage of coal. As there is a limited supply, it regrettably won’t last forever.
Figure \(\PageIndex{a}\): Fossil charcoal in weathered coal. Image by James St. John in Wikimedia Commons (CC-BY2.0)
• 16.1: Types of Fossil Fuels and Formation
Fossils fuels are extractable, nonrenewable sources of stored energy created by ancient ecosystems. The natural resources that typically fall under this category are coal, oil (petroleum), and natural gas. Coal formed from swamp vegetation, while oil and natural gas formed from marine microbes. In both cases, ancient organisms were transformed under high temperatures and pressures over millions of years.
• 16.2: Mining, Processing, and Generating Electricity
Coal is mined through surface mining or subsurface mining. Coal power plants generate electricity by combustion of coal and production of high-pressure steam, which turns a turbine. This powers a generator. Conventional oil and natural gas are extracted through drilling to piece the impervious rock that traps them. Fracking is a common approach for extracting unconventional oil and natural gas. Crude oil must be refined into petrochemicals, which each have a different function.
• 16.3: Fossil Fuel Consumption
We are heavily dependent on fossil fuels, which comprise 62.6% of electricity generation in the United States and 84.3% of global energy consumption. Coal reserves are abundant in the United States, but globally, proven oil and natural gas reserves are projected to last another 50 years.
• 16.4: Consequences of Fossil Fuels
Fossil fuels have met global and national energy needs for many years, but their use causes a range of human and environmental issues. Technologies and practices can reduce these negative impacts but do not eliminate them.
• 16.5: Data Dive- Global Fossil Fuel Consumption
• 16.6: Review
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
5.01: Fossil Fuels
Fossil fuels are nonrenewable sources of energy formed from the organic matter of plants and microorganisms that lived millions of years ago. This energy was originally captured via photosynthesis by living organisms such as plants, algae, and photosynthetic bacteria. Sometimes this is known as fossil solar energy since the energy of the sun in the past has been converted into the chemical energy within a fossil fuel. As discussed in Food Chains and Food Webs and Matter, the organic molecules store chemical energy, which is released when the higher energy (less stable) bonds in these molecules are broken to form lower energy (more stable) bonds. Fossil fuels are nonrenewable because their formation took millions of years. Furthermore, higher productivity in the ancient environment allowed for more fossil fuel accumulation, meaning that the fossil fuel reserves available now could not necessarily be regenerated millions of years in the future.
Fossil fuels are composed primarily of hydrocarbons (molecules of just carbon and hydrogen), but they contain lesser amounts nitrogen, sulfur, oxygen, and other elements as well. The precise chemical structures vary depending on the type of fossil fuel (coal, oil, or natural gas). The molecules in coal tend to be larger than those in oil and natural gas. Coal is thus solid at room temperature, oil is liquid, and natural gas is in a gaseous phase. Specifically, coal is a black or dark brown solid fossil fuel found as coal seams in rock layers formed from ancient swamp vegetation. Both oil and natural gas are fossil fuels found underground that formed from marine microorganisms. Oil (petroleum) is a liquid fossil fuel and consists of a variety of hydrocarbons while natural gas is a gaseous fossil fuel that consists of mostly methane and other small hydrocarbons.
Coal
Coal is the product of fossilized swamps, although some older coal deposits that predate terrestrial plants are presumed to come from algal buildups. Coal was formed when plant material is buried, heated, and compressed in oxygen-poor conditions over a long period of time (figure \(\PageIndex{a}\)). Millions of years ago, continents were in different locations with different climates, and swamp-like vegetation covered many regions. When the vegetation died, it could not fully decompose due to oxygen-poor conditions. Instead, it formed peat (a brown substance high in organic content). The peat was buried and formed coal after millions of years of high pressure and temperature. The pressure was from the weight of sediments as well as from continental collisions.
There are several different types of coal ranging in quality (figure \(\PageIndex{b}\)). The more heat and pressure that coal undergoes during formation, the greater is its fuel value and the more desirable is the coal. The general sequence of a swamp turning into the various stages of coal are as follows:
Swamp → Peat → Lignite → Subbituminous coal → Bituminous coal → Anthracitic coal → Graphite
Specifically, peat compacts to form solid rock through a process called lithification, producing lignite (brown coal, a low-quality form of coal). With increasing heat and pressure, lignite turns to subbituminous coal and bituminous coal. Lignite, subbituminous coal, and bituminous coal are considered sedimentary rocks because they from from compacted sediments. At very high heat and pressure, bituminous coal is transformed to anthracite, a high-grade coal that is the most desirable coal since it provides the highest energy output (figure \(\PageIndex{c}\)). Anthracite is considered a metamorphic rock because it has been compacted and transformed to the extent that it is denser than the other forms of coal and no longer contains sheet-like layers of sediments. With even more heat and pressure driving out all the components that evaporate easily and leaving pure carbon, anthracite can turn to graphite
Oil and Gas
Oil and natural gas formed from ancient marine microorganism (plankton). When plankton died, they were buried in sediments. As with coal, oxygen-poor conditions limited decomposition. As sediments continued to accumulate, the dead organisms were further buried. High temperature and pressure over millions of years ultimately produced oil and natural gas from these dead organisms.
As the rock forms from the sediments that originally trapped the plankton, the oil and gas leak out of the source rock due to the increased pressure and temperature, and migrate to a different rock unit higher in the rock column. If the rock is porous and permeable rock, then that rock can act as a reservoir for the oil and gas. Petroleum is usually found one to two miles (1.6 – 3.2 km) below the Earth’s surface, whether that is on land or ocean.
trap is a combination of a subsurface geologic structure and an impervious layer that helps block the movement of oil and gas and concentrates it for later human extraction. Traps pool the fluid fossil fuels into a configuration in which extraction is more likely to be profitable, and such fossil fuels are called conventional oil and natural gas (figure \(\PageIndex{e}\)). Extraction of oil or gas outside of a trap (unconventional oil and natural gas) is less efficient and more expensive; sometimes it is not economically viable at all (does not produce a profit). Examples of unconventional fossil fuels include oil shale, tight oil and gas, tar sands (oil sands), and coalbed methane.
Oil Shale
Oil shale is a fine-grained sedimentary rock that sometimes contains kerogen, a solid material from which petroleum products can ultimately be manufactured. In order extract the fossil fuels, the material has to be mined and heated, which is expensive and typically has a negative impact on the environment.
Tight Oil and Natural Gas
Tight oil and natural gas are also trapped in shale rock, fine-grained sedimentary rocks with relatively high porosity and low permeability. They differ from oil shale in that they can be extracted through a process called hydraulic fracturing (fracking)
Similarly, fracking can be used to extract natural gas from tight sands, which are gas-bearing, fine-grained sandstones or carbonates (rocks made of minerals containing carbonate, CO32-) with a low permeability.
Tar Sands
Tar sands, or oil sands, are sandstones that contain petroleum products that are highly viscous (like tar), and thus, can not be drilled and pumped out of the ground, unlike conventional oil (figure \(\PageIndex{f}\)). The fossil fuel in question is bitumen, which can be pumped as a fluid only at very low rates of recovery and only when heated or mixed with solvents. Thus, injections of steam and solvent or mining of the tar sands for later processing can be used to extract the tar from the sands. (See related information about strip mining with respect to coal in Mining, Processing, and Generating Electricity.) Alberta, Canada is known to have the largest reserves of tar sands in the world.
Coalbed Methane
Some natural gas is also found associated with coal deposits (coalbed methane), consisting of methane produced during coal formation.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.01%3A_Fossil_Fuels/5.1.01%3A_Types_of_Fossil_Fuels_and_Formation.txt |
Fossil fuels must be extracted or mined before use, and the specific method depends on the type of fossil fuel. Coal and natural gas and primarily used for electricity generation, while petroleum is refined to produce fuel for vehicles, planes, and heating as well as other products.
Coal
Mining
Coal is extracted by two principal methods, of which there are many variants: surface mining or subsurface mining. Surface mining uses large machines to remove the soil and layers of rock known as overburden to expose coal seams that are close to the Earth’s surface (figure \(\PageIndex{a}\)). Strip mining is a type of surface mining in which overburden is sequentially removed from each stretch (strip) of land. Once overburden is removed from the first strip, coal is removed. Overburden from the second strip is then deposited into the first strip, and coal is removed from the second strip. Overburden from the third strip is then placed in the first strip, and so on. Mountaintop removal is a more destructive type of surface mining in which all of the overburden is removed with explosives, revealing the entire coal seam at once (figure \(\PageIndex{b}\)). The large mass of overburden (the mountaintop) is dumped into a nearby valley, and the coal is them removed.
Subsurface mining (deep mining) employs underground tunnels to access deeper deposits (figure \(\PageIndex{c}\)). Some underground mines are thousands of feet deep, and extend for miles. Miners ride elevators down deep mine shafts and travel on small trains in long tunnels to get to the coal. The miners use large machines that dig out the coal. In drift mines, a tunnel is dug horizontally into the side of a mountain. In slope mines, this tunnel is diagonal. In shaft mines, elevators are used to move coal through vertical tunnels.
Processing of Coal
Once mined, coal may go to a preparation plant located near the mining site where it is cleaned and processed to remove impurities such as rocks and dirt, ash, sulfur, and other unwanted materials. This process increases the amount of energy that can be obtained from a unit of coal, known as its heating value.
Transport of Coal
Finally, the mined and processed coal must be transported. Transportation can be more expensive than mining the coal. Nearly 70% of coal delivered in the United States is transported, for at least part of its trip, by train (figure \(\PageIndex{e}\)). Coal can also be transported by barge, ship, or truck. Coal can also be crushed, mixed with water, and sent through a slurry pipeline. Sometimes, coal-fired electric power plants are built near coal mines to lower transportation costs.
Generating Electricity from Coal
Once at the power plant, coal is first pulverized into a fine powder and then mixed with hot air and blown into a furnace (figure \(\PageIndex{f}\)). This allows for the most complete combustion (burning) and maximum heat release. Purified water, pumped through pipes inside a boiler, is turned into steam by the heat from the combustion of coal. The high pressure of the steam pushing against a series of giant turbine blades turns the turbine shaft. The turbine shaft is connected to the shaft of the generator, where magnets spin within wire coils to produce electricity. After doing its work in the turbine, the steam is drawn into a condenser, a large chamber in the basement of the power plant. In this important step, millions of gallons of cool water from a nearby source (such as a river or lake) are pumped through a network of tubes running through the condenser. The cool water in the tubes converts the steam back into water that can be used over and over again in the plant. The cooling water is returned to its source without any contamination except at a higher temperature than when first extracted from the river or lake.
This video shows how heat energy can be used to generate electricity.
Oil and Natural Gas
Extraction of Conventional Oil and Natural Gas
Conventional oil and natural gas are contained under a trap (cap rock). Because natural gas consists of lighter molecules that are in a gaseous form at moderate temperatures, it is found on top of the oil, which may be floating on groundwater. To access conventional oil and natural gas, the trap is first pierced. Initially, they are under high enough pressure, and this drives them out of the well (primary recovery). Next, water (or gas) is injected to force more fossil fuels out (secondary recovery). Finally, enhanced oil recovery (tertiary recovery) may be used to extract further oil by applying heat (injecting steam) or injecting carbon dioxide, other gases, or larger molecules. For example, carbon dioxide causes the oil to thin and expand, making it easier to remove from the rocks. Note that secondary recovery simply increases pressure inside the reservoir whereas tertiary recovery changes the properties of the oil, making it easier to extract (figure \(\PageIndex{g}\)). Each stage of recovery is increasingly expensive, and extraction from a well continues as long as it remains profitable.
Oil is mainly obtained by drilling either on land (onshore) or in the ocean (offshore). Early offshore drilling was generally limited to areas where the water was less than 300 feet deep. Oil and natural gas drilling rigs now operate in water as deep as two miles. Floating platforms are used for drilling in deeper waters (figure \(\PageIndex{h}\)). These self-propelled vessels are attached to the ocean floor using large cables and anchors. Wells are drilled from these platforms which are also used to lower production equipment to the ocean floor. Some drilling platforms stand on stilt-like legs that are embedded in the ocean floor. These platforms hold all required drilling equipment as well as housing and storage areas for the work crews. Offshore production is much more expensive than land-based production.
Extraction of Unconventional Oil and Natural Gas
Tight oil and natural gas trapped in shale as well as natural gas in tight sands are extracted via hydraulic fracturing, informally referred to as “fracking”. This process uses explosives to create new fractures in these low-permeability rocks as well as increase the size, extent, and connectivity of existing fractures and then applies high-pressure fluid. First, a drill permeates the rock layers and then proceeds horizontally. Explosives then fracture rocks, freeing oil and natural gas. Finally, water, sand, and chemicals and injected, which flush out oil and natural gas (figure \(\PageIndex{i}\)).
As mentioned previously, bitumen in tar sands can be extracted by injecting steam, or they may be mined for later processing. Tar sands can mined through strip mining or open-pit mining, a type of surface mining that involves forming a progressively deeper hole. The walls of the pit are as steep as can safely be managed. A steep wall means there is less waste overburden to remove and is an engineering balance between efficient mining and mass wasting. Oil shale is extracted by strip mining, creating subsurface mines, or open-pit mining. Oil shale can be burned directly like coal or baked in the presence of hydrogen to extract liquid petroleum (figure \(\PageIndex{j}\)).
Refining Crude Oil
The result of oil recovery is crude oil (petroleum), which contains many types of hydrocarbons as well as some unwanted substances such as sulfur, nitrogen, oxygen, dissolved metals, and water all mixed together. Unprocessed crude oil is therefore, not generally useful in industrial applications and must first be separated into different useable products (petrochemicals) at a refinery. Gasoline (petrol), diesel, tar, and asphalt are examples of petrochemicals.
Fractional distillation is the key process used in oil refineries to separate the components of crude oil. During fractional distillation, crude oil is heated and then allowed to cool. The heaviest compounds sink to the bottom as residues. Components of vaporized crude oil condense at different levels in the distillation column depending on their boiling points, which is primarily due to their molecular sizes. The heaviest compounds (condense near the bottom of the column, where the temperature is still high. Lighter compounds condense at cooler temperatures higher up in the column. Some compounds remain as gases at the top of the column (figure \(\PageIndex{k}\)).
The video below explains the process of fractional distillation. The labeled distillation column at 3:00 shows heated crude oil (400 °C) separating into various petrochemicals. From bottom to top, they are bitumen (> 350 °C), diesel (250-350 °C), kerosene (160-250 °C), naphtha (70-160 °C), petrol (20-70 °C), and gas (< 20 °C).
Conversion is the chemical processing in which some of the fractions (produced from fractional distillation) are transformed in to other products. For example, a refinery can turn diesel fuel into gasoline depending on the demand for gasoline. Conversion can involve breaking larger hydrocarbon chains into smaller ones (cracking), combining smaller chains into larger ones (unification), or rearranging the molecules to created desired products (alteration).
Treatment is done to the fractions to remove impurities such as sulfur, nitrogen and water among others. Refineries also combine the various fractions (processed and unprocessed) into mixtures to make desired products. For example, different mixtures of hydrocarbon chains can create gasolines with different octane ratings, with and without additives, lubricating oils of various weights and grades (WD-40, 10W-40, 5W-30, etc.), heating oil, and many others. The products are stored onsite until they can be delivered to various markets such as gas stations, airports and chemical plants.
A 42 U.S. gallon barrel of crude oil yields about 45 gallons of petroleum products because of refinery processing gain (figure \(\PageIndex{l}\)). This increase in volume is similar to what happens to popcorn when it is popped. Gasoline makes up the largest fraction of all petroleum products obtained. Other products include diesel fuel and heating oil, jet fuel, petrochemical feedstocks (to manufacture plastics, synthetic rubber, or other chemicals), waxes, lubricating oils, and asphalt.
Transporting Oil and Natural Gas
After the refinery, the gasoline and other fuels created are ready to be distributed for use. A system of pipelines runs throughout the United States to transport oil and fuels from one location to another. There are pipelines that transport crude oil from the oil well to the refinery. At the refinery, there are additional pipelines that transport the finished product to various storage terminals where it can then be loaded onto trucks for delivery, such as to a gas station.
Once natural gas is produced from underground rock formations, it is sent by pipelines to storage facilities and then on to the end user. The United States has a vast pipeline network that transports gas to and from nearly any location in the lower 48 states. There are more than 210 natural gas pipeline systems, using more than 300,000 miles of interstate and intrastate transmission pipelines (figure \(\PageIndex{m}\)). Compressor stations that maintain pressure on the natural gas to keep it moving through the system. There are more than 400 underground natural gas storage facilities that can hold the gas until it is needed back in the system for delivery.
Generating Electricity from Oil or Natural Gas
Natural gas is burned to produce electricity following the same general process used in a coal power plant (figure \(\PageIndex{n}\)). Oil is occasionally used to generate electricity as well.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.01%3A_Fossil_Fuels/5.1.02%3A_Mining_Processing_and_Generating_Electricity.txt |
The U.S. and the world overall heavily depend on fossil fuels. In 2019, fossil fuels contributed to 62.6% of electricity generation in the U.S. with coal contributing 23.4% and natural gas contributing 38.4% (table \(\PageIndex{a}\)). Note that oil (petroleum) is primary used for transportation and thus only contributes a fraction of a percentage to electricity generation. With respect to total energy consumption, the world continues to rely on crude oil more than any other energy source (33.1%) followed by coal (27%) and natural gas (24.3%; figure\(\PageIndex{a}\)).
Table \(\PageIndex{a}\): Contribution of Each Energy Source to Electricity Generation in the U.S. in 2019
Energy source
Contribution to Electricity Generation (%)
Fossil fuels (total) 62.6%
Natural gas
38.4%
Coal
23.4%
Petroleum (total)
0.4%
Other gases
0.3%
Nuclear
19.6%
Renewables (total)
17.6%
Hydropower
7.0%
Wind
7.1%
Biomass (total)
1.4%
Solar (total)
1.7%
Geothermal
0.4%
Table modified from U.S. Energy Information Administration (public domain).
Figure\(\PageIndex{a}\): The top graph shows global energy consumption by source shows energy consumption in terrawatt-hours (TWh) on the y-axis and time in years (1800-2017) on the X-axis. The bottom graph shows the percentage that each energy source contributes to global energy consumption in 2019. Global consumption of most energy sources has increased over time. Consumption of crude oil is the highest (33.1% of global energy consumption in 2019), and it increased rapidly in the 1950s, surpassing coal consumption in the early 1960s. Coal is now the second most-consumed energy source (27%), but its global consumption has declined in recent years. Natural gas is the third most-consumed energy source (24.3%) and has also been increasing. Coal and natural gas consumption surpassed that of traditional biofuels in the early 1900s and 1970, respectively. Nuclear energy consumption has decreased recently, accounting for 4.3% of global energy consumption in 2019. Consumption of renewable energy overall (11.4%) is low compared to fossil fuels (84.3% combined), but it has generally increased in recent years. Images by Our World in Data (CC-BY).
Coal has been used by humans for at least 6000 years, mainly as a fuel source. Coal resources in Wales are often cited as a primary reason for the rise of Britain (and later, the United States) in the Industrial Revolution. Coal electricity traces its origins to the early 20th Century, when it was the natural fuel for steam engines given its abundance, high energy density and low cost. Coal is the largest domestically produced source of energy. At the end of 2018, BP estimated at 734,903 million tonnes, with nearly 23.7% of that in the United States. It is a major fuel resource that the United States controls domestically.
Proven oil reserves (or natural gas reserves) refers to the amount of oil or natural gas that can be extracted economically with current methods (such as conventional wells or fracking). The U.S. Energy Administration estimates that there are enough liquid fuels to last through 2050 (and they include biofuels in this projection). In 2016, BP projected that proven reserves of oil and natural gas can support global demands for another 50 years. Additionally, they estimate that coal reserves can last another 115 years.
Scientists and policy-makers often discuss the question of when the world will reach peak oil production, the point at which oil production is at its greatest and then declines. It was initially predicted that global peak oil would be reached in 2000, but oil production and consumption continue to rise. The United States, however, already passed peak oil production in 1970.
The concentration of oil reserves in a few regions of the world makes much of the world dependent on imported energy for transportation (figure\(\PageIndex{b}\)). The rise in the price of oil in the last decade makes dependence on imported energy for transportation an economic as well as an energy issue. The United States spent \$304.9 billion on oil imports in 2019. The United States has become more and more dependent on foreign oil since 1970 when our own oil production peaked.
The major holder of oil reserves is the Organization of Petroleum Exporting Countries, (OPEC). As of 2018, there were 15 member countries in OPEC: Algeria, Angola, Congo, Ecuador, Equatorial Guinea, Gabon, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. OPEC attempts to influence the amount of oil available to the world by assigning a production quota to each member except Iraq, for which no quota is presently set.
Overall compliance with these quotas is mixed since the individual countries make the actual production decisions. All of these countries have a national oil company but also allow international oil companies to operate within their borders. They can restrict the amounts of production by those oil companies. Therefore, the OPEC countries have a large influence on how much of world demand is met by OPEC and non-OPEC supply.
This pressure has lead the United States to developing policies that would reduce reliance on foreign oil such as developing additional domestic sources and obtaining it from non-Middle Eastern countries such as Canada, Mexico, Venezuela, and Nigeria. However, since fossil fuel reserves create jobs and provide dividends to investors, a lot is at stake in a nation that has oil reserves. Oil wealth may be shared with the country’s inhabitants or retained by the oil companies and dictatorships, such as in Nigeria prior to the 1990s.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.01%3A_Fossil_Fuels/5.1.03%3A_Fossil_Fuel_Consumption.txt |
Benefits of Using Fossil Fuels
The world is heavily dependent on fossil fuels, and existing infrastructure and technologies facilitate their continued use. An advantage of using coal for electricity is that it plentiful and inexpensive, especially in the United States, which has larger coal reserves than any other country. Furthermore, coal mining is a source of jobs and tax income. Coal's economic advantage is dwindling, however, as technologies associated with renewable sources of energy, such as solar and wind, become more efficient and inexpensive. The U.S. Energy Information Administration compared the levelized cost of electricity (LCOE) for technologies that will begin use in 2023, and the cost of coal-generated electricity exceeded that of many renewable sources (figure \(\PageIndex{a}\)). The LCOE accounts for the building and operation costs of power plants, solar panels, wind turbines, etc.
Oil and natural gas continue to meet global energy needs. Despite expansions in renewable energy use, no alternative energy source is currently sufficient to replace oil and natural gas. (A combination of different renewable sources could be possible in the future.) While the United States does rely on imported oil, it continues to produce some oil and natural gas (mostly through fracking), bolstering U.S. energy independence. Local and state economics in regions rich in oil and natural reserves depend on continued extraction of these fossil fuels.
While all fossil fuels harm cause some degree of environmental harm, natural gas is a preferred fossil fuel for electricity generation when considering its environmental impacts. When burned, coal emits nearly double the carbon dioxide that natural gas does. Additionally, much less nitrogen oxides and sulfur dioxide (both air pollutants) are emitted from burning natural gas. It also does not produce ash as coal does (see below).
Health and Environmental Impacts
The negative impacts of fossil fuel use begin with the extraction of the resource. Fossils fuels are often located far from where they are utilized so they need to be transported by pipeline, tankers, rail or trucks. These all present the potential for accidents, leakage, and spills. Additional negative impacts are associated with processing, electricity generation, and disposal of the waste generated.
Coal Mining and Usage
Surface mining of coal disrupts local ecosystems above coal deposits as overburden is removed to access them (figure \(\PageIndex{b}\)). In mountaintop removal, a large volume of overburden is dumped over nearby habitats, causing further destruction (figure \(\PageIndex{c}\)). Mountaintop removal has affected large areas of the Appalachian Mountains in West Virginia and Kentucky. Habitat loss from coal mining decreases biodiversity, resulting in a loss of ecosystem services. Both surface and subsurface mining expose rocks that can contain contaminants, such as heavy metals or sulfates, which them leach into streams or other bodies of water. This not only harms aquatic life, but it also disrupts nutrient cycling. One of the largest environmental impacts of subsurface mining may be the methane gas that must be vented out of mines to make the mines a safe place to work. Methane gas is a potent greenhouse gas and contributes to climate change. Finally, the process of mining ultimately compacts soil. This combined with the loss of trees, which slow the flow of run-off and promote infiltration, increases the risk of flooding.
Coal miners face health hazards such as explosions, mine collapse, and exposure to toxic fumes. Black lung disease is a respiratory condition characterized by coughing and shortness of breath that occurs in miners exposed to too much coal dust. Residents near mines also risk exposure to coal dust and underground toxins following explosions. As a result of exposure to toxins, birth defects and other health problems are common in residents near mines.
Coal is considered the “dirtiest” source of energy because its combustion results in the most air pollution. Coal power plants emits a variety of air pollutants including sulfur dioxide, nitrogen oxide, and heavy metals. Sulfur dioxide and nitrogen oxide are sources of acid rain (acid deposition), smog, and health issues. Heavy metals cause neurological and developmental problems in humans and other animals. Burning of coal emits particulate matter and higher amounts of carbon dioxide per unit of energy than the use of oil or natural gas. Carbon dioxide is the most frequently emitted greenhouse gas and causes climate change. In 2018, electricity generation was responsible 27% of greenhouse gas emissions in the United States, and much of this was emitted from coal power plants. The transportation of coal usually relies on fossil fuels, releasing further pollution.
Ash (including fly ash and bottom ash) is a residue created when coal is burned at power plants. In the past, fly ash was released into the air through the smokestack, where it would contribute to particulate matter air pollution. Laws now require that much of the fly ash now must be be captured by pollution control devices, like scrubbers. In the United States, fly ash is generally stored at coal power plants or placed in landfills. Ash from storage or landfills can spill or leach into groundwater, resulting in water pollution.
Conventional Extraction Oil and Natural Gas
Exploring and drilling for oil degrades land and ocean habitats. On land, extensive infrastructure such as road networks, transport pipelines and housing for workers are needed to support a full-scale drilling operation. These can pollute soil and water, fragment habitats, and disturb wildlife. Extraction of oil and natural gas is also hazardous for workers, who have a high incidence of cancer and heart disease.
Human-caused oil spills in rivers and oceans harm ecosystems. From an economic perspective, oil spills disrupt the fishing industry and tourism. Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.
Oil spills can result from supertanker accidents such as the Exxon Valdez in 1989, which spilled 10 million gallons of oil into the rich ecosystem of coastal Alaska and killed massive numbers of animals. The largest marine oil spill began in April 2010 when a natural gas explosion at an oil well 65 km offshore of Louisiana occurred on Deepwater Horizon Oil Rig. It killed 11 employees and flowed for 3 months in 2010, releasing an estimated 200 million gallons of oil (figure \(\PageIndex{d}\)). Wildlife, ecosystems, and people’s livelihood were adversely affected. A lot of money and huge amounts of energy were expended on immediate clean-up efforts. The long-term impacts are still not known. The National Commission on the Deepwater Horizon Oil Spill and Offshore Drilling was set up to study what went wrong. The worst oil spill ever occurred during the Persian Gulf war of 1991, when Iraq deliberately dumped approximately 200 million gallons of oil in offshore Kuwait and set more than 700 oil well fires that released enormous clouds of smoke and acid rain for over nine months.
During an oil spill on water, oil floats to the surface because it is less dense than water, and the lightest hydrocarbons evaporate, decreasing the size of the spill but polluting the air. Then, bacteria begin to decompose the remaining oil, in a process that can take many years. After several months only about 15% of the original volume may remain, but it is in thick asphalt lumps, a form that is particularly harmful to birds, fish, and shellfish. Cleanup operations can include a variety of components, but each has its procs and cons. Skimmer ships that vacuum oil from the water surface, but these are effective only for small spills. Controlled burning works only in early stages before the light, ignitable part evaporates, but this also pollutes the air. Dispersants are detergents that break up oil to accelerate its decomposition, but some dispersants may be toxic to the ecosystem. Bioremediation refers to adding microorganisms that specialize in quickly decomposing oil, but this can disrupt the natural ecosystem.
Unconventional Extraction of Oil and Natural Gas
Fracking causes more environmental damage than conventional extraction. The considerable use of water (figure \(\PageIndex{e}\)) may affect the availability of water for other uses in some regions, and this can affect aquatic habitats. In fact, fracking consumes more water than the use of nuclear energy, coal, or conventional oil and natural gas. If mismanaged, hydraulic fracturing fluid can be released by spills, leaks, or various other exposure pathways that contaminate land and groundwater (figure \(\PageIndex{f}\)). Fracking fluid flowback – the fluid pumped out of the well and separated from oil and gas – not only contains the chemical additives used in the drilling process but also contains heavy metals, radioactive materials (which release radiation), volatile organic compounds, benzene (a carcinogen), toluene, ethylbenze, xylene, and other toxic air pollutants. Volatile organic compounds (VOCs) can react with the atmosphere to form ground-level ozone, which is associated with respiratory disease. Toulene can cause dizziness, confusion, headaches, and miscarriages. Ethylbenzene is a possible carcinogen that also causes dizziness, eye irritation, and hearing loss. Xylene also causes dizziness and headaches and furthermore can be fatal at high concentrations. In some cases, this contaminated water is sent to water treatment plants that are not equipped to deal with some of these classes of contamination. Finally, injecting wastewater for disposal can even induce earthquakes.
Other unconventional sources of fossil fuels can also harm the environment. Surface mining of tar sands or oil shales requires the removal of all vegetation and leaves pollutants behind, causing habitat loss (figure \(\PageIndex{g}\)).
Transportation, Refineries, and Combustion
Natural gas is released into the atmosphere from coal mines, oil and gas wells, and natural gas storage tanks, pipelines, and processing plants. These leaks are the source of about 25% of total U.S. methane emissions, which translates to three percent of total U.S. greenhouse gas emissions, contributing to climate change. When natural gas is produced but cannot be captured and transported economically, it is “flared,” or burned at well sites, which converts it to carbon dioxide. This is considered to be safer and better than releasing methane into the atmosphere because carbon dioxide is a less potent greenhouse gas than methane. However, when natural gas with high concentrations of the toxic gas hydrogen sulfide is flared, it produces carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, and many other compounds (see Air Pollution for more details).
Leaks also happen when we use petrochemicals on land. For example, gasoline sometimes drips onto the ground when people are filling their gas tanks, when motor oil gets thrown away after an oil change, or when fuel escapes from a leaky storage tank. When it rains, the spilled petrochemicals get washed into the gutter and eventually flow to rivers and into the ocean. Another way that oil sometimes gets into water is when fuel is leaked from motorboats and jet skis. When a leak in a storage tank or pipeline occurs, petrochemicals can also get into the ground, and the ground must be cleaned up. To prevent leaks from underground storage tanks, all buried tanks are supposed to be replaced by tanks with a double lining.
Oil refining emits a variety of toxins and is the single largest source of benzene (figure \(\PageIndex{g}\)). As a result, residents living near oil refineries have a high incidence of cancer, asthma, and birth defects. When petrochemicals such as gasoline or diesel are burned, they release a variety of air pollutants, including carbon dioxide (a cause of climate change), sulfur dioxide, nitrous oxides, volatile organic compounds (VOCs), particulate matter, and lead (see Air Pollution for more details). The transport of oil by ship or trunk also requires energy in the form of fossil fuels, generating more pollutants. Compared to oil and coal, burning natural gas releases the fewest pollutants and greenhouse gases.
Solutions
Reclamation can mitigate the habitat damage that results from mining or extracting fossil fuels. It involves restoring the land to an extent after mining or extraction is complete. This can entail returning displaced land and covering with top soil, which protects organisms from heavy metals, radioactive materials, and other underground toxins. Additionally, acids, which often form from the leaching of sulfates from underground rocks, may be neutralized. Vegetation is then planted, and water flow if disrupted is somewhat restored. Of course, the intricate topography, network of streams, and mature vegetation (such as large trees in forest) that may have been present prior to mining cannot be recreated, but reclamation makes it easier for native species to begin recolonizing the area.
Clean coal technologies can limit the air pollution released when burning coal. Some of these technologies remove toxins from coal before burning it while others capture toxins that are released while burning coal. For example, smokestack scrubbers in power plants clean sulfur dioxide, nitrous oxide, particulate matter, and mercury from the smoke before it is released. Carbon capture and sequestration involves capturing carbon dioxide released and storing it, but it requires 25-40% more energy, reducing the efficiency of coal (figure \(\PageIndex{h}\)). In this process, smoke from a coal power plant is passed through a solvent to trap carbon dioxide, but other waste gases are still released in the smoke. Carbon dioxide is then separated from the solvent. Some can be used in industry (such as for carbonated beverages or to tertiary recovery of oil), and the rest is sequestered (stored) underground. Note that clean coal technologies can reduce coal's contribution to climate change and reduce the amount of toxins that are released, but it does not fully prevent coal-generated air pollution (figure \(\PageIndex{i}\)).
Because fossil fuels are nonrenewable, reserves will eventually be depleted, and the world will need to fully rely on other energy sources. Those concerned about the environmental and health consequences of fossil fuels advocate for making this transition as soon as possible. This is because the technologies and practices discussed above do not fully prevent fossil fuels from causing environmental damage and causing health hazards for workers and the general public. The next two chapters discuss nuclear energy and renewable energy, which are alternatives to fossil fuels. As even these alternatives have their disadvantages, energy conservation (using energy more efficiently and limiting unnecessary energy use) is also critical.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.01%3A_Fossil_Fuels/5.1.04%3A_Consequences_of_Fossil_Fuels.txt |
Overview
Our World in Data (OWID) is a scientific online publication that focuses on using research and data to help tackle global concerns such as poverty, disease, hunger, climate change, war, and inequitable treatment of our world’s most vulnerable and unstable communities. Their website is particularly known for publishing a variety of graphs, some even interactive, to present the research that helps explain causes and consequences of global concerns to the public. One example graph, seen below, illustrates global fossil fuel consumption:
Questions
1. What kind of graph is this?
2. What question(s) are the authors trying to answer with this graph?
3. What are the observed patterns of fossil fuel use (gas, oil, and coal) in this graph?
4. Make a prediction for each fossil fuel use pattern for the next 50 years. For each prediction, state why you think that pattern will occur.
5. How do you think climate scientists are using a graph like this to predict climate into the future?
Raw Data For Above Graph(s)
Raw data table link to Our World in Data graph above. (CC-BY)
Attribution
Rachel Schleiger (CC-BY-NC)
5.1.06: Review
Summary
After completing this chapter you should be able to...
• Distinguish among coal, oil, and natural gas and explain how each is formed.
• Describe the processes of mining, processing, transporting, and burning coal to produce electricity.
• Compare the processes of conventional oil and natural gas extraction and fracking.
• Identify the relative contributions of coal, oil, and natural gas to electricity generation in the U.S. and total energy consumption globally.
• Detail the advantages and disadvantages of fossil fuel use.
• Describe strategies to mitigate harm caused by fossil fuel use.
Fossil fuels are nonrenewable energy sources that were formed from ancient organisms. Coal is a solid fossil fuel formed from ancient swamp vegetation. Oil (petroleum) and natural gas both formed from marine microorganisms and are often found together; however, oil is a liquid fossil fuel, and natural gas is in gaseous form.
Coal is produced through surface and subsurface mining. Some oil and natural gas reserves can be recovered through conventional extraction, but unconventional reserves are recovered through hydraulic fracturing (tight oil and natural gas; tight sands) or mining (oil shale and tar sands). To produce electricity from coal or natural gas, the fuel is combusted (burned). The heat is used to produce steam, and the pressure from the steam turns a turbine, which powers a generator. Crude oil must be refined to separate it into a variety of petrochemicals, each with a different use.
Nationally and globally, fossil fuel consumption remains high. Proven reserves of oil and natural gas are projected to last another 50 years while coal reserves are projected to last another 115 years. The U.S. has a large supply of the world's coal but relies largely on imports to meet its oil demands. The world's oil supply is concentrated in OPEC countries, which have great influence over global rates of production.
While existing technologies facilitate continued fossil fuel use, which support local and national economies, fossil fuels cause a variety of health and environmental consequences. Workers and those living near mines or oil refineries are at the greatest risk of health consequences, but combustion of fossil fuels releases air pollutants that harm the general public and native organisms. Furthermore, mining, drilling, and fracking, destroy habitats and release pollutants. Clean coal technologies and reclamation reduces but does not eliminate these negative consequences.
Attribution
Melissa Ha (CC-BY-NC) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.01%3A_Fossil_Fuels/5.1.05%3A_Data_Dive-_Global_Fossil_Fuel_Consumption.txt |
Chapter Hook
It’s like a scene from a post-apocalyptic fictional novel. A city that is slowly deteriorating year after year with human absence. Schools, homes, and business with doors wide open, belongings strewn all over floors and tables, indicating a serious panic and rush from people that once called this city theirs. Unfortunately, Chernobyl is not a fictional novel. It was a city in the former USSR that is the site of the worst nuclear accident in history. On April 25th and 26th in 1986 one of the nuclear reactors exploded releasing up to 30% of Chernobyl’s 190 metric tons of uranium into the atmosphere. Currently, there is a 19-mile-wide prohibition zone around the epicenter of the disaster, and it is estimated not to be safe for 20,000 years! This is the terrible price to pay for the sake of electricity.
Nuclear power is energy released from the radioactive decay of elements, such as uranium, which releases large amounts of energy. It generally refers to using the heat energy released from nuclear fission reactions to produce electricity. Nuclear power plants produce no carbon dioxide and, therefore, are often considered an alternative fuel (fuels other than fossil fuels).
• 17.1: Radioactive Isotopes
Isotopes are atoms of the same element that differ in neutron level. Some isotopes are unstable (radioactive) and decay, releasing radiation. The rate of decay is measured by the half-life. Nuclear fission of uranium-235 can be induced to generate nuclear power.
• 17.2: Generating Electricity with Nuclear Energy
The nuclear fuel cycle describes the mining, milling, and enrichment of uranium ore to produce nuclear fuel as well as disposal of wastes. Nuclear reactors contain reactor cores, where nuclear fission takes place, and the machinery needed to generate electricity. Nuclear fission releases heat, which produces high-pressure steam to turn a turbine and power a generator.
• 17.3: Nuclear Energy Consumption
Nuclear power accounts for 10.4% of electricity production and 4.3% of total energy consumption globally. In the United States, it accounts for 9.6% of the electricity and 8.0% of the total energy consumption.
• 17.4: Consequences of Nuclear Energy
Nuclear power does not release greenhouse gases and air pollutants as combustion of fossil fuel does. Furthermore, a rich supply of nuclear fuels are available. However, the storage of dangerous nuclear waste and the risk of nuclear accidents with long-lasting consequences are downsides of using nuclear power.
• 17.5: Data Dive- Global Nuclear Power Generation
• 17.6: Review
Attribution
Modified by Melissa Ha and Rachel Schleiger from Non-Renewable Energy Sources from Environmental Biology by Matthew R. Fisher (licensed under CC-BY)
5.02: Nuclear Energy
Recall that an atom is the smallest component of an element that retains all of the chemical properties of that element (see Matter). As previously discussed, atoms contain uncharged neutrons and positively charged protons in the nucleus. Negatively charged electrons surround the nucleus. The atomic mass of an atom is determined by the number of protons and neutrons because the mass of electrons is negligible. Each proton or neutron weighs 1 atomic mass unit (AMU). The atomic mass values displayed in the periodic table of elements are not whole numbers because they represent the average atomic mass for atoms of that element (figure \(\PageIndex{a}\)). Atoms of the same element do not necessarily have the same mass because they can differ in neutron number.
Isotopes are different forms of the same element that have the same number of protons, but a different number of neutrons. Some elements, such as carbon, potassium, and uranium, have naturally occurring isotopes. Carbon-12, the most common isotope of carbon, contains six protons and six neutrons. Therefore, it has a mass number of 12 (six protons and six neutrons) and an atomic number of 6 (which makes it carbon). Carbon-14 contains six protons and eight neutrons. Therefore, it has a mass number of 14 (six protons and eight neutrons) and an atomic number of 6, meaning it is still the element carbon. These two alternate forms of carbon are isotopes. Some isotopes are unstable and emit radiation in the form of particles and energy to form more stable elements. Some forms of radiation are dangerous. These are called radioactive isotopes or radioisotopes (figure \(\PageIndex{b}\)). During radioactive decay, one type of atom can change into another type of atom in this way (figure \(\PageIndex{c}\)).
Half-Life
The half-life is the amount of time that it takes for half of the original radioactive isotope to decay (figure \(\PageIndex{d}\)). For example, the half-life of uranium-238 is about 4.5 billion years. After 4.5 billion years, only half (50%) of the original amount of uranium-238 will remain. The rest will have decayed to thorium-234 (which is also radioactive and quickly decays to a series of radioactive isotopes, until it ultimately becomes lead-206, which is stable; figure \(\PageIndex{e-f}\)). After two half-lives (9 billion years), only half of the 50% would remain (25% of the original). After three half-lives, only 12.5% of the original uranium-238 would remain.
Evolution in Action: Carbon Dating
Carbon-14 (14C) is a naturally occurring radioisotope that is created in the atmosphere by cosmic rays. This is a continuous process, so more 14C is always being created. As a living organism develops, the relative level of 14C in its body is equal to the concentration of 14C in the atmosphere. When an organism dies, it is no longer ingesting 14C, so the ratio will decline. 14C decays to 14N by a process called beta decay; it gives off energy in this slow process (figure \(\PageIndex{c}\)). After approximately 5,730 years, only one-half of the starting concentration of 14C will have been converted to 14N. The time it takes for half of the original concentration of an isotope to decay to its more stable form is called its half-life.
Because the half-life of 14C is long, it is used to age formerly living objects, such as fossils. Using the ratio of the 14C concentration found in an object to the amount of 14C detected in the atmosphere, the amount of the isotope that has not yet decayed can be determined. Based on this amount, the age of the fossil can be calculated to about 50,000 years (figure \(\PageIndex{g}\) below). Isotopes with longer half-lives, such as potassium-40, are used to calculate the ages of older fossils. Through the use of carbon dating, scientists can reconstruct the ecology and biogeography of organisms living within the past 50,000 years.
Nuclear Fission Reactions
Nuclear fission reactions are those that involve splitting the nucleus of an atom (figure \(\PageIndex{h}\)). They can be induced by blasting radioactive elements with neutrons. As with natural radioactive decay, induced nuclear fission reactions release energy. The heat energy released when nuclear fission can be used to generate electricity. This is the basis of nuclear power. Currently, uranium-235 (235U; an isotope of uranium with an atomic mass of 235) is currently used as fuel for nuclear fission reactions (figure \(\PageIndex{h}\)).
Attribution
Modified by Melissa Ha from Matter from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.02%3A_Nuclear_Energy/5.2.01%3A_Radioactive_Isotopes.txt |
The Nuclear Fuel Cycle
Uranium ore must be mined, milled, and enriched to produce nuclear fuel. The nuclear fuel cycle represents the progression of nuclear fuel from creation to disposal (figure \(\PageIndex{a}\)). The first stage of the nuclear fuel cycle is uranium recovery, in which uranium ore is mined. It is then milled to produce yellowcake (uranium ore concentrate/uranium oxide/U3O8). Milling separates the uranium from the other parts of the ore. Each ton of mined uranium ore typically yields 1-4 pounds of yellowcake (0.05% to 0.20% yellowcake). Next, the uranium ore concentrate is converted into uranium hexafluoride (UF6). It is then enriched to increase the concentration of uranium-235 (235U) relative to 238U. During fuel fabrication, natural and enriched UF6 is converted into into uranium dioxide (UO2) or uranium metal alloys for use as fuel for nuclear power plants. Disposal of spent fuel rods and other hazardous waste generated in this process are discussed in Consequences of Nuclear Energy.
Nuclear Reactors
The fuel, which is now in the form of cylindrical ceramic pellets are then sealed into long metal tubes called fuel rods, which are assembled in reactor cores along with control rods. Each fuel pellet, which is about 1 cm in length, stores the same amount of energy as a ton of coal. Thousands of fuel rods form the reactor core, the site of nuclear fission in a nuclear power plant (figure \(\PageIndex{b}\)).
Heat is produced in a nuclear reactor when neutrons strike uranium atoms, causing them to split in a continuous chain reaction that releases heat energy (figure \(\PageIndex{c}\)). Specifically, fission of 235U, releases additional neutrons, which then cause the fission of nearby 235U nuclei. However, if fission occurs in too many atoms simultaneously, too much energy is released, which can cause an explosion or meltdown. This is prevented by control rods, which are made of a material such as boron that absorbs excess neutrons released in nuclear fission. When the neutron-absorbing control rods are pulled out of the core, more neutrons become available for fission, and the chain reaction speeds up, producing more heat. When they are inserted into the core, fewer neutrons are available for fission, and the chain reaction slows or stops, reducing the heat generated.
Nuclear reactors (figure \(\PageIndex{d}\)) contain the reactor core and the machinery needed to generate electricity from the heat released. The reactor core is submerged in water. In addition to transferring heat energy, the water also serves to slow down, or "moderate" the neutrons which is necessary for sustaining the fission reactions. Ultimately, the heat energy is used to generate high-pressure steam, which turns a turbine to generate electricity. The mechanism is similar to that of coal- or natural gas-generated electricity, but nuclear fission rather than combustion of coal is the source of heat energy.
There are two main types of nuclear reactors: pressurized water reactors and boiling water reactors.
Pressurized Water Reactor
In a pressurized water reactor, there are three separate streams of water: the water in contact with the reactor core, the water that produces steam, and the cooling water (figure \(\PageIndex{e}\)). The reactor core is submerged in water, which is held by a steel vessel. This is surrounded by a containment structure. As the nuclear fission reaction heats the water surrounding it, the water is pumped in a cyclical stream. It transfers heat to the second stream of water, which is in a separate vessel. This second stream is kept at a lower pressure, allowing the water to boil and create steam The steam turns a turbine, generating electricity. The steam then is cooled in the condenser by a separate stream of cooling water. Because water from the reactor core does not mix with other parts of the reactor, not all of the reactor is radioactive.
Boiling Water Reactor
In a boiling water reactor, there are two separate streams of water: the water in contact with the reactor core and the cooling water (figure \(\PageIndex{f}\)). The reactor core heats the water in which it is submerged. This water is held by a steel vessel that is surrounded by a containment structure. The steam produced as the reactor core heats water turns a turbine, which generates electricity. The steam then is cooled in the condenser by a separate stream of cooling water. Because water from the reactor core comes in contact with all parts of the reactor, the entire thing is radioactive.
Attribution
Modified by Melissa Ha from the following sources:
5.2.03: Nuclear Energy Consumption
Nuclear electricity came on the energy scene remarkably quickly. Following the development of nuclear technology at the end of World War II for military ends, nuclear energy quickly acquired a new peacetime path for inexpensive production of electricity. Eleven years after the end of World War II, a very short time in energy terms, the first commercial nuclear reactor produced electricity at Calder Hall in Sellafield, England. The number of nuclear reactors grew steadily to more than 400 by 1990 (figure \(\PageIndex{a}\)), four years after the Chernobyl disaster in 1986 and eleven years following Three Mile Island in 1979 (see Consequences of Nuclear Energy). The number of operating reactors remained approximately flat for two decades, and the United States has not built a new nuclear facility since 1996. The number of operating nuclear power plants decreased in 2011, when the meltdown at the Fukushima Daiichi Nuclear Power Station caused Japan to shut down all of its nuclear power plants. Japan has since resumed use of some of its nuclear reactors.
World production of electricity from nuclear power was about 2795.96 terawatt-hours (TWh) in 2019, comprising 10.4% of electricity production and 4.3% of total energy consumption globally (figure \(\PageIndex{b}\)). (For reference, the U.S. generated about 4100 TWh of electricity total in 2019.) The United States produced and consumed about 30.5% of the world's nuclear power in 2019, where nuclear power provided about 19.6% of the electricity and 8.0% of the total energy consumption (figure \(\PageIndex{c}\)).
Attribution
Modified by Melissa Ha from Non-Renewable Energy Sources from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.02%3A_Nuclear_Energy/5.2.02%3A_Generating_Electricity_with_Nuclear_Energy.txt |
The use of nuclear energy presents an interesting dilemma. On the one hand, nuclear electricity produces no carbon emissions, a major sustainable advantage in a world facing climate change. On the other hand, there is environmental risk of storing spent fuel for thousands or hundreds of thousands of years, societal risk of nuclear proliferation, and the impact of accidental releases of radiation from operating reactors. Thoughtful scientists, policy makers, and citizens must weigh these advantages and disadvantages.
Advantages of Nuclear Energy
In contrast to fossil fuels, generating electricity from nuclear energy does not pollute the air or significantly contribute to climate change (figure \(\PageIndex{a}\)). As we continue to deplete global reserves of fossil fuels, supplies of nuclear fuel are abundant. It is estimated that uranium supplies will last over 200 years, and there is potential to use other radioactive isotopes as well. Furthermore, nuclear power plants are more reliable than any other source, with a capacity factor of 93.5% (figure \(\PageIndex{b}\)). Capacity is the amount of electricity a generator can produce when it’s running at full blast, and the capacity factor is a measure of how often a plant is running at maximum power. (A power plant with a capacity factor of 100% means that it's producing power all of the time.)
Negative Impacts of Nuclear Energy
Despite its benefits, nuclear power has downsides. It requires more water than any other energy source. Water used for cooling is released back into the environment, and while it does not contain radioactive materials or other harmful chemicals, it is warmer than before. This is called thermal pollution, and it can harm aquatic life, which are adapted to cooler temperatures. Surface mining for uranium ore degrades habitat and releases toxins from underground (similar to surface mining for coal). Nuclear power plants are expensive to build and maintain, and they require large amounts of metal and concrete. Enriched uranium for nuclear fuel if in the wrong hands can be used to make nuclear weapons (figure \(\PageIndex{c}\)). While nuclear accidents are rare, they can cause great harm, and their impacts are long-lasting. Furthermore, the problem of safely disposing spent nuclear fuel remains unresolved. The latter two concerns are discussed in more detail below.
Nuclear Waste
The main environmental challenge for nuclear power is the wastes including high-level radioactive waste, low-level radioactive waste, and uranium mill tailings. These materials have long radioactive half-lives and thus remain a threat to human health for thousands of years.
High-level radioactive waste (HLRW) consists of used nuclear reactor fuel (spent nuclear fuel rods). These contain the products of nuclear fission, which are radioactive themselves. This HLRW is temporarily stored in a pool at the nuclear power plant or a dry cask, steel cylinders within another container, made of steel or concrete (figure \(\PageIndex{d}\)). Dry casks contain inert (nonreactive) gas and may be located at the power plant, a decommissioned power plant, or a separate storage site. High-level radioactive waste may only be moved to a dry cask after one year of cooling in a pool. The U.S. has no long-term storage for HLRW, and spent fuel thus remains interim storage.
Yucca Mountain in Nevada was proposed as a long-term geologic storage site, where HLRW could be buried for hundreds of thousands of years. The storage facility was constructed, but it has not been used due to opposition from local residents and concern about the safety of transporting HLNW (figure \(\PageIndex{e}\))
Some countries reprocess (recycle) spent nuclear fuel, but no recycling or reprocessing facility or a federal waste repository is currently licensed in the United States. Reprocessing separates the useable fraction of spent fuel and recycles it through the reactor, using a greater fraction of its energy content for electricity production, and sends the remaining high-level waste to permanent geologic storage.
The primary motivation for reprocessing is greater use of fuel resources, extracting about 25 percent more energy than the once through cycle. A secondary motivation for recycling is a significant reduction of the permanent geologic storage space (to 20% or less of what would otherwise be needed) and time (from hundreds of thousands of years to thousands of years). While these advantages seem natural and appealing from a sustainability perspective, they are complicated by the risk of theft of nuclear material from the reprocessing cycle for use in illicit weapons production or other non-sustainable ends. At present, France, the United Kingdom, Russia, Japan, and China engage in some form of reprocessing; the United States, Sweden, and Finland do not reprocess.
Low-level radioactive waste (LLRW) refers to items that were exposed to radiation includes clothing, filters, and gloves. These can be contained with concrete or lead (through which radiation cannot pass; figure \(\PageIndex{f}\)). Low-level waste is typically stored at the nuclear power plant, either until it has decayed away and can be disposed of as ordinary trash, or until amounts are large enough for shipment to one of the five LLRW disposal sites in the U.S. (figure \(\PageIndex{g}\)).
Enrichment of uranium produces depleted uranium hexafluoride (DUF6), or uranium mill tailings, as a byproduct, which does not have high enough concentrations of 235U to use as nuclear fuel but is still hazardous. Tailings represent the greatest percentage of nuclear waste by volume, and there are more than 200 million tons of radioactive mill-tailings in the United States. Tailings contain several radioactive elements including radium, which decays to produce radon, a radioactive gas. They are stored in impoundments, lined pits in the ground that are flooded with water, in remote areas. Deconversion involves chemically treating the tailings to reduce their hazards so that they can be stored as LLRW.
Nuclear Disasters
There are many other regulatory precautions governing permitting, construction, operation, and decommissioning of nuclear power plants due to risks from an uncontrolled nuclear reaction. The potential for contamination of air, water and food is high should an uncontrolled reaction occur. Even when planning for worst-case scenarios, there are always risks of unexpected events. The nuclear accidents at Three Mile Island, Chernobyl (see the Chapter Hook), and Fukushima raised concerns about the safety of nuclear power.
The Three Mile Island accident occurred in Pennsylvania in 1979. It was a partial meltdown that resulted from an electrical failure and errors in operation. There were no direct deaths. Studies investigated the possibility of exposure to radiation from the accident indirectly causing deaths through increased rates of cancer or other disease, but there has not been evidence of this. In contrast, the 1986 meltdown at Chernobyl Nuclear Power Plant in what is now the Ukraine was responsible for 50 direct deaths. This disaster occurred from a test of the emergency systems gone wrong. Estimates of indirect deaths from radiation exposure range from 4,000 to 60,000.
The global discussion regarding nuclear energy has been strongly impacted by March 2011 earthquake and subsequent tsunami that hit Japan resulted in reactor meltdowns at the Fukushima Daiichi Nuclear Power Station causing massive damage to the surrounding area. The disaster disabled the cooling system for a nuclear energy complex, ultimately causing a partial meltdown of some of the reactor cores and release of significant radiation. The design of the reactors (boiling water reactors) made it more difficult to vent the system without releasing radiation. Cooling the radioactive fuel generated a large volume of contaminated water, and the disaster costed at least \$300 billion dollars. While there were no immediate deaths, one person later died from cancer attributed to radiation exposure. Thousands died as a result of stress associated with the evacuation, and about 20% of the over 160,000 evacuees had not yet returned home as of 2019.
Interactive Element
This three-minute segment, What Recovery Looks Like In Japan Almost A Decade After Fukushima Nuclear Disaster, provides on update on evacuees from the Fukushima nuclear disaster.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.02%3A_Nuclear_Energy/5.2.04%3A_Consequences_of_Nuclear_Energy.txt |
Overview
Our World in Data (OWID) is a scientific online publication that focuses on using research and data to help tackle global concerns such as poverty, disease, hunger, climate change, war, and inequitable treatment of our world’s most vulnerable and unstable communities. Their website is particularly known for publishing a variety of graphs, some even interactive, to present the research that helps explain causes and consequences of global concerns to the public. One example graph, seen below, illustrates nuclear power generation:
Questions
1. What countries generate the most energy via nuclear power?
2. Is there anything that surprises you about the patterns observed on this graph?
3. Based on what you learned in this chapter about nuclear power, do you think the trends you see in this 2019 map continue for the next 50 years? Explain.
4. Again, what is missing on this map?
Raw Data For Above Graph(s)
Raw data table link for Our World In Data graph above. (CC-BY)
Attribution
Rachel Schleiger (CC-BY-NC)
5.2.06: Review
Summary
After completing this chapter you should be able to...
• Define isotopes and radioactive isotopes.
• Explain how half-life measure the rate of radioactive decay.
• Explain how nuclear fission reactions can be induced to generate electricity.
• Outline the nuclear fuel cycle.
• Describe the structure and functioning of a nuclear reactor, distinguishing between pressurized water reactors and boiling water reactors.
• Detail the percentage that nuclear power contributes to electricity and total energy consumption globally and in the United States.
• Discuss the advantages and disadvantages of nuclear energy.
Isotopes are atoms of the same element that differ in neutron number. Some isotopes are radioactive, meaning that they are unstable and emit radiation in the form of particles and energy. The speed of this radioactive decay is measured in half-lives. A nuclear fission reaction is the splitting of an atom nucleus. Nuclear fission of uranium-235 can be induced by neutrons, and this is the basis of nuclear power.
The nuclear fuel cycle describes the process of mining uranium ore, milling it into yellowcake, and enriching it to produce nuclear fuel. It also outlines proper storage and disposal of spent fuel and other waste products.
Nuclear fission occurs in the reactor core of a nuclear reactor. It is a chain reaction in which fission releases additional neutrons that induce fission in other atoms. Fuel rods contain nuclear fuel while control rods absorb excess neutrons to prevent an explosion or meltdown. The heat released from nuclear fission ultimately generates high-pressure steam, which turns a turbine, powering a generator. In this sense the process of nuclear electricity generation is similar to that from coal. Pressurized water reactors consist of three separate streams of water, but boiling water reactors consist of two separate streams of water.
Nuclear power accounts for 10.4% of electricity production and 4.3% of total energy consumption globally. In the United States, it accounts for 9.6% of the electricity and 8.0% of the total energy consumption.
Nuclear energy is beneficial in the sense that it releases few greenhouse gases or air pollutants. It is a reliable energy source, and nuclear fuel is abundant. However, nuclear power plants consume more water than any other source of energy. Power plants are expensive to build and maintain. While there have not been many nuclear accidents globally, some have been deadly, and residents still suffer from their effects. Additionally, nuclear waste continues to emit dangerous radiation, and the U.S. does not have a long-term storage facility for high-level radioactive waste.
Attribution
Melissa Ha (CC-BY-NC) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.02%3A_Nuclear_Energy/5.2.05%3A_Data_Dive-_Global_Nuclear_Power_Generation.txt |
Chapter Hook
City water pipes, an unlikely place to be a source electricity. Yet, Portland Oregon has decided to set up hydroelectric turbines in the cities drinking water pipes. This provides around the clock local energy that doesn’t affect natural waterways as classic hydroelectric turbines do. This setup is the first of its kind in the United States and truly exemplifies the objectives that renewable energies aspire to achieve.
• 18.1: Renewable Energy History and Consumption
Renewable energy resources are regenerated on short time scales and include wind, solar, geothermal, hydropower, and biofuels. While the use of renewable energy has increased over the years, it still accounts for only about 11% of total energy use globally and in the United States.
• 18.2: Wind Energy
Wind energy is harnessed into electricity when wind spins the blades of a wind turbine, powering a generator. While wind energy creates jobs, is relatively inexpensive, and generates minimal pollution, it is intermittent. Additionally, some find the the sight and sound of them off-putting.
• 19.3: Solar Energy
Solar energy comes from the sun and can be used for lighting, heating, and electricity. Advantages of using solar energy are that it generates few air pollutants and contributes little to climate change; however, cost and limitations in battery capacity are disadvantages.
• 18.4: Geothermal Energy
Geothermal energy refers to heat from deep within the Earth. It can be used to generate electricity. Additionally, cool temperatures underground (close to the surface) can directly to heat or cool buildings. While it is reliable and generates minimal air pollution, building geothermal power plants is costly and limited to specific locations.
• 18.5: Hydropower
Hydropower (hydroelectric energy) is the energy of movement in water. Dams and reservoirs are a common use of hydropower. The filling of reservoirs destroys terrestrial habitat, which decompose to release methane. However, the operation of hydroelectric power plants does not release air pollutants. Smaller run-of-the-river hydroelectric plants have minimal environmental impact.
• 18.6: Biofuels (Biomass Energy)
Biofuels contain energy from organisms. There are many forms of biofuels, including trash, animal waste, plants and their products, and wood. Some biofuel uses are more sustainable than others, particularly those that use materials that would otherwise be discarded. Biofuels are carbon neutral, but burning them does pollute the air.
• 18.7: Energy Conservation
Energy conservation refers to reducing energy waste and increasing efficiency. This can involve behaviors or technologies. Some have no cost, but others require financial investment.
• 18.8: Data Dive- Global Renewable Energy Generation
• 18.9: Review
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
5.03: Renewable Energy
Renewable energy sources can be replenished within human lifespans. Although renewable energy is often classified as wind, solar, geothermal, hydropower (hydroelectric energy/hydroelectricity), and biofuels (biomass energy), all forms of renewable energy arise from only three sources: the light of the sun (wind, solar, hydropower, and biofuels), the heat of the earth’s crust (geothermal), and the gravitational attraction of the moon and sun (tidal energy; figure \(\PageIndex{a}\)). Sunlight provides by far the largest contribution to renewable energy. The sun provides the heat that drives the weather, including the formation of high- and low-pressure areas in the atmosphere that make wind. The sun also generates the heat required for vaporization of ocean water that ultimately falls over land creating rivers that drive hydropower, and the sun is the energy source for photosynthesis, which creates biomass. The sun is also responsible for the energy of fossil fuels, created from the organic remains of plants and sea organisms compressed and heated in the absence of oxygen in the earth’s crust for tens to hundreds of millions of years. The time scale for fossil fuel regeneration, however, is too long to consider them renewable in human terms.
Most renewable energy sources have a relatively small carbon footprint, meaning that they do not significantly contribute to climate change. However, building dams for hydropower (hydroelectric energy) does release methane, a potent greenhouse gas. Renewable energy sources are pollution free (except biofuels), and they typically have minimal environmental impact (except habitat loss from dams). Up to this point, however, no single source of renewable energy is sufficient. They generally are paired with other energy sources.
Strong interest in renewable energy in the modern era arose in response to the oil shocks of the 1970s, when the Organization of Petroleum Exporting Countries (OPEC) imposed oil embargos and raised prices in pursuit of geopolitical objectives. The shortages of oil, especially gasoline for transportation, and the eventual rise in the price of oil by a factor of approximately 10 from 1973 to 1981 disrupted the social and economic operation of many developed countries and emphasized their precarious dependence on foreign energy supplies. The reaction in the United States was a shift away from oil and gas to plentiful domestic coal for electricity production and the imposition of fuel economy standards for vehicles to reduce consumption of oil for transportation. Other developed countries without large fossil reserves, such as France and Japan, chose to emphasize nuclear (France to the 80% level and Japan to 30%) or to develop domestic renewable resources such as hydropower and wind (Scandinavia), geothermal (Iceland), solar, biomass and for electricity and heat. As oil prices collapsed in the late 1980s, interest in renewables, such as wind and solar that faced significant technical and cost barriers, declined in many countries. Other renewables, such as hydropower and biomass, continued to experience growth. As climate change worstens, the solar and wind energy has expanded globally in recent years.
Renewable energy accounted for 11.4% of total global energy consumption and 26.3% of global electricity generation in 2019 (figure \(\PageIndex{b}\)). In the United States, renewable energy also accounted for about 11% of total energy consumption but only 17.6% of electricity generation. Nearly half (43%) of total renewable energy use in the U.S. is from biofuels. For electricity generation in the U.S., wind was the greatest contributor (7.1%) followed by hydropower (7.0%), solar (1.7%), biomass (1.4%), and geothermal (0.4%).
Attribution
Modified by Melissa Ha from Renewable Energy and Challenges and Impacts of Energy Use from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.01%3A_Renewable_Energy_History_and_Consumption.txt |
Wind energy arises from the motion of the air. It is driven by solar energy (differences in air temperature causes air currents). The wind turns a turbine, which powers a generator (figure \(\PageIndex{a}\)). The rotor blades of a wind turbine work like an airplane wing or helicopter rotor blade. When wind flows across the blade, the air pressure on one side of the blade decreases, and this causes the rotor to spin. The rotor connects to the generator, either directly or through a series of gears that speed up the rotation and allow for a physically smaller generator. Similar to the electricity generation from coal, natural gas, or nuclear energy, the rotating motion causes magnets spin within wire coils to produce electricity. According to the American Wind Energy Association, 39% of all new electrical generating capacity in the United States in 2019 was due to wind.
Advantages of Wind Energy
Wind is among the lowest-cost sources of renewable energy, and its expansion creates jobs (figure \(\PageIndex{b}\)). Like many renewable energy sources, wind turbines do not release air pollutants or contribute to climate change, and they do not require water for cooling. Because a wind turbine has a small physical footprint relative to the amount of electricity it produces, many wind farms are located on crop and pasture land. They contribute to economic sustainability by providing extra income to farmers and ranchers, allowing them to stay in business and keep their property from being developed for other uses. For example, energy can be produced by installing wind turbines in the Appalachian mountains of the United States instead of engaging in mountain top removal for coal mining. Offshore wind turbines on lakes or the ocean may have smaller environmental impacts than turbines on land, and winds are up to 50% stronger and steadier offshore than on land (figure \(\PageIndex{c}\)).
Disadvantages of Wind Energy
Wind energy does have a few challenges. Wind turbines are only effective in regions with strong enough winds to generate sufficient electricity. Even in regions with strong winds, wind availability is intermittent. This can be mitigated by the use batteries to store energy, but battery capacity, despite continuous technological advances, is still limited. There are aesthetic concerns to some people when they see them on the landscape, and some people do not like the sound that wind turbine blades make. A few wind turbines have caught on fire, and some have leaked lubricating fluids, though this is relatively rare. Turbines have been found to cause bird and bat deaths particularly if they are located along their migratory path, although communication towers and domestic cats are bigger threats. There are some small impacts from the construction of wind projects or farms, such as the construction of service roads, the production of the turbines themselves, and the concrete for the foundations.
Attribution
Modified by Melissa Ha from the following sources:
5.3.03: Solar Energy
Solar energy refers to heat or light energy from the sun. Solar energy is by far the most plentiful type of renewable energy, delivered to the surface of the Earth at a rate of 120,000 Terawatts (TW) per hour, compared to the global human use of 19.8 TW in the entire year of 2019. To put this in perspective, covering 1.2% of the Sahara desert with solar panels could meet Earths energy needs. Of course, this does not consider limitations on storage capacity and the ability to distribute that energy.
Technologies to harness solar energy may be passive or active. Passive solar technologies do not require complex equipment and can be as simple as using natural light from a window or skylight to illuminate a room (figure \(\PageIndex{a}\)). Similarly, solar tubes are lined with reflective material and can concentrate light energy to better illuminate a room (figure \(\PageIndex{a}\)). These are embedded in the ceiling as regular light fixtures would be.
Solar energy can also be used as heat, which can be maximized through careful architecture (figure \(\PageIndex{b}\)). Firstly, the building requires south-facing windows (or glass doors). As sunlight passes through these areas, the energy is stored in the thermal mass of the building. This refers to heat trapping materials such as rock or tiles. The building is also designed such that heat is then distributed throughout the building. Finally, roof eaves or similar structures block sunlight from entering the home during the summer.
A simple solar water heater is a passive technology consisting of a network of tubes that are heated by the sun (figure \(\PageIndex{c}\)). The hot water is then transferred through the plumping of a home. (Some solar water heaters are more complex, using pumps, and are thus considered active solar technologies.)
Active solar technologies are more complex. For example, solar panels use light energy to generate electricity (figure\(\PageIndex{d}\)). This occurs in the units of the solar panel, which are called photovoltaic cells (PV cells; figure\(\PageIndex{e}\)). Each photovoltaic cell consists of two layers of semiconductors, substances that only conduct electricity under certain circumstances. (In contrast, conducts always conduct electricity, and insulators do not.) One semiconductor has extra electrons, but the other has extra spaces for electrons. When light shines on the photovoltaic cell, it causes electrons to move from between semiconductor layers through the conductor that connects them (such as metal wires or plates). This movement results in an electric current.
This video explains how the photovoltaic cells within solar panels generate electricity.
Another example of active solar technology is solar thermal technology. This involves using a series of mirror to concentrate solar energy, ultimately generating steam. From there, the steam turns a turbine and powers a generator (figure\(\PageIndex{f}\)).
Not only is solar energy abundant, but the use of solar panels for electricity does not generate air pollution or contribute to climate change. (The manufacture of solar panels can generate some pollution, including greenhouse gas emissions, but this is minimal compared to that of fossil fuels.) Like wind energy, expansions on solar energy can create jobs and boost economies. Also like wind, sunlight is intermittent and storage of solar energy is limited by battery capacity. Some locations do not receive consistently direct sunlight and are ill-suited for solar panels. While solar energy has historically been the most expensive form of renewable energy, new technologies have lowered its cost.
The placement of solar panels determines how their environmental impact. Solar arrays are often placed on roofs of buildings or over parking lots or integrated into construction in other ways. However, large systems may be placed on land and particularly in deserts where those fragile ecosystems could be damaged if care is not taken. Additionally, solar farms can compete for agricultural space.
Other downsides of solar energy are water consumption (for some uses) and generation of hazardous wastes. Large networks of mirrors and lenses that concentrate solar energy for electricity generation in thermal solar systems or for heating may need to be cleaned regularly with water. Water is also needed for cooling the turbine-generator. Using water from underground wells may affect the ecosystem in some arid locations. The manufacturing of photovoltaic cells generates some hazardous waste from the chemicals and solvents used in processing. Some solar thermal systems use potentially hazardous fluids (to transfer heat) that require proper handling and disposal. Nuclear power exceeds solar energy in water consumption and hazardous waste generation, however.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.02%3A_Wind_Energy.txt |
Geothermal energy originates from heat rising to the surface from Earth’s molten iron core created during the formation and compression of the early Earth as well as from heat produced continuously by radioactive decay of uranium, thorium, and potassium in the Earth’s crust. Geothermal power plants harness this heat energy to produce electricity much in the same way that heat from burning coal generates energy (figure \(\PageIndex{a-c}\)). Water is injected underground and heated. The steam that emerges can be used directly, the heat can be transferred to closed system of another fluid, which then boils (figure \(\PageIndex{c}\)). Either way, the steam (or other high-pressure gas) ultimately turns a turbine and powers a generator.
Geothermal heat pumps (ground-source heat pumps) rely on cool temperatures underground to cool or heat homes (figure \(\PageIndex{d}\)). They are sometimes considered a second type of geothermal energy, but they are also a means of energy conservation. Geothermal heat pumps use a heat-exchange system that runs in the subsurface about 20 feet (5 meters) below the surface, which is consistently cool (around 55°F, or 12.5° C). Fluid is pumped underground and then along ducts in the home. This cools the house during the summer, acting as a heat sink. During a cold winter, it warms the house to 55° F (acting as a heat source), and traditional heating systems do the rest. This reduces the energy consumption required to generate heat from gas, steam, hot water, and conventional electric air-conditioning systems.
This video explains the construction and mechanism of geothermal heat pumps.
Not only does geothermal energy have multiple applications (generating electricity, heating, and cooling), but it is reliable. While solar and wind energy are intermittent, heat is consistently radiated from deep underground. Additionally, the cool temperatures closer to the surface needed for geothermal heat pumps are present year round and at all locations. Geothermal power plants for electricity generation, however, can only be built in specific locations where hot magma is close enough to the Earth's surface. These locations are typically associated with geysers, hot springs, or volcanoes (figure \(\PageIndex{e}\)). Additionally, geothermal power plants are costly to build.
The environmental impact of geothermal energy depends on how it is being used. The use of geothermal heat pumps has almost no negative impact on the environment. Geothermal power plants do not burn fuel to generate electricity, so they generate minimal air pollution. They release less than 1% of the carbon dioxide emissions of a fossil fuel plant. Geothermal plants plants use scrubber systems to clean the air of hydrogen sulfide that is naturally found in the steam and hot water. They emit 97% less sulfur compounds (one cause of acid deposition/acid rain) than are emitted by fossil fuel plants. After the steam and water from a geothermal reservoir have been used, they are injected back into the Earth. One environmental concern associated with geothermal power plants is geothermal drilling during their construction has caused earthquakes, similar to the effects of injection wells for fracking.
Attribution
Modified by Melissa Ha from Renewable Energy and Challenges and Impacts of Energy Use from Environmental Biology by Matthew R. Fisher (licensed under CC-BY | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.04%3A_Geothermal_Energy.txt |
Hydropower (hydroelectric energy) refers to the energy in moving water, which can be used to generate electricity. It is ultimately driven by solar energy. Water at high elevations is replenished through evaporation (induced by solar heat), condensation, and precipitation. The moving water turns a turbine (figure \(\PageIndex{a}\)) and this moves magnets within a wire coil, causing the movement of electrons in a generator. The result is an electric current (electricity). Combustion of fossil fuels or biofuels, nuclear energy, wind energy, and thermal solar systems all follow this same general mechanism; the difference is what causes the turbine to spin.
There are several types of hydropower, but each generates electricity through the same general mechanism described above. The most well-known use of hydropower involves dams. Dams block the flow of rivers, producing an artificial lake (reservoir) upstream. The release of water is then controlled. Some of this water moves through a channel (penstock), and this kinetic energy (energy of motion) is harnessed into electricity (figure \(\PageIndex{b}\)). In run-of-the-river hydroelectricity, the turbine is placed directly into a river, and the natural flow of water through the river spins the turbine. Tidal energy and energy from ocean waves (figure \(\PageIndex{c}\)) are also considered forms of hydropower. However, tidal energy arises from the gravitational attraction of the moon and the more distant sun on the earth’s oceans, combined with rotation of the earth. In other words, most forms of hydropower are indirect forms of solar energy, with the exception of tidal energy.
Small hydropower projects offer power solutions for many remote communities throughout the world, such as those in Nepal, India, China, and Peru, as well as for highly industrialized countries like the United States. Small hydropower systems are those that have a capacity between 0.01 to 30 megawatt (MW) of power. For reference, a 1-MW generator operating for an hour (producing 1 MWh) generates enough electricity to powers the average home in the U.S. for a little over a month. Small hydropower systems that generate less than 0.1 MW are more specifically called microhydropower systems (figure \(\PageIndex{d}\)). Most of the systems used by home and small business owners would qualify as microhydropower systems. In fact, a 10 kW system generally can provide enough power for a large home, a small resort, or a hobby farm.
One benefit of using hydropower is that dams and reservoirs can additionally be used for recreation, flood control, and storing freshwater (see Water Scarcity and Solutions). While we will never run out of moving water, the potential to use hydropower fluctuates based on precipitation. For example, during a drought, water levels in a reservoir decreases, and there is less water released to generate electricity. As with most sources of renewable energy, hydropower is not practical everywhere, and it is most effective in mountainous regions with high rainfall and snowmelt.
Hydropower dams and the reservoirs they create degrades habitat and negatively impacts native species. For example, migration of fish to their upstream spawning areas can be obstructed by dams. In areas where salmon must travel upstream to spawn, such as along the Columbia River in Washington and Oregon, the dams block their way (figure \(\PageIndex{e}\)). This problem can be partially alleviated by using “fish ladders” that help salmon get around the dams (figure \(\PageIndex{f}\)). Fish traveling downstream, however, can get killed or injured as water moves through turbines in the dam. Reservoirs and operation of dams can also affect aquatic habitats due to changes in water temperatures, water depth, chemistry, flow characteristics, and sediment loads, all of which can lead to significant changes in the ecology and physical characteristics of the river both upstream and downstream. When reservoirs first fill with water, they inundate terrestrial (land) habitats, farms, cities, and archeological and cultural sites, sometimes forcing populations to relocate. The terrestrial vegetation slowly decomposes in oxygen-poor conditions, releasing methane into the atmosphere, a potent greenhouse gas. In this sense, hydropower generates few air pollutants during operation, but construction does contribute to climate change.
While large-scale dam hydropower projects are often criticized for their impacts on wildlife habitat, fish migration, and water flow and quality, small run-of- the-river projects are free from many of these environmental problems. Because they use the natural flow of the river, they hardly alter the stream channel and flow. Thus, effects such as oxygen depletion, increased temperature, decreased flow, and impeded upstream migration are not problems for many run-of-the-river projects.
Attribution
Modified by Melissa Ha from Renewable Energy and Challenges and Impacts of Energy Use from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.05%3A_Hydropower.txt |
Biofuels (biomass energy) contain energy produced from organisms, such as animal waste, plants, or algae. It is another indirect form of solar energy. Biofuels have many uses. They be burned directly or first converted to ethanol (often with the help of bacteria and fungi) to generate electricity. The heat from combustion produces steam and turns a turbine to power a generator. Biodiesel offers an alternative to petrochemicals for fueling vehicles. Biofuels have even been used to power small planes (figure \(\PageIndex{a}\)). Furthermore, burning wood or straw provides heating.
Unlike fossil fuels, biofuels are carbon neutral (figure \(\PageIndex{b}\)). Fossil fuels store carbon that was captured by organisms millions of years ago. When we burn them, carbon dioxide is released much more rapidly than it was removed. Biofuels removed carbon dioxide from the atmosphere more recently, and they form over shorter time spans. When biofuels are burned, this carbon dioxide that was recently removed is released back into the atmosphere.
Another advantage of biofuels is that they can be produced locally and can be cultivated in many different locations. On the other hand, they occupy space that could otherwise be used for food production. To further complicate matters, the characteristics that make a plant species ideal for biofuel (such as being resistant to pests and fast-growing) are also characteristics that help invasive species thrive. Care must taken to contain these species if grown outside of their native ranges.
Combustion of solid municipal waste (see below) or animal wastes as biofuels, reduces waste and generates electricity simultaneously. Unlike most forms of renewable energy, however, combustion of biofuels pollutes the air. (The carbon dioxide released is not an issue since biofuels are carbon neutral, but other air pollutants are also released.) In fact, indoor air pollution from fires used for cooking inside the home is a major cause of death in developing countries.
Each type of biomass must be evaluated for its environmental and social impact in order to determine if it is really advancing sustainability and reducing environmental impacts. For example, cutting down large swaths of forests just for energy production is not a sustainable option because our energy demands are so great that we would quickly deforest the world, destroying critical habitat. For biomass to be a sustainable option, it usually needs to come from waste material, such as lumber mill sawdust, paper mill sludge, yard waste, or oat hulls from an oatmeal processing plant, livestock manure, or trash. These materials would otherwise just accumulate or decompose. Several examples of biofuel use are discussed below in more detail, including the specific advantages and disadvantages of type of use.
Burning Wood
Using wood, and charcoal made from wood, for heating and cooking can replace fossil fuels and may result in lower carbon dioxide emissions. If wood is harvested from forests or woodlots that have to be thinned or from urban trees that fall down or needed be cut down anyway, then using it for biomass does not impact those ecosystems. However, wood smoke contains harmful pollutants like carbon monoxide and particulate matter (see Air Pollution).
For home heating, it is most efficient and least polluting when using a modern wood stove or fireplace insert that are designed to release small amounts of particulates. However, in places where wood and charcoal are major cooking and heating fuels such as in developing countries, the wood may be harvested faster than trees can grow resulting in deforestation (figure \(\PageIndex{c}\)). The largest share of biofuel use comes from traditional biomass, mostly fuel wood gathered for household cooking and heating, often without regard for sustainable replacement.
Biomass can be used in small power plants. For instance, Colgate College has had a wood-burning boiler since the mid-1980s (figure \(\PageIndex{d}\)). In one year it processed approximately 20,000 tons of locally and sustainably harvested wood chips, the equivalent of 1.17 million gallons (4.43 million liters) of fuel oil, avoiding 13,757 tons of emissions and saving the university over \$1.8 million in heating costs. The University’s steam-generating wood-burning facility now satisfies more than 75% of the campus’s heat and domestic hot water needs.
Municipal Solid Waste
Municipal solid waste (MSW) is commonly known as garbage and can create electricity by burning it directly or by burning the methane produced as it decays. Waste-to-energy processes are gaining renewed interest as they can solve two problems at once: disposal of waste and production of energy from a renewable resource. Many of the environmental impacts are similar to those of a coal plant: air pollution, ash generation, etc. Because the fuel source is less standardized than coal and hazardous materials may be present in MSW, incinerators and waste-to-energy power plants need to clean the gases of harmful materials. The Environmental Protection Agency in the U.S. regulates these plants very strictly and requires anti-pollution devices to be installed. Also, while incinerating at high temperature, many of the toxic chemicals may break down into less harmful compounds. The ash from these plants may contain high concentrations of various metals that were present in the original waste. If ash is clean enough it can be “recycled” as an MSW landfill cover or to build roads, cement blocks, and artificial reefs (similar to coral reefs, but built by humans).
Landfill Gas (Biogas)
Landfill gas (biogas) is a sort of human-made “biogenic” gas as discussed above (figure \(\PageIndex{e}\)). Methane is formed as a result of biological processes in sewage treatment plants, waste landfills, anaerobic composting, and livestock manure management systems. This gas is captured and burned to produce heat or electricity. The electricity may replace electricity produced by burning fossil fuels, reducing carbon dioxide emissions. The only environmental impacts are from the construction of the plant itself, similar to that of a natural gas plant.
Bioethanol and Biodiesel
Bioethanol and biodiesel are liquid biofuels manufactured from plants, typically crops. Bioethanol can be easily fermented from sugar cane juice, as is done in Brazil. Additionally, it can be fermented from broken down corn starch, as is mainly done in the United States.
The economic and social effects of growing plants for fuels need to be considered, since the land, fertilizers, and energy used to grow biofuel crops could be used to grow food crops instead. The competition of land for fuel versus food can increase the price of food, which has a negative effect on society. It could also decrease the food supply increasing malnutrition and starvation globally. Also, in some parts of the world, large areas of natural vegetation and forests have been cut down to grow sugar cane for bioethanol and soybeans and palm-oil trees to make biodiesel. This is not sustainable land use. Derived biofuels from parts of plants not used for food, such as stalks, reduces their environmental impact. Biodiesel can be made from used vegetable oil and has been produced on a very local basis. Compared to diesel, a petrochemical derived from crude oil, biodiesel combustion produces less sulfur oxides, particulate matter, carbon monoxide, and unburned and other hydrocarbons, but it produces more nitrogen oxide (see Air Pollution).
Liquid biofuels typically replace petroleum and are used to power vehicles (figure \(\PageIndex{f}\)). Although ethanol-gasoline mixtures burn cleaner than pure gasoline, they also are more volatile and thus have higher “evaporative emissions” from fuel tanks and dispensing equipment. These emissions contribute to the formation of harmful, ground level ozone and smog (see Air Pollution). Gasoline requires extra processing to reduce evaporative emissions before it is blended with ethanol.
Attribution
Modified by Melissa Ha from Renewable Energy and Challenges and Impacts of Energy Use from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.06%3A_Biofuels_%28Biomass_Energy%29.txt |
Energy conservation refers to reducing energy waste and increasing efficiency. Energy conservation can involve behavior changes as well as technologies. Some examples of energy conservation have no financial impact. These include turn off and unplugging electronics when not in use, turning down the water heater, and driving efficiently (figure \(\PageIndex{a}\)). Additionally, opening blinds on south-facing windows in the morning during the winter takes advantage of a passive solar technology. Relying on the sun for heating and lighting reduces the use of electricity.
Other examples of energy conservation require some financial investment, but they quickly pay for themselves with savings on an energy bill. An energy audit is a first step to investigate inefficiencies in one's home. This helps homeowners identify where their home is losing energy, and which problem areas and fixes they should prioritize to save energy and money. For example, an energy audit may reveal places in the home where hot escaping in the winter or entering in the summer. An energy auditor might recommend installing insulation to better seal the home as well as to insulate the hot water heater and pipes. Investing in most high-efficiency appliances also pays for itself relatively quickly (figure \(\PageIndex{b}\)).
This video provides a walkthrough of an energy audit.
Finally, some strategies for energy conservation require sizeable financial investment. They can eventually pay for themselves over extended periods of time. Once example are double-paned, low emissivity (low e) windows (figure \(\PageIndex{c}\)). The two layers of glass trap air between them, which serves as insulation. Additionally, the glass is coated with very small metal dots that allow light to pass through, but infrared (heat) energy is reflected back. If it is hotter outside, heat is emitted back outside; if warmer inside, heat will be emitted back inside. Energy-efficient air conditioners, geothermal heat pumps, and on-demand (tankless) water heaters (figure \(\PageIndex{d}\)) are also examples of energy-conserving technologies that require sizeable investment.
Attribution
Melissa Ha (CC-BY-NC) and Home Energy Audits. U.S. Department of Energy. Accessed 01-18-2021. (public domain)
5.3.08: Data Dive- Global Renewable Energy Generation
Overview
Our World in Data (OWID) is a scientific online publication that focuses on using research and data to help tackle global concerns such as poverty, disease, hunger, climate change, war, and inequitable treatment of our world’s most vulnerable and unstable communities. Their website is particularly known for publishing a variety of graphs, some even interactive, to present the research that helps explain causes and consequences of global concerns to the public. One example graph, seen below, illustrates renewable energy generation:
Questions
1. What renewable energy source has had the most consistent use globally?
2. Based on what you have learned in the chapter, what sources do you think are in the “other” category? Don’t peek on the website!
3. Describe the pattern you see for the “other” category for 1965 to 2019.
4. Moving into the future, which renewable energy source do you think will grow the most in the next 50 years? Why?
Raw Data For Above Graph(s)
Raw data table link for Our World In Data graph above. (CC-BY)
Attribution
Rachel Schleiger (CC-BY-NC)
5.3.09: Review
Summary
After completing this chapter you should be able to...
• Detail the percentage that renewable energy contributes to electricity generation and total energy consumption globally and in the United States.
• Distinguish among the five main types of renewable energy, explain the mechanisms by which they are used, and discuss their advantages and disadvantages.
• Distinguish between passive and active solar technologies and provide examples of each.
• Explain how solar panels generate electricity.
• Distinguish between geothermal power plants and geothermal (ground source) heat pumps.
• Identify the main types of hydropower.
• Explain how environmental damage associated with hydropower can be mitigated.
• Explain why combustion of biofuels is carbon neutral.
• Provide examples of biofuel use and evaluate their sustainability.
• Define energy conservation and provide examples of behaviors and technologies that conserve energy.
Renewable energy sources can be replenished within a short timeframe. This includes wind, solargeothermalhydropower, and biofuels. Each is a direct or indirect form of solar energy with the exception of geothermal energy, which comes from deep underground, and tidal energy, a type of hydropower. Most forms of renewable energy generate electricity by turning a turbine, which powers a generator. For wind energy and hydropower, the motion of air or water, respectively, turns the turbine. For geothermal energy and biofuels, heat from the Earth or from burning organisms, respectively, produce steam, which turns a turbine. Solar panels generate electricity when light energy displaces electrons in semiconductors.
Generally, renewable energy sources generate little air pollution and are not major causes of climate change, but there are exceptions. A downside of renewables is that wind and solar can only be efficiently harnessed in certain locations and are intermittently available. Geothermal energy is more reliable, but geothermal power plants can typically only be built near geysers, volcanoes, or hot springs. Hydropower that involves dams and reservoirs destroys terrestrial habitats and disrupts aquatic species, but run-of-the-river hydroelectricity causes minimal damage. Biofuels are carbon neutral, capturing as much carbon dioxide as they release. Biofuels are most sustainable when they are made from materials that would otherwise be wasted.
Energy conservation involves reducing energy use or using it more efficiently. Examples of energy conservation include turning off lights and electronics when they are not in use, driving efficiently, and purchasing energy-efficient applicances.
Attribution
Melissa Ha (CC-BY-NC | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/05%3A_Energy/5.03%3A_Renewable_Energy/5.3.07%3A_Energy_Conservation.txt |
The human presence and impact on this Earth has been changing with our population, technology, and affluence. In order to start understanding how these variables have an impact on Earth (in a general sense) the IPAT equation was created. As is the case for any equation, IPAT expresses a balance among interacting factors. It can be stated as:
$I = P \times A \times T \nonumber$
where...
• "$I$" represents the impacts of a given course of action on the environment
• "$P$" is the relevant human population for the problem at hand
• "$A$" is the level of consumption per person
• "$T$" is impact per unit of consumption. Impact per unit of consumption is a general term for technology, interpreted in its broadest sense as any human-created invention, system, or organization that serves to either worsen or uncouple consumption from impact
The equation is not meant to be mathematically rigorous; rather it provides a way of organizing information for a “first-order” analysis. To achieve meaningful reductions of human impact, there are intense debates on where the focus should lie. Where one group sees expensive remedies with little demonstrable return, another sees opportunities for investment in new technologies, businesses, and employment sectors, with collateral improvements in global and national well-being.
This unit will investigate variables that represent the biggest modern components for human impact at local and global scales. Specifically, it will focus on solid waste, pollution, and climate change.
• 19: Solid Waste Management
On average, each individual in the U.S. generates about 4.9 lbs of municipal solid waste per day. Sanitary landfills and incineration are common strategies for waste disposal. A large volume of solid waste escapes to the ocean where it harms marine life and forms garbage patches. Reducing waste at the national, state, local, and individual level limits the environmental consequences of solid waste.
• 21: Climate Change
Climate change is an alteration of long-term weather patterns. The climate change that we are currently experiencing involves an increase in average global temperature. It is caused by human activities, which release greenhouse gases such as carbon dioxide and methane.
Attribution
Modified by Rachel Schleiger from Sustainability: A Comprehensive Foundation by Openstax (licensed under CC-BY)
Thumbnail: "Oil spill cleanup program" Is in the Public Domain
06: Environmental Impacts
Chapter Hook
Flushable wipes, are flushable right? No. Over and over, plumbers and waste water treatment workers state that they do not degrade fast enough and clogs drains and sewers across the globe. Not all flushable wipes are created equal, and some are better than others. Unfortunately, there are no legal requirements these products are required to passed to be called flushable, and the only guiding body is the integrity of the company manufacturing the wipes. If you want advice about your body you go to your doctor. If you want advice about your pipes, talk to your plumber. They will tell you that the only things that should go down your toilet are the 3 P’s, pee, poo, and (toilet) paper.
• 19.1: Waste Generation
Trash is a unique human construct because in healthy ecosystems, one organisms waste is always used by another organism. Wastes may be biodegradable or nondegradable. Agriculture, industry, and mining are responsible for most waste generation globally. However, the U.S. generates about 4.9 lbs of municipal solid waste per person.
• 19.2: Waste Disposal
Open dumps, sanitary landfills, and incinerators are three primary methods of waste disposal. Open dumps increase disease transmission and pollution and are banned in the U.S. Sanitary landfills seal trash to prevent pollution. Incineration can reduce waste volume and generate electricity, but it releases some air pollutants.
• 19.3: Solid Waste and Marine Life
Ocean dumping or the escape of trash into the ocean can form garbage patches, soups of small plastic pieces trapped in circular ocean currents. Plastic harms marine life by causing choking, poisoning, and damage to internal organs.
• 19.4: Waste Reduction
The waste management hierarchy lists processes for handling waste in order of preference. Unfortunately, the least preferred process (disposal) is currently used for a large volume of waste. Individuals can limit the impacts of waste through the four R's: are refuse, reduce, reuse, and recycle. Additionally, composting at home can reduce food wastes.
• 19.5: Data Dive- "Flushable" Wipes
• 19.6: Review
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
6.01: Solid Waste Management
In natural systems, there is no such thing as waste. Everything flows in a natural cycle of use and reuse. Living organisms consume materials and eventually return them to the environment, usually in a different form, for reuse. Solid waste (or trash) is a human concept. It refers to a variety of discarded materials, not liquid or gas, that are deemed useless or worthless (figure \(\PageIndex{a}\)). Humans modify natural substances, making them more difficult to breakdown, or store matter under conditions that slow its degradation. However, what is worthless to one person may be of value to someone else, and solid wastes can be considered misplaced resources. Learning effective ways to reduce the amount of wastes produced and to recycle valuable resources contained in the wastes is important if humans wish to maintain a livable and sustainable environment.
Types of Waste
There are many subcategories of waste (figure \(\PageIndex{b}\)). Biodegradable waste can be broken down by microbes whereas nondegradable waste does not readily break down. Hazardous waste is trash that presents a health risk. Specifically, hazardous wastes are defined as materials which are toxic, carcinogenic (cause cancer), mutagenic (cause DNA mutations), teratogenic (cause birth defects), highly flammable, corrosive, or explosive. Examples include batteries, fluorescent lights, various cleaners, and e-waste, which arises from discarded electronics. Precious metals can be extracted and recycled from hazardous waste, but it must be done safely.
Interactive Element
How do you dispose of household hazardous wastes? Check Earth 911 for disposal sites near you.
Solid Waste Sources and Composition
Agriculture and industry generate most of the waste globally followed by mining (figure \(\PageIndex{c}\)). Together, these generate non-municipal solid waste. Some common items that are classified as non-municipal waste are: construction materials (roofing shingles, electrical fixtures, bricks); waste-water sludge; incinerator residues; ash; scrubber sludge; oil/gas/mining waste; railroad ties, and pesticide containers. The remaining waste, municipal solid waste (MSW), is made up of discarded solid materials from residences, businesses, and city buildings. Globally, waste generated from industry generated was nearly 18 times that of MSW, and waste generated from agriculture was more than 4.5 times that of MSW.
The world generates 2.21 billion tons of municipal solid waste annually. Municipal solid waste makes up 3-9% of all waste in the U.S., and 292.4 million tons were generated in U.S. in 2018 (4.9 lbs per person per day). This contrasts with average values in Sub-Saharan Africa (1.01 lbs per person per day), South Asia (1.15 lbs per person per day), and East Asia and the Pacific (1.23 lbs per person per day). Daily waste generation per person in high income countries is projected to increase by 19 percent by 2050, compared to low- and middle-income countries where it is anticipated to increase by approximately 40 percent or more.
Municipal solid waste consists of materials from plastics to food scraps. The most common waste product is paper (about 23% of the total; figure \(\PageIndex{d}\)). Other common components are yard waste (green waste), plastics, metals, wood, glass and food waste. The composition of the municipal wastes can vary from region to region and from season to season.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.01%3A_Solid_Waste_Management/6.1.01%3A_Waste_Generation.txt |
There are three primary methods for waste disposal: open dumps, sanitary landfills, and incineration. Sanitary landfills and incineration prevent reuse, recycling, and proper decomposition. While open dumps promote decomposition better than other methods of waste disposal and allow discarded materials to be salvaged or recycled, they promote disease spread and cause water pollution. They are thus illegal in many countries.
Open Dumps
Open dumps involve simply piling up trash in a designated area and is thus the easiest method of waste disposal (figure \(\PageIndex{a}\)). Open dumps can support populations of organisms that house and transmit disease (reservoirs and vectors, respectively). Additionally, contaminants from the trash mix with rain water forming leachate, which infiltrates into the ground or runs off. This liquid leachate may contain toxic chemicals such as dioxin (a persistent organic pollutant), mercury, and pesticides.
Sanitary Landfills
After recycling, composting, and incineration, the remaining 50% of municipal solid waste (MSW) in the U.S. was discarded in sanitary landfills (figure \(\PageIndex{b}\)). Trash is sealed from the top and the bottom to reduce contamination of surroundings (figure \(\PageIndex{c}\)). Rainwater that percolates through a sanitary landfill is collected in the bottom liner, and this bottom layer thus prevents contamination of groundwater. The groundwater near the landfill is closely monitored for signs of contamination from the leachate. Layers of soil on top prevent disease spread. Each day after garbage is dumped in the landfill, it is covered with clay or plastic to prevent redistribution by animals or the wind.
Several practices can reduce the environmental impact of sanitary landfills. Compacting in landfills reduces water and oxygen levels, slowing decomposition and promoting methane release. In the U.S., the Clear Air Act requires that landfills of a certain size collect landfill gas (biogas), which can be used as a biofuel for heating or electricity generation. Other gases such as ammonia and hydrogen sulfide may also be released by the landfill, contributing to air pollution. These gases are also monitored and, if necessary, collected for disposal. To address the often dry condition of wastes within landfills, the concept of bioreactor landfills has emerged. These recirculate leachate and/or inject other liquids to increase moisture and promote decomposition (and therefore increasing the rate of biogas production). Upon closure, many landfills undergo "land recycling" and can be redeveloped as golf courses, recreational parks, and other beneficial uses.
With respect to waste mitigation options, landfilling is quickly evolving into a less desirable or feasible option. Landfill capacity in the United States has been declining for several reasons. Older existing landfills are increasingly reaching their authorized capacity. Additionally, stricter environmental regulations have made establishing new landfills increasingly difficult. Finally, public opposition delays or, in many cases, prevents the approval of new landfills or expansion of existing facilities.
Incineration
Incineration is simply burning trash. This has several advantages: it reduces volume and can be used to generate electricity (waste-to-energy). In fact, the sheer volume of the waste is reduced by about 85%. Incineration is costly, however, and it pollutes air and water. Air pollutants released by incineration include particulates, sulfur dioxide, nitrogen oxides, methane, heavy metals (such as lead and mercury), and dioxins. The byproduct of incineration, ash, is often toxic. Depending on its composition, ash might require special disposal; other types of ash can be repurposed.
An incinerator processes trash and burns it in a combustion chamber (figure \(\PageIndex{d-e}\)). The heat boils water, and the resultant steam is used to generate electricity. The smoke (called flue gases) goes through a pollution-removal before it is released, but it still contains some pollutants. The U.S. incinerated 11.8% of MSW in 2018.
There are two kinds of waste-to-energy systems: mass burn incinerators and refuse-derived incinerators. In mass burn incinerators all of the solid waste is incinerated. The heat from the incineration process is used to produce steam. This steam is used to drive electric power generators. Acid gases from the burning are removed by chemical scrubbers. Any particulates (small particles that remain suspended in the air) in the combustion gases are removed by electrostatic precipitators, which charge particulates and remove them with electrodes. The cleaned gases are then released into the atmosphere through a tall stack. The ashes from the combustion are sent to a landfill for disposal.
It is best if only combustible items (paper, wood products, and plastics) are burned. In a refuse-derived incinerator, non-combustible materials are separated from the waste. Items such as glass and metals may be recycled. The combustible wastes are then formed into fuel pellets which can be burned in standard steam boilers. This system has the advantage of removing potentially harmful materials from waste before it is burned. It also provides for some recycling of materials.
Attribution
Modified by Melissa Ha from the following sources:
6.1.03: Solid Waste and Marine Life
Ocean dumping has also been a popular way for coastal communities to dispose of their solid wastes. In this method, large barges carry waste out to sea and dump it into the ocean (figure \(\PageIndex{a}\)). That practice is now banned in the United States due to the pollution problems it created. However, much trash escapes to the ocean through littering and illegal dumping. Additionally, wind carries trash off of overfilled containers, landfills, or open dumps (where they are still used).
Garbage patches form from waste that escapes to the ocean. Plastic breaks down into smaller pieces when exposed to sunlight and ample oxygen. These pieces of plastic are trapped in calm parts of the ocean that are surrounded by strong, circular currents (figure \(\PageIndex{b}\)). Garbage patches may not be visible from the surface of the ocean, and the plastic pieces may be up to 20 meters deep.
Plastic and other trash harms marine life in several ways. Old fishing nets and plastic six-pack rings trap wildlife. Additionally, organisms that ingest plastic risk choking. Ingested plastic may cut internal organs, limit space available for food, and carry toxins (figure \(\PageIndex{c}\)).
Interactive Element
Edible six-pack rings offer a solution to the problem of plastic six-pack rings harming wildlife. You can read more about them here.
Attribution
Melissa Ha (CC-BY-NC) and Solid Waste from AP Environmental Science by University of California College Prep (CC-BY). Download for free at CNX. | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.01%3A_Solid_Waste_Management/6.1.02%3A_Waste_Disposal.txt |
The waste management hierarchy lists processes to address waste in order of preference with the goals of limiting waste, minimizing environmental impact, and maximizing additional benefits (such as electricity generation or production of recycled goods). It is symbolized as an upside triangle, meaning that the largest volume of waste should be handled using the first process (most preferred), and the smallest volume should be handled using the last process (least preferred). These processes in order of preference are reduction, recycling, energy recovery (such as incineration), treatment, and disposal (figure \(\PageIndex{a}\)). Individuals can exercise the first two processes by applying the four R's (see below). Unfortunately, the U.S. and the world overall, handles a large volume of waste using the least preferred method (disposal). As previously mentioned, about half of municipal solid waste (MSW) goes to a sanitary landfill for disposal. In contrast, only 23.5% of municipal solid waste (MSW) was recovered and recycled and another 8.5% was composted in 2018. Waste stream percentages also vary widely by region. As an example, San Francisco, California recycles or composts 80% of its waste material, whereas Houston, Texas recycles or composts only 19%.
Figure \(\PageIndex{a}\): Left: The waste management hierarchy lists processes for handling waste from most to least preferable. They are source reduction, recycling, energy recovery, treatment, and disposal or other releases. Right: The food recovery hierarchy is a waste management hierarchy specific to food waste. It begins with source reduction (reduce the volume of surplus food generated). Next is feed hungry people (donate extra food to food banks, soup kitchens, and shelters. Third is feed animals (divert food scraps to animal food. Fourth is industrial uses (provide waste oils for rendering and fuel conversion and food scraps for digestion to recover energy. Fifth is composting (create a nutrient-rich soil amendment). The remaining waste goes to landfill or incineration as a last resort to disposal. Images by EPA (public domain).
Source reduction (waste minimization) refers to the strategies that minimize the amount of generated waste and/or reduce the toxicity of the resultant waste when designing or manufacturing products or services. Waste can be reduced by reusing materials, using less hazardous substitute materials, or by modifying components of design and processing. Source reduction in manufacturing not only saves resources, but it also reduces costs for the manufacturer and indirectly for the consumer. For example, minimal packaging reduces material use, increases distribution efficiency, and reduces fuel consumption and resulting air emissions. Similarly, building materials can be designed to reduce the overall mass of material needed for a given structure.
Recycling refers to recovery and reprocessing of useful materials. Numerous examples of successful recycling and reuse efforts are encountered every day. Many construction materials can be reused, including concrete, asphalt materials, masonry, and reinforcing steel. "Green" plant-based wastes are often recovered and immediately reused for mulch or fertilizer applications. Many industries also recover various byproducts for reuse. In some cases, the recycled materials are used as input materials and are heavily processed into end products. Common examples include the use of scrap paper for new paper manufacturing, or the processing of old aluminum cans into new aluminum products. In other cases, reclaimed materials undergo little or no processing prior to their reuse. Some common examples include the use of tree waste as wood chips, or the use of brick and other fixtures into new structural construction. In any case, the success of recycling depends on effective collection and processing of recyclables, markets for reuse, and public acceptance and promotion of recycled products and applications utilizing recycled materials.
The Four R's
The four R's (refuse, reduce, reuse, and recycle) are strategies that allow individuals to limit the volume and negative impacts of the waste they generate. They resemble the waste management hierarchy, but focus at the individual scale rather than the scale of a company or waste management system. They are listed in order of most to least environmentally beneficial, and they are all better alternatives than discarding trash into the landfill. Recycling is last because it requires energy to reprocess waste.
To refuse is to decline products or processes that harm the environment if you do not need them. Choosing products without packaging is an example of refusing. To reduce is to choose products or processes with lower ecological footprint (the area of land required to produce them). Examples include products with limited packaging or durable items rather than flimsy or disposable ones. Reuse refers to using a product multiple times or finding an alternative use for it. For example, one could share, borrow, or rent items. A plastic yogurt or pudding container could be repurposed for storage or gardening. As noted above, recycling means to return used items to be reprocessed (figure \(\PageIndex{b}\)). Commonly recycled materials include cardboard, glass, cans, and certain plastics.
Figure \(\PageIndex{b}\): Recycling, or returning materials to be reprocessed, is the last of the four R's. If items cannot be refused, reduced, or reused, recycling is a better alternative than discarding into the landfill. Image by Intel Free Press (CC-BY).
Resin identification codes are the triangular symbols on recyclable plastics that indicate their composition (figure \(\PageIndex{c}\)). A variety of materials make up plastics, and they are not all recycled the same way. Furthermore, your local recycling service may recycle some types of plastics but not others. Plastics with codes 1 and 2 are commonly recycled. For the codes, check with your local recycling service. Local businesses may house collection bins for plastics that are not commonly recycled. For example, grocery stores commonly have receptacles for recycling plastic bags, which fall under code 4.
Interactive Element
Which items can be recycled is based on where you live and the waste management service available there. The Environmental Protection Agency provides general recycling guidelines. You local waste collector may provide an interactive website to help you determine which items to recycle. For example Recology, which serves Northern California, has a searchable website called What Bin.
Composting
Compost is organic material that can be added to soil to help plants grow (figure \(\PageIndex{d}\)). Food scraps and yard waste together currently make up more than 30% of what we throw away and could be composted instead. Making compost keeps these materials out of landfills where they take up space and release methane, a potent greenhouse gas that contributes to climate change. Furthermore, compost enriches soil, helping retain moisture and suppress plant diseases and pests. It reduces the need for chemical fertilizers and encourages the production of beneficial bacteria and fungi. Composting can be done at an industrial scale, such as with yard waste collected from homes in a city. It can also be done at home.
All composting requires three basic ingredients: browns, greens, and water. "Browns" are materials such as dead leaves, branches, and twigs. "Greens" are materials such as grass clippings, vegetable waste, fruit scraps, and coffee grounds. The brown materials provide carbon for your compost, the green materials provide nitrogen, and the water provides moisture to help break down the organic matter. A compost pile should have an equal amount of browns to greens. Layers of these organic materials with different particle sizes should be alternated.
Backyard Composting
Backyard composting requires a compost bin or pile to be placed in dry, shady spot near a water source (figure \(\PageIndex{e}\)). Brown and green materials are added as they are collected, and larger pieces are chopped or shredded before they are added to the pile. Dry materials are moistened as they are added. Once the compost pile is established, grass clippings and green waste are mixed into the pile when added. When fruit and vegetable wastes are added, they are buried under 10 inches of compost material. Some homeowners cover the top of the compost with a tarp to keep it moist. When the material at the bottom is dark and rich in color, the compost is ready to use. This usually takes anywhere between two months to two years.
Indoor Composting
For those who do not have the space for an outdoor compost pile, materials can be composted indoors using a special type of bin, which can be purchased at a local hardware store, gardening supplies store, or made at home. Care must be taken to properly manage the compost pile and keep track of what is added such that it does not attract pests or rodents or smell bad. The compost should be ready in two to five weeks.
Interactive Element
Not all food scraps can go into compost. If you want to start a compost pile and are not sure which food scraps are suitable, see the lists on the Environmental Protection Agency website.
Attribution
Modified by Melissa Ha from the following sources:
6.1.05: Data Dive- Flushable Wipes
Overview
Ryerson University published a 2019 report titled, Defining “Flushability” for Sewer Use. This publication had the objective of making the public think twice about what you flush down the toilet in order to save money and the environment. In this experiment they tested 101 single use products, some labeled (and some not labeled) flushable. Some of the results of this can be seen in the graph below:
Questions
1. What type of data is this (qualitative or quantitative)?
2. What question(s) are the authors trying to answer with this graph?
3. What result is this graph illustrating relative to products labeled as “flushable?”
4. Provide a brief reflection for how these results make you feel and what they make you think about?
5. Do you think there should be a policy put in place that places restrictions on what the word “flushable” means? Why?
Attribution
Rachel Schleiger (CC-BY-NC)
6.1.06: Review
Summary
After completing this chapter you should be able to...
• Distinguish between biodegradable and nondegradable waste.
• Provide examples of hazardous waste.
• List the major waste generating processes globally.
• Compare the volume of waste generated per person per day in the U.S. with other countries around the world.
• Define municipal solid waste and describe its composition in the U.S.
• Compare open dumps, sanitary landfills, and incineration, outlining the advantages and disadvantages of each approach.
• Explain how trash enters the ocean and how it harms marine life.
• Explain the waste management hierarchy.
• List the four R's and provide examples of each.
• Explain the benefits and process of composting.
Solid waste refers to a variety of discarded materials that are deemed useless and discarded by humans. Waste may be easily broken down (biodegradable) or nondegradable. Hazardous waste is harmful to human health. Examples include batteries, cleaners, and e-waste. Agriculture, industry, and mining generate most of the world's waste. Municipal solid waste (MSW) is discarded from residences, businesses, and city buildings, and the U.S. generates more MSW per person per day than most countries around the world.
Three strategies for disposing of waste are open dumps, sanitary landfills, and incinerators. Open dumps cause disease spread, air pollution, and water pollution, and are thus illegal in the U.S. About half of the MSW in the U.S. goes to sanitary landfills, which compact trash and seal it to prevent pollution. Incinerators burn trash, which reduces its volume while generating energy.
Ocean dumping and escape of trash from overfilled bins and open dumps has contaminated the ocean with many plastics. These break into small pieces and form garbage patches. Plastic in the ocean can trap, poison, or otherwise harm marine life.
The waste management hierarchy diagrams the priorities of waste reduction. Source reduction and recycling are key to limiting waste and mitigating its environmental impacts. However, a large volume of trash goes to disposal, the least preferred method for handling waste. Individuals can limit their own waste by employing the four R'srefusereducereuse, and recycleComposting at home also reduces food and yard waste.
Attribution
Melissa Ha (CC-BY-NC | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.01%3A_Solid_Waste_Management/6.1.04%3A_Waste_Reduction.txt |
Chapter Hook
In the midst of the COVID-19 pandemic many people in the United States were feeling the fatigue of wearing face masks for protection. However, people in the United States should consider themselves lucky that normally their air is clean enough that face masks are only really necessary for people who have sensitive immune systems (to things like the flu season, wildfire season, and allergy season). Thus, masks are not a normal part of life for people in the United States. However, in some places around the world, masks are normally worn due to heavy air pollution. For example, people living or working in the cities of China wear masks as a daily part of life. Every day, people wear masks to protect their lungs. Although pollution is decreasing due to policies set in place to fight pollution, it hasn’t yet made masks an unnecessary part of everyday life.
Attribution
Modified by Rachel Schleiger (CC-BY-NC).
6.02: Pollution
Water pollution is the contamination of water by an excess amount of a substance that can cause harm to human beings and/or the ecosystem. Contaminants may come from from direct or indirect sources, or captured from air by rain. The level of water pollution depends on the abundance of the pollutant, the ecological impact of the pollutant, and the use of the water.
Attribution
Modified by Melissa Ha from Water Pollution from Environmental Biology by Matthew R. Fisher (licensed under CC-BY)
• 20.1.1: Water Pollutants and Their Sources
Water can be contaminated by various human activities or by existing natural features, like mineral-rich geologic formations. Agricultural activities, industrial operations, landfills, animal operations, and small and large scale sewage treatment processes, among many other things, all can potentially contribute to contamination. As water runs over the land or infiltrates into the ground, it dissolves material left behind by these potential contaminant sources.
• 20.1.2: Water Treatment
Untreated waste water contributes to hundreds of thousands of deaths every year. In the U.S., most wastewater is treated at a wastewater treatment plant or through a septic tank system, but billions of gallons of untreated waste water still escape each year.
• 20.1.3: Mitigating Water Pollution
Point source water pollution is regulated by the Clean Water Act. Remediation functions in cleaning up existing pollution. Watershed management relies on riparian areas to promote water quality.
6.2.01: Water Pollution
Although natural processes such as volcanic eruptions or evaporation sometimes can cause water pollution, most pollution is derived from human, land-based activities. Pollutants can spread through different water reservoirs, as the water carrying them progresses through stages of the water cycle (figure \(\PageIndex{a}\)). Residence time (the average time that a water molecule spends in a reservoir) is key to pollution problems because it affects pollution potential. Water in rivers has a relatively short residence time, so pollution usually is there only briefly. Of course, pollution in rivers may simply move to another reservoir, such as the ocean, where it can cause further problems. Groundwater is typically characterized by slow flow and longer residence time, which can make groundwater pollution particularly problematic. Finally, pollution residence time can be much greater than the water residence time because a pollutant may be taken up for a long time within the ecosystem or absorbed onto sediment.
Water can be contaminated by various human activities or by existing natural features, like mineral-rich geologic formations. Agricultural activities, industrial operations, landfills, animal operations, and small and large scale sewage treatment processes, among many other things, all can potentially contribute to contamination. As water runs over the land or infiltrates into the ground, it dissolves material left behind by these potential contaminant sources. The risks and type of remediation for a contaminant depend on the type of chemicals present.
Point source pollution can be attributed to a single, definable origin. For example, animal factory farms (figure \(\PageIndex{b}\)) raise a large number and high density of livestock such as cows, pigs, and chickens. Combined sewer systems that have a single set of underground pipes to collect both sewage and storm water runoff from streets for wastewater treatment can also be major point sources of pollutants. During heavy rain, storm water runoff may exceed sewer capacity, causing it to back up. This spills untreated sewage directly into surface waters (figure \(\PageIndex{c}\)). Other examples include pipes from factories, waste disposal sites, storage tanks, and chemical spills.
Nonpoint source pollution is from multiple dispersed sources. The whole of the contribution of pollutants is harmful, but the individual components may not reach harmful concentrations. Nonpoint sources of pollution include agricultural fields, cities, and abandoned mines. Rainfall runs over the land and through the ground, picking up pollutants from throughout the watershed (including areas of land and smaller streams that drain into a particular body of water). These pollutants might include herbicides, pesticides, and fertilizer from agricultural fields and lawns; oil, antifreeze, animal waste, and road salt from urban areas; and acid and toxic elements from abandoned mines. Then, this pollution is carried by runoff into surface water bodies and groundwater. Nonpoint source pollution, which is the leading cause of water pollution in the U.S., is usually much more difficult and expensive to control than point source pollution because of its low concentration, multiple sources, and much greater volume of water.
According to a 2016 report, there were 20,912 cases of impaired water bodies in the United States, which means they could neither support a healthy ecosystem nor meet water quality standards (table \(\PageIndex{a}\)). Selected causes of impairment (water pollutants) are discussed below, categorized according to whether they arise from chemical, biological, or physical processes.
Table \(\PageIndex{a}\): The leading causes of impaired bodies of water in the United States in 2016. Data from EPA (public domain).
Cause of Impairment Number of Impaired Bodies of Water
Polychlorinated biphenyls (PCBs) 3,712
Pathogens 2,248
Nutrients 2,228
Mercury 2,138
Metals (other than mercury) 2,075
Cause unknown- impaired biota 1,852
Organic enrichment/oxygen depletion 1,281
Turbidity 1,175
Pesticides 795
Salinity/total dissolved solids/chlorides/sulfates 576
pH/acidity/caustic conditions 489
Sediment 453
Temperature 358
Total toxics 282
Algal growth 174
Cause unknown 159
Dioxins 136
Toxic organics 127
Toxic inorganics 99
Chemical Pollutants
Chemical pollution from agriculture, industry, cities, and mining threatens global water quality. Air pollutants from these activities can also enter bodies of water (and become water pollutants) through dry deposition, precipitation, and runoff. Some chemical pollutants have serious and well-known health effects, whereas many others have poorly known long-term health effects.
Any natural water contains dissolved chemicals, some of which are important human nutrients while others can be harmful to human health. The concentration of a water pollutant is commonly given in very small units such as parts per million (ppm) or even parts per billion (ppb). An arsenic concentration of 1 ppm means 1 part of arsenic per million parts of water. This is equivalent to one drop of arsenic in 50 liters of water. To give you a different perspective on appreciating small concentration units, converting 1 ppm to length units is 1 cm (0.4 in) in 10 km (6 miles) and converting 1 ppm to time units is 30 seconds in a year. Total dissolved solids (TDS) represent the total amount of dissolved material in water. Average TDS values for rainwater, river water, and seawater are about 4 ppm, 120 ppm, and 35,000 ppm, respectively.
Organic Pollutants
Organic pollutants include herbicides and pesticides, pharmaceuticals, fuel (such as oil spills), industrial solvents and cleansers, and synthetic hormones associated with pharmaceuticals. These synthetic hormones can act as endocrine disruptors. Many are persistent organic pollutants (POPs), which are long-lived in the environment, biomagnify through the food chain, and can be toxic. As previously mentioned, DDT (pesticide), dioxin (herbicide by-product), and PCBs (polychlorinated biphenyls, which were used as a liquid insulator in electric transformers), are all POPs.
An example of organic chemical contamination is the Love Canal, in Niagara Falls, New York (Figure \(\PageIndex{d}\)). From 1942 to 1952, the Hooker Chemical Company disposed of over 21,000 tons of chemical waste, including chlorinated hydrocarbons, into a canal and covered it with a thin layer of clay. Chlorinated hydrocarbons are a large group of organic chemicals that have chlorine functional groups, most of which are toxic and carcinogenic to humans (DDT and PCBs are an examples.) The company sold the land to the New York School Board, who developed it into a neighborhood. After residents began to suffer from serious health ailments and pools of oily fluid started rising into residents’ basements, the neighborhood had to be evacuated. This site became a U.S. Environmental Protection Agency Superfund Site, a site with federal funding and oversight to ensure its cleanup.
Inorganic Pollutants
Inorganic pollutants (figure \(\PageIndex{e}\)) include nutrients like nitrate (NO3-) and phosphate (PO43-), heavy metals, chloride (Cl-), and radioactive isotopes released from mining or nuclear accidents (such as cesium, iodine, uranium, and radon gas). Nutrients can be from geologic material, like phosphorus-rich rock, but are most often sourced from fertilizer and animal and human waste. Untreated sewage and agricultural runoff concentrate nitrogen and phosphorus which are essential for the growth of microorganisms. Nutrients like nitrate and phosphate in surface water can promote the growth of microbes, like blue-green algae (cyanobacteria), which in turn deplete dissolved oxygen (O2) and produce toxins. This process is known as eutrophication (discussed below as well as previously in Biogeochemical Cycles, Threats to Biodiversity, and Industrial Agriculture).
Examples of heavy metals include arsenic, mercury, lead, cadmium, and chromium, and they can bioaccumulate and biomagnify through the food chain. Arsenic (As) enters the water supply naturally from weathering of arsenic-rich minerals and from human activities such as coal burning and smelting of metallic ores. The worst case of arsenic poisoning occurred in the densely populated impoverished country of Bangladesh, which had experienced 100,000s of deaths from diarrhea and cholera each year from drinking surface water contaminated with pathogens due to improper sewage treatment. In the 1970s the United Nations provided aid for millions of shallow water wells, which resulted in a dramatic drop in pathogenic diseases. Unfortunately, many of the wells produced water naturally rich in arsenic. Tragically, there are an estimated 77 million people (about half of the population) who inadvertently may have been exposed to toxic levels of arsenic in Bangladesh as a result. The World Health Organization has called it the largest mass poisoning of a population in history.
Mercury enters the water supply naturally from weathering of mercury-rich minerals and, like mercury, from human activities such as coal burning and metal processing. A famous mercury poisoning case in Minamata, Japan involved methylmercury-rich industrial discharge that caused high mercury levels in fish. People in the local fishing villages ate fish up to three times per day for over 30 years, which resulted in over 2,000 deaths. During that time the responsible company and national government did little to mitigate, help alleviate, or even acknowledge the problem.
Salt, typically sodium chloride, is a common inorganic contaminant. It can be introduced into groundwater from natural deposits or from anthropogenic sources like the salts applied to roads in the winter to keep ice from forming (figure \(\PageIndex{f}\)). Salt contamination can also occur from saltwater intrusion, where cones of depression around fresh groundwater pumping near ocean coasts induce the encroachment of saltwater into the freshwater body.
The acidity or alkalinity of a body of water can also impact its quality. pH is a measure of the concentration of hydrogen ions (protons) in a solution, which determines how acidic or basic (alkaline) a solution is. Acidic solutions have a high hydrogen ion concentration and a pH less than 7, and basic solutions have a pH of greater than 7. The pH of freshwater usually ranges from 5 to 9, and saltwater is slightly basic (pH = 8.2) in a healthy ecosystem. When conditions are too acidic, some aquatic animals cannot reproduce, and calcium carbonate structures (clams, snails, corals, etc.) dissolve. Acid deposition is further discussed later in this chapter, and ocean acidification is discussed in the next chapter.
Hard water contains abundant calcium and magnesium, which reduces its ability to develop soapsuds and enhances scale (calcium and magnesium carbonate minerals) formation on hot water equipment. Water softeners remove calcium and magnesium, which allows the water to lather easily and prevent the minerals from precipitating on surfaces (figure \(\PageIndex{g}\)). Hard water develops naturally from the dissolution of calcium and magnesium carbonate minerals in soil; it does not have negative health effects in people.
Biological Pollutants
Pathogens (infectious microorganisms or viruses) enter water primarily from human and animal fecal waste due to inadequate sewage treatment. In many underdeveloped countries, sewage is discharged into local waters either untreated or after only rudimentary treatment. In developed countries untreated sewage discharge can occur from overflows of combined sewer systems, poorly managed livestock factory farms, and leaky or broken sewage collection systems. Water with pathogens can be remediated by adding chlorine or ozone (O3), by boiling, or by treating the sewage in the first place.
Physical Sources of Pollution
Trash, sediments, and thermal pollution arise from physical sources of pollution (figure \(\PageIndex{h}\)). Trash was discussed extensively in Solid Waste Management. Excess sediments enter bodies of water when various land uses, such as mining, deforestation, and agriculture increases erosion. Sediments can carry toxins or excess nutrients with them, and they cloud the water (resulting in turbidity). Turbidity obstructs aquatic plants from accessing sufficient sunlight. Thermal pollution occurs when water temperature exceeds its natural range. Many power plants (such as coal, natural gas, nuclear, etc.) rely on water from the environment for cooling. This water is released back into bodies of water at a higher temperature than usual. High temperature disrupt aquatic organisms for several reasons; one is that warmer waters cannot hold as much dissolved oxygen (see below; figure \(\PageIndex{i}\)). Dams can also raise water temperature to the detriment or the organisms that live there.
Biochemical Oxygen Demand, Hypoxia, and Eutrophication
Oxygen-demanding waste is an extremely important pollutant to ecosystems. Most surface water in contact with the atmosphere has a small amount of dissolved oxygen, which is needed by aquatic organisms for cellular respiration. Decomposers, such as bacteria and fungi, also conduct cellular respiration and consume oxygen as they break down dead organic matter.
Too much decaying organic matter in water is a pollutant because it removes oxygen from water, which can kill fish, shellfish, and aquatic insects. The amount of oxygen used by aerobic (in the presence of oxygen) decomposition of organic matter is called biochemical oxygen demand (BOD). The major source of dead organic matter in many natural waters is sewage; grass and leaves are smaller sources.
An unpolluted water body with respect to BOD is a turbulent river that flows through a natural forest. Turbulence continually brings water in contact with the atmosphere where the dissolved oxygen content is restored. The dissolved oxygen content in such a river ranges from 10 to 14 ppm. When biological oxygen demand is low, clean-water fish such as trout thrive (figure \(\PageIndex{j}\)).
A polluted water body with respect to BOD is a stagnant, deep lake in an urban setting with a combined sewer system. This system favors a high input of dead organic carbon from sewage overflows and limited chance for water circulation and contact with the atmosphere. In such a lake, the dissolved oxygen content is ≤ 5 ppm. Biological oxygen demand is high, and fish tolerant to low oxygen levels, such as carp and catfish dominate (figure \(\PageIndex{k}\)).
Excessive nutrients, particularly nitrogen (N) and phosphorous (P), are pollutants closely related to oxygen-demanding waste. Plants and algae require 15-20 nutrients for growth, most of which are plentiful in water. Nitrogen and phosphorus are called limiting nutrients, however, because they usually are present in water at low concentrations and therefore restrict the total amount of plant growth. This explains why nitrogen and phosphorus are major ingredients in most fertilizer.
High concentrations of limiting nutrients, particularly nitrogen (N) and phosphorous (P), from human sources (mostly agricultural and urban runoff including fertilizer, sewage, and phosphorus-based detergent) can cause cultural eutrophication, which leads to the rapid growth of aquatic producers, particularly algae. Thick mats of floating algae or rooted plants lead to a form of water pollution that damages the ecosystem by clogging fish gills and blocking sunlight (figure \(\PageIndex{k}\)). A small percentage of algal species produce toxins that can kill animals, including humans. Exponential growths of these algae are called toxic algal blooms.
When the prolific algal layer dies, it becomes oxygen-demanding waste, which can create very low oxygen concentrations in the water (< 2 ppm), a condition called hypoxia. This results in a dead zone because it causes death from asphyxiation to organisms that are unable to leave that environment (figure \(\PageIndex{l}\)). Approximately 50% of lakes in North America, Europe, and Asia are negatively impacted by eutrophication. Eutrophication and hypoxia are difficult to combat because they are caused primarily by nonpoint source pollution, which is difficult to regulate, and nitrogen and phosphorus are difficult to remove from wastewater.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.01%3A_Water_Pollution/6.2.1.01%3A_Water_Pollutants_and_Their_Sources.txt |
The most deadly form of water pollution, pathogenic microorganisms that cause waterborne diseases, killed 485,000 million people (mostly in developing countries) in 2017. The best strategy for addressing this problem is proper sewage (wastewater) treatment. Untreated sewage is not only a major cause of pathogenic diseases, but also a major source of other pollutants, including oxygen-demanding waste, excess nutrients, and toxic heavy metals. Wastewater treatment is done at a sewage treatment plant in urban areas and through a septic tank system in rural areas.
The wastes generated by some 80% of U.S. households are collected in sewer systems. Each day, the United States processes about 34 billion gallons of wastewater (99.9% of this is water). In 2004, an Environmental Protection Agency (EPA) report estimated that 860 billion gallons of untreated wastewater (raw sewage) escaped into rivers, streams, and the ocean, mainly from combined sewage systems (see Water Pollutants and Their Sources). As of 2020, the EPA has assessed nearly 96% of the systems responsible for wastewater overflow and addressed them with a civil complaint, enforcement order, or permit requirement. However, in 2017, the EPA estimated that were still 40,000 or more wastewater overflow events, which released raw sewage into bodies of water.
To reduce water pollution problems, separate sewer systems (where street runoff goes to rivers and only wastewater goes to a wastewater treatment plant) are much better than combined sewer systems, which can overflow and release untreated sewage into surface waters during heavy rain. Some cities such as Chicago, Illinois have constructed large underground caverns and also use abandoned rock quarries to hold storm sewer overflow. After the rain stops, the stored water goes to the sewage treatment plant for processing.
Wastewater Treatment
The sewage that is properly directed to a wastewater treatment plant undergoes several steps: pretreatment, primary treatment, tertiary treatment, and disinfection and discharge (figure \(\PageIndex{a}\)). Pretreatment involves the screening and removal of sand and gravel. Primary treatment involves settling or floatation to remove organic solids, fat, and grease. The undissolved solids in raw sewage to settle out of suspension forming sludge. Such primary treatment removes only one-third of the biological oxygen demand (BOD) and virtually none of the dissolved minerals. Attempts to use digested sludge as a fertilizer have been hampered by its frequent contamination by toxic chemicals derived from industrial wastes.
Next, the organic solids in the effluent are decomposed by aerobic (oxygen-requiring) bacteria in secondary treatment. Here the effluent is brought in contact with oxygen. Aerobic microorganisms break down much of the organic matter to harmless substances such as carbon dioxide. Primary and secondary treatment together can remove up to 90% of the BOD. After chlorination to remove its content of bacteria, the effluent from secondary treatment is returned to the local surface water.
The concentrated organic solid produced during primary and secondary treatment (sludge) is treated in a variety of ways including landfill disposal, incineration, use as fertilizer, and anaerobic bacterial decomposition, which is done in the absence of oxygen. Anaerobic decomposition of sludge produces methane gas, which can be used as an energy source.
Although the combination of primary and secondary treatment removes most of the organic matter in sewage, lowering BOD, most of the nitrogen and phosphorus in sewage remains in the effluent (liquid portion of the sewage). In tertiary treatment, bacteria are used to remove the remaining nutrients, and filtration occurs. Additionally, several techniques are available to remove dissolved salts from sewage effluent, but all are quite expensive.
During disinfection, further treatment involves disinfection with chlorine, ozone, ultraviolet light, or bleach to kill most microbes. Finally, the treated water is discharged to surface waters (usually a local river) or reused for some other purpose, such as irrigation, habitat preservation, and artificial groundwater recharge
Septic Tank System
A septic tank system is an individual sewage treatment system for homes in typically rural settings. The basic components of a septic tank system (figure \(\PageIndex{b}\)) include a sewer line (inlet) from the house, a septic tank, and the drain field. The septic tank is a large container where sludge settles to the bottom, where microorganisms decompose the organic solids anaerobically. The drain field is a network of perforated pipes where the clarified water seeps into the soil and is further purified by bacteria. Water pollution problems occur if the septic tank malfunctions, which usually occurs when a system is established in the wrong type of soil or maintained poorly.
Addressing Water Treatment Globally
For many developing countries, financial aid is necessary to build adequate wastewater treatment facilities. The World Health Organization estimates an estimated cost savings at least \$5 for every \$1 invested in clean water delivery and sanitation. The cost savings are from health care savings, gains in work and school productivity, and prevented deaths. Simple and inexpensive techniques for treating water at home include chlorination, filters, and solar disinfection. Another alternative is to use constructed wetlands technology (marshes built to treat contaminated water), which is simpler and cheaper than a conventional sewage treatment plant.
Attributions
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.01%3A_Water_Pollution/6.2.1.02%3A_Water_Treatment.txt |
Water pollution can be mitigated through regulation, bioremediation, and watershed management.
Regulation
During the early1900s, rapid industrialization in the U.S. resulted in widespread water pollution due to free discharge of waste into surface waters. The Cuyahoga River in northeast Ohio caught fire numerous times, including a famous fire in 1969 that caught the nation’s attention (figure \(\PageIndex{a}\)). In 1972 Congress passed one of the most important environmental laws in U.S. history, the Federal Water Pollution Control Act, which is more commonly called the Clean Water Act (CWA). The purpose of the Clean Water Act and later amendments is to maintain and restore water quality, or in simpler terms to make our water swimmable and fishable. It became illegal to dump pollution into surface water unless there was formal permission. The CWA regulates pollution from a single source such as that from industry or sewage treatment plants by setting pollution standards (maximum levels of each pollutant that can be in bodies of water or released at a time). United States water quality improved significantly as a result, but as there is still more work to be done.
Remediation
Remediation is the act of cleaning contamination. Biological remediation (bioremediation) is a waste management technique that involves the use of organisms such as plants, bacteria, and fungi to remove or neutralize pollutants from a contaminated site. According to the United States EPA, bioremediation is a “treatment that uses naturally occurring organisms to break down hazardous substances into less toxic or nontoxic substances”. This type of remediation is usually used on organic chemicals but also works on reducing or oxidizing inorganic chemicals like nitrate. Phytoremediation is a type of bioremediation that uses plants to absorb the chemicals over time.
Bioremediation is widely used to treat human sewage and has also been used to remove agricultural chemicals (pesticides and fertilizers) that leach from soil into groundwater. Certain toxic metals, such as selenium and arsenic compounds, can also be removed from water by bioremediation. Mercury is an example of a toxic metal that can be removed from an environment by bioremediation. Several species of bacteria can carry out the biotransformation of toxic mercury into nontoxic forms. These bacteria, such as Pseudomonas aeruginosa, can convert a charged form of mercury (Hg2+) to an uncharged form (Hg), which is less toxic to humans.
Probably one of the most useful and interesting examples of the use of prokaryotes for bioremediation purposes is the cleanup of oil spills. To clean up these spills, bioremediation is promoted by adding inorganic nutrients that help bacteria already present in the environment to grow. Hydrocarbon-degrading bacteria feed on the hydrocarbons in the oil droplet, breaking them into inorganic compounds. Some species, such as Alcanivorax borkumensis, produce surfactants that break the oil into droplets, making it more accessible to the bacteria that degrade the oil. In the case of oil spills in the ocean, ongoing, natural bioremediation tends to occur, inasmuch as there are oil-consuming bacteria in the ocean prior to the spill. Under ideal conditions, it has been reported that up to 80 percent of the nonvolatile components (those that do not readily evaporate) in oil can be degraded within one year of the spill. Researchers have genetically engineered other bacteria to consume petroleum products; indeed, the first patent application for a bioremediation application in the U.S. was for a genetically modified oil-eating bacterium.
There are a number of cost/efficiency advantages to bioremediation, which can be employed in areas that are inaccessible without excavation. For example, hydrocarbon spills (specifically, oil spills) or certain chlorinated solvents may contaminate groundwater, which can be easier to treat using bioremediation than more conventional approaches. This is typically much less expensive than excavation followed by disposal elsewhere, incineration, or other off-site treatment strategies. It also reduces or eliminates the need for “pump and treat”, a practice common at sites where hydrocarbons have contaminated clean groundwater. Using microorganisms for bioremediation of hydrocarbons also has the advantage of breaking down contaminants at the molecular level, as opposed to simply chemically dispersing the contaminant.
Chemical remediation uses the introduction of chemicals to remove the contaminant or make it less harmful. One example is reactive barriers, a permeable wall in the ground or at a discharge point that chemically reacts with contaminants in the water. Reactive barriers made of limestone can increase the pH of acid mine drainage, making the water less acidic and more basic, which removes dissolved contaminants by precipitation into a solid form. Physical remediation consists of removing the contaminated water and either treating it (aka pump and treat) with filtration or disposing of it. All of these options are technically complex, expensive, and difficult, with physical remediation typically being the most costly.
Watershed Management
Watershed management involves reducing chemicals applied to land in the watershed (which will drain into a body of water) and runoff of those chemicals (figure \(\PageIndex{b-c}\)). This strategy is more effective for nonpoint source pollution than setting pollution standards (as the CWA does) because it does not require each source of pollution be identified.
Maintaining or restoring riparian areas (riparian zones) is key to watershed management (figure \(\PageIndex{d}\)). These are areas of land close enough to a body of water to be affected by that body of water, for example, the lush region of vegetation surrounding a river. Riparian areas provide many ecosystem services that promote water quality and limit pollution. The vegetation absorbs nutrients that could otherwise cause eutrophication. It also provide shade, keeping the water cool and increasing its capacity to hold dissolved oxygen. The roots of the vegetation cling to soil, combating erosion. Additionally, roots and low-lying plants slow the flow of run-off, promoting infiltration. High infiltration rates have several benefits: (1) less runoff is available to bring pollution to the river, lake, or bay, (2) pollutants will be filtered from the runoff as it soaks into the ground, and (3) aquifers are replenished.
Watershed management plans typically leave undisturbed riparian vegetation directly adjacent to a body of water (figure \(\PageIndex{e}\)). Next (moving away from the water), could be managed forest followed by agriculture. The most intensive agriculture should be farthest from the body of water, particularly when pesticides and fertilizers are in use.
In urban areas can also be carefully structured to limit water pollution. Rain gardens next to buildings are areas with soil and vegetation that promote infiltration. Permeable pavement, which allows water to pass through it, also promotes infiltration, and reduces runoff, creating fewer opportunities for the water to acquire pollutants from washing over a dirty street.
Attribution
Modified by Melissa Ha from the following sources: | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.01%3A_Water_Pollution/6.2.1.03%3A_Mitigating_Water_Pollution.txt |
Air pollution occurs in many forms but can generally be thought of as gaseous and particulate contaminants that are present in the earth’s atmosphere. Chemicals discharged into the air that have a direct impact on the environment are called primary pollutants. These primary pollutants sometimes react with other chemicals in the air to produce secondary pollutants.
Air pollution is typically separated into two categories: outdoor air pollution and indoor air pollution. Outdoor air pollution involves exposures that take place outside of the built environment. Examples include fine particles produced by the burning of coal, noxious gases such as sulfur dioxide, nitrogen oxides and carbon monoxide; ground-level ozone and tobacco smoke. Indoor air pollution involves exposures to particulates, carbon oxides, and other pollutants carried by indoor air or dust. Examples include household products and chemicals, out-gassing of building materials, allergens (cockroach and mouse dropping, mold, pollen), and tobacco smoke.
This video summarizes the causes, consequences, and solutions to air pollution.
Sources of Air Pollution
A stationary source of air pollution refers to an emission source that does not move, also known as a point source. Stationary sources include factories, power plants, and dry cleaners. The term area source is used to describe many small sources of air pollution located together whose individual emissions may be below thresholds of concern, but whose collective emissions can be significant. Residential wood burners are a good example of a small source, but when combined with many other small sources, they can contribute to local and regional air pollution levels. Area sources can also be thought of as non-point sources, such as construction of housing developments, dry lake beds, and landfills.
A mobile source of air pollution refers to a source that is capable of moving under its own power. In general, mobile sources imply “on-road” transportation, which includes vehicles such as cars, sport utility vehicles, and buses. In addition, there is also a “non-road” or “off-road” category that includes gas-powered lawn tools and mowers, farm and construction equipment, recreational vehicles, boats, planes, and trains.
Agricultural sources arise from operations that raise animals and grow crops, which can generate emissions of gases and particulate matter. For example, animals confined to a barn or restricted area produce large amounts of manure. Manure emits various gases, particularly ammonia into the air. This ammonia can be emitted from the animal houses, manure storage areas, or from the land after the manure is applied. In crop production, the misapplication of fertilizers, herbicides, and pesticides can potentially result in aerial drift of these materials and harm may be caused.
Unlike the above mentioned sources of air pollution, air pollution caused by natural sources is not caused by people or their activities. An erupting volcano emits particulate matter and gases, forest and prairie fires can emit large quantities of pollutants (figure \(\PageIndex{a}\)), dust storms can create large amounts of particulate matter, and plants and trees naturally emit volatile organic compounds which can form aerosols that can cause a natural blue haze. Wild animals in their natural habitat are also considered natural sources of “pollution”.
Criteria Air Pollutants
The Environmental Protection Agency has identified six common air pollutants called criteria air pollutants. They are particulate matter, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants can harm health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. The U.S. Environmental Protection Agency (EPA) regulates them by developing criteria based on considerations of human and environmental health.
1. Ground-level ozone is not emitted directly into the air, but is created by chemical reactions between nitrogen oxides (NOX) and the gaseous oxygen (O2) in the atmosphere react in the presence of sunlight. It also forms when nitrogen oxides and volatile organic compounds (VOCs) react. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOX and VOCs. Breathing ozone can trigger a variety of health problems, particularly for children, the elderly, and people of all ages who have lung diseases such as asthma. Ground level ozone can also have harmful effects on sensitive vegetation and ecosystems. (Ground-level ozone should not be confused with the ozone layer, which is high in the atmosphere and protects Earth from ultraviolet light; ground-level ozone provides no such protection).
2. Particulate matter, also known as particle pollution, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles. Examples of human-generated particulate matter are from combustion (such as burning wood or coal) and mining (which releases dust). Wildfires or wind erosion are natural sources of particulate matter. The size of particles is directly linked to their potential for causing health problems. EPA is concerned about particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Furthermore, particles that are 2.5 micrometers in diameter or smaller can pass from the lungs into the bloodstream, through which they are transported to various organs and cause serious health effects.
3. Carbon monoxide (CO) is a colorless, odorless gas emitted from combustion processes. Nationally and, particularly in urban areas, the majority of CO emissions to ambient air come from vehicles. However, volcanic eruptions and wildfires also release carbon monoxide. Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body’s organs (like the heart and brain) and tissues. At extremely high levels, CO can cause death.
4. Nitrogen oxides (NOX) are a group of highly reactive gasses, which includes nitrogen monoxide (NO) and nitrogen dioxide (NO2). EPA’s National Ambient Air Quality Standard uses NO2 as the indicator for the larger group of nitrogen oxides. Nitrogen oxides forms quickly from emissions from cars, trucks and buses, power plants, and off-road equipment. Additionally, nitrogen oxides are released naturally by certain bacteria. In addition to contributing to the formation of ground-level ozone, and fine particle pollution, nitrogen oxides react in the atmosphere to form nitric acid (HNO3) and nitrous acid (HNO2), which are components of Acid Deposition. Nitrogen oxides is linked with a number of adverse effects on the respiratory system.
5. Sulfur dioxide (SO2) is mainly released from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. Volcanoes are a natural source of SO2. Sulfur dioxide is linked with a number of adverse effects on the respiratory system. It reacts in the atmosphere to form sulfuric acid (H2SO4), a component of Acid Deposition.
6. Lead is a metal found naturally in the environment as well as in manufactured products. The major sources of lead emissions have historically been from fuels in on-road motor vehicles (such as cars and trucks) and industrial sources. As a result of regulatory efforts in the U.S. to remove lead from on-road motor vehicle gasoline, emissions of lead from the transportation sector dramatically declined by 95 percent between 1980 and 1999, and levels of lead in the air decreased by 94 percent between 1980 and 1999. Today, the highest levels of lead in air are usually found near lead smelters. The major sources of lead emissions to the air today are ore and metals processing and piston-engine aircraft operating on leaded aviation gasoline. Volcanoes and erosion are natural sources of lead.
Indoor Air Pollution (Major concerns in developed countries)
Most people spend approximately 90 percent of their time indoors. However, the indoor air we breathe in homes and other buildings can be more polluted than outdoor air and can increase the risk of illness. There are many sources of indoor air pollution in homes. They include biological contaminants such as bacteria, molds and pollen, burning of fuels and environmental tobacco smoke, building materials and furnishings, household products, central heating and cooling systems, and outdoor sources. Outdoor air pollution can enter buildings and become a source of indoor air pollution.
Sick building syndrome is a term used to describe situations in which building occupants have health symptoms that are associated only with spending time in that building. Causes of sick building syndrome are believed to include inadequate ventilation, indoor air pollution, and biological contaminants. Usually indoor air quality problems only cause discomfort. Most people feel better as soon as they remove the source of the pollution. Making sure that your building is well-ventilated and getting rid of pollutants can improve the quality of your indoor air.
Secondhand Smoke (Environmental Tobacco Smoke)
Secondhand smoke is the combination of smoke that comes from a cigarette and smoke breathed out by a smoker. When a non-smoker is around someone smoking, they breathe in secondhand smoke.
Secondhand smoke is dangerous to anyone who breathes it in. There is no safe amount of secondhand smoke. It contains over 7,000 harmful chemicals, at least 250 of which are known to damage human health. It can also stay in the air for several hours after somebody smokes. Even breathing secondhand smoke for a short amount of time can hurt your body.
Over time, secondhand smoke can cause serious health issues in non-smokers. The only way to fully protect non-smokers from the dangers of secondhand smoke is to not allow smoking indoors. Separating smokers from nonsmokers (like “no smoking” sections in restaurants)‚ cleaning the air‚ and airing out buildings does not completely get rid of secondhand smoke.
Source: Smokefree.gov
Addressing Air Pollution
A combination of regulatory, economic, and technological strategies can reduce air pollution. The 1970 Clean Air Act is a key federal regulation that has successfully reduced emissions of air pollutants such as lead and sulfur dioxide. The Environmental Protection Agency sets an air quality standard for large emitters of criteria air pollutants, which is the maximum allowable amount of the pollutant that can be released. Each state then develops a plan to comply with these standards. Note that hundreds of air pollutants beyond the six criteria air pollutants are regulated under the Clean Air Act.
Economic incentives make it financially beneficial for individuals, institutions, or companies to use technologies or otherwise take action that limits air pollution. For examples, green taxes increase the cost of an environmentally harmful action. For example, Canada levies a green tax on fuel-inefficient vehicles. Subsidies, on the other hand reduce the cost of environmentally beneficial choices. For example, the federal solar tax credit in the United States allows homeowners to claim a percentage of the cost of installing solar panels when their filing taxes This amount would thus reduce taxes owed or be issued as a tax refund. (Increased usage of solar electricity ultimately reduces the need for coal and natural gas power plants, which generate air pollution.)
Tradable permits (cap-and trade) is another economic incentive. First, the total allowable amount of emissions for an entity (such as a state or country) is set. Next, emission credits are distributed to potential polluters. Industries that reduce emissions can sell their credits, while those with high emissions may be required. For example, large emitters of greenhouse gases in California must by carbon pollution permits. The purchase of these permits funds the California Climate Credit, which Californians receive as a reduction to their April and October electricity bills.
Finally, a variety of technologies reduce air pollution. For example, air filters and proper ventilation are essential for limiting indoor air pollution. Advances in public transportation (and policies that promote them), and energy-efficient vehicles further reduce air pollution. Electric vehicles also reduce air pollution (figure \(\PageIndex{b}\)), particularly if the the electricity that supplies them comes from a clean, renewable source, such as solar panels. Catalytic converters make emissions from standard vehicles less harmful by facilitating chemical reactions. For example, they catalyze reactions that convert nitrogen oxides (NOX) to nitrogen gas (N2) and carbon monoxide (CO) to carbon dioxide (CO2). (While carbon dioxide is a greenhouse gas, it is not directly poisonous as carbon monoxide is.)
Other technologies limit emissions from industry. For example, smokestack scrubbers remove some pollutants from power plant emissions before they are released and have reduced sulfur dioxide emissions from burning coal. Electrostatic precipitators negatively charge pollutants and remove charged pollutants with a positive electrode (figure \(\PageIndex{c}\)). While electrostatic precipitators were originally developed for industry, smaller versions can be used as air purifiers in homes or businesses.
Attribution
Modified by Melissa Ha from the following sources:
6.2.02: Air Pollution
The ozone depletion process begins when CFCs (chlorofluorocarbons) and other ozone-depleting substances (ODS) are emitted into the atmosphere (figure \(\PageIndex{a}\)). CFC molecules are extremely stable, and they do not dissolve in rain. After a period of several years, ODS molecules reach the stratosphere, about 10 kilometers above the Earth’s surface (figure \(\PageIndex{b}\)). CFCs were used by industry as refrigerants, degreasing solvents, and propellants.
Ozone (O3) is constantly produced and destroyed in a natural cycle, as shown in figure \(\PageIndex{c}\). However, the overall amount of ozone is essentially stable. This balance can be thought of as a stream’s depth at a particular location. Although individual water molecules are moving past the observer, the total depth remains constant. Similarly, while ozone production and destruction are balanced, ozone levels remain stable. This was the situation until the past several decades. Large increases in stratospheric ODS, however, have upset that balance. In effect, they are removing ozone faster than natural ozone creation reactions can keep up. Therefore, ozone levels fall.
Policies to Reduce Ozone Destruction
One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone-destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs.
Two years after the British Antarctic Survey report, the “Montreal Protocol on Substances that Deplete the Ozone Layer” was ratified by nations all over the world. The Montreal Protocol controls the production and consumption of 96 chemicals that damage the ozone layer. CFCs have been mostly phased out since 1995, although they were used in developing nations until 2010. Some of the less hazardous substances will not be phased out until 2030. The Protocol also requires that wealthier nations donate money to develop technologies that will replace these chemicals.
Because CFCs take many years to reach the stratosphere and can survive there a long time before they break down, the ozone hole did not immediately disappear after CFC emissions were reduced; however, it has been shrinking (figure \(\PageIndex{d}\)).
Interactive Element
The ozone hole is shrinking due to reductions in CFC emissions. You can read more here.
Health and Environmental Effects of Ozone Layer Depletion
There are three types of UV light: UVA, UVB, and UVC. Reductions in stratospheric ozone levels will lead to higher levels of UVB reaching the Earth’s surface. The sun’s output of UVB does not change; rather, less ozone means less protection, and hence more UVB reaches the Earth. Studies have shown that in the Antarctic, the amount of UVB measured at the surface can double during the annual ozone hole.
Laboratory and epidemiological studies demonstrate that UVB causes non-melanoma skin cancers and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts, a clouding of the eye’s lens. All sunlight contains some UVB, even with normal stratospheric ozone levels. Therefore, it is always important to protect your skin and eyes from the sun. Ozone layer depletion increases the amount of UVB and the risk of health effects.
UVB is generally harmful to cells, and therefore all organisms. UVB cannot penetrate into an organism very far and thus tends to only impact skin cells. Microbes like bacteria, however, are composed of only one cell and can therefore be harmed by UVB,
Attribution
Modified by Melissa Ha from Ozone Depletion from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.02%3A_Air_Pollution/6.2.2.01%3A_Ozone_Depletion.txt |
Acid deposition is a term referring to a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. The precursors, or chemical forerunners, of acid deposition formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) resulting from fossil fuel combustion (figure \(\PageIndex{a}\)). Acid deposition occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. The result is a mild solution of sulfuric acid and nitric acid. When sulfur dioxide and nitrogen oxides are released from power plants and other sources, prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles.
Acid deposition is measured using a scale called “pH.” The lower a substance’s pH, the more acidic it is. Pure water has a pH of 7.0. However, normal rain is slightly acidic because carbon dioxide (CO2) dissolves into it forming weak carbonic acid, giving the resulting mixture a pH of approximately 5.6 at typical atmospheric concentrations of CO2. The average pH of precipitation in the United States in 1980 was 4.6, but it has been gradually increasing due to reductions in sulfur dioxide and nitrogen oxide emissions (figure \(\PageIndex{b}\)).
Effects of Acid Deposition
Acid deposition causes acidification of lakes and streams and contributes to the damage of trees at high elevations (for example, red spruce trees above 2,000 feet) and many sensitive forest soils. In addition, acid deposition accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation’s cultural heritage. Prior to falling to the earth, sulfur dioxide (SO2) and nitrogen oxide (NOx) gases and their particulate matter derivatives—sulfates and nitrates—contribute to visibility degradation and harm public health.
The ecological effects of acid deposition are most clearly seen in the aquatic, or water, environments, such as streams, lakes, and marshes. Most lakes and streams have a pH between 6 and 8, although some lakes are naturally acidic even without the effects of acid deposition. Acid deposition primarily affects sensitive bodies of water, which are located in watersheds whose soils have a limited ability to neutralize acidic compounds (called “buffering capacity”). Lakes and streams become acidic (i.e., the pH value goes down) when the water itself and its surrounding soil cannot buffer the acid deposition enough to neutralize it. In areas where buffering capacity is low, acid deposition releases aluminum from soils into lakes and streams; aluminum is highly toxic to many species of aquatic organisms. Acid deposition causes slower growth, injury, or death of forests. Of course, acid deposition is not the only cause of such conditions. Other factors contribute to the overall stress of these areas, including air pollutants, insects, disease, drought, or very cold weather. In most cases, in fact, the impacts of acid deposition on trees are due to the combined effects of acid deposition and these other environmental stressors.
Acid deposition contributes to the corrosion of metals (such as bronze) and the deterioration of paint and stone (such as marble and limestone). These effects significantly reduce the societal value of buildings, bridges, cultural objects (such as statues, monuments, and tombstones), and cars (figure \(\PageIndex{c}\)).
Sulfates and nitrates that form in the atmosphere from sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions contribute to visibility impairment, meaning we cannot see as far or as clearly through the air. The pollutants that cause acid deposition—sulfur dioxide (SO2) and nitrogen oxides (NOx)—damage human health. These gases interact in the atmosphere to form fine sulfate and nitrate particles that can be transported long distances by winds and inhaled deep into people’s lungs. Fine particles can also penetrate indoors. Many scientific studies have identified a relationship between elevated levels of fine particles and increased illness and premature death from heart and lung disorders, such as asthma and bronchitis.
Attribution
Modified by Melissa Ha from Acid Rain from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.02%3A_Air_Pollution/6.2.2.02%3A_Acid_Deposition.txt |
Overview
Our World in Data (OWID) is a scientific online publication that focuses on using research and data to help tackle global concerns such as poverty, disease, hunger, climate change, war, and inequitable treatment of our world’s most vulnerable and unstable communities. Their website is particularly known for publishing a variety of graphs, some even interactive, to present the research that helps explain causes and consequences of global concerns to the public. One example graph, seen below, illustrates the pathway by which plastic pollution enters the world’s oceans:
Questions
1. Reflect on how this bar graph is different than a standard bar graph. What do you like or not like about it?
2. What is this graph is illustrating about plastic waste?
3. Note that the global plastic waste is higher than the global plastic production. What does that tell you about the amount of plastic not yet classified as “waste”?
4. Provide a brief reflection for how these results make you feel and what they make you think about?
5. How can the results of this graph be used to inform future policies about plastic waste?
Raw Data From Above Graph(s)
Table \(\PageIndex{a}\): Raw data for plastic pathway into the ocean by million tonnes per year. Graph by Our World in Data (CC-BY-SA).
Waste Category Tonnes Per Year
Global primary waste production 270 million
Global plastic waste 275 million
Coastal plastic waste 99.5 million
Mismanaged coastal plastic waste 31.9 million
Plastic inputs to the oceans 8 million
Plastic in surface waters 10,000s to 100,000s
Attribution
Rachel Schleiger (CC-BY-NC)
6.2.04: Review
Summary
After completing this chapter you should be able to...
• Distinguish between point source and nonpoint source water pollution.
• Name and describe common water pollutants, including chemical, biological, and physical pollutants.
• Explain the mechanism of eutrophication.
• Summarize the current state of wastewater treatment globally.
• Describe the process of wastewater treatment, including pretreatment, primary treatment, secondary treatment, tertiary treatment, and disinfection and discharge.
• Summarize strategies for reducing water pollution.
• Identify sources of air pollution.
• List common air pollutants.
• Explain how CFCs caused ozone depletion, and global efforts to address this issue.
• Describe the causes and consequences of acid deposition.
Water pollution may arise from a single origin (point source pollution), or it may arise from multiple dispersed sources throughout the watershed (nonpoint source pollution). Water pollutants may be chemicalbiological, or physical. Oxygen-demanding waste increases biological oxygen demand and causes hypoxia, depriving aquatic organisms of oxygen. This results from eutrophication, in which excess nutrients cause algal blooms
Pathogens are the most deadly form of water pollution. They cause waterborne diseases, killing 485,000 people every year. Resolution of the global water pollution crisis requires multiple approaches to improve the quality of fresh water. The best strategy for addressing this problem is proper wastewater treatment. Strategies to reduce water pollution in general include the Clean Water Actremediation, and watershed management.
Air pollution can be thought of as gaseous and particulate contaminants that are present in the Earth’s atmosphere. Chemicals discharged into the air that have a direct impact on the environment are called primary pollutants. These primary pollutants sometimes react with other chemicals in the air to produce secondary pollutants. The commonly found air pollutants, known as criteria air pollutants, are particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants can harm health and the environment and cause property damage.
The ozone depletion process begins when chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS) are emitted into the atmosphere. Reductions in stratospheric ozone levels lead to higher levels of harmful ultraviolet radiation, particularly UVB, reaching the Earth’s surface. The sun’s output of UVB does not change; rather, less ozone means less protection, and hence more UVB reaches the Earth. The Montreal Protocol is an international effort to phase out CFCs, and has been successful in limiting ozone depletion.
Acid deposition occurs when certain air pollutants react with atmosphere to produce nitric and sulfuric acids. It can reach Earth as various forms of precipitation or as dry particles that later react to form acid. The precursors of acid deposition result from both natural sources, such as volcanoes and decaying vegetation, and anthropogenic (human) sources, primarily emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) resulting from fossil fuel combustion. Acid deposition causes acidification of lakes and streams, contributes to the damage of trees and many sensitive forest soils. In addition, acid deposition accelerates the decay of building materials and paints, contributes to the corrosion of metals and damages human health. However, the severity of acid deposition has declined due ot regulations and technologies that limit air pollution.
Attribution
Modified by Melissa Ha from Water Availability and Use and Air Pollution, Climate Change, & Ozone Depletion from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.02%3A_Pollution/6.2.03%3A_Data_Dive-_Plastic_in_World_Oceans.txt |
Chapter Hook
The iconic Grand Canal of Venice, Italy, doesn’t need high quality instruments to note effects of climate change. The Grand Canal was built in a way that the water levels are directly correlated with the sea level. As such, the steps leading into the canal have become rulers for sea level changes over the hundreds of years of their existence. The last step leading into the canal directly reflected the sea level at the time of creation and currently, the water level is 3 feet above this. In the last quarter century, sea levels have been rising much faster than previously measured. This puts Venice in a difficult position moving into a future where scientists predict the sea level to continue to rise, estimating that the city will be underwater by 2100, along with many other coastal cities. Unfortunately, rising seas are only one of the many predicted outcomes of global climate change.
Climate change refers to any significant change in the measures of climate lasting for an extended period of time. In other words, climate change includes major changes in temperature, precipitation, or wind patterns, among other effects, that occur over several decades or longer. Global warming refers to the recent and ongoing rise in global average temperature near Earth’s surface. It is caused mostly by increasing concentrations of greenhouse gases in the atmosphere. Global warming is causing climate patterns to change. However, global warming itself represents only one aspect of climate change.
A common misconception about global climate change is that a specific weather event occurring in a particular region (for example, a very cool week in June in central Indiana) is evidence of global climate change. However, a cold week in June is a weather-related event and not a climate-related one. These misconceptions often arise because of confusion over the terms climate and weather.
Climate refers to the long-term, predictable atmospheric conditions of a specific area. The climate of a biome is characterized by having consistent temperature and annual rainfall ranges. Climate does not address the amount of rain that fell on one particular day in a biome or the colder-than-average temperatures that occurred on one day. In contrast, weather refers to the conditions of the atmosphere during a short period of time. Weather forecasts are usually made for 48-hour cycles. Long-range weather forecasts are available but can be unreliable.
To better understand the difference between climate and weather, imagine that you are planning an outdoor event in northern Wisconsin. You would be thinking about climate when you plan the event in the summer rather than the winter because you have long-term knowledge that any given Saturday in the months of May to August would be a better choice for an outdoor event in Wisconsin than any given Saturday in January. However, you cannot determine the specific day that the event should be held on because it is difficult to accurately predict the weather on a specific day. Climate can be considered “average” weather.
Attributions
Modified by Melissa Ha and Rachel Schleiger from the following sources:
6.03: Climate Change
Earth’s Temperature is a Balancing Act
Earth’s temperature depends on the balance between energy entering and leaving the planet. When incoming energy from the sun is absorbed, Earth warms. When the sun’s energy is reflected back into space, Earth avoids warming. When energy is released from Earth into space, the planet cools. Many factors, both natural and human, can cause changes in Earth’s energy balance, including:
• Changes in the greenhouse effect, which affects the amount of heat retained by Earth’s atmosphere;
• Variations in the sun’s energy reaching Earth;
• Changes in the reflectivity of Earth’s atmosphere and surface.
Scientists have pieced together a picture of Earth’s climate, dating back hundreds of thousands of years, by analyzing a number of indirect measures of climate such as ice cores, tree rings, glacier size, pollen counts, and ocean sediments. Scientists have also studied changes in Earth’s orbit around the sun and the activity of the sun itself.
The historical record shows that the climate varies naturally over a wide range of time scales. In general, climate changes prior to the Industrial Revolution in the 1700s can be explained by natural causes, such as changes in solar energy, volcanic eruptions, and natural changes in greenhouse gas (GHG) concentrations. Recent changes in climate, however, cannot be explained by natural causes alone. Research indicates that natural causes are very unlikely to explain most observed warming, especially warming since the mid-20th century. Rather, human activities, especially our combustion of fossil fuels, explains the current warming (figure \(\PageIndex{a}\)). The scientific consensus is clear: through alterations of the carbon cycle, humans are changing the global climate by increasing the effects of something known as the greenhouse effect.
The Greenhouse Effect Causes the Atmosphere to Retain Heat
Gardeners that live in moderate or cool environments use greenhouses because they trap heat and create an environment that is warmer than outside temperatures. This is great for plants that like heat, or are sensitive to cold temperatures, such as tomato and pepper plants. Greenhouses contain glass or plastic that allow visible light from the sun to pass. This light, which is a form of energy, is absorbed by plants, soil, and surfaces and heats them. Some of that heat energy is then radiated outwards in the form of infrared radiation, a different form of energy. Unlike with visible light, the glass of the greenhouse blocks the infrared radiation, thereby trapping the heat energy, causing the temperature within the greenhouse to increase.
The same phenomenon happens inside a car on a sunny day. Have you ever noticed how much hotter a car can get compared to the outside temperature? Light energy from the sun passes through the windows and is absorbed by the surfaces in the car such as seats and the dashboard. Those warm surfaces then radiate infrared radiation, which cannot pass through the glass. This trapped infrared energy causes the air temperatures in the car to increase. This process is commonly known as the greenhouse effect.
The video below made for kids, but provides a clear and simple introduction to the greenhouse effect.
The greenhouse effect also happens with the entire Earth. Of course, our planet is not surrounded by glass windows. Instead, the Earth is wrapped with an atmosphere that contains greenhouse gases (GHGs). Much like the glass in a greenhouse, GHGs allow incoming visible light energy from the sun to pass, but they block infrared radiation that is radiated from the Earth towards space (figure \(\PageIndex{b}\)). In this way, they help trap heat energy that subsequently raises air temperature. Being a greenhouse gas is a physical property of certain types of gases; because of their molecular structure they absorb wavelengths of infrared radiation, but are transparent to visible light. Some notable greenhouse gases are water vapor (H2O), carbon dioxide (CO2), and methane (CH4). GHGs act like a blanket, making Earth significantly warmer than it would otherwise be. Scientists estimate that average temperature on Earth would be -18º C without naturally-occurring GHGs.
What is Global Warming?
Global warming refers to the recent and ongoing rise in global average temperature near Earth’s surface. It is caused mostly by increasing concentrations of greenhouse gases in the atmosphere. Global warming is causing climate patterns to change. However, global warming itself represents only one aspect of climate change.
What is Climate Change?
Climate change refers to any significant change in the measures of climate lasting for an extended period of time. In other words, climate change includes major changes in temperature, precipitation, or wind patterns, among other effects, that occur over several decades or longer.
The Main Greenhouse Gasses
The most important GHGs directly emitted by humans include CO2 and methane. Carbon dioxide (CO2) is the primary greenhouse gas that is contributing to recent global climate change. CO2 is a natural component of the carbon cycle, involved in such activities as photosynthesis, respiration, volcanic eruptions, and ocean-atmosphere exchange. Human activities, primarily the burning of fossil fuels and changes in land use, release very large amounts of CO2 to the atmosphere, causing its concentration in the atmosphere to rise.
Atmospheric CO2 concentrations have increased by 45% since pre-industrial times, from approximately 280 parts per million (ppm) in the 18th century to 409.8 ppm in 2019 (figure \(\PageIndex{c}\)). The current CO2 level is higher than it has been in at least 800,000 years, based on evidence from ice cores that preserve ancient atmospheric gases (figure \(\PageIndex{d-f}\)). Human activities currently release over 30 billion tons of CO2 into the atmosphere every year. While some volcanic eruptions released large quantities of CO2 in the distant past, the U.S. Geological Survey (USGS) reports that human activities now emit more than 135 times as much CO2 as volcanoes each year. This human-caused build-up of CO2 in the atmosphere is like a tub filling with water, where more water flows from the faucet than the drain can take away.
Other Greenhouse Gasses
Although this concentration is far less than that of CO2, methane (CH4) is 28 times as potent a greenhouse gas. Methane is produced when bacteria break down organic matter under anaerobic conditions and can be released due to natural or anthropogenic processes. Anaerobic conditions can happen when organic matter is trapped underwater (such as in rice paddies) or in the intestines of herbivores. Anthropogenic causes now account for 60% of total methane release. Examples include agriculture, fossil fuel extraction and transport, mining, landfill use, and burning of forests. Specifically, raising cattle releases methane due to fermentation in their rumens produces methane that is expelled from their GI tract. Methane is more abundant in Earth’s atmosphere now than at any time in at least the past 650,000 years, and CH4 concentrations increased sharply during most of the 20th century. They are now more than two and-a-half times pre-industrial levels (1.9 ppm), but the rate of increase has slowed considerably in recent decades.
Water vapor is the most abundant greenhouse gas and also the most important in terms of its contribution to the natural greenhouse effect, despite having a short atmospheric lifetime. Some human activities can influence local water vapor levels. However, on a global scale, the concentration of water vapor is controlled by temperature, which influences overall rates of evaporation and precipitation. Therefore, the global concentration of water vapor is not substantially affected by direct human emissions.
Ground-level ozone (O3), which also has a short atmospheric lifetime, is a potent greenhouse gas. Chemical reactions create ozone from emissions of nitrogen oxides and volatile organic compounds from automobiles, power plants, and other industrial and commercial sources in the presence of sunlight (as discussed in section 10.1). In addition to trapping heat, ozone is a pollutant that can cause respiratory health problems and damage crops and ecosystems.
Changes in the Sun’s Energy Affect how Much Energy Reaches Earth
Climate can be influenced by natural changes that affect how much solar energy reaches Earth. These changes include changes within the sun and changes in Earth’s orbit. Changes occurring in the sun itself can affect the intensity of the sunlight that reaches Earth’s surface. The intensity of the sunlight can cause either warming (during periods of stronger solar intensity) or cooling (during periods of weaker solar intensity). The sun follows a natural 11-year cycle of small ups and downs in intensity, but the effect on Earth’s climate is small. Changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis can also affect the amount of sunlight reaching Earth’s surface.
Changes in the sun’s intensity have influenced Earth’s climate in the past. For example, the so-called “Little Ice Age” between the 17th and 19th centuries may have been partially caused by a low solar activity phase from 1645 to 1715, which coincided with cooler temperatures. The Little Ice Age refers to a slight cooling of North America, Europe, and probably other areas around the globe. Changes in Earth’s orbit have had a big impact on climate over tens of thousands of years. These changes appear to be the primary cause of past cycles of ice ages, in which Earth has experienced long periods of cold temperatures (ice ages), as well as shorter interglacial periods (periods between ice ages) of relatively warmer temperatures.
Changes in solar energy continue to affect climate. However, solar activity has been relatively constant, aside from the 11-year cycle, since the mid-20th century and therefore does not explain the recent warming of Earth. Similarly, changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis affect temperature on relatively long timescales (tens of thousands of years), and therefore cannot explain the recent warming.
Changes in Reflectivity Affect How Much Energy Enters Earth’s System
When sunlight energy reaches Earth it can be reflected or absorbed. The amount that is reflected or absorbed depends on Earth’s surface and atmosphere. Light-colored objects and surfaces, like snow and clouds, tend to reflect most sunlight, while darker objects and surfaces, like the ocean and forests, tend to absorb more sunlight. The term albedo refers to the amount of solar radiation reflected from an object or surface, often expressed as a percentage. Earth as a whole has an albedo of about 30%, meaning that 70% of the sunlight that reaches the planet is absorbed. Sunlight that is absorbed warms Earth’s land, water, and atmosphere.
Albedo is also affected by aerosols. Aerosols are small particles or liquid droplets in the atmosphere that can absorb or reflect sunlight. Unlike greenhouse gases (GHGs), the climate effects of aerosols vary depending on what they are made of and where they are emitted. Those aerosols that reflect sunlight, such as particles from volcanic eruptions or sulfur emissions from burning coal, have a cooling effect. Those that absorb sunlight, such as black carbon (a part of soot), have a warming effect.
Natural changes in albedo, like the melting of sea ice or increases in cloud cover, have contributed to climate change in the past, often acting as feedbacks to other processes. Volcanoes have played a noticeable role in climate. Volcanic particles that reach the upper atmosphere can reflect enough sunlight back to space to cool the surface of the planet by a few tenths of a degree for several years. Volcanic particles from a single eruption do not produce long-term change because they remain in the atmosphere for a much shorter time than GHGs.
Human changes in land use and land cover have changed Earth’s albedo. Processes such as deforestation, reforestation, desertification, and urbanization often contribute to changes in climate in the places they occur. These effects may be significant regionally, but are smaller when averaged over the entire globe.
Scientific Consensus: Global Climate Change is Real
The Intergovernmental Panel on Climate Change (IPCC) was created in 1988 by the United Nations Environment Programme and the World Meteorological Organization. It is charged with the task of evaluating and synthesizing the scientific evidence surrounding global climate change. The IPCC uses this information to evaluate current impacts and future risks, in addition to providing policymakers with assessments. These assessments are released about once every every six years. The most recent report, the 5th Assessment, was released in 2013. Hundreds of leading scientists from around the world are chosen to author these reports. Over the history of the IPCC, these scientists have reviewed thousands of peer-reviewed, publicly available studies. The scientific consensus is clear: global climate change is real and humans are very likely the cause for this change.
Additionally, the major scientific agencies of the United States, including the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), also agree that climate change is occurring and that humans are driving it. In 2010, the US National Research Council concluded that “Climate change is occurring, is very likely caused by human activities, and poses significant risks for a broad range of human and natural systems”. Many independent scientific organizations have released similar statements, both in the United States and abroad. This doesn’t necessarily mean that every scientist sees eye to eye on each component of the climate change problem, but broad agreement exists that climate change is happening and is primarily caused by excess greenhouse gases from human activities. Critics of climate change, driven by ideology instead of evidence, try to suggest to the public that there is no scientific consensus on global climate change. Such an assertion is patently false.
Current Status of Global Climate Change and Future Changes
Greenhouse gas concentrations in the atmosphere will continue to increase unless the billions of tons of anthropogenic emissions each year decrease substantially. Increased concentrations are expected to do the following:
• Increase Earth’s average temperature (figure \(\PageIndex{g}\)),
• Influence the patterns and amounts of precipitation,
• Reduce ice and snow cover, as well as permafrost,
• Raise sea level (figure \(\PageIndex{h}\)),
• Increase the acidity of the oceans.
Figure \(\PageIndex{h}\): Sea height variation (mm) over time. Sea height has increased about 3.3 millimeters per year on average since 1993. Data is from satellite sea level observations by the NASA Goddard Space Flight Center. Image by NASA (public domain).
These changes will impact our food supply, water resources, infrastructure, ecosystems, and even our own health. The magnitude and rate of future climate change will primarily depend on the following factors:
• The rate at which levels of greenhouse gas concentrations in our atmosphere continue to increase,
• How strongly features of the climate (e.g., temperature, precipitation, and sea level) respond to the expected increase in greenhouse gas concentrations,
• Natural influences on climate (e.g., from volcanic activity and changes in the sun’s intensity) and natural processes within the climate system (e.g., changes in ocean circulation patterns).
Past and Present-day GHG Emissions Will Affect Climate Far into the Future
Many greenhouse gases stay in the atmosphere for long periods of time. As a result, even if emissions stopped increasing, atmospheric greenhouse gas concentrations would continue to remain elevated for hundreds of years. Moreover, if we stabilized concentrations and the composition of today’s atmosphere remained steady (which would require a dramatic reduction in current greenhouse gas emissions), surface air temperatures would continue to warm. This is because the oceans, which store heat, take many decades to fully respond to higher greenhouse gas concentrations. The ocean’s response to higher greenhouse gas concentrations and higher temperatures will continue to impact climate over the next several decades to hundreds of years.
Future Temperature Changes
Climate models project the following key temperature-related changes:
• Average global temperatures are expected to increase by 2°F to 11.5°F by 2100, depending on the level of future greenhouse gas emissions, and the outcomes from various climate models.
• By 2100, global average temperature is expected to warm at least twice as much as it has during the last 100 years.
• Ground-level air temperatures are expected to continue to warm more rapidly over land than oceans.
• Some parts of the world are projected to see larger temperature increases than the global average.
Future Precipitation and Storm Events
Patterns of precipitation and storm events, including both rain and snowfall are likely to change. However, some of these changes are less certain than the changes associated with temperature. Projections show that future precipitation and storm changes will vary by season and region. Some regions may have less precipitation, some may have more precipitation, and some may have little or no change. The amount of rain falling in heavy precipitation events is likely to increase in most regions, while storm tracks are projected to shift towards the poles. Climate models project the following precipitation and storm changes:
• Global average annual precipitation through the end of the century is expected to increase, although changes in the amount and intensity of precipitation will vary by region.
• The intensity of precipitation events will likely increase on average. This will be particularly pronounced in tropical and high-latitude regions, which are also expected to experience overall increases in precipitation.
• The strength of the winds associated with tropical storms is likely to increase. The amount of precipitation falling in tropical storms is also likely to increase.
• Annual average precipitation is projected to increase in some areas and decrease in others.
Future Ice, Snowpack, and Permafrost
Arctic sea ice is already declining drastically. The area of snow cover in the Northern Hemisphere has decreased since 1970. Permafrost temperature has increased over the last century, making it more susceptible to thawing. Over the next century, it is expected that sea ice will continue to decline, glaciers will continue to shrink, snow cover will continue to decrease, and permafrost will continue to thaw.
For every 2°F of warming, models project about a 15% decrease in the extent of annually averaged sea ice and a 25% decrease in September Arctic sea ice. The coastal sections of the Greenland and Antarctic ice sheets are expected to continue to melt or slide into the ocean. If the rate of this ice melting increases in the 21st century, the ice sheets could add significantly to global sea level rise. Glaciers are expected to continue to decrease in size. The rate of melting is expected to continue to increase, which will contribute to sea level rise.
Future Sea Level Change
Warming temperatures contribute to sea level rise by expanding ocean water, melting mountain glaciers and ice caps, and causing portions of the Greenland and Antarctic ice sheets to melt or flow into the ocean. Since 1870, global sea level has risen by about 8 inches. Estimates of future sea level rise vary for different regions, but global sea level for the next century is expected to rise at a greater rate than during the past 50 years. The contribution of thermal expansion, ice caps, and small glaciers to sea level rise is relatively well-studied, but the impacts of climate change on ice sheets are less understood and represent an active area of research. Thus, it is more difficult to predict how much changes in ice sheets will contribute to sea level rise. Greenland and Antarctic ice sheets could contribute an additional 1 foot of sea level rise, depending on how the ice sheets respond.
Regional and local factors will influence future relative sea level rise for specific coastlines around the world (figure \(\PageIndex{i}\)). For example, relative sea level rise depends on land elevation changes that occur as a result of subsidence (sinking) or uplift (rising), in addition to things such as local currents, winds, salinity, water temperatures, and proximity to thinning ice sheets. Assuming that these historical geological forces continue, a 2-foot rise in global sea level by 2100 would result in the following relative sea level rise:
• 2.3 feet at New York City
• 2.9 feet at Hampton Roads, Virginia
• 3.5 feet at Galveston, Texas
• 1 foot at Neah Bay in Washington state
Future Ocean Acidification
Ocean acidification is the process of ocean waters decreasing in pH. Oceans become more acidic as carbon dioxide (CO2) emissions in the atmosphere dissolve in the ocean. This change is measured on the pH scale, with lower values being more acidic. The pH level of the oceans has decreased by approximately 0.1 pH units since pre-industrial times, which is equivalent to a 25% increase in acidity. The pH level of the oceans is projected to decrease even more by the end of the century as CO2 concentrations are expected to increase for the foreseeable future. Ocean acidification adversely affects many marine species, including plankton, mollusks, shellfish, and corals. As ocean acidification increases, the availability of calcium carbonate will decline. Calcium carbonate is a key building block for the shells and skeletons of many marine organisms. If atmospheric CO2 concentrations double, coral calcification rates are projected to decline by more than 30%. If CO2 concentrations continue to rise at their current rate, corals could become rare on tropical and subtropical reefs by 2050.
Mismatched Interactions
Climate change also affects phenology, the study of the effects of climatic conditions on the timing of periodic lifecycle events, such as flowering in plants or migration in birds. Researchers have shown that 385 plant species in Great Britain are flowering 4.5 days sooner than was recorded earlier during the previous 40 years. In addition, insect-pollinated species were more likely to flower earlier than wind-pollinated species. The impact of changes in flowering date would be mitigated if the insect pollinators emerged earlier. This mismatched timing of plants and pollinators could result in injurious ecosystem effects because, for continued survival, insect-pollinated plants must flower when their pollinators are present.
Likewise, migratory birds rely on daylength cues, which are not influenced by climate change. Their insect food sources, however, emerge earlier in the year in response to warmer temperatures. As a result, climate change decreases food availability for migratory bird species.
Spread of Disease
This rise in global temperatures will increase the range of disease-carrying insects and the viruses and pathogenic parasites they harbor. Thus, diseases will spread to new regions of the globe. This spread has already been documented with dengue fever, a disease the affects hundreds of millions per year, according to the World Health Organization. Colder temperatures typically limit the distribution of certain species, such as the mosquitoes that transmit malaria, because freezing temperatures destroy their eggs.
Not only will the range of some disease-causing insects expand, the increasing temperatures will also accelerate their lifecycles, which allows them to breed and multiply quicker, and perhaps evolve pesticide resistance faster. In addition to dengue fever, other diseases are expected to spread to new portions of the world as the global climate warms. These include malaria, yellow fever, West Nile virus, zika virus, and chikungunya.
Climate change does not only increase the spread of diseases in humans. Rising temperatures are associated with greater amphibian mortality due to chytridiomycosis (see Invasive Species). Similarly, warmer temperatures have exacerbated bark beetle infestations of coniferous trees, such as pine an spruce.
Climate Change Affects Everyone
Our lives are connected to the climate. Human societies have adapted to the relatively stable climate we have enjoyed since the last ice age which ended several thousand years ago. A warming climate will bring changes that can affect our water supplies, agriculture, power and transportation systems, the natural environment, and even our own health and safety.
Carbon dioxide can stay in the atmosphere for nearly a century, on average, so Earth will continue to warm in the coming decades. The warmer it gets, the greater the risk for more severe changes to the climate and Earth’s system. Although it’s difficult to predict the exact impacts of climate change, what’s clear is that the climate we are accustomed to is no longer a reliable guide for what to expect in the future.
We can reduce the risks we will face from climate change. By making choices that reduce greenhouse gas pollution, and preparing for the changes that are already underway, we can reduce risks from climate change. Our decisions today will shape the world our children and grandchildren will live in.
You can take steps at home, on the road, and in your office to reduce greenhouse gas emissions and the risks associated with climate change. Many of these steps can save you money. Some, such as walking or biking to work, can even improve your health! You can also get involved on a local or state level to support energy efficiency, clean energy programs, or other climate programs.
Suggested Supplementary Reading
Intergovernmental Panel on Climate Change. 2013. 5th Assessment: Summary for Policymakers.
NASA. 2018. Global Climate Change: Vital Signs of the Planet. This website by NASA provides a multi-media smorgasbord of engaging content. Learn about climate change using data collected by NASA satellites and more.
Attributions
Modified by Melissa Ha from the following sources:
6.3.02: Data Dive- Flooding in Venice Italy
Overview
Historically, Venice Italy has a history of flooding that is caused from a multitude of both natural and human caused phenomena. Currently, these issues are being exacerbated by sea level changes as a result of climate change. As such, the City of Venice has been carefully tracking frequency of flooding through the years. The graph below represents the frequency of water level was above 110cm per 10-year period:
Questions
1. What is the independent (explanatory) variable and the dependent (response) variable?
2. What question(s) are the authors trying to answer with this graph?
3. What are the results of this graph illustrating about flooding in Venice?
4. How can other coastal cities around the world learn from what patterns are emerging in this graph?
5. Provide a brief reflection for how these results make you feel and what they make you think about.
Raw Data For Above Graph(s)
Table \(\PageIndex{a}\): Raw data for the frequency of flooding exceeding 110cm in Venice Italy. Graph by Rachel Schleiger (CC-BY-NC) modified from data published by the City of Venice.
Ten Year Interval Frequency
1870-79 4
1880-89 2
1890-99 3
1900-09 2
1910-19 3
1920-29 3
1930-39 8
1940-49 5
1950-59 13
1960-69 31
1970-79 31
1980-89 26
1990-99 44
2000-09 52
2010-19 69
Attribution
Rachel Schleiger (CC-BY-NC)
6.3.03: Review
Summary
After completing this chapter you should be able to...
• Define global climate change.
• Summarize the effects of the Industrial Revolution on global atmospheric carbon dioxide concentration.
• Describe three natural factors affecting long-term global climate.
• List two or more greenhouse gases and describe their role in the greenhouse effect.
The historical record shows that the climate system varies naturally over a wide range of time scales. In general, climate changes prior to the Industrial Revolution in the 1700s can be explained by natural causes, such as changes in solar energy, volcanic eruptions, and natural changes in greenhouse gas concentrations. Recent climate changes, however, cannot be explained by natural causes alone. Natural causes are very unlikely to explain most observed warming, especially warming since the mid-20th century. Rather, human activities can explain most of that warming.
The primary human activity affecting the amount and rate of climate change is greenhouse gas emissions from the burning of fossil fuels. Greenhouse gas concentrations in the atmosphere will continue to increase unless the billions of tons of our annual emissions decrease substantially. Increased concentrations are expected to increase Earth’s average temperature, influence the patterns and amounts of precipitation, reduce ice and snow cover, as well as permafrost, raise sea level and increase the acidity of the oceans. These changes will impact our food supply, water resources, infrastructure, ecosystems, and even our own health.
Attribution
Modified by Melissa Ha from Air Pollution, Climate Change, & Ozone Depletion from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/06%3A_Environmental_Impacts/6.03%3A_Climate_Change/6.3.01%3A_The_Greenhouse_Effect_and_Climate_Change.txt |
Connecting Environmental Science to Sustainability
Both environmental science and sustainability originated out of necessity due to past and current issues to find solutions for the now and the future. As such, there are many parallels to these subjects basic objectives. However, environmental science focuses on environmental/ecological solutions (as outlined in this book), whereas sustainability focuses on environmental/ecological, social, and economic goals. That's even more interdisciplinary, and thus complex, than environmental science! As such, this chapter will solely introduce essential concepts of sustainability and will not be entirely comprehensive.
Attribution
Rachel Schleiger (CC-BY-NC)
Thumbnail - "Sustainability diagram" Is in the Public Domain
07: Sustainability
Chapter Hook
Cities in today’s modern world are struggling to balance a sustainable society, economy, and environment. According to a 2016 report that rated sustainability across 32 indicators, Zurich, Switzerland, was ranked number one. Zurich invests in renewable energies, sustainable public transport, public green space, and public education. One of the most notable ways Zurich is leading global sustainability efforts is their dedication to keeping their carbon dioxide emissions low. Figure \(\PageIndex{a}\) below shows the difference in emissions for the United States and Switzerland:
Introduction
Sustainability is derived from two Latin words: sus which means up, and tenere which means to hold. Thus, sustainability is essentially about holding up human existence by meeting the needs of the present without compromising the ability of future generations to meet their needs.
There are three dimensions that sustainability seeks to integrate: economic, environmental, and social (including sociopolitical).
• Economic interests define the framework for making decisions, the flow of financial capital, and the facilitation of commerce, including the knowledge, skills, competences and other attributes embodied in individuals that are relevant to economic activity.
• Environmental aspects recognize the diversity and interdependence within living systems, the goods and services produced by the world’s ecosystems, and the impacts of human wastes.
• Social/Socio-political refers to interactions between institutions/firms and people, functions expressive of human values, aspirations and well-being, ethical issues, and decision-making that depends upon collective action.
The intersection of social and economic elements can form the basis of social "equitability". In the sense of enlightened management, "viability" is formed through consideration of economic and environmental interests. Between environment and social elements lies “bearability,” the recognition that the functioning of societies is dependent on environmental resources and services. At the intersection of all three of these lies sustainability (figure \(\PageIndex{b}\)).
The three main elements of the sustainability paradigm are thought of as equally important, however, tradeoffs occur depending on the local/global objective. For example, in some instances it may be deemed necessary to degrade a particular ecosystem in order to facilitate commerce, or food production, or housing. In reality, the extent to which tradeoffs can be made before irreversible damage results is not always known, and in any case there are definite limits on how much substitution among the three elements is wise (to date, humans have treated economic development as the dominant one of the three). This has led to the notion of strong sustainability, where tradeoffs among natural, human, and social capital are not allowed or are very restricted, and weak sustainability, where tradeoffs are unrestricted or have few limits. Whether or not one follows the strong or weak form of sustainability, it is important to understand that while economic and social systems are human creations, the environment is not. Rather, a functioning environment underpins both society and the economy.
Attribution
Modified by Rachel Schleiger from Sustainability: A Comprehensive Foundation by Openstax (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.01%3A_Introduction_to_Sustainability.txt |
Taking The Long View: Sustainability an Evolutionary and Ecological Perspective
Of the different forms of life that have inhabited the Earth in its three to four billion year history, 99.9% are now extinct. Against this backdrop, the human enterprise with its roughly 200,000-year history barely merits attention. As the American novelist Mark Twain once remarked, if our planet’s history were to be compared to the Eiffel Tower, human history would be a mere smear on the very tip of the tower. But while modern humans (Homo sapiens) might be insignificant in geologic time, we are by no means insignificant in terms of our recent planetary impact. A 1986 study estimated that 40% of the product of terrestrial plant photosynthesis — the basis of the food chain for most animal and bird life — was being appropriated by humans for their use. More recent studies estimate that 25% of photosynthesis on continental shelves (coastal areas) is ultimately being used to satisfy human demand. Human appropriation of such natural resources is having a profound impact upon the wide diversity of other species that also depend on them.
Evolution normally results in the generation of new lifeforms at a rate that outstrips the extinction of other species; this results in strong biological diversity. However, scientists have evidence that, for the first observable time in evolutionary history, another species — Homo sapiens — has upset this balance to the degree that the rate of species extinction is now estimated at 10,000 times the rate of species renewal. Human beings, just one species among millions, are crowding out the other species we share the planet with. Evidence of human interference with the natural world is visible in practically every ecosystem from the presence of pollutants in the stratosphere to the artificially changed courses of the majority of river systems on the planet. It is argued that ever since we abandoned nomadic, gatherer-hunter ways of life for settled societies some 12,000 years ago, humans have continually manipulated their natural world to meet their needs. While this observation is a correct one, the rate, scale, and the nature of human-induced global change — particularly in the post-industrial period — is unprecedented in the history of life on Earth.
There are three primary reasons for this:
1. Mechanization of both industry and agriculture in the last century resulted in vastly improved labor productivity which enabled the creation of goods and services. Since then, scientific advance and technological innovation — powered by ever-increasing inputs of fossil fuels and their derivatives — have revolutionized every industry and created many new ones. The subsequent development of western consumer culture, and the satisfaction of the accompanying disposable mentality, has generated material flows of an unprecedented scale. The Wuppertal Institute estimates that humans are now responsible for moving greater amounts of matter across the planet than all natural occurrences (earthquakes, storms, etc.) put together.
2. The sheer size of the human population is unprecedented. Every passing year adds another 90 million people to the planet. Even though the environmental impact varies significantly between countries (and within them), the exponential growth in human numbers, coupled with rising material expectations in a world of limited resources, has catapulted the issue of distribution to prominence. Global inequalities in resource consumption and purchasing power mark the clearest dividing line between the haves and the have-nots. It has become apparent that present patterns of production and consumption are unsustainable for a global population that is projected to reach between 12 billion by the year 2050. If ecological crises and rising social conflict are to be countered, the present rates of over-consumption by a rich minority, and under-consumption by a large majority, will have to be brought into balance.
3. It is not only the rate and the scale of change but the nature of that change that is unprecedented. Human inventiveness has introduced chemicals and materials into the environment which either do not occur naturally at all, or do not occur in the ratios in which we have introduced them. These persistent chemical pollutants are believed to be causing alterations in the environment, the effects of which are only slowly manifesting themselves, and the full scale of which is beyond calculation. CFCs and PCBs are but two examples of the approximately 100,000 chemicals currently in global circulation. (Between 500 and 1,000 new chemicals are being added to this list annually.) The majority of these chemicals have not been tested for their toxicity on humans and other life forms, let alone tested for their effects in combination with other chemicals. These issues are now the subject of special UN and other intergovernmental working groups.
The Evolution of Sustainability Itself
Our Common Future (1987), the report of the World Commission on Environment and Development, is widely credited with having popularized the concept of sustainable development. It defines sustainable development in the following ways…
• …development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
• … sustainable development is not a fixed state of harmony, but rather a process of change in which the exploitation of resources, the orientation of the technological development, and institutional change are made consistent with future as well as present needs.
The concept of sustainability, however, can be traced back much farther to the oral histories of indigenous cultures. For example, the principle of inter-generational equity is captured in the Inuit saying, ‘we do not inherit the Earth from our parents, we borrow it from our children’. The Native American ‘Law of the Seventh Generation’ is another illustration. According to this, before any major action was to be undertaken its potential consequences on the seventh generation had to be considered. For a species that at present is only 6,000 generations old and whose current political decision-makers operate on time scales of months, or few years at most, the thought that other human cultures have based their decision-making systems on time scales of many decades seems wise but unfortunately inconceivable in the current political climate.
Precautionary Principle
The precautionary principle is an important concept in environmental sustainability. A 1998 consensus statement characterized the precautionary principle this way: “when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically”. For example, if a new pesticide chemical is created, the precautionary principle would dictate that we presume, for the sake of safety, that the chemical may have potential negative consequences for the environment and/or human health, even if such consequences have not been proven yet. In other words, it is best to proceed cautiously in the face of incomplete knowledge about something’s potential harm.
Attribution
Modified by Melissa Ha and Rachel Schleiger from Environment and Sustainability from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.02%3A_History_of_Sustainability.txt |
Introduction
The concept of ethics involves standards of conduct. These standards help to distinguish between behavior that is considered right and that which is considered wrong. As we all know, it is not always easy to distinguish between right and wrong, as there is no universal code of ethics. For example, a poor farmer clears an area of rainforest in order to grow crops. Some would not oppose this action, because the act allows the farmer to provide a livelihood for his family. Others would oppose the action, claiming that the deforestation will contribute to soil erosion and global warming. Right and wrong are usually determined by an individual's morals, and to change the ethics of an entire society, it is necessary to change the individual ethics of a majority of the people in that society.
Moral extensionism defines how far a persons values extend outside of themselves (Figure 7.2a). There are many variables that can influence where the limit lies for each individual person. For example: religion, culture, education, and personal interests (just to name a few).
Attribution
Modified by Rachel Schleiger from Sustainability: A Comprehensive Foundation by Openstax (licensed under CC-BY)
7.03: Environmental Ethics
Environmental Equity
Environmental equity describes a country, or world, in which no single group or community faces disadvantages in dealing with environmental hazards, disasters, or pollution. While much progress is being made to improve resource efficiency, far less progress has been made to improve resource distribution. Currently, just one-fifth of the global population is consuming three-quarters of the earth’s resources.
Global Consumption Inequality - 24% of the global population (mostly in the high income countries) accounts for...
• 92% Cars
• 70% Carbon dioxide emissions
• 86% Copper and aluminum
• 81% Paper
• 80% Iron and steel
• 48% Cereal crops
• 60% Artificial fertilizer
If the remaining three-quarters were to exercise their right to grow to the level of the rich minority it would result in ecological devastation. So far, global income inequalities and lack of purchasing power have prevented poorer countries from reaching the standard of living (and also resource consumption/waste emission) of the industrialized countries. Countries such as China, Brazil, India, and Malaysia are, however, catching up fast. In such a situation, global consumption of resources and energy needs to be drastically reduced to a point where it can be repeated by future generations. But who will do the reducing? Poorer nations want to produce and consume more. Yet so do richer countries: their economies demand ever greater consumption-based expansion. Such stalemates have prevented any meaningful progress towards equitable and sustainable resource distribution at the international level. These issue of fairness and distributional justice remain unresolved.
Environmental Justice
Environmental Justice is defined as the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. It will be achieved when everyone enjoys the same degree of protection from environmental and health hazards and equal access to the decision-making process to have a healthy environment in which to live, learn, and work.
In Flint Michigan, the city decided to save money by drawing water for residents from the Flint River in 2014. Residents complained about the taste, smell, and color of the water. A couple of scientific studies determined that there was a failure to apply corrosion inhibitors to the water, resulting in lead from aging pipes to leach into the water supply, exposing around 100,000 residents to elevated lead levels. Although the city switched back to it's original water source, the damage was already done. Not only did this crisis expose so many to lead, especially concerning for children, but also most pipes needed to be replaced as they were no longer safe to use (Figure a). In 2017 a settlement was reached to replace all the pipes, a \$87 million project. However, as of Jan 2021 this project is only just now approaching completion. Citywide lead levels have tested within the safe range for consumption, though houses considered high risk do continue to show elevated levels.
During the 1980’s minority groups protested that hazardous waste sites were preferentially sited in minority neighborhoods. In 1987, Benjamin Chavis of the United Church of Christ Commission for Racism and Justice coined the term environmental racism to describe such a practice. The charges generally failed to consider whether the facility or the demography of the area came first. Most hazardous waste sites are located on property that was used as disposal sites long before modern facilities and disposal methods were available. Areas around such sites are typically depressed economically, often as a result of past disposal activities. Persons with low incomes are often constrained to live in such undesirable, but affordable, areas. The problem more likely resulted from one of insensitivity rather than racism. Indeed, the ethnic makeup of potential disposal facilities was most likely not considered when the sites were chosen.
Decisions in citing hazardous waste facilities are generally made on the basis of economics, geological suitability and the political climate. For example, a site must have a soil type and geological profile that prevents hazardous materials from moving into local aquifers. The cost of land is also an important consideration. The high cost of buying land would make it economically unfeasible to build a hazardous waste site in Beverly Hills. Some communities have seen a hazardous waste facility as a way of improving their local economy and quality of life. Emelle County, Alabama had illiteracy and infant mortality rates that were among the highest in the nation. A landfill constructed there provided jobs and revenue that ultimately helped to reduce both figures.
In an ideal world, there would be no hazardous wastes to plague this planet. Unfortunately, we live in a world with rampant pollution, dumping of hazardous wastes, and people with "living for the now" attitudes. Our industrialized society has necessarily produced wastes during the manufacture of products for our basic needs. Until technology can find a way to manage (or eliminate) hazardous waste, disposal facilities will be necessary to protect both humans and the environment. By the same token, this problem must be addressed. Industry and society must become more socially sensitive in the selection of future hazardous waste sites. All humans who help produce hazardous wastes must share the burden of dealing with those wastes, not just the poor and minorities.
Indigenous People
Since the end of the 15th century, most of the world’s frontiers have been claimed and colonized by established nations. Invariably, these conquered frontiers were home to people indigenous to those regions. Some were wiped out or assimilated by the invaders, while others survived while trying to maintain their unique cultures and way of life. The United Nations officially classifies indigenous people as those “having an historical continuity with pre-invasion and pre-colonial societies,” and “consider themselves distinct from other sectors of the societies now prevailing in those territories or parts of them.” Furthermore, indigenous people are “determined to preserve, develop and transmit to future generations, their ancestral territories, and their ethnic identity, as the basis of their continued existence as peoples in accordance with their own cultural patterns, social institutions and legal systems.” A few of the many groups of indigenous people around the world are: the many tribes of Native Americans (i.e., Navajo, Sioux) in the contiguous 48 states, the Inuit of the arctic region from Siberia to Canada, the rainforest tribes in Brazil, and the Ainu of northern Japan.
Many problems face indigenous people including the lack of human rights, exploitation of their traditional lands and themselves, and degradation of their culture. In response to the problems faced by these people, the United Nations proclaimed an “International Decade of the World’s Indigenous People” beginning in 1994. The main objective of this proclamation, according to the United Nations, is “the strengthening of international cooperation for the solution of problems faced by indigenous people in such areas as human rights, the environment, development, health, culture and education.” Its major goal is to protect the rights of indigenous people. Such protection would enable them to retain their cultural identity, such as their language and social customs, while participating in the political, economic and social activities of the region in which they reside.
Despite the lofty U.N. goals, the rights and feelings of indigenous people are often ignored or minimized, even by supposedly culturally sensitive developed countries. In the United States many of those in the federal government are pushing to exploit oil resources in the Arctic National Wildlife Refuge on the northern coast of Alaska. The “Gwich’in,” an indigenous people who rely culturally and spiritually on the herds of caribou that live in the region, claim that drilling in the region would devastate their way of life (Figure b). Thousands of years of culture would be destroyed for a few months’ supply of oil. Drilling efforts have been stymied in the past, but mostly out of concern for environmental factors and not necessarily the needs of the indigenous people. Curiously, another group of indigenous people, the “Inupiat Eskimo,” favor oil drilling in the Arctic National Wildlife Refuge. Because they own considerable amounts of land adjacent to the refuge, they would potentially reap economic benefits from the development of the region.
The heart of most environmental conflicts faced by governments usually involves what constitutes proper and sustainable levels of development. For many indigenous peoples, sustainable development constitutes an integrated wholeness, where no single action is separate from others. They believe that sustainable development requires the maintenance and continuity of life, from generation to generation and that humans are not isolated entities, but are part of larger communities, which include the seas, rivers, mountains, trees, fish, animals and ancestral spirits. These, along with the sun, moon and cosmos, constitute a whole. From the point of view of indigenous people, sustainable development is a process that must integrate spiritual, cultural, economic, social, political, territorial and philosophical ideals.
Attribution
Modified by Melissa Ha and Rachel Schleiger from Environmental Justice and Indigenous Struggles and Environment and Sustainability from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.03%3A_Environmental_Ethics/7.3.01%3A_Environmental_Justice_and_Indigenous_Struggles.txt |
Frontier Ethic
The ways in which humans interact with the land and its natural resources are determined by ethical attitudes and behaviors. Early European settlers in North America rapidly consumed the natural resources of the land. After they depleted one area, they moved westward to new frontiers. Their attitude towards the land was that of a frontier ethic. A frontier ethic assumes that the earth has an unlimited supply of resources. If resources run out in one area, more can be found elsewhere or alternatively human ingenuity will find substitutes. This attitude sees humans as masters who manage the planet. The frontier ethic is completely anthropocentric (human-centered), for only the needs of humans are considered.
Most industrialized societies experience population and economic growth that are based upon this frontier ethic, assuming that infinite resources exist to support continued growth indefinitely. In fact, economic growth is considered a measure of how well a society is doing. The late economist Julian Simon pointed out that life on Earth has never been better, and that population growth means more creative minds to solve future problems and give us an even better standard of living. However, now that the human population has passed seven billion and few frontiers are left, many are beginning to question the frontier ethic. Such people are moving toward an environmental ethic, which includes humans as part of the natural community rather than managers of it. Such an ethic places limits on human activities (e.g., uncontrolled resource use), that may adversely affect the natural community.
Some of those still subscribing to the frontier ethic suggest that outer space may be the new frontier. If we run out of resources (or space) on earth, they argue, we can simply populate other planets. This seems an unlikely solution, as even the most aggressive colonization plan would be incapable of transferring people to extraterrestrial colonies at a significant rate. Natural population growth on earth would outpace the colonization effort. A more likely scenario would be that space could provide the resources (e.g. from asteroid mining) that might help to sustain human existence on earth.
Sustainable Ethic
A sustainable ethic is an environmental ethic by which people treat the earth as if its resources are limited. This ethic assumes that the earth’s resources are not unlimited and that humans must use and conserve resources in a manner that allows their continued use in the future. A sustainable ethic also assumes that humans are a part of the natural environment and that we suffer when the health of a natural ecosystem is impaired. A sustainable ethic includes the following tenets:
• The earth has a limited supply of resources.
• Humans must conserve resources.
• Humans share the earth’s resources with other living things.
• Growth is not sustainable.
• Humans are a part of nature.
• Humans are affected by natural laws.
• Humans succeed best when they maintain the integrity of natural processes sand cooperate with nature.
For example, if a fuel shortage occurs, how can the problem be solved in a way that is consistent with a sustainable ethic? The solutions might include finding new ways to conserve oil or developing renewable energy alternatives. A sustainable ethic attitude in the face of such a problem would be that if drilling for oil damages the ecosystem, then that damage will affect the human population as well. A sustainable ethic can be either anthropocentric or biocentric (life-centered). An advocate for conserving oil resources may consider all oil resources as the property of humans. Using oil resources wisely so that future generations have access to them is an attitude consistent with an anthropocentric ethic. Using resources wisely to prevent ecological damage is in accord with a biocentric ethic.
Land Ethic
Aldo Leopold, an American wildlife natural historian and philosopher, advocated a biocentric ethic in his book, A Sand County Almanac. He suggested that humans had always considered land as property, just as ancient Greeks considered slaves as property. He believed that mistreatment of land (or of slaves) makes little economic or moral sense, much as today the concept of slavery is considered immoral. All humans are merely one component of an ethical framework. Leopold suggested that land be included in an ethical framework, calling this the land ethic.
“The land ethic simply enlarges the boundary of the community to include soils, waters, plants and animals; or collectively, the land. In short, a land ethic changes the role of Homo sapiens from conqueror of the land-community to plain member and citizen of it. It implies respect for his fellow members, and also respect for the community as such.” (Aldo Leopold, 1949)
Leopold divided conservationists into two groups: one group that regards the soil as a commodity and the other that regards the land as biota, with a broad interpretation of its function. If we apply this idea to the field of forestry, the first group of conservationists would grow trees like cabbages, while the second group would strive to maintain a natural ecosystem. Leopold maintained that the conservation movement must be based upon more than just economic necessity. Species with no discernible economic value to humans may be an integral part of a functioning ecosystem. The land ethic respects all parts of the natural world regardless of their utility, and decisions based upon that ethic result in more stable biological communities.
“Anything is right when it tends to preserve the integrity, stability and beauty of the biotic community. It is wrong when it tends to do otherwise.” (Aldo Leopold, 1949)
Case Study: Hetch Hetchy
In 1913, the Hetch Hetchy Valley – located in Yosemite National Park in California – was the site of a conflict between two factions, one with an anthropocentric ethic and the other, a biocentric ethic. As the last American frontiers were settled, the rate of forest destruction started to concern the public.
The conservation movement gained momentum, but quickly broke into two factions. One faction, led by Gifford Pinchot, Chief Forester under Teddy Roosevelt, advocated utilitarian conservation (i.e., conservation of resources for the good of the public). The other faction, led by John Muir, advocated preservation of forests and other wilderness for their inherent value. Both groups rejected the first tenet of frontier ethics, the assumption that resources are limitless. However, the conservationists agreed with the rest of the tenets of frontier ethics, while the preservationists agreed with the tenets of the sustainable ethic.
The Hetch Hetchy Valley was part of a protected National Park, but after the devastating fires of the 1906 San Francisco earthquake, residents of San Francisco wanted to dam the valley to provide their city with a stable supply of water. Gifford Pinchot favored the dam.
“As to my attitude regarding the proposed use of Hetch Hetchy by the city of San Francisco…I am fully persuaded that… the injury…by substituting a lake for the present swampy floor of the valley…is altogether unimportant compared with the benefits to be derived from it’s use as a reservoir.
“The fundamental principle of the whole conservation policy is that of use, to take every part of the land and its resources and put it to that use in which it will serve the most people.” (Gifford Pinchot, 1913)
John Muir, the founder of the Sierra Club and a great lover of wilderness, led the fight against the dam. He saw wilderness as having an intrinsic value, separate from its utilitarian value to people. He advocated preservation of wild places for their inherent beauty and for the sake of the creatures that live there. The issue aroused the American public, who were becoming increasingly alarmed at the growth of cities and the destruction of the landscape for the sake of commercial enterprises. Key senators received thousands of letters of protest.
“These temple destroyers, devotees of ravaging commercialism, seem to have a perfect contempt for Nature, and instead of lifting their eyes to the God of the Mountains, lift them to the Almighty Dollar.” (John Muir, 1912)
Despite public protest, Congress voted to dam the valley. The preservationists lost the fight for the Hetch Hetchy Valley, but their questioning of traditional American values had some lasting effects. In 1916, Congress passed the “National Park System Organic Act,” which declared that parks were to be maintained in a manner that left them unimpaired for future generations. As we use our public lands, we continue to debate whether we should be guided by preservationism or conservationism.
Attribution
Modified by Melissa Ha and Rachel Schleiger from Environmental Ethics from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.03%3A_Environmental_Ethics/7.3.02%3A_Perspectives_of_the_Environment.txt |
Introduction
It is not uncommon to think of the sustainability paradigm as being a recent interpretation of environmental policy, one that was given credence by the United Nations report "Our Common Future" (the Brundtland Report) when it was first presented in 1987. However, it would be a mistake to conclude that sustainability as a mental construct and policy framework for envisioning the relationship of humans and nature came into being suddenly and at a single moment in time. Most environmental historians who have studied U.S. policy have discerned at least three distinct periods during which new concepts and ideas, scientific understandings, technological advances, political institutions, and laws and regulations came or were brought into being in order to understand and manage human impacts on the environment.
1. The American conservation movement: This 19th century movement had the main objective for conservation of American land and resources, it grew from opposite philosophies. On one side you had people like Gifford Pinchot (first head of the US National Forest Service) that were very pragmatic about their desire for conservation. For example, these people observed that policies for harvesting some resource (like lumber) were not sustainable, so they began conservation/sustainability research and new policies so the resource would not run out in the foreseeable future. On the other side were people like John Muir and Theodore Roosevelt that saw land/habitats/wildlife as intrinsic entities, meaning that had value in their own right (meaning nothing to do with money).
2. The rise of environmental risk management as a basis for policy: The beginnings of environmental risk management can be traced to the fields of public health, industrial hygiene, and sanitary engineering, which came into prominence in the latter decades of the 19th century and beginning of the 20th. The spread of disease was a particularly troublesome problem as the country continued to urbanize. In addition, environmental scientists of the day were alarmed by the extent and degree of damage that they were documenting. The publication of Silent Spring in 1962 by Rachel Carson (1907-1964), about the impact of the widespread and indiscriminate use of pesticides, was a watershed moment, bringing environmental concerns before a large portion of the American, and global, public. Carson, collected scientifically documented evidence on the effects of pesticides, particularly DDT, heptachlor, and dieldrin, on humans and mammals, and the systemic disruption they caused to ecosystems. Silent Spring is credited with bringing about a ban on the use of DDT in the United States, and setting in motion a chain of events that would ultimately result in the transformation of environmental public policy from one based on the problems and attitudes that brought about nineteenth century conservation, to one based on the management of risks from chemical toxins. The U.S. Environmental Protection Agency was established in 1970, just eight years after the publication of Silent Spring. The same year Earth Day was created.
3. The integration of social and economic factors to create what we now refer to as the sustainability paradigm: Eventually, we (humanity) realized that in order to solve environmental issues (like ones identified by Rachel Carson), that the "human factors" (both social and economical) had to be accounted for. This is what defines the sustainability paradigm: environmental, social, and economic disciplines. Only Band-Aid solutions can be applied if we only take a one-minded approach.
History of Environmental Policy
Environmental policies are typically driven by problems of the day, real and perceived, that require systemic solutions. For example:
• Early conservationists were alarmed at the inefficiencies of human resource management and the encroachment of humans on unspoiled lands... Leading to conservation legislation.
• During the 20th century many groups (scientists, economists, politicians, and ordinary citizens) became alarmed and fearful of the consequences of toxic pollutant loads to the environment that included localized effects on human health and well-being... Leading to clean air and water legislation.
• As we proceed into the 21st century, an array of complex problems that have the potential to alter substantially the structure and well-being of large segments of human societies, calls for a renewal and reassessment of our approach to environmental policy.
This has, thus far, proven to be a difficult transition. Many of these complex problems have multiple causes and impacts, affect some groups of people more than others, are economically demanding, and are often not as visibly apparent to casual observers as previous impacts, nor are the benefits perceived to be commensurate with costs. Devising a regulatory strategy for such problems requires an adaptive and flexible approach that current laws do not foster.
Table \(\PageIndex{a}\): Table illustrating evolution of environmental policy. Table by Sustainability: A Comprehensive Foundation in Openstax (CC-BY).
1850-1920 1960-1990 1990-Present
Focus
Conservation/sanitation Media/site/problem specific Complex regional/ global problems
Outcome Land preservation/efficiency/control of disease Manage anthropocentric and ecological risk Global sustainable development
Principal Activity Resource management reform/simple contaminant controls Compliance/remediation/technological emphasis on problem solving Integration of social, economic, and technological information for holistic problem solving
Economic Focus Profit maximization/public health Cost minimization Strategic investments/long-term societal well-being
Regulatory Activity Low Heavy Adaptive and flexible
Conceptual Model Expansion vs preservation Command and control Systems/life cycle approach
Disciplinary Approach Disciplinary and insular Multidisciplinary Interdisciplinary/integrative
Table \(\PageIndex{b}\): Table illustrating major environmental legislation, society, and organization conceptions. Table by Rachel Schleiger (CC-BY-NC).
Year
Policy/Society/Organization Conception
1899
Refuse Act
1905 National Forest Service
1916 National Park Service
1918 Migratory Bird Treaty Act
1930's State Parks
1948 Federal Water Pollution Control Act
1950 The Nature Conservancy
1955 Air Pollution Control Act
1961 World Wildlife Federation
1963 Clean Air Act (1970, 1977, 1990 updates)
1965 Solid Waste Disposal Act (1976 update)
1965 Water Quality Act (1987 update)
1967 Air Quality Act
1969 National Environmental Policy Act
1970 Occupational Safety and Health Act
1970 Environmental Protection Agency
1971 Occupational Safety and Health Administration
1972 Consumer Product Safety Act
1972 Federal Insecticide, Fungicide, and Rodenticide Act
1972 Clean Water Act (1977 update)
1972 Noise Control Act
1973 Endangered Species Act
1974 Safe Drinking Water Act (1986, 1996 updates)
1975 Hazardous Materials Transportation Act
1976 Resource Conservation and Recovery Act
1976 Toxic Substances Control Act
1980 CERCLA (Superfund)
1984 Hazardous and Solid Waste Amendments
1986 Superfund Amendments and Reauthorization Act
1986 Emergency Wetlands Resources Act
1990 Oil Pollution Act
1993 North American Free Trade Agreement
2003 Healthy Forest Initiative
Attribution
Modified by Rachel Schleiger from Sustainability: A Comprehensive Foundation by Openstax (CC-BY). | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.04%3A_Environmental_Policy.txt |
Introduction
Sustainability, from science to philosophy to lifestyle, finds expression in the way we shape our cities. Cities are not just a collection of structures, but rather groups of people living different lifestyles together. When we ask if a lifestyle is sustainable, we’re asking if it can endure. Some archaeologists posit that environmental imbalance doomed many failed ancient civilizations. What could the sustainable city look like, how would it function, and how can we avoid an imbalance that will lead to the collapse of our material civilization? While attempting to envision the “sustainable city” we must discern what factors will influence its shape and form in the future.
So what is the major hindrance for designing/updating for a “sustainable city”?
Sprawl: The outward expansion of human populations (typically in low-density residential and commercial development) into the outer edges of cities/towns.
As sprawl expands, it eats at natural and agricultural lands and isolates people. People have to travel further and further to go to work, the grocery store, a hospital, etcetera. What this means is that cities/towns have to find solutions to moving water, waste, power, services, road development/upkeep, etcetera to these communities. As such, there are chronic issues with sprawl on both sides that make opportunity and progress difficult due to economic constraints.
It’s important to note that sprawl can happen at different scales:
• Low-density sprawl: Small 1-2 story buildings in high densities. Low-density sprawl can be further distinguished by income as neighborhoods tend to be segregated by this. (Ex: North America)
• High-density sprawl: High rise buildings in high densities (Ex: China)
So what can be done to design/update and move towards “sustainable cities”?
• Mixed use development: Lends residential, commercial, cultural, institutional, or industrial uses, where those functions are physically and functionally integrated, and that provides pedestrian connections. Making cities walkable!
• Geographic equity: Circulation system defined by ratios of how people move. This means more bikes, walking, public transportation (in many forms) and not cars. Equitability of the streets!
• Preserve: Preserve land, culture, and biodiversity as much as possible.
• Mix: Mix incomes, cultures, green spaces, public transport options, etcetera as much as possible. Allow people to connect and become neighbors not strangers.
• Focus: Match density of a community to meet transit/service needs.
Video \(\PageIndex{a}\): Perspectives: Peter Calthrope describes 7 principles for building better cities.
Attribution
Rachel Schleiger modified from Environment and Society in a Changing World by PennState OER Initiative (CC-BY-NC-SA)
7.06: Sustainability and the Future
Ecological Footprint
The ecological footprint (EF), developed by Canadian ecologist and planner William Rees, is basically an accounting tool that uses land as the unit of measurement to assess per capita consumption, production, and discharge needs. It starts from the assumption that every category of energy and material consumption and waste discharge requires the productive or absorptive capacity of a finite area of land or water. If we (add up) all the land requirements for all categories of consumption and waste discharge by a defined population, the total area represents the Ecological Footprint of that population on Earth whether or not this area coincides with the population’s home region.
Land is used as the unit of measurement for the simple reason that, according to Rees, “Land area not only captures planet Earth’s finiteness, it can also be seen as a proxy for numerous essential life support functions from gas exchange to nutrient recycling … land supports photosynthesis, the energy conduit for the web of life. Photosynthesis sustains all important food chains and maintains the structural integrity of ecosystems.”
What does the ecological footprint tell us? Ecological footprint analysis can tell us in a vivid, ready-to-grasp manner how much of the Earth’s environmental functions are needed to support human activities. It also makes visible the extent to which consumer lifestyles and behaviors are ecologically sustainable calculated that the ecological footprint of the average American is – conservatively – 5.1 hectares per capita of productive land. With roughly 7.4 billion hectares of the planet’s total surface area of 51 billion hectares available for human consumption, if the current global population were to adopt American consumer lifestyles we would need two additional planets to produce the resources, absorb the wastes, and provide general life-support functions.
Common Cause and Sustainability
Common cause: Brings about change in all people/interest groups/world leaders because of common goals. Below are a list of sustainability goals across the sustainability paradigm. Most, if not all, are common cause goals for the now, and into the future.
Society
• No poverty
• Zero hunger
• Good health
• Quality education
• Gender equality
• Peace, justice, and strong institutions
• Clean water and sanitation
• Reduced inequalities
Environment
• Terrestrial life/habitats conservation and restoration
• Oceanic life/habitats conservation and restoration
• Climate action
• Reduced waste/pollution
Economy
• Affordable and clean energy
• Decent work and economic growth
• Industry, innovation, and infrastructure
• Responsible consumption and production
• Sustainable cities and communities
• Partnerships locally and globally
Sustainable Living
Sustainable living describes a lifestyle that attempts to reduce/eliminate an individuals (or societies) use of resources so as to be as close as possible to "net zero living". As such, an individual (or society) focuses on reducing their footprint (ecologically, carbon, socially, etc) through their choices/methods of:
• Use of resources (energy/diet/transportation/water/etc)
• Support of people/companies (voting/economic/social/etc)
• Practices of reducing, reusing, and recycling
• Consciousness of priority and focus for local concerns/needs versus global concerns/needs
• Sharing knowledge with their community (all ages)
The thought of getting started with sustainable living can be overwhelming! However, it is important to note that although we can acknowledge all the things that need to be accomplished, that that entire burden does not lie with just one individuals control (see figure below). It takes a multi-layerd approach to appropriately take action at the individual, societal, and political levels (see figure above).
The Bionic World
This book will conclude by stating a huge myth held by most of today's society, the myth of the Bionic World. It is the belief that science and technology will solve the pressing issues of human’s impact on this earth. If society follows this logic, we have no tough choices to make about how we view and treat our surroundings, and decisions can be put off until the economic markets demand or justify a solution. Society can hope to be right…. However, until supporting evidence emerges that humanity can solve all their own problems with the ever shrinking timeline to do so, then we need to start making tough choices to ensure an equitable and sustainable future.
Video \(\PageIndex{a}\): Perspectives: Michael Green discusses sustainability goals and what we can do moving forward (Videos from 2015 and 2018)
Attribution
Modified by Melissa Ha and Rachel Schleiger from Environment and Sustainability from Environmental Biology by Matthew R. Fisher (licensed under CC-BY) and The Myths of Restoration Ecology by Robert H. Hilderbrand, Adam C. Watts and April M. Randle 2005 (CC-BY-NC)
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Overview
Climate change is the major focus of conversation across many different disciplines and interest groups. With a huge array of global sustainability challenges both now and in the future, investors are starting to re-evaluate where they want to spend their money. Today, sustainable investing is increasing exponentially! The graph below displays the global growth in sustainable investments between 2012 and 2018:
Questions
1. What kind of graphs are these?
2. What major differences are there between the 2012 graph and the 2018 graph?
3. Which country(ies) is the major leader for sustainable investments?
4. Are there any countries/regions that are not represented on the graph that you would have predicted would be there?
5. Is there anything that surprises you about the results displayed in these graphs? Explain your answer.
Raw Data From Above Graph(s)
Table \(\PageIndex{a}\): Raw data from 2012 and 2018 global sustainable investments. Graph by Rachel Schleiger (CC-BY-NC) modified from data in Global Sustainable Investment Alliance 2019.
Country/Continent 2012 Investments (USD\$ Trillion) 2018 Investments (USD\$ Trillion)
United States 3.7 12
Europe 8.8 14.1
Japan 0.01 2.2
Canada 0.59 1.7
Australia/New Zealand 0.18 0.7
Attributions
Rachel Schleiger (CC-BY-NC)
7.08: Review
Summary
After completing this chapter you should be able to...
• Define sustainability and the sustainability paradigm
• Describe the historic events that lead to the sustainability paradigm
• Describe how ethics and moral extensionism connect to sustainability
• Understand that true sustainability promotes environmental equity and justice, thus eliminating environmental racism
• Describe the evolution of ethics leading to the modern environmental ethic
• Understand how environmental policy has changed based on movements and need in the US
• Define what sustainable cities are
• Describe how sprawl is a hindrance to sustainable cities
• Describe how sustainable lifestyle choices influence sustainability
• Acknowledge that the Bionic World is a myth
Sustainability is focused on meeting current needs without compromising the future generations to meet theirs. Sustainability is a paradigm created out of necessity from our past negligence to society, ecology, and economy (the three main components of sustainability).
Ethics plays a large role in addressing current and future sustainability goals necessitated from historic action/inaction. This is especially true for matters of environmental justice and racism, in addition to environmental policies and movements.
Sustainable cities are also discussed to address the large-scale sustainability concerns of how humanity lives. Sprawl is the biggest hindrance for creating the sustainable city. There are two main types of sprawl, low-density and high-density, that can be observed in many differently populated city layouts.
The ecological footprint is a tool to help illustrate the imbalance between lifestyles and behaviors and what is ecologically sustainable. In order to decrease ecological footprints, in addition to environmental injustices, sustainability promotes common cause sustainability goals. These emphasize that most goals humanity have are the same, and that these should be what both motivate and unite us as we move towards an uncertain future. In addition, humanity should also consider how we are approaching meeting these goals. The myth of the bionic world warns us not to make assumptions or take the easy way out. Only through tough decisions can we ensure an equitable and sustainable future.
Attribution
Rachel Schleiger (CC-BY-NC) | textbooks/bio/Ecology/Environmental_Science_(Ha_and_Schleiger)/07%3A_Sustainability/7.07%3A_Data_Dive-_Sustainable_Investments.txt |
Learning Objectives
• Explain the multiple benefits of fish conservation.
• Define fish and describe multiple approaches used for classifying fish.
• Describe changes in history of fishing over time.
• Classify and compare major types of fishing practices.
• Compare and contrast the importance of commercial, recreational, and subsistence fishing.
• Describe why fish matter to humans.
• Describe the types of ecosystem services provided by fish.
• Construct a list of threats and trends in the uses of fish.
1.1 Introduction
Fish live on every continent and in all types of aquatic environments. Think about a fish that you are most familiar with. Its value to you depends on if, how, and where you interact with the fish. The essence of this fish depends on your perspectives. Your familiar fish may be valued as a living room pet, favorite food, trophy, or the source of your livelihood.
Imagine you are sitting in a meeting of the Alaska Board of Fisheries, which conserves and develops the state’s fishery resources. Before the formal meeting you would hear commercial gillnetters speak of their concerns about season lengths and quotas. Outfitters and local tourism officials are concerned about crowding during sportfishing seasons and what locals call combat fishing because of anglers competing to find and protect fishing spots. Native American tribal fishers, like many others, would complain about declining quotas and gradual loss of culture and identities tied to salmon fishing. You thought you knew all about salmon, but the conversations are filled with unfamiliar terms, such as over-escapement, subsistence, hatchery strays, purse seiners, humpies, ocean warming, the salmon enhancement tax, drought, heat stress, damn seals, and Pebble Mine. More than once you hear someone say, “Fishing is in my blood.” Fish and fishing may be central to everyone present, but everyone has different preferences.
It is a challenge to ensure that the benefits provided by fish and fishing continue long into the future. Fish of the world are becoming increasingly imperiled, and the search for simple, generally applicable solutions for fish conservation often elude us. Humans and ecosystems alike benefit from the very presence of fish in all aquatic habitats on earth, but it is this ubiquitous presence that also results in conflicts with other human activities.
Fish and fishing are complicated subjects. Conservation of fish is not easy. Fish represent over half the vertebrate animals on our planet, but receive little attention in major conservation initiatives compared to birds and mammals. Think of the Bald Eagle (Haliaeetus leucocephalus), Gray Wolf (Canis lupus), Giant Panda (Ailuropoda melanoleuca), Tiger (Panthera tigris), and African Elephant (Loxodonta africana). These are flagship species, or ‘‘popular, charismatic species that serve as symbols and rallying points to stimulate conservation awareness and action.’’ (Caro 2010). Most of the fish lack such high levels of public awareness.
Ultimately, because fish inhabit diverse environments and serve many important ecological and anthropogenic services, fish conservation and management issues come down to our value systems. Goals for conservation are derived by asking “What should we care about?” Personally, I believe that fish conservation should be to ensure that fish persist so that future generations may decide on how they will interact with these fascinating animals. Values influence how we define sustainable fishing and how we reverse the tendency for overharvest and degradation of aquatic ecosystems. Planning for fish conservation requires ethical reasoning about fish and fishing. Answers to fundamental questions about conservation of fish may involve rethinking and adopting ethical principles in governance and giving people a bigger role in conservation. Thinking about fish as sophisticated and sentient creatures may change our perspective about how fishing should be conducted. Ethical issues such as social justice, corporate responsibility, and power sharing in democratic decision making should be central to fish conservation. From the case studies provided in later chapters, we learn that the keys to successful conservation of fish include persistence, passionate leadership, partnerships, trust, and optimism. I propose the following working principle that serves as an overarching guide: passionate and persistent people who understand the fish and the place will find a way to create partnerships to conserve valued fish in perpetuity.
In next sections, I characterize the types of fish and fishing, and how the way humans interact with fish can influence the way in which we classify and value fish. In doing so, we begin our exploration into why fish matter, and the challenges facing us we work to conserve fishing and fishing in the Anthropocene.
1.2 Types of Fish
What is a Fish? A biologist would define a fish as a “cold-blooded animal that lives in water, breathes with gills, and usually has fins and scales.” (Berra 1981). But that definition, though accurate, does not fully describe the essence of a fish. That indispensable quality of a fish is given by humans. An evolutionary biologist might say that fish are the dominant vertebrate group, highly successful in their radiation, colonizing every conceivable habitat niche in almost every part of the world. After 400 million years of evolutionary innovations, fish comprise some of the most sophisticated and complex examples of evolution. For example, pupfish can live in geothermal springs at 94°F, icefish occur at temperatures below freezing, and wrasses change sex from female to male to ensure mating success.
Ichthyologists classify fish into five major classes. The most ancestral groups are the jawless lampreys and hagfish, which are in classes Petromyzontida and Myxini, respectively. All other fish have jaws; these include the sharks, skates, and rays (class Chondrichthyes), coelacanths and lungfish (Sarcopterygii), and the ray-finned fish (class Actinopterygii). The ray-finned fish represent the largest and most diverse group, containing 96% of the 36,345 valid fish species (Fricke et al. 2022). Given this diversity of fish, simple definitions seem uninspiring.
Major class of fish Number of species
Hagfishes — Myxini 88 species
Lampreys — Petromyzontida 48 species
Cartilaginous fishes — Chondrichthyes 1,291 species
Lobe-fin fishes — Sarcopterygii 8 species
Rayfinned fishes — Actinopterygii 34,910 species
Table 1.1: Number of fish species for each of the five major classes of fish.
Beyond taxonomic classification, scientists can classify fish in other ways that describe their human uses or ecological characteristics. For example, fish can be described by their habitat requirements or preferences (freshwater and saltwater or stream fish), their behavior (highly migratory or sedentary), whether they are targeted by anglers (sport fish and nongame fish), and many others. Some use terms such as “rough,” “coarse,” or “trash” fish, pejoratives ascribing low-to-zero values. However, use of such terms say more about the person using the term than about the fish itself.
One way that scientists classify fish is based on the species’ life-history traits, namely precocial, opportunist, survivor, extreme survivor, and episodic (Figure 1.1). Precocial fish, such as seahorses, have few large offspring, small body size, rapid growth, early maturity, and short lifespan. Opportunist fish, such as herring, have many small offspring, small body size, rapid growth, early maturity, and a short lifespan. Survivor fish, such as sharks, have few large offspring, large body size, slow growth, late maturity, and a long lifespan. Some sharks such as Greenland sharks live over 400 years and are extreme examples of survivors. Episodic fish, such as Brown-Marbled Grouper, have many small offspring, large body size, slow growth, late maturity, and a long lifespan (Kindsvater et al. 2016). Classifying fish by life-history traits often provides insights into species’ unique conservation needs and challenges.
Yet, scientific classifications may mean little to the average person. When humans think of fish, we may connect more strongly to the water, the life-giving element of the world, than to scientific jargon. In some cultures, fish symbolize rebirth, good fortune, fertility, strength, or endurance. In 2017, ethologist Jonathan Balcombe in What a Fish Knows explored evidence of perception and cognition in fish, thereby changing our view of fish from simple to more complex. No longer were fish the dead-eye offerings at the fish market, the fish oil in a capsule, or processed flesh in cans. Thinking about fish as sentient, aware, intelligent, and social beings changes our relationship with fish. Fish may still be the target of your next fishing trip, but your actions are certainly influenced by what you know about the fish. The more you know about the target of your fishing, the more likely you are to be successful. More people are finding ways to view fish in their environment via mask, snorkel, and SCUBA, and even deepwater submersibles. For these reasons, how fish are classified often extends beyond strict scientific definitions and depends on how humans interact with fish. Some classifications may be based on methods to capture fish, while others may focus on how a fish is used for food or recreation.
Question to ponder
Before reading the chapter, how would you normally classify fish or which dominant values would you place on fish? How does this reflect your personal cultural biases?
1.3 Types of Fishing
Humans have been capturing fish for tens of thousands of years. Stone Age burial heaps in Africa contained harpoons, spears, fish bones, and a wide range of terrestrial animals dated from 90,000 to 75,000 years BP (Sahrhage and Lundbeck 1992; Robbins et al. 1994; Henshilwood et al. 2001). It’s only in the last 1,000 years that humans have developed a pervasive culture around fishing for profit (Pitcher and Lam 2015). Today, there are many types of fishing, and fish can be classified by how, where, and by whom they are caught.
To manage fishing, one must first understand the types of fishing, fishers, and communities, to impose the correct regulation from a diverse array of management actions. The term “fisheries” refers to the place or occupation or industry of catching fish. Fisheries are based on the capture of fish or shellfish, even if there is the possibility of their release after capture. Historically, humans have focused on highly valued food fish, such as tuna, bass, salmon, and cod, which continued to be intensively harvested for food (Figure 1.2; Greenberg 2011). Commercial fishing is the activity of catching fish or seafood for commercial profit, and is the last wild harvest of wild food. Given this, and perhaps not surprisingly, most valued fish are easily overfished. Meeting the future demands for fish will depend on domestication and fish culture to supply the increasing demand as consumption per capita increases (FAO 2018).
There are many ways to commercially fish, and gear selection plays a role in determining cost, efficiency at catching the target species, and rate of bycatch of nontarget species. Seines (including purse seines), trawls, gill nets, and longline gears are responsible for over 90% of the commercial catch (Figure 1.3), and successive technological improvements to fishing gear and vessels have increased their effectiveness (Watson et al. 2006). Small fish, low on the food chain, are typically caught in seines and bottom trawls, either intentionally or unintentionally as part of bycatch. Large top predators are most often caught via longline gears. Industrial fisheries are a subset of commercial fishing that harvests fish with a high level of technology, investment, and impact, often with large purse seiners, trawlers, and factory boats.
Commercial fishing may target seafood for human consumption, or for nonfood purposes, such as fish oil and fish meal. Commercial fishing most frequently occurs in oceans where most of the landings consist of only 200 marine fish species, or roughly 1% of all species found in oceans (Palomares and Pauly 2019). Despite our substantial scientific knowledge of fish and fishing, we are faced with troubling headlines about the dismal state of the world’s fisheries (Worm et al. 2009). Fishing occurs on more than 55% of ocean area and has a spatial extent more than four times that of agriculture (Kroodsma et al. 2018). Commercial fishing in the high seas is dominated by countries that subsidize fishing fleets, in particular China, Taiwan, Japan, South Korea, Spain, France, the United States, and Indonesia. Governments subsidized high-seas fishing with \$4.2 billion in 2014, far exceeding the net economic benefit of fishing in the high seas (Sala et al. 2018). Drifting longliners and purse seiners, targeting mainly large, mobile, high-value fish such as tuna and sharks, are among the most profitable high-seas fisheries. Deep-sea bottom trawling catches everything, much of which is wasted. Despite our long history of commercial fishing, unresolved fisheries problems, such as widespread unreporting, unfair wages or forced labor, and shipment at sea, remain (Pew Charitable Trusts 2019).
Fisheries employ 260 million people, and fish are the primary protein source for ~40% of the world’s population. Over the past 50 years, annual global consumption of seafood products per person has more than doubled, from almost 10 kg in 1960 to over 20 kg (or approximately 200 servings) in 2014 (Figure 1.4). Overfishing is therefore common, which threatens the food security in countries dependent of fish for protein (Pauly and Zeller 2016).
Many nations rely on imports to meet national demands for seafood products, which complicates the management of commercial fishing at national level. As much as 60% of the fish harvested for fish meal or fish oil enters international trade markets rather than local markets (Guillen et al. 2018) Some of this is used in developing aquaculture feed, which is more efficiently converted to human food than livestock, poultry, or pork.
Inland fisheries are also important sources of nutritional, recreational, and economic value. While only 1.2% of the Earth’s water is fresh and surface water, inland capture fisheries contributed 12.7% of the global fish catch in 2019 (FAO 2019). The actual inland fish harvest is likely substantially higher due to methodological or reporting issues (Cooke et al. 2016). While most marine fishing is commercial or subsistence, inland fisheries may be commercial, recreational, or subsistence. The biggest commercial inland fisheries are in Asia and Africa, whereas, recreational freshwater fisheries predominate in higher latitude and developed countries (Funge-Smith and Bennett 2019).
Question to ponder
What types of fish are most overfished and where? Do a quick search on Google News (or similar) for the term “overfishing.” What about the term “fishing down the food web?” How many hits do you get? What species and places are in the current news?
Recreational fishing uses a variety of gear types, but the most common is rod and line to catch fish for fun and/or food. Recreational fishing is defined as the fishing of aquatic animals (mainly fish) using one or more of several possible techniques in which aquatic animals do not constitute the individual’s primary resource to meet basic nutritional needs and are not sold or otherwise traded on export or domestic or black markets (Cooke et al. 2018). The objective of recreational fishing is the overall recreational experience, and catch is only one important component. The propensity to harvest or to engage in voluntary catch-and-release varies among cultures, locations, species, and fisheries. The role of recreational fishing in supporting nutrition (and thus food security) at regional, national, or global scales is underappreciated (Cooke et al. 2018).
In addition to being a valuable food source, recreational fishing can also contribute significantly to local economies. In the United States, there are over 49 million recreational anglers that are a potent economic force due to spending habits. Outdoor recreation in general and sportfishing in particular are growing enterprises that contribute greatly to the overall economy. Fishing licenses and boat registration, taxes on boat motor fuel, and fishing equipment provide the funding for recreational fisheries management programs. Recreational angler motivations change over time from catch any, to catch many, to catch big fish, and finally to catch no fish but pass on knowledge and passion for fishing (Table 1.2; McKenna 2013). At some point many successful anglers wish to help others catch fish or to help researchers better assure that the fish and fishing experiences enjoyed in the past will still be around well into the future (Oh and Ditton 2008).
Stage Motivation
1 I just want to catch a fish!
2 I want to catch a lot of fish!
3 I want to catch big fish.
4 I’m just happy to be out fishing.
5 I want to give back. I want to pass on my knowledge and passion for fishing and help others or the fish themselves.
Table 1.2: Stages of development of the recreational angler.
1.4 Fish Harvest
Human perception of fish and fisheries depends not only on fishing method, but also on whether the fishery intends to harvest their catch. For indigenous peoples who live on islands or on the water, fish are a principal source of protein and nutrition. Because fish flesh spoils quickly, many methods have been developed to make fish last longer in different parts of the world. Therefore, we have canned, smoked, fermented, pickled, dried, pureed, and even lye-soaked fish (i.e., lutefisk) to increase their shelf life. Today, fish are important nutritional resources. Fish are a source of many micronutrients, and fish consumption can prevent nutrient-deficiency diseases, a leading cause of infant deaths worldwide (Hicks et al. 2019). Marine-derived oils in fish (omega-3 fatty acids) provide many human health benefits, reduce risk of coronary and neural disease, and enhance cognitive development (Morris et al. 2003, 2016; Hibbeln et al. 2019). In many instances, fish are more affordable animal-based food with a lower environmental impact (Willett et al. 2019). Because of the prevalence of fish in our diet, contamination of aquatic environments (e.g, mercury, polychlorinated biphenyls, or PCBs) is a global health concern.
Traditional small-scale fisheries are prominent in many parts of the world. These artisanal and subsistence fisheries generate about one-third to one-half of the global catch that is used for direct human consumption and employ more than 99% of the worlds 51 million fishers (Pauly and Zeller 2016; Jones et al. 2018). Small-scale fisheries may also be described as (1) subsistence, (2) aboriginal, or (3) artisanal fisheries. Subsistence fisheries are “local, noncommercial fisheries, oriented not primarily for recreation but for the procurement of fish for consumption of the fishers, their families and community” (Berkes 1988). Subsistence fishers may forever be the “forgotten stepchild” in fisheries management and are adversely affected by the attention lavished on the commercial and recreational sectors (Schumann and Macinko 2007). Aboriginal or indigenous fisheries harvest fish for sustenance and customary and traditional uses. One example would be Alaska Native tribes’ harvest of Pacific Halibut. Artisanal fisheries employ small vessels and short fishing trips to capture fish for local consumption and can be commercial or subsistence. These are traditional fishers who employ small vessels and short fishing trips to capture fish for local consumption.
In many cases, fish are killed by nonfishing activities. Legally, this is referred to as “take.” Section 3(18) of the Federal Endangered Species Act (16 U.S.C. § 1531 et seq.) defined “take” to mean “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” Bowhunting, minnow trapping, noodling, and all take fish and are typically regulated by inland fisheries agencies.
The diversity of fishing practices complicates conservation and management strategies. We don’t often appreciate the diversity of fishing practices and behaviors. While we know there is no such thing as the average angler or the average boat or typical fishing day, we often assume as much to simplify analyses. Regulations on fishing must be compatible with the type of fishing. For example, recreational anglers do not appreciate quotas because they may close fishing just when recreational anglers are vacationing to fish. If inappropriate regulations are imposed on some types of fishers, they will lose confidence in the management authority and the likelihood of noncompliance will increase. In the case of recreational angling, the angler may choose to quit participating, resulting in a loss of license revenues to support fish conservation. Effective management and conservation require that we know our fishers well because the diversity of perceptions and fishing styles influences how they will comply with fishing regulations (Boonstra and Hantati-Sundberg 2016).
Question to ponder
A healthy, balanced diet should include at least two 3-ounce portions of fish a week, including one of oily fish. Which of the following fish products do you think is most expensive? Bluefin Tuna, sardine, farmed Atlantic Salmon, or Haddock. How does the cost of the most expensive fish compare with cost of porterhouse steak (per pound)? Do a quick google search for “fresh seafood for sale” to find current prices for fresh fish. Why are salmon, tuna, bass, and cod so highly valued by humans?
1.5 Why Fish Matter
Valuation of fish populations for human societies has predominantly focused on fishing, yet fish can also be classified by the direct services they provide to humans and other organisms. For example, fish provide four types of ecosystem services, namely provisioning, regulating, supporting, and cultural (Figure 1.5; Cowx and Aya 2011). Fundamental services are essential for ecosystem function, such as nutrient cycling. These are ultimately a prerequisite for human existence. Demand-derived ecosystem services are formed by human values and demands, and not necessarily fundamental for the survival of human societies. These include recreational activities.
Scuba diving is a fast-growing form of special interest tourism that attracts individuals interested in underwater recreation and fish watching. Scuba diving is now a multibillion-dollar industry and one of the world’s fastest growing recreational sports (Ong and Musa 2011; Musa and Dimmock 2013). Although there is generally no harvest of fish, scuba diving can have negative effects on fish populations, as heavily dived sites experience habitat damage, and popular areas are managed to regulate diver carrying capacity. Similarly, fish watching with snorkeling is a low-cost entry into this recreational activity, and many localities are facilitating growth of this activity. Other new and growing fish-watching activities include Whale Sharks, stingrays, and cage diving to watch Great White Sharks.
Fish keeping has grown 14% per year since the 1970s, and the global aquarium fish trade is valued at between \$15 and 30 billion and involves >5,300 freshwater and 1,802 marine fish species (Penning et al. 2009; Raghavan et al. 2013; and Evers et al. 2019). The Guppy (Poecilia reticulata) and Neon Tetra (Paracheirodon innesi) dominate by numbers but certainly not value. Aquarium keeping supports an extremely lucrative industry and sparks conservation efforts among the serious participants (Marchio 2018).
Among the ornamental fish, the Koi are special forms that originated in Japan in 1781 and is now a global commodity with as many as 120 different varieties produced by breeders (DeKock and Gomelsky 2015). Many varieties are judged at competitions based on their colors (Hi = red, Shiroji = white, and Sumi = black) along with their degrees of finish, body size, and steps in the patterns. These fish are swimming jewels, and their colors and elegant bodies create a feast for the eyes in many ornamental koi ponds (Figure 1.6).
Question to ponder
Imagine the variety of tropical fish that are kept by aquarium hobbyists. What do you think are the most expensive ornamental fish? Do a google shopping search for “tropical fish for sale” or “saltwater fish for sale” to find online stores that advertise price. What was the most expensive fish you found for sale?
Other examples of ecosystem services provided by fish include disease vector control. Some fish eat mosquito larvae, which could reduce local abundance of adult Anopheles mosquitoes that transmit the Plasmodium parasites that cause malaria (Walsche et al. 2017). Some cichlids feed on snails that serve as hosts for Schistosomiasis, a disease caused by parasites (Stauffer et al. 1997). After these snail-eating cichlids were overfished or lost due to changes in water quality in Lake Malawi, the prevalence of schistosomiasis increased dramatically from initial zero prevalence (Madsen et al. 2011).
Fish play ecological roles in life and in death. Think about the brown bears eating salmon as they migrate upstream. Bears transfer marine-derived nutrients from the salmon to the terrestrial ecosystems. Carcasses from anadromous fish have been shown to constitute a substantial transfer of carbon and nutrients from marine to freshwater and terrestrial ecosystems. These increased nutrients stimulate productivity of freshwater streams and fish growth rates (Wipfli et al. 2003; Collins et al. 2015; Twining et al. 2017). Many fish serve as bioturbation agents, meaning that their activity can rework sediments and modify the substrate. Salmon disturbance of the streambed during redd digging can have strong short-term and seasonal effects on stream microbes. Similarly, many other fish mix bottom sediments.
Some parrotfish species feed directly on live corals and produce large quantities of carbonate sediment (i.e., sand) as a by-product of grazing on reef surfaces (Perry et al. 2015). Parrotfish are building coral reef islands! Fish serve as nutrient sinks through their feeding behavior. Some fish, such as Gizzard Shad, via their feeding behavior, resuspend adsorbed nutrients from benthic substrates into the water column (Havens 1991; Vanni 2002). Coral reef fish, such as the Gray Snapper, slowly and steadily feed (via concentrated urine) the coral reef ecosystems that, in turn, provide food and shelter to the fish (Allgeier et al. 2016).
Fish feed us, fish inspire us, and fish are part of our living natural history. Louis Agassiz, a famous Swiss naturalist and zoologist, would exhort his students to “Take this fish and look at it.” Professor Agassiz knew that a full appreciation of the specimen required the full examination of its internal and external anatomy. Why do fish matter? I urge you to take a look at the fish and look at it to provide your own answer. Let the fish inspire you and learn how and where they live.
For thousands of years, humans have found inspiration in fish as they painted fish and fishing scenes (Jackson 2012). Living fish were painted depicting their natural habitats and flowing movements during the Song Dynasty (AD 960–1279; Figure 1.7). The Golden Age of painting included many sea fish paintings, depicting landed fish in the sixteenth and seventeenth centuries. The “Fish Market” painting by Frans Snyder depicts an endless variety of fish and other inhabitants of rivers, seas, and lakes (Figure 1.8). Whether depicted being caught or cooked, fish remain a constant source of fascination for artists and writers. Some classic literature on fish and fishing includes A River Runs through It (Norman Maclean), The Old Man and the Sea (Ernest Hemingway), The Founding Fish (John McPhee), Cod: A Biography of the Fish That Changed the World (Mark Kurlansky), Your Inner Fish (Neil Shubin), and The Compleat Angler (Izaak Walton).
1.6 Fish Conservation in the Anthropocene
Conservation is “securing populations of species in natural habitats for the long term” (Barongi et al. 2015). In the Anthropocene geological epoch, which began at the start of significant human impact on Earth’s geology and ecosystems, conservation of fish will require substantial change in policy and human behavior (Steneck and Pauly 2019). Fish conservation and management professionals and citizens must deal with the long-standing and emerging threats from climate change, overfishing, deforestation of watersheds, widespread overfishing, dams and hydropower, irrigation, invasive species, eutrophication, plastics, dead zones, harmful algal blooms, and more (Reid et al. 2018). As demand for fish increases, fishers implement technological innovations, and use more efficient methods to harvest many species before management policies are in place.
In the next chapter, we explore a values framework for examining efforts to conserve and manage fisheries. An interdisciplinary approach is essential to successful conservation of fish. For example, the naturalistic fallacy is often suggested. This belief suggests that if we could just go back to the way things were, fisheries and ecosystems would be restored to their previous state. However, this view fails to recognize that there is no chance of going back to an earlier pristine world without the effects of humans. We can mourn the loss of the past, but your experiences with fish and fishing will not be the same as those of your parents or grandparents. For that reason, this book emphasizes effective, forward-looking conservation which relies on many elements, including: (1) public education and participation; (2) ecological research, management, and monitoring; and (3) a legal framework for enforcement (Jacobson 1995). Collectively, the chapters provide ample evidence that successful conservation depends on people who display persistence, passionate leadership, partnerships, trust, and strategic optimism. Therefore, in each chapter I profile at least one conservation professional in “profiles in fish conservation.”
Question to ponder:
Select one of your favorite fish. Discuss three ways of classifying that fish. How do these different schemes influence how the fish is protected or conserved in the future?
Profile in Fish Conservation: Holly K. Kindsvater, PhD
Holly Kindsvater is an Assistant Professor in the Department of Fish and Wildlife Conservation at Virginia Tech. She received her undergraduate degree in marine biology from University of California, Santa Cruz, and a Ph.D. from Yale University in ecology and evolutionary biology. Her research group examines basic and applied questions in marine and freshwater systems, from high seas fisheries to Appalachian salamanders. From advancements in understanding the life-history theory, she connects unique fish biology to population models for fishes such as tuna, sharks, rays, and grouper, and estimates rates of population decline and species loss. Many of these fishes are at risk from overfishing and, without the advancements from her lab group, investigators would lack sufficient data for sophisticated analyses. The Shark Conservation Fund supports her lab’s development of a large data base, SharkTraits https://www.sharktraits.org, to aid in the assessment of risks of overfishing and extinction.
Previous investigations examined how social interactions and variation in mate quality affect reproduction in species with parental care, including swordtails, darters, and wrasses. Kindsvater and associates validated a novel approach for reconstructing mathematical models to understand the consequences of this variability for the life-history traits of numerous populations of tuna that sustain some of the world’s largest and most valuable fisheries. Grouper and salmon are two valuable fish groups that display aggregation behaviors that increase catchability in fisheries. In the case of grouper, overfishing risk is further increased because “plate‐sized” fish are highly preferred in the live reef food fish trade and sex changes from female to male as grouper grow. Kindsvater and associates analyzed the consequences of size-selective harvesting in grouper, thereby providing management rules in allow sustainable harvest.
Holly Kindsvater was raised in the Mojave Desert in southern California and was fascinated with fish from an early age. Early visits to Puget Sound and visits to the Monterey Aquarium stoked her curiosity about rockfish, a large, long-lived live bearer that lives in the kelp forest. She wanted a career that kept her in contact with the ocean and learned about the controversy related to overfishing rockfish in California by commercial fishing fleets. She worked during college as a field technician for the National Oceanic and Atmospheric Administration (NOAA) on surveys of salmon streams in California. These experiences led her to appreciate how the role of human modifications via barriers and water use influenced salmon viability. She also realized you can get paid to study fish.
Both field and analytical skills allowed her to investigate numerous fishes in a variety of habitats around the world. Clever wrasses quickly learned how to avoid capture, and in field studies Kindsvater improved her skill to collect fish with a small dip net underwater while using SCUBA or mask and snorkel. Kindsvater examines the effects of fishing because “Fishing gives us a window on the world of the ocean.” Fishing is exploration and often the first sign of a change in ocean conditions. The notion that evolution happens on current time scales was first revealed in a landmark study on fishery-induced evolution (Conover and Munch 2002) that Holly Kindsvater read as a graduate student in 2002. She witnessed the scientists debating on the topic and realized that “this must be important.” Through her persistence and many collaborations, she is making a difference today in examining the effects of fishing intensity and fishing selectivity and providing advice for sustainable fishing practices. In “Ten principles from evolutionary ecology essential for effective marine conservation” published in 2016, Kindsvater and her associates provide ensuring a sustainable relationship with our seafood.
For more information about her work, review the website https://kindsvater.fishwild.vt.edu/.
Key Takeaways
• Fish are cold-blooded animals that live in water, breathe with gills, and usually have fins and scales.
• Fish are highly successful in colonizing every conceivable aquatic habitat on the planet.
• Fish are classified by their taxonomic position, human uses, ecological characteristics, or life history.
• Commercial fishing is the last wild harvest of wild food, recreational fishing dominates fishing in inland waters, and subsistence fishing is the dominant type of fishing in much of the developing world.
• Not all types of fish are harvested for food, many are converted to fish oil and fish meal.
• Fish provide benefits to ecosystems in the form of provisioning resources, regulating, supporting ecosystem components, and contributing to human cultures.
• In addition to feeding us, fish inspire humans to create art and literature.
• Fish conservation and management are complicated issues, and the goals of those endeavors depend on our value systems.
This chapter was reviewed by Holly Kindsvater.
Long Descriptions
Figure 1.1: High adult mortality and low juvenile mortality include, Precocial: few large offspring, small body size, rapid growth, early maturity, short lifespan, example: Tiger Tail Seahorse; Opportunist: many small offspring, small body size, rapid growth, early maturity, short lifespan, example: Atlantic Herring; Low adult mortality and high juvenile mortality include, Survivor: few large offspring, large body size, slow growth, late maturity, long lifespan, example: Smalltooth Sawfish; Episodic: many small offspring, large body size, slow growth, late maturity, long lifespan, example: Brown-marbled; Extreme Survivors have an overall low mortality: very few large offspring, very large body size, very slow growth, very late maturity, very long lifespan, example: N Pacific Spiny Dogfish. Jump back to Figure 1.1.
Figure 1.2: Pink salmon (bright greenish-blue on top and silvery on its sides), skipjack tuna (streamlined body that is mostly without scales; their backs are dark purple-blue and their lower sides and bellies are silver with four to six dark bands), European sea bass (silvery gray to bluish on the back, silvery on the sides, and white on the belly; elongated body, larger scales, and a stripe down their sides), and Atlantic Cod (heavy-bodied with a large head, blunt snout, and a distinct barbel under the lower jaw). Jump back to Figure 1.2.
Figure 1.3: Top: The fishing vessel surrounds a school of fish with a large net that has floats to keep the top of net at sea level and weights holding the bottom of net below. The bottom of the net is brought together and then hauled on-board. Bottom: The fishing vessel drags a long line with baited hooks behind it. Jump back to Figure 1.3.
Figure 1.4: Steady increases in global aquaculture and capture fisheries starting in 1950 with 20 million tonnes leading to 2018; aquaculture = 180 million tonnes and inland waters =140 million tonnes; capture = 80 million tonnes and inland waters = 10 million tonnes. Jump back to Figure 1.4.
Figure 1.5: Ecosystem Services include: 1) provisioning, products obtained from ecosystems, ex. food, fish meal, oils; 2) regulating, benefits obtained from regulation of ecosystem processes, ex. disease vector control; 3) cultural, non-material benefits obtained from ecosystems, ex. indigenous fishing; 4) supporting, services necessary for the production of all other ecosystem services, ex. sand, corals, whales, seabirds. Jump back to Figure 1.5.
Figure 1.8: Painting of a scene at a fish market from the 1600’s. Various general and exotic species of fish lay in piles on a table and a seller pours them from a basket into a large display area. Jump back to Figure 1.8.
Figure References
Figure 1.1: Classification of life history of fishes. Kindred Grey. 2022. CC BY 4.0. Adapted from https://doi.org/10.1002/ece3.2012 (CC BY). Includes Seahorse by Laymik, 2017 (Noun Project license, https://thenounproject.com/icon/seahorse-1078152/), Herring by Mallory Hawes, 2012 (Noun Project license, https://thenounproject.com/icon/herring-7089/), Smalltooth Sawfish by NOAA (public domain, https://www.fisheries.noaa.gov/species/smalltooth-sawfish), Pacific Spiny Dogfish by NOAA (public domain, https://www.fisheries.noaa.gov/species/pacific-spiny-dogfish), and Brown-Marbled Grouper by Rickard Zerpe, 2020 (CC BY 2.0, https://commons.wikimedia.org/wiki/File:Brown-marbled_grouper_(Epinephelus_fuscoguttatus).jpg).
Figure 1.2: The four most consumed food fish are: (A) Pink Salmon, (B) Skipjack Tuna, (C) European Sea Bass, and (D) Atlantic Cod. Kindred Grey. 2022. CC BY 4.0. Includes Pink Salmon FWS by Timothy Knepp, 2001 (public domain, https://commons.wikimedia.org/wiki/File:Pink_salmon_FWS.jpg), Katsuwonus pelamis by NOAA FishWatch, 2012 (public domain, https://commons.wikimedia.org/wiki/File:Katsuwonus_pelamis.png), FMIB 51236 Bass (Labrax lupus) by Reinhold Thiele, 1904 (public domain, https://commons.wikimedia.org/wiki/File:FMIB_51236_Bass_(Labrax_lupus).jpeg), and Atlantic cod by NOAA Photo Library, 2004 (public domain, https://commons.wikimedia.org/wiki/File:Atlantic_cod.jpg).
Figure 1.3: Purse seines (top) and long lines (bottom) are common techniques for commercial fishing. Kindred Grey. CC BY SA 4.0. Includes Purse-Seine by Lauren Packard, 2013 (CC BY 2.0, https://flic.kr/p/i2VTBd) and Ecomare – tekening visserijtechniek longline (longline) by Ecomare/Oscar Bos, 2016 (CC BY-SA 4.0, https://commons.wikimedia.org/wiki/File:Ecomare_-_tekening_visserijtechniek_longline_(longline).jpg).
Figure 1.4. World capture fisheries and aquaculture production. Kindred Grey. 2022. CC BY 4.0. Data from FAO, 2020 (page 20 of https://www.fao.org/3/ca9229en/ca9229en.pdf)
Figure 1.5: Four types of ecosystem services provided by fish with examples. Kindred Grey. 2022. CC BY 4.0.
Figure 1.6: A variety of ornamental koi (Cyprinus rubrofuscus). Bernard Spragg. NZ. 2009. Public domain. https://flic.kr/p/2o1rKG8
Figure 1.7: “Goldfish from fish swimming amid falling flowers,” by Liu Cai. Liu Cai. c.1080–1120. Public domain. https://commons.wikimedia.org/wiki/File:Goldfish_in_Fish_Swimming_Amid_Falling_Flowers_by_Liu_Cai_(cropped).jpg
Figure 1.8: “Fish market” by Frans Snyders. Frans Snyders. 1620s. Public domain. https://commons.wikimedia.org/wiki/File:Frans_Snyders_-_Fish_Market_-_WGA21513.jpg
Figure 1.9: Holly Kindsvater, PhD. Used with permission from Holly Kindsvater. CC BY 4.0.
Text References
Allgeier, J. E., A. Valdivia, C. Cox, and C. A. Layman. 2016. Fishing down nutrients on coral reefs. Nature Communications. DOI: 10.1038/ncomms12461.
Barongi, R., F. A. Fisken, M. Parker, and M. Gusset, editors. 2015. Committing to conservation: the World Zoo and Aquarium Conservation Strategy. WAZA Executive Office, Gland, Switzerland.
Berkes, F. 1988. Subsistence fishing in Canada: a note on terminology. Arctic 41(4):319–320.
Berra, T. M. 1981. An atlas of distribution of the freshwater fish families of the world. University of Nebraska Press, Lincoln.
Boonstra, W.J., and J. Hantati-Sundberg. 2016. Classifying fishers’ behavior: an invitation to fishing styles. Fish and Fisheries 17:78–100.
Caro, T. 2010. Conservation by proxy: indicator, umbrella, keystone, flagship, and other surrogate species. Island Press, Washington, D.C.
Collins, S. F., A. M. Marcarelli, C. V. Baxter, and M. S. Wipfli. 2015. A critical assessment of the ecological assumptions underpinning compensatory mitigation of salmon-derived nutrients. Environmental Management 56:571–586.
Conover, D. O., and S. B. Munch. 2002. Sustaining fisheries yields over evolutionary time scales. Science 297:94–a96.
Cooke, S. J., E. H. Allison, T. D. Beard, Jr., R. Arlinghaus, A. H. Arthington, D. M. Bartley, I. G. Cowx, C. Fuentevilla, N. J. Leonard, K. Lorenzen, A. J. Lynch, V. M. Nguyen, S.-J. Youn, W. W. Taylor, and R. L. Welcomme. 2016. On the sustainability of inland fisheries: finding a future for the forgotten. Ambio. DOI 10.1007/s13280-016-0787-4.
Cooke, S. J., W. M. Twardek, R. J. Lennox, Z. J. Zolderdo, S. D. Bower, L. F. G. Gutowsky, A. J. Danylchuk, R. Arlinghaus, and D. Beard. 2018. The nexus of fun and nutrition: recreational fishing is also about food. Fish and Fisheries 19:201–224.
Cowx, I. G., and M. P. Aya. 2011. Paradigm shifts in fish conservation: moving to the ecosystem services concept. Journal of Fish Biology 79:1663–1680.
De Kock, S., and B. Gomelsky. 2015. Japanese ornamental koi carp: origin, variation and genetics. Pages 27–53 in C. Pietsch and P. Hirsch, editors. Biology and ecology of carp. CRC Press, Taylor & Francis Group.
EIFAC (European Inland Fisheries Advisory Commission) 2008. EIFAC Code of Practice for Recreational Fisheries. EIFAC Occasional Paper 42, Food and Agriculture Organization of the United Nations, Rome.
Evers, H-G., J. K. Pinnegar, and M. I. Taylor. 2019. Where are they all from?: sources and sustainability in the ornamental freshwater fish trade. Journal of Fish Biology. https://doi.org/10.1111/jfb.13930.
FAO, 1997. Review of the state of world fishery resources: marine fisheries. FAI Fisheries Circular No. 920 FIRM: C920. FAO, Fisheries Department, Rome. ONLINE. Available: https://www.fao.org/3/w4248e/w4248e00.htm.
FAO. 2019. FAO FishStatJ database: 2019 dataset. https://www.fao.org/fishery/en/statistics/software/fishstatj. Accessed 10 October 2019.
FAO. 2020. The state of world fisheries and aquaculture 2020: sustainability in action. Rome. https://doi.org/10.4060/ca9229en.
Fricke, R., W. N. Eschmeyer, and R. van der Laan, editors. 2022. Eschmeyer’s Catalog of Fishes: genera, species, references. http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. Electronic version accessed 17 October 2022.
Funge-Smith, S., and A. Bennett. 2019. A fresh look at inland fisheries and their role in food security and livelihoods. Fish and Fisheries. DOI: 10.1111/faf.12403.
Greenberg, P. 2011. Four fish: the future of the last wild food. Penguin Books, New York.
Guillen, J., F. Natale, N. Carvalho, J. Casey, J. Hofherr, J-N. Druon, G. Fiore, M. Gibin, A. Zanzi, and J. Th. Martinsohn. 2018. Global seafood consumption footprint. Ambio 48:111–122.
Havens, K. E. 1991. Fish-induced sediment resuspension: effects on phytoplankton biomass and community structure in a shallow hypereutrophic lake. Journal of Plankton Research 13:1163–1176.
Henshilwood, C. S., J. C. Sealy, R. Yates, K. Cruz-Uribe, P. Goldberg, F. E. Grine, R. G. Klein, C. Poggenpoel, K. van Niekerk, and I. Watts. 2001. Blombos Cave, Southern Cape, South Africa: preliminary report on the 1992–1999 excavations of the Middle Stone Age levels. Journal of Archaeological Science 28:421–448.
Hibbeln, J. R., P. Spiller, J. T. Brenna, J. Golding, B. J. Holub, W. S. Harris, P. Kris-Etherton, B. Lands, S. L. Connor, G. Myers, J. J. Strain, M. A. Crawford, and S. E. Carlson. 2019. Relationships between seafood consumption during pregnancy and childhood and neurocognitive development: two systematic reviews. Prostaglandins, Leukotrienes and Essential Fatty Acids. https://www.sciencedirect.com/science/article/pii/S0952327819301929.
Hicks, C. C., P. J. Cohen, N. A. J. Graham, K. L. Nash, E. H. Allison, C. D’Lima, D. J. Mills, M. Roscher, S. H. Thilsted, A. L. Thorne-Lyman, and M. A. MacNeil. 2019. Harnessing global fisheries to tackle micronutrient deficiencies. Nature 574:95–98.
Jackson, C. E. 2012. Fish in art. Reaktion Books, London.
Jacobson, S. K., editor. 1995. Conserving wildlife: international education and communications approaches. Columbia University Press, New York.
Jones, B. L., R. K. F. Unsworth, S. Udagedara, and L. C. Cullen-Unswrorth. 2018. Conservation concerns of small-scale fisheries: by-catch impacts of a shrimp and finfish fishery in a Sri Lankan lagoon. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2018.00052.
Kindsvater, H. K., M. Mangel, J. D. Reynolds, and N. K. Dulvy. 2016. Ten principles from evolutionary ecology essential for effective marine conservation. Ecology and Evolution 6(7):2125–2138.
Kroodsma, D. A., J. Mayorga, T. Hochberg, N. A. Miller, K. Boerder, F. Ferretti, A. Wilson, B. Bergman, T. D. White, B. A. Block, P. Woods, B. Sullivan, C. Costello, and B. Worm. 2018. Tracking the global footprint of fisheries. Science 359:904–908.
Madsen, H., P. Bloch, P. Makaula, H. Phiri, P. Furu, and J. R. Stauffer Jr. 2011. Schistosomiasis in Lake Malawi villages. EcoHealth 8:163–176.
Marchio, E. A. 2018. The art of aquarium keeping communicates science and conservation. Frontiers in Communication 3(17). doi: 10.3389/fcomm.2018.00017.
McKenna, M. 2013. Five stages of a fisherman’s life. Sun Valley Magazine, March 18, 2013. Accessed 7 February 2019. https://sunvalleymag.com/five-stages-of-a-fishermans-life/.
Morris, M. C., J. Brockman, J. A. Schneider, Y. Wang, D. A. Bennett, C. C. Tangney, and O. van de Rest. 2016. Association of seafood consumption, brain mercury level, and APOE ε4 status with brain neuropathology in older adults. Journal of the American Medical Association 315(5). doi:10.1001/jama.2015.19451.
Morris, M. C., D. A. Evans, J. L. Bienias, C. C. Tangney, D. A. Bennett, R. S. Wildon, N. Aggarwal, and J. Schneider. 2003. Consumption of fish and n-3 fatty acids and risk of incident Alzheimer disease. Archives Neurology 60:940–946.
Musa, G., and K. Dimmock. 2013. Scuba diving tourism. Routledge, Taylor and Francis, London and New York.
Oh, C.-O., and R. B. Ditton. 2008. Using recreation specialization to understand conservation support. Journal of Leisure Research 40:556–573. doi: 10.1080/00222216.2008.11950152.
Ong, T. F., and G. Musa. 2011. An examination of recreational divers’ underwater behaviour by attitude-behaviour theories. Current Issues in Tourism 14:1–17.
Palomares, M. L. D., and D. Pauly. 2019. On the creeping increase of vessels’ fishing power. Ecology and Society 24(3):31. https://doi.org/10.5751/ES-11136-240331.
Pauly, D., and D. Zeller. 2016. Catch reconstructions reveal that global marine fisheries catches are higher than reported and declining. Nature Communications 7:10244.
Penning, M., G. McG. Reid, H. Koldewey, G. Dick, B. Andrews, K. Arai, P. Garratt, S. Gendron, J. Lange, K. Tanner, S. Tonge, P. Van den Sande, D. Warmolts, and C. Gibson, editors. 2009. Turning the tide: a global aquarium strategy for conservation and sustainability. World Association of Zoos and Aquariums, Bern, Switzerland.
Perry, C. T., P. S. Kench, M. J. O’Leary, K. M. Morgan, and F. Januchowski-Hartley. 2015. Linking reef ecology to island building: Parrotfish identified as major producers of island-building sediment in the Maldives. Geology 43:503–506.
Pew Charitable Trusts. 2019. Report finds transshipments in western and central Pacific likely underreported. Issue Brief. https://www.pewtrusts.org/en/research-and-analysis/issue-briefs/2019/09/report-finds-transshipments-in-western-and-central-pacific-likely-underreported. Accessed October 20, 2019.
Pitcher, T. J., and M. E. Lam. 2015. Fish commoditization and the historical origins of catching fish for profit. Maritime Studies 14(2). https://doi.org/10.1186/s40152-014-0014-5.
Raghavan, R., N. Dahanukar, M. F. Tlusty, A. L. Rhyne, K. K. Kumar, S. Molur, and A. M. Rosser. 2013. Uncovering an obscure trade: threatened freshwater fishes and the aquarium pet markets. Biological Conservation 164:158–169.
Reid, A. J., A. K. Carlson, I. F. Creed, E. J. Eliason, P. A. Gell, P. T. J. Johnson, K. A. Kidd, T. J. MacCormack, J. D. Olden, S. J. Ormerod, J. P. Smol, W. W. Taylor, K. Tockner, J. C. Vermaire, D. Dudgeon, and S. J. Cooke. 2018. Emerging threats and persistent conservation challenges for freshwater biodiversity. Biological Reviews 94(3):849–873. https://doi.org/10.1111/brv.12480.
Robbins, L. H., M. L. Murphy, K. M. Stewart, A. C. Campbell, and G. A. Brook. 1994. Barbed bone points, paleoenvironment, and the antiquity of fish exploitation in the Kalahari Desert, Botswana. Journal of Field Archaeology 21:257–264.
Sahrhage, D., and J. Lundbeck. 1992. A history of fishing. Springer-Verlag, New York.
Sala, E., J. Mayorga, C. Costello, D. Kroodsma, M. L. D. Palomares, D. Pauly, U. R. Sumaila, and D. Zeller. 2018. The economics of fishing the high seas. Science Advances 4(6). DOI: 10.1126/sciadv.aat2504.
Schumann, S., and S. Macinko. 2007. Subsistence in coastal fisheries policy: What’s in a word? Marine Policy 31:706–718.
Stauffer, J. R., Jr., M. E. Arnegard, M. Cetron, J. J. Sullivan, L. A. Chitsulo, G. F. Turner, S. Chiotha, and K. R. McKaye. 1997. Controlling vectors and hosts of parasitic diseases using fishes. BioScience 47(1):41–49.
Steneck, R. S., and D. Pauly. 2019. Fishing through the Anthropocene. Current Biology 29:R942–R995.
Twining, C. W., E. P. Palkovacs, M. A. Friedman, D. J. Hasselman, and D. M. Post. 2017. Nutrient loading by anadromous fishes: species-specific contributions and the effects of diversity. Canadian Journal of Fisheries and Aquatic Sciences 74:609–619.
Vanni, M. J. 2002. Nutrient cycling by animals in freshwater ecosystems. Annual Review of Ecology and Systematics 33:341–370.
Walshe, D. P., P. Garner, A. A. Adeel , G. H. Pyke, and T. R. Burkot. 2017. Larvivorous fish for preventing malaria transmission. Cochrane Database of Systematic Reviews 2017(12): CD008090. DOI: 10.1002/14651858.CD008090.pub3.
Watson, R. A., C. Revenga, and Y. Kura. 2006. Fishing gear associated with global marine catches. I. Database development. Fisheries Research 79:97–102.
Wipfli, M. S., J. P. Hudson, J. P. Caouette, and D. T. Chaloner. 2003. Marine subsidies in freshwater ecosystems: salmon carcasses increase the growth rates of stream-resident salmonids. Transactions of the American Fisheries Society 132:371–381.
Worm, B., R. Hilborn, J. K. Baum, T. A. Branch, J. S. Collie, C. Costello, M. J. Fogarty, E. A. Fulton, J. A. Hutchings, S. Jennings, O. P. Jensen, H. K. Lotze, P. M. Mace, T. R. McClanahan, C. Minto, S. R. Palumbi, A. M. Parma, D. Ricard, A. A. Rosenberg, R. Watson, R., and D. Zeller. 2009. Rebuilding global fisheries. Science 325: 578–585. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.01%3A_Fish_Fishing_and_Why_They_Matter.txt |
The land ethic simply enlarges the boundaries of the community to include soils, waters, plants, and animals, or collectively: the land. . . . In short, a land ethic changes the role of Homo sapiens from conqueror of the land-community to plain member and citizen of it.
—Leopold 1949
Learning Objectives
• Describe multiple value orientations of people.
• Apply the notions of values, rules, and knowledge as aspects of decision-making contexts that enable or constrain adaptation.
• Apply appropriate approaches for fish conservation and management that match values and knowledge in a particular place.
• Adopt and justify use of existing seafood certification initiatives.
2.1 Introduction
Values, the importance or usefulness of something, are important influences on how people will behave regarding uses of fish. Imagine that your favorite fish is a wild Cutthroat Trout. If so, it is likely that you value spending time in the wild places. Contrast that with a resident of a small Pacific Island where fish may be the only source of protein. This island resident values fish for providing essential nutrition. Whether you are inclined to engage in activities to protect nature depends on your experiences, values, and beliefs about natural environments.
The theory of emotional affinity explains that a person’s ties to nature depend on the importance of spending time in nature, sharing positive experiences and feelings in nature (Kals et al. 1999). Another theory, the value-belief-norm (VBN) theory, postulates a causal relationship from values to beliefs, norms, or attitudes (Figure 2.1; Stern 2000). These complementary theories may be used to explain behaviors that involve nature (Fulton et al. 1996; Jacobs et al. 2012). People derive value from their relationship to fish or fishing, and these values are important to their well-being. In creating conservation plans it is critically important to consider the individual’s internal value orientations, which are stable and central to their beliefs. It is also important that multiple value orientations are included so that many types of fishing are considered in management plans.
Conservation and management plans that are successful at achieving their measurable objectives over long periods of time require passionate leadership, persistence, partnerships, trust, and strategic optimism. While the first two characteristics are possessed by individuals, the other characteristics require participatory engagement to overcome uncertainty and other obstacles. It takes persistence, because finding ways to develop trusting partnerships and to compare values as different as personal well-being, cultural importance, and financial gains in policy formulation is complex. Social acceptance of management actions is a key element of contemporary management. Trust only develops through repeated collaborative interactions between parties aimed to avoid conflict and facilitate management (Stern and Coleman 2015).
Ultimately, questions of law and policy regarding fish conservation reflect deep value preferences. If you need to eat to survive, you will value fish as food. For others whose essential nutritional needs are met, they may desire the experience of fishing more than the nutrition it provides. Fishing fanatics may exhibit values that reflect more general philosophical tenets that may border on religious beliefs (Snyder 2007). Fly fishers often refer to rivers as their church and to nature as sacred, thereby justifying initiatives to preserve these places. Values are classified as intrinsic or instrumental. Intrinsic values are inherent and exist independent of their use to humans. Instrumental values include goods, services, and psychospiritual benefits and are, therefore, utilitarian or anthropocentric. An important difference between intrinsic and instrumental values relates to who must demonstrate harm in disputes. For example, the burden of proof lies with the conservationists if values are only instrumental. On the other hand, if values are intrinsic as well as instrumental, the burden of proof will be on the fishers (Callicott 2005).
The differing value orientations matter for inclusive decision making and policy development for fish conservation. We may also use the term “relational values.” Relational values are all values that can arise out of a person’s or society’s relationship with nature (Chan et al. 2016; Skubel et al. 2019). Ecosystem services, first introduced in Chapter 1, are relational values that include relational, intrinsic, and instrumental values. Imagine that you are the owner and operator of a shark ecotourism company in The Bahamas. For you, the relational values important to you are financial. When we talk with others about fish, fishing, and conservation, we often encounter pufferfish moments. The pufferfish gulps water to increase its size when threatened. While the adaptation protects the pufferfish, it renders it unable to perform other functions. We frequently encounter people with differing value orientations who lack the ability to communicate or understand their perspectives or attitudes. We are like a pufferfish that instinctively avoids conflicts, and we are unable to relate. To deal with our pufferfish moments, we should seek first to understand the values and beliefs of others.
Values can be based on more than simple utilitarian reasons. For example, people in Hawaii and China both have historical preferences for eating sharks. Shark fins were a luxury food item as early as the Sung dynasty (AD 960–1279). In China, shark consumption has always been associated with a belief that the consumer would become strong like a shark, and the shark fin, consumed in soup, was associated with wealth and prestige. As the population of China expanded, more and more of the sharks consumed had to be imported. Currently, Hong Kong is a top global importer of sharks, creating a global shark conservation conflict with Hong Kong fish markets selling at-risk species (Fields et al. 2018). In Hawaii, on the other hand, the shark held mythical, cosmological, and spiritual significance. Today, laws in Hawaii make it illegal to capture, possess, entangle, or abuse any sharks and rays. The Hawaiian longline fishery uses monofilament leaders to prevent bycatch of sharks. The shark consumption story emphasizes how understanding the values and beliefs for human behavior may lead to successful conservation interventions.
Value orientations for wildlife are often classified along two dimensions, labeled as domination and mutualism (Manfredo et al. 2009). Domination values are tied to a belief that wildlife exists for human use, whereas mutualist values arose due to a modernized lifestyle wherein people were removed from direct contact with wildlife and, given the human tendency to anthropomorphize, began to view wildlife as deserving of certain rights or opportunities. Such differing views on values complicate conservation (Table 2.1).
Values Beliefs Actions
Livelihood Manage fish for maximum profit Commercial fishing
Leisure Renewed by contact with wild fish Recreational fishing
Local food Environment sustains us Subsistence fishing
Emotional bonds Comfort from seeing wild fish SCUBA diving
Table 2.1: Examples of values, beliefs, and actions for different uses of fish.
Conservation is complicated by divergent ethical frameworks. For example, ecocentrists will naturally focus on ecological attributes or processes; anthropocentrists do not worry about ecological impacts unless they drive economic or social damages; and zoocentrists accord equal moral consideration to every living being and oppose eradication plans (Epstein 2017). Successful conservation requires that we acknowledge and consider pluralistic values of a diverse society.
Globally, illegal and unreported fishing make sustainable fishing impossible and hinder recovery of overexploited fish populations (Agnew et al. 2009). In small island states, such as The Bahamas, illegal, unreported, and unregulated fishing coupled with inadequate regulations and enforcement, along with other anthropogenic impacts, are the main factors contributing to the decline of Bahamian fisheries (Sherman et al. 2018). Compliance with fishing regulations depends in part on underlying attitudes of the anglers. Are they oriented to catch-and-release angling, fishing for food, or are they tied to fishing in a particular place? Certain regulations may result in reduced participation rather than compliance with the regulation (Murphy et al. 2019). Participation of local stakeholders may lead to improved conservation management strategies that have the potential to improve economic and food security.
A lack of a full understanding of the biological, legal, social, and economic factors hinders the success of fisheries management (Defeo et al. 2017). The decision context should consider the interconnected system of values, rules, and knowledge (Figure 2.2; Gorddard et al. 2016; Colloff et al. 2017). Consider your role in the process of making decisions about setting fishing regulations. Your values may influence the way people select actions and evaluate proposed changes. Rules are norms, practices, and habits that include regulations, legislation, treaties, and ordinances. Knowledge includes evidence and experiential meanings applied by experts and nonexperts in decision making. Your unique knowledge about a fish, the place, and how the fish are harvested should play a role in determining management rules. It is one of several factors in making decisions. The decision-making context involves iterative learning where the decision problem is defined, options are evaluated and implemented, and the outcomes monitored. A richer array of management actions via the values-rules-knowledge framework should enable more sensible and equitable decisions.
Question to ponder
What are your dominant uses of fish? What values and beliefs are most important in leading to these actions?
2.2 History of Values in Fisheries Conservation
Many simple solutions—fallacies in some cases—have been proposed to fix the complex problem of fisheries, primarily concerning commercial fisheries (Pitcher and Lam 2010). The essence of the overfishing problem is that human demands for fish and fish products often exceed the sustainable production, and harvesting methods often have negative consequences for the ecosystem. In 1918, Fedor Baranov wrote that “the exploitable stock of fish is a changeable quantity, which depends on the intensity of the fishery. The more fish we take from a body of water, the smaller is the basic stock remaining in it; and the less fish we take, the greater is the basic stock, approximating to the natural stock when the fishery approaches zero” (Gordon 1954).
Furthermore, how we depend on fish for livelihoods or lifestyles or both results in a bias toward our personal interests (Arlinghaus 2008; Cochrane 2008). Each of the following approaches may be of interest in the conservation and management of fish and represent what people value when conserving fish. Differing values, rules, and knowledge illustrate the wide variety of management and conservation ideas that guide people’s actions. You may feel an affinity to some but not all of these approaches.
Privatization arose as a solution from economists extending the legal concept of property rights to public-trust fisheries resources. Fishers are given ownership rights or individual transferable quotas (ITQ) to harvest an allocation of the fishery resources. ITQ theory seeks to use market forces in which harvest rights can be traded, thereby giving harvesters incentives to manage the fishing wisely. ITQs are not property rights but rather dedicated access privileges. While ITQs may reduce the conflicts over scarce fish and end the “race for fish,” in practice they do not always eliminate illegal fishing (Costello et al. 2008; Birkenbach et al. 2017). One well-publicized application has been the Pacific Halibut (Hippoglossus stenolepsis), in which the open season in 1990 lasted just six days, and 435 vessels fished subject to unknown weather (Fina 2011). With a short season, processing facilities were inadequate, and few vessels made money. Today, with the application of ITQs, fewer vessels fish over an eight-month season in a directed halibut fishery, and all halibut can be landed in local communities where they are sold fresh. The fallacy of ITQs relates to the belief that ownership promotes good stewardship and social justice is achieved via allocation of ITQs (Gibbs 2009). In other examples, the allocation of catch shares or ITQs has marginalized artisanal fisheries and communities all over the world (Bailey 2018).
Total economic valuation deals with capturing the total economic value of ecosystem services and future generations to sustain healthy and productive fish stocks into the future. Without explicit values, fish are often implicitly valued in policy decisions, and that reduces protections. However, using market-based instruments to place financial values on fishing and ecosystem services will not serve the interests of the poor in society. Economic valuation of saltwater marsh habitats provided a direct link to many marine saltwater fish that depend on marsh habitats during their life (Bell 1997). In this example, economic valuation provides justification for acquiring land for preservation to save it from development. Valuation of fish that are not harvested for commercial or recreational fisheries provides a value to justify preservation of rare or endangered fish (Bishop et al. 1987). Social equity and intergenerational equity concerns are not addressed by conventional discounting using market interests. Adding social and cultural values of fish may result in more holistic perspectives for management.
Laissez-faire strategies presume that if commercial fishers were allowed to manage their own fishing, they would efficiently allocate fishery resources. Laissez-faire strategies value freedom above all. However, many examples prove otherwise: fishers act from the perspective of private interest and will continue to fish even as fish stocks decline. Laissez-faire strategies for fisheries were devised in the seventeenth century and accepted up through the nineteenth century, leading to overfishing of stocks of cod and flatfish. Overcoming laissez-faire strategies continues to this day throughout the world. New England’s commercial harvesters were slow to respond to technological change, as predicted by unrestrained laissez-faire strategies. Rather, they actively opposed fishing innovations (Gersuny and Poggie 1974). Famous fishery collapses attributed to relaxed regulations include the Atlantic Cod (Gadus morhua) in the northwest Atlantic Ocean (Myers et al. 1997) and the Nassau Grouper (Epinephelus striatus) in the Caribbean (Whitehouse et al. 2020).
Selective fishing technology is a solution often proposed by commercial fishing interests that imagine improvements in fishing gears to eliminate bycatch and discards and damage to habitat. This approach focuses on regulating fishing gear to achieve conservation goals. Restricting harvest to a limited range of ages (or sizes) can provide long-term sustainability even at high rates of fishing mortality (Reed 1980). Harvest slot length restrictions as applied in recreational angling and Maine lobster fisheries typically outperform minimum length limit rules (Comeau and Hanson 2018; Ahrens et al. 2020). However, improvements in fishing technology sometimes increase the numbers of species caught and result in serial depletions of fish stocks (Berkes et al. 2006).
Recreation fishing regulations are often imposed to fit the unique motivations of recreational anglers and often involve size restrictions or daily creel restrictions. Not all recreational anglers have the same fishing preferences. Participation in recreational fishing varies widely, from ~2% in South Africa to 30% in Norway, and averages 10.5% in industrialized countries. Typically, an angler selects gear and locations for a particular target fish. The continuum between fishing as a contemplative sport versus a competitive sport may lead to conflicts among angler groups. Consequently, the approaches to managing recreational fishing vary greatly and seek to maximize the participation and angler satisfaction rather than harvest.
Marine protected areas (MPA) are protected areas of the ocean where human activities are restricted to achieve conservation objectives, mainly supporting a goal of protecting biodiversity. “No-take” marine reserves are permanently closed to all fishing and other extractive uses, whereas zones of integrated ocean management are MPAs that regulate uses within zones. By protecting against risk and uncertainties from traditional stocks assessments, they serve as ecological insurance policies. Unfortunately, less than 1% of the oceans are in marine reserves and 94% of marine protected areas allow fishing (Costello and Ballantine 2015). Reserves and protected areas are very seldom applied to inland waters. Success of an MPA depends on size, implementation, and enforcement (Sala and Giakoumi 2018). Although the original intent of MPAs was to protect ecosystems within their boundaries, they have also been shown to enhance local fisheries and food security and to create jobs and new incomes through ecotourism (Cabral et al. 2020; Chen et al. 2020).
Maximum sustainable yield (MSY) is derived from classical fisheries science and deals narrowly with sustainability in a single-species fishery. MSY has been defined with reference to the maximum catch levels that can be maintained and is based on individual priorities toward catching fish. MSY seeks to find the exploitation rate that results in highest long-term harvest (Figure 2.3).
Consider the basic equation of how change in abundance (N) varies with abundance:
$\frac{d N}{d t \ N}=r\left\{1-\frac{N}{K}\right\}$
where N = abundance, K is carrying capacity, and r is the intrinsic rate of growth (Verhulst 1938). Given reasonably accurate estimates of parameters and fish biomass, this equation may allow determination of sustainable yields (Quinn and Colley 20005). Sophisticated single-species, density-dependent population dynamics models are data intensive and parameter rich, yet they may still miss important features in human and fish dynamics. However, most fisheries of the world are data poor. Furthermore, five major challenges with this approach are the facts that (1) many fisheries catch more than one species; (2) it is difficult to forecast recruitment accurately; (3) landing limits are often disregarded; (4) underreporting has biased the data; and (5) trust between fishers and scientists has been destroyed. An epitaph was written in 1977, but MSY is still alive and kicking (Larkin 1977).
Larkin’s Epitaph for MSY
M.S.Y. 1930s–1970s
Here lies the concept, MSY.
It advocated yields too high,
And didn’t spell out how to slice the pie.
We bury it with the best of wishes,
Especially on behalf of fishes.
We don’t know yet what will take its place,
But hope it’s as good for the human race.
R.I.P.
Maximum economic yield (MEY) represents the harvest level that maximizes profit, which is typically a commercial fishing goal. MEY seeks to gain economic wealth and is based on individual priority of profit (Figure 2.4). However, in open access fisheries, regulations often fail to control fishing mortality, so MEY is seldom attained. In other cases, subsidies for fishing permit development of fisheries that are only marginally profitable but maximize employment.
Pretty good yield (PGY) is defined as “sustainable yield at least 80% of the maximum sustainable yield. Such yields are generally obtained over a broad range of stock sizes (20–50% of unfished stock abundance), and this range is not sensitive to the population’s basic life-history parameters, such as natural mortality rate, somatic growth rate, or age at maturity” (Worm et al. 2009). In the analysis of 166 global fish stocks, most stocks have fallen below the biomass that supports maximum yield (B < BMSY) but have the potential to recover if the low exploitation rates (u < uMSY) are maintained long enough (Worm et al. 2009; Hilborn 2010). PGY cares mostly about catch levels and is most appropriate in multispecies fisheries, for which single-species analysis is impractical.
Optimum sustainable yield (OSY) is a deliberate melding of biological, economic, social, and political values in determining management targets (Roedel 1975). OSY seeks to incorporate such considerations as the nonmonetary values of recreational fisheries, the conservational value of fish stocks, the sustainability of fishing communities, quality of the fish caught or the fishing experience, and ecosystem integrity. In many recreational fisheries, most anglers are seeking a quality fishing experience where size of fish caught is more important than the total biomass of fish harvested. The idea of OSY has expanded the need for human dimensions information to be collected and incorporated into management decisions (Arlinghaus et al. 2002). For example, there are four types of trout anglers: occasional anglers, generalists, technique specialists, and technique and setting specialists. Acceptable fishing regulations will vary among the four groups, and specialists are likely to oppose trout stocking. Increasing recreational fishing opportunities requires enhancing many nonfishing-related aspects, such as access, water quality, scenery, and other aspects of the fishing experience. In the United States, the Magnuson-Stevens Fishery Conservation and Management Act requires that “conservation and management measures shall prevent overfishing while producing, on a continuing basis, the optimum yield from each fishery for the United States fishing industry.”
Community-based management (CBM) lets local stakeholders and coastal communities share authority in developing management rules. This type of comanagement seeks to empower the local fishers and encourage conservation of fish on which they depend for food and livelihood. Some examples exist in the Pacific islands, Alaska, and British Columbia and with Maine lobster and Arapaima in parts of the Amazon. In experimental management of the Pirarucu (Arapaima spp.) in the Amazon basin, the fishers play an active role in management process, such as collecting data and enforcing rules, and thereby increased monetary returns (Castello et al. 2009). While it can be successful, success requires financial investment, local infrastructure, targeted public education, and strong legal support.
Traditional ecological knowledge (TEK) attempts to incorporate local, cultural information and values in the governance of fishing. While this approach is appealing, in practice, the diversity of local stakeholders may have many ways of interpreting evidence and understanding of nature (Hind 2015). River herring (Alosa spp.) were culturally important to East Coast Native American tribes and First Nations in the United States and Canada. These men and women, by virtue of time spent on the water, had knowledge of the distribution, abundance, and migration behavior gained from firsthand observations. River herring were harvested for centuries and are an important part of the region’s fishing heritage. Furthermore, the fishermen and women were able to detect changes in fish stocks before the changes were evident from data collected by fisheries scientists.
Managers and conservationists can engage in an equitable exchange of knowledge with local fishers to improve knowledge of fish taxonomy, ecological interactions, and seasonal movement and behavior so that TEK complements conventional scientific methods (Gaspare et al. 2015). View the video to learn more about the perspectives of river herring harvesters and other community members who know more than anyone else about the fish in their local rivers.
Precautionary approach involves the application of prudent foresight and considers the uncertainties in fisheries. The precautionary approach values risk avoidance and applies primum non nocere or “first, do no harm” fisheries management. It was first introduced in 1995 in the Food and Agriculture Organization’s Code of Conduct for Responsible Fisheries (FAO 1995). There is little consensus on how the precautionary approach should be applied. Many marine fisheries have an overcapacity of fishing fleets, and some countries subsidize fishing fleets. Consequently, short-term economic pressures dominate. A precautionary approach reduces fishing to restore the population size to above the limit point if it has fallen or is about to fall below that level. The red-yellow-green typology (Figure 2.5) shows the use of both limit and precautionary reference points for spawning biomass and fishing mortality metrics. When a fishery is characterized by fishing-induced habitat damage, a stock rebuilding strategy that incorporates both harvest control rules and marine reserves (a precautionary approach) will outperform a strategy that uses the two control mechanisms individually (Nichols et al. 2018). Because of the gaps in our knowledge and the failure to acknowledge them, regulations often fall short of being precautionary (Abrams et al. 2016).
Ecosystem-based management (EBM) is the most comprehensive conceptual approach. It focuses on keeping the trophic web intact while calling for (1) taking account of environmental factors influencing growth, maturation, natural mortality, and recruitment; (2) creating accountability for the full footprint of fisheries; (3) making governance broadly inclusive with meaningful stakeholder participation; and (4) integrative management (Beard et al. 2011; Rice 2011). Each of these components is equally important and challenging to implement. For example, the footprint of fisheries includes gear impacts on habitats, mortality because of bycatch of other fish, invertebrates, seabirds, mammals, and turtles, and indirect trophic impacts because of the altered abundances of targeted and bycaught species. One-quarter of 200 fisheries assessments in the United States included at least one type of interaction between the assessed species and its ecosystem, especially physical drivers of habitat and climate, though assessments of diets were less common (Marshall et al. 2019).
While EBM explicitly includes humans as part of an ecosystem, in practice, it often falls short from an ethical perspective that places humans at the apex, benefiting from goods and services provided by ecosystems, as well as controlling use. This is a fishy version of Leopold’s A-B cleavage between utilitarian value versus a broader definition of value in nature (Leopold 1949). Many scholars propose a radical rethinking of the traditional approach to implement ecosystem-based management (Bundy et al. 2008; Berkes 2012; Patrick and Link 2015a, 2015b; Berkes and Nayak 2018). Humans are provided goods and services from the natural resources, and as a result, ecosystems are degraded. An alternative perspective considers ethics, including social justice arguments, and corporate responsibility in a form of governance that shares the power in decision making. We still have a long way to go to fully implement ecosystem-based management.
Ecosystem-services approach is based on the instrumental values provided by intact ecosystems, whereas conventional practices focus on single species or habitats. However, fisheries systems are characterized by complex interrelationships between society and the natural environment. Threats to freshwater fisheries originate mainly from outside the fishing sector; thus, sustainable conservation practices must be considered as integrated parts of a holistic management of (specific) aquatic ecosystems or watersheds. Unfortunately, in many scenarios these three domains (including scientific research) are disconnected, which constrains the application of the ecosystem-services approach (Cowx and Aya 2011).
Naturalistic fallacy is the belief that if we could just go back to the way things were, fisheries and ecosystems would be restored. This type of historically based restoration seeks to turn back the clock when there is no chance of going back. Many ecosystems have been fundamentally altered by overfishing for so long that they are unlikely to recover. A more practical restoration agenda based on achievable EBM could adopt the concept of an optimal restorable biomass (Pitcher and Pauly 1998). But there is no going back to a pristine, historic condition.
Question to ponder
Consider a fishery that is familiar to you. Which of the approaches to thinking are evident in the rules and regulations? Are there different types of fishers who may prefer markedly different fishing rules?
2.3 Seeking Sustainable Fisheries
None of the previous ways of thinking has proven consistently optimal for fisheries management. Traditional conceptions of exploitation (MSY, MEY, PGY) may promote an exploitative use of fish stocks with little focus on human or ecosystem well-being. Ways of thinking about fisheries decisions often ignore considerations for welfare, freedom, and justice that are discussed in Chapter 4. Fishery policy goals are visions of what a society desires for its future (Lam and Pitcher 2012). As such, goals are choices to be made before instituting regulations. Failures of fish conservation may result from the widespread failure to consider management of fisheries as a whole system or from inadequate communications between science and decision making. Many large industrialized commercial fisheries have favored economy of things (marketed goods and services) over relationships (embedded in communities and ecosystems). Despite differences in approaches, most practitioners agree to adopt a management-oriented paradigm that involves (1) formulating management objectives that are measurable, (2) specifying sets of rules for decision making, and (3) specifying the data and methods to be used, all in such a way that the properties of the resultant system can be evaluated in advance (Karjalainen and Marjomäki 2005). For a fishery to be sustainable, there must be a fishery management system that can serve to adjust fishing pressure to appropriate levels as needed (Hilborn et al. 2015). Where fisheries are intensively managed with such an approach, the fish stocks are above target levels or rebuilding (Hilborn et al. 2020).
Fisheries management is management of people, habitat, and fish. The interplay of diverse human interests, values, and preferences with respect to fishery resources is a global challenge that cannot be easily solved. Rather, conflicts and challenges are to be expected in all but the very simplest fishing situations. For example, the urgent need to feed people may override the desire for sustainable fisheries. Today’s global fisheries operate at an average trophic level of about 3.3, meaning that we are harvesting mostly carnivores that eat herbivores. However, reducing this to 2.3 (eating mostly herbivores) would theoretically increase the world’s food harvest tenfold (Pitcher and Lam 2010). Forage fish, that is, small and medium-sized pelagic fish eaten by larger fish, seabirds, and marine mammals—are caught for nonfood purposes, such as reduction to fishmeal, feed for poultry and carnivorous fish in aquaculture, and fish oil used in the food industry. Industrial uses of fish products compete with traditional human consumption of lower trophic–level fish. Evaluation of ethical fisheries and the use of multiple criteria for decision making will change how we manage fisheries (Aguado et al. 2016).
Seafood certification, or ecolabeling, provided by third parties such as the Marine Stewardship Council and Seafood Watch, attempts to certify ethical fisheries. Fishing practices changed dramatically in response to public outrage over harvest of dolphins in tuna purse seining, demonstrating that consumer demands can influence fishing practices. Fisheries that meet Marine Stewardship criteria are highly selective for the target species, limited access, well regulated, enforced, and often involve comanagement between government, scientists, and fishers. These third-party certifications of sustainability have not yet delivered on the promise of price premiums, improved governance, or improved environmental conditions (Roheim et al. 2018). Challenges remain in the implementation of seafood sustainability due to potential for confusion about the overlapping goals of a growing range of sustainability initiatives (Figure 2.6; McClenachan et al. 2016; Marine Stewardship Council 2019; Tlusty et al. 2019).
Do fishers have a right or a privilege to fish? What’s the desired goal of fisheries management? These fundamental questions involve ethical reasoning about values as applied in the local context. In fisheries we are faced with challenges for fisheries management in inland and ocean waters. Inland fisheries contribute over 40% of the world’s reported finfish fisheries and aquaculture production. Inland capture fisheries comprise less than 10% of this reported total, but the actual fish harvest is likely substantially higher (Cooke et al. 2016). The importance and plight of inland fisheries are poorly recognized by society (Youn et al. 2014). Yet, sportfishing is a potent economic industry in many industrialized countries (American Sportfishing Association 2018). To enhance inland fisheries, we need to (1) raise awareness of diverse values of inland fish, (2) balance the multiple use and conservation objectives, and (3) ensure productive inland fisheries given externalities (Lynch et al. 2017). Global marine fisheries can be enhanced via fewer subsidies and capital investments for fishing, precautionary management, and greater equity in distribution of benefits (McClenachan et al. 2016). The language of ethical analyses may assist in addressing these challenges via effective management so that there can still be “plenty more fish in the sea” and a continuous flow of benefits for our future (Watson et al. 2017).
In summary, it may at first appear that our communities have many overlapping core values. Some may feel that they have overlapping core values within themselves. The wisdom of embracing a pluralistic view of these overlapping core values is evident from taking a pragmatic view (Norton 2005), which opens value questions to community discussion and problem solving. Pragmatism is a philosophy that embraces multiple core values and relies on participatory processes to increase listening, build trust, and consciously cultivate a ground of mutual respect (Cooke et al. 2013; Clayton and Myers 2015; Young et al. 2016). Environmental pragmatists believe that the diversity of values should be respected to allow for deliberate, creative conflict mediation and social learning in contrast to some quest for ethical perfection. The use of social media is likely to play a more prominent role in the future (Giovos et al. 2018). No single management approach can be a panacea; instead, the answer lies in adopting a participatory governance style that works for the local and regional context (Ostrom 1990, 2007).
Question to ponder
What values are most relevant to you when you select a seafood product to buy? If you do not eat fish, what are the values and beliefs you hold that led to that decision?
A thing is right when it tends to preserve the integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise.
—Leopold 1949
Profile in Fish Conservation: Larry Gigliotti
Larry Gigliotti is Professor and Assistant Unit Leader at the South Dakota Cooperative Fish and Wildlife Research Unit, located on the campus of South Dakota State University. He has a BS in wildlife ecology from Pennsylvania State University and an MS and PhD in human dimensions from Michigan State University. Gigliotti maintains certifications as both a Certified Wildlife Biologist and a Certified Fisheries Scientist. His research examines attitudes, values, perceptions, beliefs, and expectations of hunters, anglers, and others related to recreation and resource use. As such, he provides novel information for resource management by understanding the social and psychological determinants of angler behavior and attitude formation and how to involve various publics in conflict resolution and planning.
His first job was as a wildlife biologist in New York and Michigan, and he entered graduate school with a goal of developing unique strengths in research in human dimensions of fish and wildlife. Consequently, he was the first human dimensions specialist hired by the South Dakota Game, Fish and Parks Department. In this position he piloted several innovations to guide the agency’s efforts to be more responsive to citizens, especially hunters and anglers. In particular, he spearheaded many surveys of hunters, landowners, anglers, and residents. His research examined internet-based surveys and revealed important findings regarding response rates and age-related biases.
As an early researcher on the human dimensions of fish and wildlife, his contributions are unique and varied. His perspective as an agency professional and researcher over his career furthered the status of human dimensions as an essential specialization, which draws on sociology, psychology, communications, economics, recreation, education, anthropology, statistics, and other subjects with biology and ecology to make wise management decisions concerning renewable natural resources. One example of his unique influence is the development of a measurement scale to measure crowding among deer hunters, one of many determinants of a hunter’s satisfaction with the hunting experience. He did one of the early investigations of the effects of illegal harvesting behavior among anglers on common sport fishes. He promoted an ecosystem approach to the Great Lakes Lake Trout rehabilitation and explicitly considered the beliefs and attitudes of multiple stakeholders. His investigations on angler use and satisfaction revealed that the opportunities provided to younger anglers by community fishing lakes enhanced their satisfaction with fishing trips. Most recently, he and his associates examined landowner trust in natural resource management agencies as related to competence and fairness, a rarely studied question.
Larry Gigliotti was an early adopter and developer in the human dimensions field and supported fisheries managers in managing for benefits, reflecting a wide range of social values and segmenting anglers based on attitudes and beliefs.
Key Takeaways
• People develop both strong positive and negative thoughts, feelings, and actions toward use of fish.
• Two frameworks, the value-belief-norm and emotional affinity, help to explain how personal values and experiences lead to behavioral norms.
• People will differ with respect to their values and beliefs.
• Commercial fisheries globally have relied on the concept of maximum sustainable yield as a management goal for many decades.
• In recreational fishing, angler satisfaction is more related to noncatch-related factors.
• An ecosystem approach to fisheries management will require additional research and development before it can be fully implemented.
• Seafood certification, or ecolabeling, provided by third parties represents the beginnings of evaluation of ethical fisheries.
• Developing communications and developing partnerships and trust are keys to conservation.
This chapter was reviewed by Larry Gigliotti.
URLs
Long Descriptions
Figure 2.1: Four boxes are connected with arrows showing that biocentrism influences inherent value in all living things, which influences animal welfare expected, which influences adopt aquaculture best practices. Jump back to Figure 2.1.
Figure 2.3: Line graph depicting dome-shaped relationship between yield and fish biomass and linear decline in intrinsic rate of increase. Jump back to Figure 2.3.
Figure 2.4: Line graph depicting dome-shaped relationship between revenues for a fishery as a function of fishing effort, linear increase in costs, and location on curve for maximum economic yield, maximum sustainable yield, and bioeconomic equilibrium. Jump back to Figure 2.4.
Figure 2.5: Regions of safe fishing, a precautionary buffer zone, and stock and fleet overfishing related to spawning biomass and fisheries mortality. Jump back to Figure 2.5.
Figure 2.6: Three overlapping circles: 1) Fair Trade, no forced or child labor; 2) Local, reduced carbon footprint; 3) Eco-label, reduced habitat destruction. Where fair trade and local overlap, socioeconomic development and diversification. Where Eco-Label and Local overlap, improved stock status and reduced bycatch. Where all overlap, traceability. Jump back to Figure 2.6.
Figure References
Figure 2.1: Causal chain of influence between biocentrism, inherent value in all living things, animal welfare expected, and adopt aquaculture best practices. Kindred Grey. 2022. CC BY 4.0.
Figure 2.2: The values-rules-knowledge perspective (VRK) for identifying those aspects of societal decision-making contexts that enable or constrain adaptation. Kindred Grey. 2022. CC BY 4.0.
Figure 2.3: Equilibrium relation between yield (Y, green curve) and intrinsic rate of population increase (r, tan line) and population biomass. Kindred Grey. 2022. Adapted under fair use from Maximum Sustainable Yield, by Athanassios C. Tsikliras and Rainer Froese, 2019 (https://doi.org/10.1016/B978-0-12-409548-9.10601-3).
Figure 2.4: Gordon–Schaefer bioeconomic model of costs and sustainable revenues for a fishery as a function of fishing effort (f). MEY = maximum economic yield, MSY = maximum sustainable yield, and BE = bioeconomic equilibrium. Kindred Grey. 2022. Adapted under fair use from The Economic Theory of a Common-Property Resource: The Fishery, by Gordon H. Scott, 1954 (doi:10.1086/257497) and Some Considerations of Population Dynamics and Economics in Relation to the Management of the Commercial Marine Fisheries, by M. B. Schaefer, 1957. doi:10.1139/f57-025.
Figure 2.5: Visualization of a harvest control rule (HCR) specifying when a rebuilding plan is mandatory in terms of precautionary and limit reference points for spawning biomass and fishing mortality rate. Kindred Grey. 2022. CC BY 4.0. Adapted from Harvest Control Rule graph by Arnejohs, 2006 (public domain, https://commons.wikimedia.org/wiki/File:Harvest_Control_Rule_graph.gif).
Figure 2.6: Three types of seafood sustainability initiatives and example goals of each. Kindred Grey. 2022. Adapted under fair use from Fair Trade Fish: Consumer Support for Broader Seafood Sustainability, by Loren Mcclenachan and Sahan T. M. Dissanayake, 2016 (DOI:10.1111/faf.12148).
Figure 2.7: Larry Gigliotti. USGS. 2016. Public domain. https://www.usgs.gov/media/images/larry-gigliotti
Text References
Abrams, P. A., D. G. Ainley, L. K. Blight, P. K. Dayton, J. T. Eastman, and J. L. Jacquet. 2016. Necessary elements of precautionary management: implications for the Antarctic Toothfish. Fish and Fisheries 17:1152–1174.
Agnew, D. J., J. Pearce, G. Pramod, T. Peatman, R. Watson, J. R. Beddington, and T. J. Pitcher. 2009. Estimating the worldwide extent of illegal fishing. PLoS ONE 4(2): e4570. https://doi.org/10.1371/journal.pone.0004570
Aguado, S. H., I. S. Segado, and T. J. Pitcher. 2016. Towards sustainable fisheries: a multi-criteria participatory approach to assessing indicators of sustainable fishing communities: a case study from Cartagena (Spain). Marine Policy 65:97–106.
Ahrens, R. N., M. S. Allen, C. Walters, and R. Arlinghaus. 2020. Saving large fish through harvest slots outperforms the classic minimum-length limit when the aim is to achieve multiple harvest and catch-related objectives. Fish and Fisheries 21:483–510.
American Sport Fishing Association (ASFA). 2018. Sportfishing in America: an economic force for conservation. Accessed 30 October 2019. https://www.fishwildlife.org/application/files/6015/3719/7579/Southwick_Assoc_-_ASA_Sportfishing_Econ.pdf
Arlinghaus, R. 2008. Social barriers to sustainable recreational fisheries management under quasicommon property fishing rights regime. Pages 195–122 in J. Nielsen, J. J. Dodson, K. Friedland, T. R. Hamon, J. Musick, E. Verspoor, and M. A. Bethesda, editors, Reconciling fisheries with conservation: Proceedings of the Fourth World Fisheries Congress. American Fisheries Society Symposium 49, Bethesda, MD.
Arlinghaus, R., T. Mehner, and I. G. Cowx. 2002. Reconciling traditional inland fisheries management and sustainability in industrialized countries, with emphasis on Europe. Fish and Fisheries 3:261–316.
Bailey, K. M. 2018. Fishing lessons: artisanal fisheries and the future of our oceans. University of Chicago Press.
Beard, T. D. Jr., R. Arlinghaus, S. J. Cooke, P. B. McIntyre, S. de Silva, D. Bartley, and I. G. Cowx. 2011. Ecosystem approach to inland fisheries: research needs and implementation strategies. Biology Letters 7:481–483. doi:10.1098/rsbl.2011.0046.
Bell, F. W. 1997. The economic valuation of saltwater marsh supporting marine recreational fishing in the southeastern United States. Ecological Economics 21:243–254.
Berkes, F. 2012. Implementing ecosystem-based management: evolution or revolution? Fish and Fisheries 13:465–476.
Berkes, F., T. P. Hughes, R. S. Steneck, J. A .Wilson, D. R. Bellwood, B. Crona, C. Folke, L. H. Gunderson, H. M. Leslie, J. Norberg, M. Nyström, P. Olsson, H. Österblom, M. Scheffer, and B. Worm. 2006. Globalization, roving bandits, and marine resources. Science 311(5767):1557–1558.
Berkes, F., and P. K. Nayak. 2018. Role of communities in fisheries management: “one would first need to imagine it.” Maritime Studies 17:241–251. DOI:10.1007/s40152-018-0120-x.
Birkenbach, A. M., D. J. Kaczan, and M. D. Smith. 2017. Catch shares slow the race to fish. Nature 544:223–226.
Bishop, R. C., K. J. Boyle, and M. P. Welsh. 1987. Towards total economic valuation of Great Lakes fishery resources. Transactions of the American Fisheries Society 116:339–345.
Bundy A., R. Chuenpagdee, S. Jentoft, and R. Mahon. 2008. If science is not the answer, what is? An alternative governance model for the world’s fisheries. Frontiers in Ecology and the Environment 6:152–155. http://dx.doi.org/10.1890/060112.
Cabral, R. B., D. Bradley, J. Mayorga, W. Goodell, A. M. Friedlander, E. Sala, C. Costello, and S. D. Gaines. Proceedings of the National Academy of Sciences 117(45):28134–28139.
Callicott, J. B. 2005. Conservation values and ethics. Pages 111–135 in M. J. Groom, G. K. Meffe, and C. R. Carroll, editors. Principles of conservation biology. 3rd ed. Sinauer, Sunderland, MA.
Castello, L., J. P. Viana, G. Watkins, M. Pinedo-Vasquez, and V. A. Luzadis. 2009. Lessons from integrating fishers of Arapaima in small-scale fisheries management at the Mamirauá Reserve. Environmental Management 43:197–209.
Chan, K. M. A., P. Balvanera, K. Benessaiah, M. Chapman, S. Díaz, E. Gómez-Baggethun, R. Gould, N. Hannahs, K. Jax, S. Klain, G. W. Luck, B. Martín-López, B. Muraca, B. Norton, K. Ott, U. Pascual, T. Satterfield, M. Tadaki, J. Taggart, and N. Turner. 2016. Opinion: Why protect nature? Rethinking values and the environment. Proceedings of the National Academy of Science USA 113:1462–1465. doi: 10.1073/pnas.1525002113.
Chen, F., M. Lai, and H. Huang. 2020. Can marine park become an ecotourism destination? Evidence from stakeholders’ perceptions of the suitability. Ocean & Coastal Management 196: 105307. https://doi.org/10.1016/j.ocecoaman.2020.105307.
Clayton, S., and G. Myers. 2015. Conservation psychology: understanding and promoting human care for nature. Wiley Blackwell, Oxford, UK.
Cochrane, K. L. 2008. What should we care about when attempting to reconcile fisheries with conservation? Pages 5–24 in J. Nielsen, J. J. Dodson, K. Friedland, T. R. Hamon, J. Musick, E. Verspoor, and M. A. Bethesda, editors, Reconciling fisheries with conservation: Proceedings of the Fourth World Fisheries Congress. American Fisheries Society Symposium 49, Bethesda, MD.
Colloff, M. J., B. Martín-López, S. Lavorel, B. Locatelli, R. Gorddard, P-Y. Longaretti, G. Walters, L. van Kerkhoff, C. Wyborn, A. Coreau, R. M. Wise, M. Dunlop, P. Gegeorges, H. Grantham, I. C. Overton, R. D. Williams, M. D. Doherty, T. Capon, T. Sanderson, and H. T. Murphy. 2017. An integrative research framework for enabling transformative adaptation. Environmental Science and Policy 68:87–96.
Comeau, M., and J. M. Hanson. 2018. American lobster: persistence in the face of high, size-selective, fishing mortality—a perspective from the southern Gulf of St. Lawrence. Canadian Journal of Fisheries and Aquatic Sciences 75:2401–2411.
Cooke, S. J ., E. H. Allison, T. D. Beard Jr., R. Arlinghaus, A. H. Arthington, D. M. Bartley, I. G. Cowx, C. Fuentevilla, N. J. Leonard, K. Lorenzen, A. J. Lynch, V. M. Nguyen, S.-J. Youn, W. W. Taylor, and R. L. Welcomme. 2016. On the sustainability of inland fisheries: finding a future for the forgotten. Ambio 45(7):753–764. DOI:10.1007/s13280-016-0787-4.
Cooke, S. J., N. W. R. Lapointe, E. G. Martins, J. D. Thiem, G. D. Raby, M. K. Taylor, T.D. Beard Jr., and I. G. Cowx. 2013. Failure to engage the public in issues related to inland fishes and fisheries: strategies for building public and political will to promote meaningful conservation. Journal of Fish Biology 83:997–1018. doi:10.1111/jfb.12222.
Costello, C., S. D. Gaines, and J. Lynham. 2008. Can catch shares prevent fisheries collapse? Science 321:1678–1681.
Costello, M. J., and B. Ballantine. 2015. Biodiversity conservation should focus on no-take marine reserves: 94% of marine protected areas allow fishing. Trends in Ecology and Evolution 30:507–509.
Cowx, I. G., and M. P. Aya. 2011. Paradigm shifts in fish conservation: moving to the ecosystem services concept. Journal of Fish Biology 79:1663–1680.
Defeo, O., T. R. McClanahan, and J. C. Castilla. 2017. A brief history of fisheries management with emphasis on society participatory roles. Pages 3–21 in T. R. McClanahan and J. C. Castilla, editors, Fisheries management: progress towards sustainability. Blackwell, Oxford, UK.
Epstein, G. 2017. Invasive alien species management: a personal impasse. Frontiers in Environmental Science 5. https://doi.org/10.3389/fenvs.2017.00068.
FAO. 1995. Code of conduct for responsible fisheries. Food and Agriculture Organization of the United Nations, Rome.
Fields, A. T., G. A. Fischer, S. K. Shea, H. Zhang, D. L. Abercrombie, K. A. Feldheim, E. A. Babcock, and D. D. Chapman. 2018. Species composition of the international shark fin trade assessed through a retail-market survey in Hong Kong. Conservation Biology 32(2):376–389. DOI:10.1111/cobi.13043.
Fina, M. 2011. Evolution of catch share management: lessons from catch share management in the North Pacific. Fisheries 36(4):164–177.
Fulton, D. C., M. J. Manfredo, and J. Lipscomb. 1996. Wildlife value orientations: a conceptual and measurement approach. Human Dimensions of Wildlife 1:24–47.
Gaspare, L., I. Bryceson, and K. Kulindwa. 2015. Complementarity of fishers’ traditional ecological knowledge and conventional science: contributions to the management of grouper (Epinephelinae) fisheries around Mafia Island, Tanzania. Ocean and Coastal Management 114:88–101.
Gersuny, C., and J. J. Poggie Jr. 1974. Luddites and fishermen: a note on response to technological change. Maritime Studies and Management 2:38–47.
Gibbs, M. T. 2009. Individual transferable quotas and ecosystem-based fisheries management: it’s all in the T. Fish and Fisheries 10:470–474.
Giovos, I., I. Keramidas, C. Antoniou, A. Deidun, T. Font, P. Kleitou, J. Lloret, S. MatiĆ-Skoko, A. Said, F. Tiralongo, and D. K. Moutopoulos. 2018. Identifying recreational fisheries in the Mediterranean Sea through social media. Fisheries Management and Ecology 25:287–295.
Gorddard, R., M. J. Colloff, R. M. Wise, D. Ware, and M. Dunlap. 2016. Values, rules and knowledge: adaptation as change in the decision context. Environmental Science and Policy 57:60–69.
Gordon, H. S. 1954. The economic theory of a common-property resource: the fishery. Journal of Political Economy 62(2):124–142.
Hilborn, R. 2010. Pretty Good Yield and exploited fishes. Marine Policy 34:193–196.
Hilborn, R., R. O. Amoroso, C. M. Anderson, J. K. Baum, T. A. Branch, C. Costello, C. L. de Moor, A. Faraj, D. Hively, O.P. Jensen, H. Kurota, L. R. Little, P. Mace, T. McClanahan, M. C. Melnychuk, C. Minto, G. C. Osio, A. M. Parma, M. Pons, S. Segurado, C. S. Szuwalski, J. R. Wilson, and Y. Ye. 2020. Effective fisheries management instrumental in improving stock status. Proceedings of the National Academy of Science 117(4):2218–2224. https://doi.org/10.1073/pnas.1909726116.
Hilborn, R., E. A. Fulton, B. S. Green, K. Harmann, S. R. Tracey, and R. A. Watson. 2015. When is a fishery sustainable? Canadian Journal of Fisheries and Aquatic Sciences 72:1433–1441.
Hind, E. J. 2015. A review of the past, the present, and the future of fisher’s knowledge research: a challenge to established fisheries science. ICES Journal of Marine Science 72(2):341–358.
Jacobs, M. H., J. J. Vaske, T. L. Teel, and M. J. Manfredo. 2012. Human dimensions of wildlife. Pages 77–86 in L. Steg, A. E. van den Berg, and J. de Groot, editors, Environmental psychology: an introduction. John Wiley and Sons, Hoboken, NJ.
Kals, E., D. Schumache, and L. Montada. 1999. Emotional affinity toward nature as a motivational basis to protect nature. Environmental Behavior 31:178–202. doi:10.1177/00139169921972056
Karjalainen, J., and T. J. Marjomäki. 2005. Sustainability in fisheries management. In A. Jalkenen and P. Nygren, editors, Sustainable use of renewable natural resources: from principles to practices. University of Helsinki Department of Forest Ecology Publications 34:249–267. http://www.helsinki.fi/mmtdk/mmeko/sunare.
Lam, M. E., and T. J. Pitcher. 2012. The ethical dimensions of fisheries. Current Opinion in Environmental Sustainability 4:364–373.
Larkin, P. A. 1977. An epitaph for the concept of maximum sustained yield. Transactions of the American Fisheries Society 106:1–11.
Leopold, A. 1949. A Sand County almanac: and sketches here and there. Oxford University Press.
Lynch, A. J., S. J. Cooke, T. D. Beard Jr., K. Yu-Chun, K. Lorenzen, A. F. M. Song, M. S. Allen, Z. Basher, D. B. Bunnell, E. V. Camp, I. G. Cowx, J. A. Freedman, V. M. Nguyen, J. K. Nohner, M. W. Rogers, Z. A. Siders, W. W. Taylor, and S.-J. Youn. 2017. Grand challenges in the management and conservation of North American inland fishes and fisheries. Fisheries 42(2):115–124. DOI:10.1080/03632415.2017.1259945.
Mace, P. M. 2001. A new role for MSY in single-species and ecosystem approaches to fisheries stock assessment and management. Fish and Fisheries 2:2–32.
Manfredo, M. J., T. L. Teel, and K. L. Henry. 2009. Linking society and environment: a multi-level model of shifting wildlife value orientations in the western U.S. Social Science Quarterly 90:407–427.
Marine Stewardship Council. 2019. Working together for thriving oceans: the MSC Annual Report 2018–2019. Available at msc.org/annualreport. Accessed 12 May 2020.
Marshall, K. N., L. E. Koehn, P. S. Levin, T. E. Essington, and O. P. Jensen. 2019. Inclusion of ecosystem information in US fish stock assessments suggests progress toward ecosystem-based fisheries management. ICES Journal of Marine Science 76:1–9.
McClenachan, L., S. T. M. Dissanayake, and X. Chen. 2016. Fair trade fish: consumer support for broader seafood sustainability. Fish and Fisheries 17:825–838.
Murphy, R., Jr., S. Scyphers, S. Gray, and J. H. Grabowski. 2019. Angler attitudes explain disparate reactions to fishery regulations. Fisheries 44(10):475–487.
Myers, R. A., J. A. Hutchings, and N. J. Barrowman. 1997. Why do fish populations collapse? The collapse of cod in Atlantic Canada. Ecological Applications 7:91–106.
Nichols, R., S. Yamazaki, and S. Jennings. 2018. The role of precaution in stock recovery plans in a fishery with habitat effect. Ecological Economics 146:359–369.
Norton, B. G. 2005. Sustainability: a philosophy of adaptive ecosystem management. University of Chicago Press.
Ostrom, E. 1990. Governing the commons: the evolution of institutions for collective action. Cambridge University Press.
Ostrom, E. 2007. A diagnostic approach for going beyond panaceas. Proceedings of the National Academy of Science USA 104:15181–15187.
Patrick, W. S., and J. S. Link. 2015a. Myths that continue to impede progress in ecosystem-based fisheries management. Fisheries 40(4):155–159.
Patrick, W. S., and J. S. Link. 2015b. Hidden in plain sight: using optimum yield as a policy framework to operationalize ecosystem-based fisheries management. Marine Policy 62:74–81.
Pitcher, T. J., and D. Pauly. 1998. Rebuilding ecosystems, not sustainability, as the proper goal of fishery management. Pages 311–329 in T. J. Pitcher, P. J. B. Hart, and D. Pauly, editors, Reinventing fisheries management. Kluwer, Dordrecht, The Netherlands.
Pitcher, T. J., and M. E. Lam 2010. Fishful thinking: rhetoric, reality, and the sea before us. Ecology and Society 15(2):12. http://www.ecologyandsociety.org/vol15/iss2/art12/.
Reed, W. J. 1980. Optimum age-specific harvesting in a nonlinear population model. Biometrics 36:579–593.
Rice, J. 2011. Managing fisheries well: delivering the promises of an ecosystem approach. Fish and Fisheries 12:209–231.
Roedel, P. M. 1975. Optimum sustainable yield as a concept in fisheries management. American Fisheries Society Special Publication 9, Bethesda, MD.
Roheim, C. A., S. R. Bush, F. Asche, J. N. Sanchirico, and H. Uchida. 2018. Evolution and the future of sustainable seafood market. Nature Sustainability 1:392–398.
Sala, E., and S. Giakoumi. 2018. No-take marine reserves are the most effective protected areas in the ocean. ICES Journal of Marine Science 75:1166–1168. doi:10.1093/icesjms/fsx059.
Sherman, K. D., A. D. Shultz, C. P. Dahlgren, C. Thomas, E. Brooks, A. Brooks, D. R. Brumbaugh, and L. Gittens. 2018. Contemporary and emerging fisheries in The Bahamas: conservation and management challenges, achievements and future directions. Fisheries Management and Ecology 25(1681). doi:10.1111/fme.12299.
Skubel, R. A., M. Shriver-Rice, and G. M. Maranto. 2019. Introducing relational values as a tool for shark conservation, science, and management. Frontiers in Marine Science 6:53. https://doi.org/10.3389/fmars.2019.00053.
Snyder, S. 2007. New streams of religion: fly fishing as a lived, religion of nature. Journal of the American Academy of Religion 75:896–922.
Sovacool, B., and D. J. Hess. 2017. Ordering theories: typologies and conceptual frameworks for sociotechnical change. Social Studies of Science 47(5):703–750.
Stern, M. J., and K. J. Coleman. 2015. The multidimensionality of trust: application in collaborative natural resource management. Society and Natural Resources 28:117–132.
Stern, P. C. 2000. New environmental theories: toward a coherent theory of environmentally significant behavior. Journal of Social Issues 56:407–424. doi:10.1111/0022-4537.00175.
Tlusty, M. F., P. Tyedmers, M. Bailey, F. Ziegler, P. J. G. Henricksson, C. Béné, S. Bush, R. Newton, F. Asche, D. C. Little, M. Troell, and M. Jonell. 2019. Reframing the sustainable seafood narrative. Global Environmental Change 59:101991.
Tsikliras, A. C., and R. Froese. 2018. Maximum sustainable yield. In Reference module in earth and environmental sciences. Encyclopedia of ecology. 2nd ed., vol. 1:108–115. https://www.sciencedirect.com/science/article/pii/B9780124095489106013?via%3Dihub
Verhulst, P.‐F. 1838. Notice sur la loi que la population poursuit dans son accroissement. Correspondence mathématique et physique 10:113–121. Available at http://books.google.com/books?hl=fr&id=8GsEAAAAYAAJ&jtp=113#v=onepage&q=&f=fals. Accessed April 23, 2010.
Watson, R. A., T. J. Pitcher, and S. Jennings. 2017. Plenty more fish in the sea. Fish and Fisheries 18:105–113.
Whitehouse, L., S. A. Heppell, C. V. Pattengill-Semmens, C. McCoy, P. Bush, B. C. Johnson, and B. X. Semmens. 2020. Recovery of critically endangered Nassau grouper (Epinephelus striatus) in the Cayman Islands following targeted conservation actions. Proceedings of the National Academy of Sciences 117:1587–1595.
Worm, B., R. Hilborn, J. K. Baum, T. A. Branch, J. S. Collie, C. Costello, C., M. J. Fogarty, E. A. Fulton, J. A. Hutchings, S. Jennings, O. P. Jensen, H. K. Lotze, P. M. Mace, T. R. McClanahan, C. Minto, S. R. Palumbi, A. M. Parma, D. Ricard, A. A. Rosenberg, R. Watson, and D. Zeller. 2009. Rebuilding global fisheries. Science 325: 578–585. doi:10.1126/science.1173146.
Youn, S. J., W. W. Taylor, A. J. Lynch, I. G. Cowx, T. D. Beard Jr., D. Bartley, and F. Wu. 2014. Inland capture fishery contributions to global food security and threats to their future. Global Food Security 3:142–148. doi:10.1016/j.gfs.2014.09.005.
Young, J. C., K. Searle, A. Butler, P. Simmons, A. D. Watt, and A. Jordan. 2016. The role of trust in the resolution of conservation conflicts. Biological Conservation 195:196–202. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.02%3A_Values_Drive_Fish_Conservation.txt |
Learning Objectives
• Recognize the adaptive significance of sensory capabilities of fish.
• Compare and contrast the sensory system of humans and fish.
• Relate the sensitivities of fish to the characteristics of the underwater world.
• Describe how sensory capabilities relate to the fish’s ability to communicate and orient.
• Express how the sensory abilities lead to responses to environmental stimuli.
• Apply concepts of fish sensory capabilities to predict effects of humans on fish.
3.1 Introduction
Fish may seem alien to us because they evolved in water and their senses are more adapted to an aquatic environment. Yet, like humans, fish depend on many senses for survival. Vision is a dominant sense in fish, and we humans can appreciate the capability for depth perception and color discrimination. But what happens when you attempt to see underwater? Your vision is very blurry underwater. Somehow fish solved the problem of seeing underwater. Sensory capabilities of fish are adapted to accommodate the special characteristics of the aquatic environment.
Imagine, if you will, a day in the life of a fish. Without eyelids, their eyes are open all the time. Daily cycles of light intensity are sensed by photoreceptors in the eye and pineal organ in the brain, which contains light-sensitive nerve endings. Vision is a dominant sense of fish that we humans can appreciate. Whether the fish finds a meal or becomes prey depends on many senses, such as the abilities to see, hear, smell, taste, and to detect water movement and electrical fields. Fish have a special sense that humans do not have: the ability to detect vibrations moving through water. Because sound vibrations move easily through water, fish do not need external ear openings, and yet they also have sensitive hearing.
Together, fish use these senses to inspect the world around them. Imagine an angler tossing a lure nearby. The fish will feel the vibrations caused by the waves moving from the lure. With wide-angle vision, the fish moves toward the lure to inspect it. With an acute sense of smell, it detects no signal that suggests it’s living. In some cases, the fish will grab a bait, taste it with sensitive taste buds, and reject it as nonfood. If captured, the fish has many sensory structures in the skin to detect touch and temperature changes.
But fish use sense for more than just finding food. Fish can rely on one or more sensory cues and different sensory mechanisms to gain information about their environment and guide their behavior. Senses are engaged whether the fish is moving toward a sound, away from a threat, or following a scent of food or pheromones. For example, young glass eels (Anguilla spp.) return to estuaries and detect currents using their magnetic compass to memorize magnetic direction of tidal flows (Cresci et al. 2019). As you learn more about the sensory capabilities of fish, you will be better able to understand their behavior.
3.2 Characteristics of the Water Shape Sensory Capabilities
Humans share some homologous organs and body parts with fish (Table 3.1). However, characteristics of water exert evolutionary pressures on fish to enhance their sensory capabilities in water. Water is dense, colorless, and odorless and can refract and reflect light waves in such a way that some colors are absorbed, particularly at deeper depths. Consequently, sound waves travel fast, scents are rapidly dissolved and detected in low concentrations, and vision is keen in fish that are active during the daytime. There is less oxygen dissolved in water than in the atmosphere. Therefore, gills are highly efficient at oxygen diffusion, and oxygen-sensing cells are sensitive at detecting changes in oxygen content of the water, sending signals to increase gill ventilation as oxygen declines. Similarly, terrestrial vertebrates have oxygen-sensing cells in the lungs to signal a change in breathing rate.
It’s not just the presence but also the location of sensory organs that reflects these evolutionary pressures (Figure 3.1). Fish smell with nares, far forward on the head, in front of the eyes, so that new scents are detected as the fish swims forward. Taste buds in fish are not restricted to the mouth but are distributed throughout parts of the body to allow the fish to taste its environment. Eyes are typically above the midline and on either side of the head, allowing fish a wide field of vision in front and along the sides and above—locations of typical predator threat. Water flow patterns are detected along the entire length of the body via sensory hair cells in the lateral line and other locations. In this way, the fish detects the flow field as it swims forward and detects disturbances in the flow field made by prey and predators. For example, when a fish detects the accelerating flows of suction or ram actions of predators, it will instinctively make a turn or C-shaped body bend and move in an opposite direction (Mirjany et al. 2011). The reaction occurs within 10 milliseconds.
Some fish have evolved a reduced or negative capacity for some senses to match their environment. Fish in muddy water habitats often have very small eyes because vision is less important. Some fish that live in dark caves have totally lost the sense of vision. Blind cavefish use the flow-sensing capabilities of their lateral line system rather than vision to avoid swimming into obstacles.
Human Fish
Lungs Gills
Stomach Stomach
Liver Liver
Kidneys Kidneys
Ears Lateral line, otoliths, and inner ear
Skin Scales and slime layer
Nose Nares
Arms Pectoral fins
Legs Pelvic fins
Table 3.1: Homologous organs in humans and fish.
Question to ponder:
You are assigned a task at work to create the perfect marketable fish bait. Draw (with color) and describe the most ideal bait for either a catfish or a tuna. Describe how this will move through the water when fished and other features that would make it more marketable to anglers. Modify your design and description after you complete your reading of this chapter.
3.3 How We Study Sensory Ecology
Sensory ecology focuses on the study of animal sensory systems to understand how environmental information is perceived, how this information is processed, and how this affects interactions between the animal and its environment (Dangles et al. 2009). The stimulus-response model (Figure 3.2) describes the basic reactions from the stimulus, through receptors to the central nervous system and brain, which are then transmitted to neurons and organs that respond due to detection of the stimulus. A stimulus is any change in the environment (either external or internal) that is detected by a receptor. It may be a predator threat, an easy prey item, or a potential mate. Receptors transform environmental stimuli into electrical nerve impulses. These impulses are then transmitted via neurons to the central nervous system and brain where decision making occurs. When a response is selected (consciously or unconsciously), the signal is transmitted via neurons to effectors. Effectors are organs (either muscles or glands) that produce a response to a stimulus. A response is a change in the organism resulting from the detection of a stimulus.
Three types of neurons are required to transmit information via the stimulus-response pathway: (1) sensory neurons transmit information from sensory receptors to the central nervous system (CNS); (2) relay neurons (interneurons) transmit information within the CNS as part of the decision-making process; and (3) motor neurons transmit information from the CNS to effectors (muscles or glands), to initiate a response.
The fascinating interplay between the different sensory abilities of the fish leads to their unique response to environmental stimuli that we observe. Consequently, biologists who study sensory ecology apply both behavioral and physiological approaches. The behavioral approach involves training or conditioning fish so that they respond to a stimulus. The fish is trained to do some tasks, such as move to one side of a tank, when it receives a stimulus such as a sound, a smell, or a visual cue. In this way, biologists can measure the reaction of fish to various stimuli.
The electrophysiological approach measures the responses to a stimulus by placing electrodes close to the nerve. The approach does not require any behavioral response by the fish; it only indicates that the stimulus was detected. The basic pathway for a nerve impulse is described by the stimulus-response model. The locations of sensory neurons of cutaneous taste buds of catfish were mapped in detail long ago (Herrick 1901), which allowed the first studies that exposed taste buds on the skin to various chemical stimuli and measured the responses in specific nerves via electrodes and amplifiers to display the electrical signal response (Hoagland 1933).
Catfish have a keen sense of taste and smell, and their taste buds are densely packed on the barbels, mouth, and skin. Barbels are particularly useful for catfish, as they literally “taste” the surrounding environment in the dark of night. As an example of the behavioral approach, a study of catfish in a large aquarium revealed that small catfish quickly responded to a small drop of pork juice and could locate the source with taste alone within 24 seconds (Bardach et al. 1967). The value of the behavioral approach is also revealed by a study that demonstrated the ability of sharks and rays to locate a flatfish buried in the sand by using their ability to detect weak electric fields generated by the hidden flatfish (Kalmijn 1971; King and Long 2020). Understanding the behavior of fish is of widespread interest, especially in the study of anthropocentric pollution that may obscure or interfere with detection of stimuli that fish use to make sense of their surroundings.
3.4 Distant Touch and Hearing
Humans hear sound when air molecules vibrate and move in a pattern called waves or sound waves. Fish have sensitive hearing that is adapted to the underwater environment, where sound waves move four times faster than in air because water particles are packed closer together. Because sound waves move faster in aquatic environments, the underwater world is filled with myriad sound sources that provide the fish with information from far greater distances than do other sensory stimuli. Fish use their hearing abilities to assess their surrounding soundscape and determine the availability of food, mates, or competitors, as well as the threat of predators (Putland et al. 2019). Fish may not hear the sounds of two anglers speaking in a boat because their sound waves are traveling through the air. However, fish will hear the propeller from an electric trolling motor from a good distance away.
Sound perception is so critical to survival of fish that the hearing anatomy is fully developed within two days of hatching, when fish are just developing swimming and other sensory capabilities. Unlike humans, which have external ears, fish have two organs for hearing that are not obvious to the casual observer. Fish have an internal ear and an external lateral line system. The lateral line is an organ of microscopic pores primarily used to sense vibrations and pressure in the water (Figure 3.3; Montgomery et al. 2014). The pores are lined with neuromasts, which contain sensory hair cells (Figure 3.4). Each hair cell has bundles of cilia embedded in a gelatinous structure, called the cupula. Water movements deflect the cupula and cilia bundles, creating a change in membrane potential that is transmitted to the sensory neuron.
In addition to neuromasts found in the lateral line canal (see Figure 3.4), fish also have neuromasts in canals and on the surface of the skin in clusters on the head, trunk, and tail fin. The number and location of neuromasts influence the sensitivity. For example, the Goldfish has more superficial neuromasts and is more sensitive to water vibrations than the Rainbow Trout. Biologists have found that fish spend much of their time orienting their body, and the ability to sense local water movements is essential to the motion of the fish (Liao 2007; Coombs and Montgomery 2014). The small adipose fin, which is only present in some families of fish, detects water flow across the dorsal surface near the caudal region of the body and aids in swimming (Stewart and Hale 2013). Another unique specialization of neuromasts is the extended lateral line canal along the bottom jaw of the halfbeak fish, which allows it to detect, track, and intercept small but relatively fast-moving prey without using vision (Montgomery and Saunders 1985).
Fish utilize the lateral line to detect movements of prey, predators, currents, and objects in the water. If there is any difference between the relative movements of the body of the fish and the movements of the surrounding water, it will be sensed by the lateral line (Mogdans 2019). In this way, the fish knows if it is swimming in highly turbulent or still waters. The lateral line is also very sensitive to water vibrations from great distances underwater, so this sixth sense is sometimes called the far-field hearing (Figure 3.5).
The inner ear of bony fish consists of semicircular canals connected to organs with otoliths, or ear stones (Figure 3.6). It is similar to the cochlea in humans and other vertebrates. When sound waves go through a fish, the denser ear stone moves more slowly and the sensory hair cells and cilia are deflected, thereby sending signals to the brain. Some deflections are interpreted as sounds, and some signal acceleration of the fish (Tavolga et al. 1981; Popper and Schilt 2008; Popper et al. 2019). Swim bladders in bony fish vibrate as well, and direct connections to the inner ear enhance the hearing sensitivity in certain fish, such as Goldfish.
Far-field and near-field hearing are adaptations for increased survival, feeding success, and breeding in fish. During the early development of many fish that occupy coral reefs, the planktonic larvae drift in the currents. Drifting larval fish use sounds produced by different underwater habitats to orient and locate suitable habitats to settle into. Furthermore, some fish use sound to discriminate between habitats when moving from sheltering to feeding habitats at night. Herring and shad have elongated gas ducts that extend from the swim bladder to the skull, which enhances hearing to ultrasound up to 100,000 Hz, overlapping the range of echolocation sounds of dolphins and porpoises. When American Shad hear ultrasonic clicks like those of dolphins, the fish either swim in the opposite direction of the sound source or move chaotically, making it harder for the dolphin to detect and capture the fish (Mann et al. 1997). Herring also escape approaching predators by detecting changes in water flow that the predator causes. In many sound-producing fish, the males produce sounds to attract a receptive female in initial courtship interactions. For example, females tend to choose males based on calling rate or effort, which is linked to body fat reserves and gonad size. Consequently, these and many other examples demonstrate how fish survival and breeding success are enhanced by specialized hearing.
3.5 Vision
Every experienced angler is aware of the keen vision of fish and uses this knowledge to catch more fish. The eyes of most fish are placed laterally on the head and tilted forward and upward. Vision is therefore nearly absent downward and to the rear, providing wide-angle monocular vision and a narrow zone of binocular vision. Consequently, for most sport fish, the angler’s best line of attack is directly behind in the blind zone (Figure 3.7A). The angler also knows that light waves are reflected, refracted, or absorbed, depending on the angle. Therefore, fish have a cone-shaped range of vision that is approximately two times the depth of the fish. Outside this cone, the fish sees nothing and the angler’s approach is hidden. The water surface around the window is either black or a mirror, depending on the angle at which light rays are reflected (Figure 3.7B).
Tips for stalking fish based on fish vision (Mayer 2019):
• Bottom brim of your hat should be a dark color.
• Wear dark or camouflage clothing and avoid wearing shiny objects.
• Wear polarized sunglasses that cover the sides of your eyes thoroughly.
• Block unwanted reflected rays by placing your arm beneath your chin.
• Keep the sun at your back and watch your shadow.
• Approach from downstream and keep a low profile.
• Place your fly upstream and within the binocular zone (a 30–36° angle) of a position-holding trout.
• Remember that the fish is holding position deeper and closer than it looks.
The eye of a fish has a similar anatomy to humans and consists of a cornea, iris, lens, sclera, choroid, and retina and is filled with a gel (or vitreous humor) between the lens and the retina (Figure 3.8). However, a fish’s eye operates differently than that of a human to accommodate underwater sight. The lens of a fish’s eye is purely spherical, unlike ours, and it has a refractive index (light-bending ability) of 1.65, which is higher than that of any other group of vertebrates. The lens focuses light waves on the retina, which influences the sensitivity of fish vision (Li and Maaswinkel 2006). Furthermore, the lens is fixed in its shape, meaning its shape cannot be adjusted to facilitate focusing on nearer or more distant objects. Therefore, unlike humans, most fish adjust focus by moving the lens closer or further from the retina. Bony fish do so by contracting a muscle.
Also like humans, the retina of the fish’s eye is made up of photosensitive rods and cones. The rods detect only the presence or absence of light, and the cones detect color (Douglas and Djamgoz 1990). Most bony fish can detect color (Marshall et al. 2017). Most sharks, however, have only rods, and therefore they distinguish contrast, not color. In most bony fish, rods for low-light vision are much more common than cones, which are better for bright-light vision. As a general rule, the deeper a fish lives the fewer cones it has.
Color vision in fish is a hotly debated topic for some anglers. This is because fish do not see colors as humans do, and color sensing is highly variable among different fish. Walleye, for example, are adapted to low-light conditions, and their eyes have more rods than cones, whereas Rainbow Trout color vision is more like human color vision. Furthermore, different color wavelengths travel through water differently. Longer wavelengths disappear more quickly than shorter waves. Therefore, the depth of fish will influence light penetration and color availability. The vivid reds and yellows on your fishing lure will lose that brightness as long wavelengths are absorbed in deeper water. In turbid water, light waves disappear even quicker. Commercial gill-net fishers dye nets blue or green so they blend into the background color in very deep water. The subject of color selection for trout angling is fully explored in many books, such as The New Scientific Angling: Trout and Ultraviolet Vision; What Fish See: Understanding Optics and Color Shifts for Designing Lures and Flies; and Trout Sense: A Fly Fisher’s Guide to What Trout See, Hear, & Smell. For the angler, it is often more about the contrast that the lure provides than the colors.
Two visual capabilities of some bony fish include polarization and ultraviolet (UV) vision. It is at dusk and dawn when the maximum amount of polarized light is refracted in water, and much of it is in the UV wavelengths. Humans perceive polarized light as glare. However, certain fish can discriminate polarized light. Damselfish, clownfish, trout, minnows, and anchovy may use this ability to enhance detection of small prey within the fish’s field of vision (Kamermans and Hawryshyn 2011). Many shallow-dwelling fish are capable of detecting UV radiation. Because humans cannot see UV light, the significance of this capability was initially a mystery. Scientists hypothesized that the ability of some fish to see UV reflections could represent a secret communication channel, hidden from predators. In coral reef fish, visual communication is a key mechanism for recognizing members of the same species. Experiments with damselfish demonstrated that they use their UV capabilities to discriminate between UV facial patterns of closely related species and their own (Siebek et al. 2010). These same facial patterns are invisible to humans and other fish but provide a hidden communication signal in damselfish.
Question to ponder:
Consider your favorite fishing target and their preferred habitat. How do you expect that the ability to hear (near and far) and vision influence your preferred choice of fishing lure or bait?
If you do not have a favorite fishing target, consider the Walleye and review this website.
3.6 Taste and Smell
Fish have an especially sensitive system for taste and smell, which have been well studied (Zielinski and Hara 2006; Kasumyan 2019). Smell occurs in the sensory folds with the nares on the head of a fish. However, fish are unique among vertebrates because they have taste buds that occur in many locations, which means a fish can literally taste its environment or food without putting it in its mouth. Taste buds can be seen on fish with a magnifying lens and appear as small pores with sensory cells connected to nerves (Figure 3.9). Fish have the highest number of taste buds recorded for vertebrate animals, and the amount of neural tissue devoted to sensing taste approaches 20% of the entire brain mass in some fish (Kotrschal and Palzenberger 1992). Fish are unique among vertebrates because they have external taste buds on their body in addition to taste buds on the lips and mouth. As early as 1827, taste buds of Common Carp were first described, and subsequently distribution of taste buds was studied in many other freshwater and marine fish. The location of taste buds on the body, barbels, or fin tips means that the fish can taste its environment as it moves and adapt or orient to potential food (Bardach and Atema 1971; Burton and Burton 2017). Studies frequently noted that the fish excelled humans in tasting tested substances and surprisingly showed a strong response to human saliva (Konishi and Zotterman 1961)—so there’s no evidence to support the idea that spitting on your bait brings good luck.
In some bony fish, taste and smell are dominant sensory modalities. In fact, some substances are both tasted and smelled. Taste sensors detect the presence and location of distant food sources. However, taste and smell are not just for feeding: they can also play a role in the protection of the young and in courtship.
The key drivers for feeding are hunger and satiety. What is chosen to eat, however, is not determined solely by physiological or nutritional needs but by other factors such as the sensory properties of food. An encounter with food odor evokes feeding agitation and searching activity in fish and in most cases precedes grasping of the detected food item. The odor of familiar or habitual food makes fish grasp and test many previously indifferent dietary items, even those that in size, shape, or coloration only distantly remind the fish of real food.
The fact that odors attract certain fish has been used by recreational and commercial fishers for a long time. Worms are often kept in damp coffee grounds because the coffee smell attracts fish. Many baits and smelly fish are used in hoop nets and traps to attract catfish, lobsters, and crabs. Trout anglers have used garlic-scented marshmallows and corn for years because they work. Numerous scents are infused in formulated baits, such as Powerbait® and Gulp®. Many oils, such as menhaden milk, herring oil, shrimp oil, and squid oil, are used as fish attractants.
Serious catfish anglers have their favorite, secret recipe for stink baits made from liver, shad guts, old cheese, peanut butter, garlic, and many other aromatic foods.
The taste buds within the mouth allow fish to demonstrate strong and stable preferences for some foods. Fish quickly spit out a nonfood or nonpreferred food item. For example, common amino acids (L-alanine, L-cysteine, L-aspartic acid, glycine), sugars, and citric acid are preferred substances, and formulated diets for captive fish often use this information to formulate palatable artificial feed (Konishi and Zotterman 1961).
In addition to finding food, bullhead catfish use their sense of smell not only to identify but also to remember individuals in a group. This sense helps us to explain the development of dominance hierarchies in the bullheads. In dominance hierarchies, catfish will know one another; there will be one dominant catfish and others known as subordinates. The behaviors and recognition depend on the chemical cues, because even blinded individuals are capable of social recognition (Todd 1971).
Question to ponder:
Why might it be a good thing that fish have a keen sense of taste and do not consume everything that enters their mouth?
3.7 Electrosensory and Magnetosensory Capabilities
Some fish can receive signals from weak sensitive fields. Imagine swimming along the ocean bottom and sensing a live, hidden fish that you cannot see nor smell. Sharks are more sensitive to electric fields than any other animal, responding to charges from weak electrical potentials generated by muscle contractions of marine fish (Newton et al. 2019). Sharks, skates, and rays have hundreds or more small pores, known as ampullae of Lorenzini, that detect electric fields in the water (Figure 3.10). The pores are filled with a conductive gel that allows the potential to be transmitted to the nerve. This stimulus may be interpreted as a prey nearby, and the shark can orient toward the prey that is generating electric fields. Pores are primarily located around the mouth and body in sharks, skates, and rays to allow the fish to orient toward the prey (Collin et al. 2016). A secondary function of electroreception is detection of predators in less mobile juveniles.
Certain electrosensitive fish also have an electric organ that generates a very weak electric field (Figure 3.11). The electric field generated helps the fish to navigate, communicate, incapacitate prey, and defend the fish from predators. Common examples include the electric ray, African elephantnose fish, and South American knifefish. Elephantnose fish can switch between relying on visual and electric sense, just as humans switch between sight and touch sensors. Processing electrical senses requires a very large brain and, therefore, electric fish use more oxygen for brain functions compared with humans. Interestingly, the brain size in Peters’s Elephantnose Fish is 3% of body mass, which is higher than the brain/body mass ratio of 2% in humans (Nilsson 1996).
Because of their electrosensitivity, sharks avoid certain rare-earth elements, such as lanthanide, which have magnetic properties. Experiments are ongoing to test whether certain metals or strong magnets can induce sufficient avoidance that they may be used for reducing bycatch in certain fishing gears (Richards et al. 2018).
Many fish possess the ability to detect and respond to the direction and intensity of magnetic fields (Formicki et al. 2019). Discovered relatively recently, the magnetic sense helps to explain the predictability of long-distance migration patterns observed in eels, sharks, tuna, and salmon. Salmon respond to the magnetic field with magnetoreceptor cells located in the nose of the fish.
Question to ponder:
How are the senses different from a shark (an open-water predator) and a flounder (benthic predator)?
3.8 Nociception
Nociception is the detection of harmful or unpleasant stimuli. When exposed to any harmful substance, fish make a reflex reaction and quickly withdraw. Stimuli that could cause tissue damage include high mechanical pressure, extremes of temperature, acids, venoms, and prostaglandins. While nociception is underexplored in fish, the free nerve endings (nociceptors) exist in the skin of Rainbow Trout, Zebrafish, Common Carp, and Goldfish and act as an alarm system to alert the fish to potential harm (Sneddon 2007). In the next chapter, the issues of pain and welfare are introduced.
3.9 Sensory Orientations
Variation in sensory capabilities is extremely high among groups of fish. This variation reflects the fact dominant habitats and habits are exhibited by different fish along with their evolutionary history. The jawless hagfish and lampreys are the oldest lineages of fish and have well-developed olfactory bulbs and a prominent brain stem, yet other senses (including sight) as measured by the size of brain parts are less developed. Cartilaginous fish (sharks, skates, and rays) have a highly developed sense of odors, as well as electric fields. In the bony fish, those that colonized and occupy a bottom-dwelling or benthic lifestyle, often have enhanced senses of taste, smell, and touch, which are more important than vision. Fish of clear water lakes and streams have excellent vision (Kotrschal and Palzenberger 1992; Kotrschal et al. 1998). Fish adapted to large, turbid rivers and estuaries have enhanced senses of taste and smell. Open-water fish rely more heavily on the lateral line sense. The cichlids and butterfly fish rely on integrating multiple sensory capabilities to allow life in complex spatial and social relationships. Therefore, we should never conclude that all types of fish have the same sensory specializations. Rather, sensory capabilities reflect the dominant habitats and way of life.
3.10 Sensory Disruptions and Human Presence
When we think of pollution to aquatic environments, we often picture images of trash and dirty water. However, human activities also add sensory pollutants that alter aquatic environments in ways that decrease the ability of fish to sense their underwater world. Imagine a world in which one or more of your senses was eliminated or greatly impaired by interference of some kind. In coastal embayments that surround ports and harbors, the ambient sound level is estimated to double in intensity every decade (Merchant et al. 2012). Further, pollution, toxicants, anthropogenic noise, and dams are human modifications that may influence sensory functions, depending on degree and type of change. Fish, in habitats greatly altered by humans, experience what biologists are calling sensory smog from many artificial stimuli (Preston 2019). Motorboats, pile driving, seismic airguns, and other activities produce sounds that may drown out other sounds. Ocean acidification influences the sense of smell in sea bass, decreasing their chances of detecting food or predators (Porteus et al. 2018). Ocean acidification and reductions in dissolved oxygen alters otoliths, which may affect sensory development (Simpson et al. 2011; Hamilton et al. 2019). Water pollution decreases underwater visibility and interferes with feeding and communication in fish (Fisher et al. 2006). Toxicants may influence the sensitive organs involved in taste and smell. Mitigation measures may protect animals from impacts of human activities. For example, activities that produce sound may be undertaken in ways that will reduce not just the levels and characteristics of the sound but also their effects on aquatic animals (Popper et al. 2020). Artificial light levels at night alter the biorhythms of fish, raising concerns that fish in urban waters may have impaired sleep (Kupprate et al. 2020). The future global changes will likely influence sensory behavior in fish, and many gaps in our understanding remain (Draper and Weissburg 2019; Dominoni et al. 2020).
Profile in Fish Conservation: Andrij Z. Horodysky, PhD
Andrij Z. Horodysky is Associate Professor at Hampton University. He is a broadly trained organismal fisheries ecologist with research interests centered on the ecophysiology, behavior, and conservation biology of commercially and recreationally important estuarine, coastal, and pelagic marine fish. His research investigations use comparative interdisciplinary approaches that integrate field, laboratory, and specimen-based techniques with tools ranging in scale from microscopes to satellites.
Findings from Horodysky’s research have led to a number of direct applications to recreational billfish management. Most of the U.S. billfish effort is from recreational tournament and charter fisheries. Consequently, Horodysky studied White Marlin caught and released by recreational angling with an innovative tag technology called pop-up satellite archival tag. Instead of having to retrieve the animal carrying the tag to get the data, these devices send the data to the researcher via satellite. Once the pin dissolves, the slightly buoyant tag floats to the surface and starts transmitting the continuous record of temperature, light, and pressure (depth) to satellites. In this way, Horodysky was able to determine hook trauma and survival of White Marlin caught on circle and straight-shank hooks in the recreational fishery and released. White Marlin that survived catch and release moved into areas of varying depths and temperature, whereas White Marlin that died quickly sank to the seafloor and to constant temperatures. White Marlin caught on circle hooks were much more likely to survive release from recreational fisheries than those caught on straight-shank or “J” hooks. J hooks are more likely to cause bleeding, deep hooking, and tissue damage. Regulations requiring the use of circle hooks in natural baits for all U.S. Atlantic billfish tournaments took effect on the first of January 2008.
Horodysky is one of very few experts on the visual world of game fish. In an innovative study of visual function in a variety of fish including sharks and drums, Horodysky’s lab used electroretinographic techniques to describe light sensitivities and the color wavelengths that these fish respond to. The five fish studied occupy turbid coastal and estuarine habitats throughout their range, and their visual systems are well adapted to prevailing light conditions. Environmental changes may alter the behavior of these fish.
Most recent investigations have applied physiological approaches to uncover the mechanisms through which climate change and habitat alterations may affect fish. These avenues of research have great potential to improve stock assessments, describe essential fish habitat, predict rates of postrelease mortality, develop effective bycatch reduction strategies, and forecast the population effects of increases in global temperatures and ocean acidification.
When not engaged in teaching and research, Horodysky is an accomplished recreational angler and fly tyer and designer. For more background, refer to his website.
Key Takeaways
• Understanding and appreciating the diversity of fish requires that we know some basics of sensory capabilities and the ability to learn.
• The stimulus-response model for understanding sensory systems in fish is the same model used for all vertebrate organisms.
• Fish have excellent systems for hearing as well as a lateral line for detection of far-field water movements.
• Senses of smell and taste are well developed in fish, and there are many applications of that information in formulating artificial feeds and baits for fishing.
• Fish that live in shallow, clear waters often see well in color, while other fish may see contrasts in low-light conditions.
• Electrosensory perception evolved in a number of unrelated groups of fish and permits enhanced prey detection and capture.
• Some fish can generate an electric field, which is used for communication, defense, and foraging.
• Fish senses differ among fish based on their preferred environment.
• Human activities may interfere with some sensory systems of fish, and many gaps in our understanding limit our ability to predict the influence of global changes.
This chapter was reviewed by Andrij Z. Horodysky.
URLs
Horodysky: https://home.hamptonu.edu/science/
Long Descriptions
Figure 3.1: Left: Simple drawing of fish showing location of nasal cavity in front of eye, a nerve above eye, and brain behind eye at back of head. Right: A more complex drawing of a fish shows location of taste buds in protruding appendages from chin, inner ear above and behind eye, lateral line at the center of main body, adipose fin before back fin, and taste buds on underside close to back fin. Jump back to Figure 3.1.
Figure 3.2: Drinking cup is a stimulus, arrow points to eyeball as receptor, nerves attached to a line is sensory neuron leading to a circle and line representing relay neuron, (brain to the right of line), leads to motor neuron, with nerves leading to a muscled arm lifting the drinking cup as effector, the drinking cup being brought up by the arm is the response. Jump back to Figure 3.2.
Figure 3.4: Drawing of close-up lateral line of fish, including epidermis, nerves, scales, water displacement, external opening, and lateral line canal. Movements of water in canal cause capula to move, to stimulate sensory hair cells. Jump back to Figure 3.4.
Figure 3.5: Line graph depicts the sound levels detected by fish by inner ear and lateral line when sound source is near, which are higher than sound levels detected by inner ear alone when sound source is distant. Jump back to Figure 3.5.
Figure 3.6: Two line drawings, one depicting inner ear and the other depicts close up of sacculus with labels for posterior semicircular canal, statolith of lagena, lagena, nerve;sacculus, sensory epithelium and utriculus. Jump back to Figure 3.6.
Figure 3.7: Two diagrams that show top and side views of how light waves are refracted and resulting field of vision and blind spots for fish. Blind spot is behind the fish. Jump back to Figure 3.7.
Figure 3.8: Drawing of vertical cross section of fish eye, including dermal layer of cornea, scleral layer of cornea, lens, aqueous humour, iris, autochthonous layer of cornea, retractor lentis muscle, falciform process, optic nerve, vitreous humour, retina, choroidea, sclera suspensory ligament, and epichorioidal lymph space. Jump back to Figure 3.8.
Figure 3.11: Photograph of an electric ray with two upside down triangles drawn on either side of the eyes, an arrow leads to a drawing of stacked coin shapes to represent electrocytes, and an arrow to four drawings of stacked electric organs. Jump back to Figure 3.11.
Figure References
Figure 3.1: Locations of sensory structures on the body of a fish. (A) Nares, eye, pineal, and brain locations. (B) Inner ear, lateral line, adipose fin, and taste bud locations. Kindred Grey. 2022. Adapted under fair use from “Ocean Fish Are under Threat if We Don’t Curb Carbon Dioxide Emissions,” by Cosima Porteus, 2018 (https://theconversation.com/ocean-fish-are-under-threat-if-we-dont-curb-carbon-dioxide-emissions-107312). Includes Blue Catfish by Louisiana Sea Grant College Program Louisiana State University, 2007 (https://flic.kr/p/2A7sP1).
Figure 3.2: Diagram of the connections in the stimulus-response model in fish, which displays a stimulus, odor receptor (nares), sensory neuron, relay neuron, motor neuron, brain, effector, and response. Kindred Grey. 2022. CC BY 4.0. Includes drinking glass by sumhi_icon, 2017 (Noun Project license, https://thenounproject.com/icon/drinking-glass-1274096/), bicep muscle by Vectors Point, 2020 (Noun Project license, https://thenounproject.com/icon/bicep-muscle-3149162/), eyeball by ME, 2017 (Noun Project license, https://thenounproject.com/icon/eyeball-931632/), brain by Mahmure Alp, 2019 (Noun Project license, https://thenounproject.com/icon/brain-2300842/).
Figure 3.3: Scales along the lateral line (see arrow) of the Roach Rutilus rutilus. Piet Spaans. 2006. CC BY-SA 2.5. https://commons.wikimedia.org/wiki/File:RutilusRutilusScalesLateralLine.JPG.
Figure 3.4: Schematic of the lateral line system of fish. Movements of water in the lateral line canal cause the cupula to move, thereby stimulating sensory hair cells connected to nerves. Kindred Grey. 2022. CC BY SA 3.0. Adapted from LateralLine Organ by Thomas.haslwanter, 2012 (CC BY-SA 3.0, https://commons.wikimedia.org/wiki/File:LateralLine_Organ.jpg).
Figure 3.5: Sound level in decibels plotted as a function of distance from the source. Kindred Grey. 2022. Adapted under fair use from “The Potential Overlapping Roles of the Ear and Lateral Line in Driving ‘Acoustic’ Responses,” by Dennis M. Higgs and Craig A. Radford, 2016 (https://doi.org/10.1007/978-3-319-21059-9_12).
Figure 3.6: (A) Labyrinth of a flying fish (Exocoetus). (B) Section through the sacculus of the trout. Key structures. Nicol, J. A. Colin. c. 1960s. Public domain. https://flic.kr/p/wLFLig.
Figure 3.7: Diagram shows the refraction of light at the interface of air and water and the cone-shaped range of vision in the fish. (A) Top view. (B) Side view. Kindred Grey. 2022. Adapted under fair use from “Some Important and Interesting Aspects about Yellowfish” (https://www.fishingowl.co.za/flyfishyel2.html) and “The Science of Stalking Fish,” by Alan Bulmer, 2017 (https://activeanglingnz.com/2017/02/01/the-science-of-stalking-fish/). Includes Goldfish top view by Oleksandr Panasovskyi, 2020 (Noun Project license, https://thenounproject.com/icon/goldfish-top-view-3635952/) and “Fish,” by Kangrif, 2017 (Noun Project license, https://thenounproject.com/icon/fish-1186818/).
Figure 3.8: Diagrammatic vertical section through the eye of a teleost fish, after Walls (1942). Kindred Grey. 2022. CC BY-SA 4.0. Adapted from “Bony Fish Eye Multilang,” by Gretarsson, 2019 (CC BY-SA 4.0, https://commons.wikimedia.org/wiki/File:Bony_fish_eye_multilang.svg).
Figure 3.9: Diagram of the taste buds in fish. Herbert Vincent and Herbert Wilbur. 1939. Public domain. https://flic.kr/p/wsuopv.
Figure 3.10: Pores with ampullae of Lorenzini in snout of Tiger Shark. Albert kok. 2009. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:Lorenzini_pores_on_snout_of_tiger_shark.jpg.
Figure 3.11: An electric ray (Torpediniformes) showing locations of electric organs and electrocytes stacked within them. Kindred Grey. 2022. CC BY-SA 3.0. Includes Fish4345 – Flickr – NOAA Photo Library by NOAA, 2007 (public domain, https://commons.wikimedia.org/wiki/File:Fish4345_-_Flickr_-_NOAA_Photo_Library.jpg) and “Elektroplax Rochen,” by Alexander Graetz, 2006 (CC BY-SA 3.0, https://commons.wikimedia.org/wiki/File:Elektroplax_Rochen.png).
Figure 3.12: Andrij Z. Horodysky, PhD. Used with permission from Andrij Horodysky. Photo by Stjani Ben (May 2015; Thingvallavatn, Iceland). CC BY 4.0.
Text References
Bardach, J. E., and J. Atema. 1971. Handbook of sensory physiology, vol. 4: Chemical senses, part 2.: The sense of taste in fishes.
Bardach, J. E., J. H. Todd, and R. Crickmer. 1967. Orientation by taste in fish of the genus Ictalurus. Science 155:1276–1278.
Burton, D., and M. Burton. 2017. Perception and sensation: sensory cells, organs and systems. Pages 241–263 in D. Burton and M. Burton, Essential fish biology: diversity, structure, and function. Oxford University Press.
Collin, S. P., R. M. Kempster, and K. E. Yopak. 2016. How elasmobranchs sense their environment. Pages 19–99 in R. E. Shadwick, A. P. Farrell, and C. J. Brauner, editors. Fish Physiology 34(A: Physiology of elasmobranch fishes: structure and interaction with environment. Elsevier, Amsterdam.
Coombs, S., and J. Montgomery. 2014. The role of flow and the lateral line in the multisensory guidance of orienting behaviors. Pages 65–101 in H. Bleckmann et al., editors, Flow sensing in air and water, Springer-Verlag, Berlin and Heidelberg.
Cresci, A., C. M. Durif, C. B. Paris, S. D. Shema, A. B. Skiftesvik, and H. I. Browman. 2019. Glass eels (Anguilla anguilla) imprint the magnetic direction of tidal currents from their juvenile estuaries. Communications Biology 2:366. https://doi.org/10.1038/s42003-019-0619-8.
Dangles, O., D. Irschick, L. Chittka, and J. Casas. 2009. Variability in sensory ecology: expanding the bridge between physiology and evolutionary biology. Quarterly Review of Biology 84:51–74.
Dominoni, D. M., W. Halfwerk, E. Baird, R. T. Buxton, E. Fernández-Juricic, K. M. Fristrup, M. F. McKenna, D. J. Mennitt, E. K. Perkin, B. M. Seymoure, D. C. Stoner, J. B. Tennessen, C. A. Toth, L. P. Tyrrell, A. Wilson, C. D. Francis, N. H. Carter, and J. R. Barber. 2020. Why conservation biology can benefit from sensory ecology. Nature Ecology and Evolution 4:502–511. https://www.nature.com/articles/s41559-020-1135-4.
Douglas, R. H. and M. B. A. Djamgoz, editors. 1990. The visual system of fish. Chapman and Hall, London.
Draper, A. M., and M. J. Weissburg. 2019. Impacts of global warming and elevated CO2 on sensor behavior in predator-prey interactions: a review and synthesis. Frontiers in Ecology and Evolution 7:72. https://doi.org/10.3389/fevo.2019.00072.
Fisher, H. S., B. B. M. Wong, and G. G. Rosenthal. 2006. Alteration of the chemical environment disrupts communication in a freshwater fish. Proceedings of the Royal Society B 273:1187–1193.
Formicki, K., A. Korkzelecka-Orkisz, and A. Tanski. 2019. Magnetoreception in fish. Journal of Fish Biology 95:73–91.
Hamilton, S. L., N. S. Kasef, D. M. Stafford, E. G. Mattiasen, L. A. Kapphahn, C. A. Logan, E. P. Bjorkstedt, and S. M. Sogard. 2019. Ocean acidification and hypoxia can have opposite effects on rockfish otolith growth. Journal of Experimental Marine Biology and Ecology 521:151245. https://doi.org/10.1016/j.jembe.2019.151245.
Herrick, C. J. 1901. Nerves of siluroid fishes. Journal of Comparative Neurology 11:177–262.
Hoagland, H. 1933. Specific nerve impulses from gustatory and tactile receptors in catfish. Journal of General Physiology 16:685–693.
Kalmijn, A. J. 1971. The electric sense of sharks and rays. Journal of Experimental Biology 55:371–383.
Kamermans, M., and C. Hawryshyn. 2011. Teleost polarization vision: how it might work and what it might be good for. Philosophical Transactions of the Royal Society B 366:742–756.
Kasumyan, A. O. 2019. The taste system in fishes and the effects of environmental variables. Journal of Fish Biology 95:155–178.
King, B., and J. Long. 2020. How sharks and other animals evolved electroreception to find their prey. Phys Org website. Accesseded 18 May 2020. https://phys.org/news/2018-02-sharks-animals-evolved-electroreception-theirprey.html.
Konishi, J., and Y. Zotterman. 1961. Taste functions in the Carp: an electrophysiological study on gustatory fibres. Acta Physiological Scandinavica 52:150–161.
Kotrschal, K., and M. Palzenberger. 1992. Neuroecology of cyprinids: comparative, quantitative histology reveals diverse brain patterns. Environmental Biology of Fishes 33:135–152.
Kotrschal, K., M. J. van Staaden, and R. Huber. 1998. Fish brains: evolution and environmental relationships. Reviews in Fish Biology and Fisheries 8:373–408.
Kupprate, F., F. Hölker, and W. Kloas. 2020. Can skyglow reduce nocturnal melatonin concentrations in Eurasian Perch? Environmental Pollution 262:114324. https://doi.org/10.1016/j.envpol.2020.114324.
Li, L., and H. Maaswinkel. 2006. Visual sensitivity and signal processing in teleosts. Pages 179–241 in T. J. Hara and B. Zielinski, Sensory systems neuroscience, Elsevier Science & Technology, Amsterdam.
Liao, J. C. 2007. A review of fish swimming mechanics and behaviour in altered flows. Philosophical Transactions of the Royal Society of London B 362:1973–1993.
Mann, D. A., Z. Lu, and A. N. Popper.1997. A clupeid fish can detect ultrasound. Nature 389(6649):341–341. https://doi.org/10.1038/38636.
Marshall, N. J., F. Cortesi, F. de Busserolles, U. E. Siebeck, and K. L. Cheney. 2019. Colours and colour vision in reef fishes. Journal of Fish Biology 95:5–38.
Mayer, L. 2019. Sight fishing for trout. 2nd ed. Stackpole Books, Lanham, MD.
Merchant, N. D., M. J. Witt, P. Blondel, B. J. Godley, and G. H. Smith. 2012. Assessing sound exposure from shipping in coastal waters using a single hydrophone and automatic identification system (AIS) data. Marine Pollution Bulletin 64:1320–1329.
Mirjany M., T. Preuss, and D. S. Faber. 2011. Role of the lateral line mechanosensory system in directionality of Goldfish auditory evoked escape response. Journal of Experimental Biology 214:3358–3367.
Mogdans, J. 2019. Sensory ecology of the fish lateral-line system: morphological and physiological adaptations for the perception of hydrodynamic stimuli. Journal of Fish Biology 95:53–72.
Montgomery, J., H. Bleckmann, and S. Coombs. 2014. Sensory ecology and neuroethology of the lateral line. Pages 121–150 in S. Coombs et al., editors, The lateral line system, Springer, New York.
Montgomery, J. C., and A. J. Saunders. 1985. Functional morphology of the Piper Hyporhamphus ihi with reference to the role of the lateral line in feeding. Proceedings of the Royal Society of London B 224:197–208.
Neal, H. V., and H. W. Rand. 1939. Chordate anatomy. Blakiston’s Son, Philadelphia.
Newton, K. C., A. B. Gill, and S. M. Kajiura. 2019. Electroreception in marine fishes: chondrichthyans. Journal of Fish Biology 95:135–154.
Nicol, J. A. C. 1960. The biology of marine animals. Wiley Interscience, New York.
Nilsson, G. E. 1996. Brain and body oxygen requirements of Gnathonemus petersii, a fish with an exceptionally large brain. Journal of Experimental Biology 199:603–607.
Popper, A. N., A. D. Hawkins, O. Sand, and J. A. Sisneros. 2019. Examining the hearing abilities of fishes. Journal of the Acoustical Society of America 146:948–955.
Popper, A. N., A. D. Hawkins, and F. Thomsen. 2020. Taking the animal’s perspective regarding anthropogenic underwater sound. Trends in Ecology and Evolution 35(9):787–794. https://doi.org/10.1016/j.tree.2020.05.002.
Popper, A. N., and C. R. Schilt. 2008. Hearing and acoustic behavior: basic and applied considerations. Pages 17–48 in J. F. Webb, A. N. Popper, and R. R. Fay, editors, Fish bioacoustics, Springer handbook of auditory research 32, Springer, Berlin and Heidelberg.
Porteus, C. S., P. C. Hubbard, T. M. Uren Webster, R. van Aerle, A. V. M. Canário, E. M. Santos, and R. W. Wilson. 2018. Near-future CO2 levels impair the olfactory system of a marine fish. Nature Climate Change 8:737–743.
Preston, E. 2019. Lost at sea. Science 364(6446):1124–1127. DOI: 10.1126/science.364.6446.1124.
Putland, R. L., J. C. Montgomery, and C. A. Radford. 2019. Ecology of fish hearing. Journal of Fish Biology 95:39–52.
Richards, R. J., V. Raoult, D. M. Powter, and T. F. Gaston. 2018. Permanent magnets reduce bycatch of benthic sharks in an ocean trap fishery. Fisheries Research 208:16–21.
Siebek, U. E., A. N. Parker, D. Sprenger, L. M. Mäthger, and G. Wallis. 2010. A species of reef fish that uses ultraviolet patterns for covert face recognition. Current Biology 20:407–410.
Simpson, S. D., P. L. Munday, M. L. Wittenrich, R. Manassa, D. L. Dixson, M. Gagliano, and H. Y. Yan. 2011. Ocean acidification erodes a crucial auditory behavior in a marine fish. Global Change Biology 7:917–920. https://doi.org/10.1098/rsbl.2011.0293.
Sneddon, L. U. 2007. Sensory systems neuroscience. Vol. 25, pages 153–178 in T. J. Hara and B. Zielinski, editors, Fish physiology series, Elsevier, New York.
Stewart, T. A., and M. E. Hale. 2013. First description of a musculoskeletal linkage in an adipose fin: innovations for active control in a primitively passive appendage. Proceedings of the Royal Society B 280: 20122159. https://doi.org/10.1098/rspb.2012.2159.
Tavolga, W. N., A. N. Popper, and R. R. Fay. 1981. Hearing and sound communication in fishes. Springer-Verlag, New York.
Todd, J. H. 1971. The chemical languages of fishes. Scientific American 224(5):99–106.
Walls, G. L. 1942. The vertebrate eye and its adaptive radiation. Cranbrook Institute of Science Bulletin 19, Bloomfield Hills, MI (published as reprint in 1963 by Hafner, doi:10.5962/bhl.title.7369, see fig. 169, 577).
Zielinski, B. S. and T. J. Hara. 2006. Olfaction. Pages 1–43 in T. J. Hara and B. Zielinski, Sensory systems neuroscience, Elsevier Science & Technology, Amsterdam. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.03%3A_Sensory_Capabilities_of_Fish.txt |
I have purposely presented the land ethic as a product of social evolution because nothing so important as an ethic is ever “written.” . . . It evolves in the minds of a thinking community.
—Aldo Leopold, The Land Ethic, A Sand County Almanac
Learning Objectives
• Identify ethical dilemmas, intrinsic and extrinsic values, and value chains.
• Distinguish between normative and factual statements in an ethical argument.
• Compare and contrast common ethical theories and advantages and disadvantages.
• Recognize ethical dilemmas common to managing different types of fisheries and conserving rare and endangered species.
• Examine our personal values and how they influence our ethical norms.
• Identify the ethical principles involved in co-management and collaborative planning.
• Examine different ethical codes of conduct.
• Apply ethical reasoning steps in issues involving uses of fish.
4.1 Ethical Questions and Practical Ethics
Ethics involves deliberating about the moral principles that inform (or should inform) our actions. The human and natural worlds are too complex to expect easy-to-identify rules and absolute truths to guide our actions. In our modern world, people follow many different ethical theories to help them identify what actions are right. Ethical thinkers are needed today more than ever to help us understand our own and each other’s ethics and work together to develop policies for humans to coexist with each other and fish in natural and human-altered ecosystems.
In policy making, just as in our personal lives, we are often faced with a difficult choice between two possible moral imperatives, neither of which is clearly acceptable nor preferable. For example, regulating the take from a fish population to conserve options for future generations conflicts with the moral imperative of freedom to pursue fishing without restriction. The complexity arises because following one moral imperative (freedom) would result in transgressing another (conservation). For example, is it ever acceptable to kill one animal in order to save another (e.g., kill sea lamprey to protect more valuable fish)? Is it acceptable to displace people from their local community to create a protected area to save an endangered species? Should we kill all nonnative trout to restore a unique population of Cutthroat Trout? How do you restrict access to fishing to maintain productivity of fish and provide livelihood opportunities for future generations? Should we compensate for salmon losses at hydroelectric projects with mass release of hatchery-reared salmon from large-scale artificial production facilities? Should you eat farmed fish raised in cages or wild-caught fish?
Depending on your needs, preferences, and interests, you may differ in how you answer these questions. Our conscience is that inner feeling or voice that guides us to a morally right behavior, yet when two actions with morally laudable goals conflict, we have an ethical dilemma. In these cases, explicit consideration of values at stake should be part of careful debate about human involvement and what constitutes good or bad interventions. The explicit application of ethical principles while considering the opportunities, constraints, and interests is what we refer to as practical ethics.
Question to ponder
Can you characterize your prevailing use of fish? Do you consider fish to be primarily valuable to you as a source of food, sport, livelihood, cultural or spiritual connections, or are there other ways that you value fish?
4.2 Values
Philosophers provide us with many useful tools to help us think through these questions. Though they often disagree on their theories and answers to very difficult questions, there is surprising agreement on what we need to do morally in our everyday life. An essential tool we use to explore moral choices and dilemmas is to distinguish different types of values.
Intrinsic values lie at the very heart of ethics. When we speak of the value a fish has in and of itself, we are speaking of its intrinsic value. Many philosophers maintain that all animals have some type of intrinsic value in themselves, irrespective of their usefulness to other animals (human or otherwise), such as the beauty of a sailfish. The opposite of intrinsic value is extrinsic value (also called use or instrumental values), such as the value we place on a highly palatable food fish because it is useful for eating. Fish, lobsters, crabs, and oysters all have extrinsic value to various people because they eat them, enjoy delicious flavors, and are provided with valuable livelihoods and economic benefits.
It is common for fish to hold both intrinsic and instrumental values. For example, marlin have very high extrinsic value when used in sashimi and in big game fishing. They also have a high intrinsic value because of their unique size, power, and rareness among offshore fish. Table 4.1 shows many different types of values, categorized into instrumental and intrinsic values.
Value Examples
Instrumental
Food Prevents hunger with lean protein, low in saturated fat
Nutrition Lowers risk of heart disease and hypertension and source of calcium, phosphorus, niacin, vitamin B-12, and omega-3 fatty acids
Products Fish oils, fish meal, glue, biofuels, candles, gelatin, isinglass, biopolymers, bio-piezoelectric nanogenerator, cosmetics, biomedicine, tools, apparel, jewelry, musical instruments, souvenirs (Olden et al. 2020)
Livelihood Employing workers in capture fisheries, aquaculture, recreational tourism, and boats and fishing tackle
Recreation Pleasure, competition, sport, pets, aquarium and pond displays
Culture Music, cooking, and products that are related to local fish and fishing traditions
Art Depictions of fish from ancient Egypt to the present, reflecting importance of fish
Ecological Regulating nutrient cycles and disease vectors, biological control
Educational Examples of vertebrate evolutionary change, specimens for laboratory dissection
Scientific Medaka and zebra fish are research models for laboratory studies of genetics and developmental biology
Intrinsic
Spiritual Fish offerings to gods, symbols (Ichthys, Figure 4.2) of the faithful not driven by passions
Art Beauty of fish
Existence Their existence has value in and of itself
Table 4.1: Diverse values of fish. Isinglass refers to a kind of gelatin obtained from fish, especially sturgeon, and used in making jellies, glue, or clarifying ale. Bio-piezoelectric generator refers to a type of generator that converts one form of energy to another form.
A problem arises when fish are viewed only as resources that provide benefits to humans—we are holding exclusively extrinsic or instrumental values. When fish are viewed only as resources for humans, we tend to overexploit fisheries and not conserve them for future human uses. When people overexploit a fishery, this is more of a problem of short-term thinking, or immediate needs, since they are destroying the fishery they presumably want to continue to use. The conservation movement arose to help ensure that we could maintain the use value of natural resources, including fisheries, for the long run for human uses.[1] A potential problem with viewing fish as having only use value is that management of fish for the long run can still have cascading ecological impacts that cause harm to the environment (e.g., salmon farms that spread disease to wild salmon populations and alter ecosystems from excess nutrients). Conservationists who recognize that these adverse impacts to the environment harm the use value of the environment have proposed actions to reduce those impacts.
Some argue that we must believe that fish and ecosystems have only intrinsic value so we do everything we can to protect them. Generally, a belief that something has only intrinsic value leads to the conclusion that we are not allowed to use it at all. For fish, then, if someone believes that they have only intrinsic value, the logical conclusion is that the use of fish for fishing and food should be banned because these are uses of fish. Some accept this conclusion, but it is unlikely that many people would accept this conclusion as reasonable. Fortunately, philosophers reasoned long ago that things with intrinsic value, such as our fellow humans, also have use value to each other through the work we do for each other. The problem is when a person’s intrinsic value—and our obligation to respect them—is violated by abusing how we use their work, through stealing their labor through wage theft or slavery, for example.
The Latin phrase abusus non tollit usum (“abuse does not cancel use”) in this case means that there is no justifiable reason to condemn all uses of fish because some individuals may overexploit them. Norton (2005) argued that people logically can and do believe that fish have only use value and still accept their obligation to protect fisheries and ecosystems, while others logically can and do believe that fish have both intrinsic and use value and support the same policies.
4.3 Ethical Obligations and Actions
Our understanding of ethics and fishing needs to recognize four categories of actions. These are (1) morally forbidden, (2) permissible, (3) obligatory, and (4) supererogatory. The first three consider the actions that are easily understood as right or wrong or good or bad. Supererogatory actions are acts that are morally praiseworthy but not morally obligatory or beyond the call of duty. Most ethical dilemmas involve distinguishing two very different types of moral obligations: direct obligations and indirect obligations. Disagreements over beliefs in intrinsic versus extrinsic values can become quite vehement, and they can prevent us from finding agreement that we both want to protect fish. Likewise, disagreements over whether we have direct moral obligations to fish to protect them, or whether we have indirect moral obligations to protect them, too often get in the way of realizing that we both believe we have moral obligations to protect fish. Let’s examine these definitions so we can figure out how to find agreements when possible.
Direct obligations are defined as those we have directly to a fish, usually because we believe that a fish has some type of intrinsic value that gives it direct moral considerability. People have widely differing views about the intrinsic value of fish, as a result of having different views about the facts concerning whether or not fish can feel pain similar to people and can make plans and suffer if they don’t get to fulfill those plans.
For example, if we believe that a fish has the capacity to feel pain similarly to humans, then we would generally conclude that fish require our moral consideration regarding pain. They are in our moral circle for feeling pain. The moral consideration can be said to be a direct moral obligation to avoid causing it pain similar to human pain. Likewise, if we think that fish create long-term plans like humans and that fish feel some kind of mental loss and suffering from not executing those plans, then we can logically conclude that we have a direct moral obligation to fish to allow them to fulfill their plans. In this situation, it is logical that fish can both feel pain similarly to humans and suffer from not fulfilling their plans, so we have stronger direct moral obligations to fish. These obligations depend on the capacity of fish to feel pain similarly to humans or to have aims like humans and feel mental loss like humans. This relationship of facts and intrinsic value and moral obligations is important to understand, since people have very different beliefs about the facts, and science is making new discoveries. What if we disagree that fish can feel pain similarly enough to humans to require our moral consideration? If they can’t feel pain like that, but they are under stress due to an aquatic habitat that is so polluted by heat, nutrients, or lack of food that they die, do we have some type of obligation to them? This is where the concept of an indirect moral obligation is helpful.
Indirect moral obligations are those that we must fish because we have direct obligations to something else (usually humans) to protect the fish. For example, most people believe we have a moral obligation to sustainably protect fisheries so other humans have access to fisheries for economic and food benefits they provide. It is a direct obligation to other people to protect the fisheries. It is an indirect obligation to the fishery to protect it so we can fulfill our direct obligations to other people. This is a rather complex way to talk about our obligations, so why do it? It makes it easier to identify if we have agreement on whether or not we have any type of obligation to fish.
For example, if we believe we have a moral obligation (be it indirect or direct) to protect the many individual fish that comprise a fishery from dying from adverse environmental conditions, then we can agree that we need to eliminate those environmental conditions by passing policies to do so. Policies to reduce heat pollution or nonpoint source pollution can be supported by those who have different beliefs about intrinsic versus use values and direct versus indirect moral obligations. Similarly, we may disagree over whether or not any catching of fish that causes pain similarly to humans could be allowed, but progress would be made to reduce waste and bycatch. The effort, and habit, of finding commonalities in support for protection of fish is critical to passing policies that can be passed now, while laying groundwork for discussions on more sophisticated policies. As scientific research discovers facts about fish and other animals’ capacities to feel pain and make plans similarly to humans, we can identify how we can (or ought not to) fish in ways to meet our direct or indirect obligations to reduce suffering of fish.
An important concept in ethics concerns our moral obligations to act. We all likely have wondered if we are really obligated to perform an action that would help another person but would cost us greatly in terms of money, physical or mental or social harm, or our life. In ethics, an act is supererogatory if it is good but not morally required to be done. For example, let’s imagine that you conclude that the destruction of a fishery through overfishing is morally wrong and that you are obligated to help protect the fishery. Different ethical systems might conclude that you have slightly different moral obligations, but none would say that you needed to starve yourself to death rather that eat fish from such a fishery if that were your only way to survive. Neither would an ethical system require you to put your life in danger to stop a commercial fishing boat from fishing. Rather, they might require you to make sure that you purchase only from sustainable fisheries or to educate others and make efforts to change policies to stop overexploitation of fisheries. These latter obligations would meet the obligation to act without being supererogatory.
4.4 Burden of Proof in Value Systems
Now we turn to consideration of how beliefs in intrinsic or use value affect discussions about policies. An important difference between intrinsic and instrumental values that is relevant to fish conservation relates to who must demonstrate harm in disputes (Figure 4.1). For example, the burden of proof lies with the conservationists if values are only instrumental. On the other hand, if values are intrinsic as well as instrumental, the burden of proof will be on the fishers or others who are harming fish or their environment (Callicott 1995).
The diversity of values associated with fish and fishing complicates conservation. Two main approaches to conservation include (1) the wise use of nature and (2) the preservation of nature. These two approaches both reject the unthinking marginalization or destruction of nature. But when it comes to the actual management of fish, the two approaches differ. The wise-use approach aims to accommodate humanity’s continuous use of wild nature as a resource for food, oils, and other raw materials, as well as for recreation. The idea of wise use appeals to the best interests of humans, or to the interests of humans over time, including future people (this approach is often called “sustainable use”). The goal of management is to enhance and maintain nature’s yield as a valuable resource for human beings.
For the preservationist, on the other hand, the goal is to protect pristine nature, not to use it, carefully or otherwise. If human intervention has damaged wild nature (e.g., by pollution), then it is important to restore nature to something like its former state. From a preservationist perspective, wild places should be allowed to develop on their own with as little interference from humans as possible. The “otherness” or “naturalness” of the non-human world is what is most valued here. The only use allowed by humans in protected areas is for recreation, and this is only if recreation leaves no trace behind. Values beside resource values and the value of “untouched” nature have become increasingly important. These include the value of untouched nature, whole ecological systems, the value of species, and, in particular, the importance of animal welfare.
Preservationists tend to recognize that humans need to use natural resources to survive and thrive. So how do they reconcile the fact that humans need to use natural resources to survive while they are against using natural resources? Generally, it is by supporting the idea that humans should only use what is necessary for our welfare and to use natural resources in ways that protect nature.
4.5 Ethical Norms
When communicating about fishing and conservation issues, we should distinguish between normative and descriptive language. Descriptive language in ethics refers to observable facts about the world. Science can explain facts and descriptive patterns. For example, we know much about the behavior and competitive displacement of trout species and the effects of fishing on survival of fish. When we describe, not evaluate, the ethical beliefs of the public through interviews and surveys, our findings are descriptive ethics.
Normative language is used in ethics to make claims about how things should be, which actions are right or wrong, and so on. Ethical norms are patterns of behavior generally acceptable for a society, company, or organization. Norms reflect the way the group believes the world should be. The statement “Do not harvest juvenile fish” is a normative claim of fish conservationists. Norms may be formalized in policies, regulations, or standards of conduct. For example, when recreational anglers treat the fish they catch in a humane manner or avoid disturbing another angler’s fishing spot, they are following fishing norms.
However, deciding what is right or wrong involves consideration of values. David Hume (1711–1776) articulated the “is-ought” problems or the fact-value gap. His philosophical law maintains that one cannot make statements about what ought to be based on descriptive statements about what is. The NOFI (No-Ought-From-Is) idea that one cannot deduce an “ought” from an “is” means that we can make no logically valid arguments from the nonmoral (descriptive) to the moral (normative) without clearly introducing a normative argument. A much-needed skill in working with others is the ability to identify the facts and the values being used in discussions about conservation policy. When faced with a normative question, after the values that are sought are identified, then it is usually important to identify the facts of the situation.
Question to ponder
Think about a favorite fish or a fish that you know well. Describe examples of the different ways in which the fish has value to you or others. Review Table 4.1 for types of values. Can you write a normative statement and a descriptive statement about this fish? Can you write a descriptive statement about the value of fish to someone other than yourself?
4.6 Where Do Ethics Come From?
Metaethics is a branch of philosophy that explores the foundations and existence of moral values. There are many different philosophical arguments for morality and ethics, some based on religious beliefs and some not. In this section, we explore various religious traditions and their environmental ethics toward fish. Those raised in the same religious tradition tend to hold common beliefs and follow common norms. In some religions, there are specific beliefs about values of fish and wildlife, and in other religions values are ambiguous. From the first book of Genesis, one gets a clear view of the prevailing Christian view of our relationship with fish and fowl until about the latter half of the 20th century (i.e., 1960s to 1990s).
And God said, Let us make man in our image, after our likeness: and let them have dominion[2] over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
So God created man in his own image, in the image of God created he him; male and female created he them.
And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Genesis 1:26–28
During the latter half of the 20th century, coinciding with the rise of the environmental movement, the “greening” of Christianity led to a new mainstream view that did not focus on human domination of nature but rather on human stewardship of nature. It was based on the second book of Genesis.
Yahweh God took the man and settled him in the garden of Eden to cultivate and take care of it.
Genesis 2:15
In the Buddhist view, however, “One should not kill a living being, nor cause it to be killed, nor should one incite another to kill” (Nalaka Sutta, Sutta Nipāta III:11, 26–27). The fact that Buddhist teachings considered animals to have moral significance is evident in his condemnation of occupations that involve slaughtering animals (Saṃyutta Nikāya 19), instruction for monks to avoid wearing animal skins, and prohibition of behavior that intentionally causes harm to animals. A Buddhist-based tradition maintains that it is compassionate not to kill or harm animals. One should be compassionate. So, one should not kill or harm animals (Chengzhong 2014).
Buddhism believes in reincarnation and teaches us that all living beings around you can be or may have been your mother in a previous or next incarnation or life. The very animal you shoot may have been your friend in a previous life. Whether you believe in reincarnation or not, it is true that every being’s fate can once become your fate as well. There are no or very few hunters or fishers in Buddhist traditions. The only exception is killing in self-defense or in order to end its physical suffering when an animal is severely wounded.
Any well-functioning social group depends on ethical norms for behavior. These norms often reflect society and the collective beliefs and values of its citizens, and they may or may not reflect religion (Crabtree 2014; Guglielmo 2015). Major religions influence our perspectives about biodiversity conservation and hunting and fishing. Christianity, Islam, Hinduism, Daoism (also known as Taoism), Buddhism, Jainism, Judaism, and Shinto are some religions practiced globally. Zoroastrianism, one of the world’s oldest, continuously practiced religions, shaped Judaism, Christianity, and Islam with concepts of a single god, heaven, hell, and a day of judgment.
One of the oldest conservation tools for biodiversity conservation of ancient people practiced was to declare certain natural areas as sacred or taboo. Today, conservationists engage religious and other spiritually motivated communities for their support of and advocacy for marine protected areas (Schaefer 2017; Murray and Agyare 2018). Beliefs about what wild foods are permissible were derived by ancient religions. For example, Jews did not eat catfish because it was considered “unclean,” as it did not have fins and scales (Leviticus 11:19). According to the Shafi’i, Maliki, and Hanbali branches of Islam (Quran 2:173), “all fish and shellfish would be halal” (permissible to eat). Off the coast of Tanzania, fishers used dynamite, a very damaging technique, to harvest fish. Local Muslim sheikhs used passages from the Koran that promote pro-environmental behavior to convince the fishers that dynamite fishing was against Muslim teaching (Bauman et al. 2017).
Religions provide a long history of symbols associated with use and values of fish and fishing (Figure 4.2; Lynch 2014). Ichthys is a Christian symbol of a fish and signifies the person who uses it is a Christian. In Islam, according to the Quran, the fish is a symbol of eternal life and also of knowledge. In Hinduism, in the sect of Vaishnavism’s Supreme God (Vishnu) first appeared as Matsya, a fish that helped the first man survive the great flood.
Question to ponder
What religious or cultural tradition(s) most influenced you during your childhood? How does your upbringing and early learning through your early social interactions influence your perspectives on fishing or conservation?
4.7 Ethical Theories: Schools of Thought
The ethical systems and conclusions that societies believe and act upon change over time for many reasons. The disadvantages of ethical systems lead philosophers to develop new ethical theories. Changing needs and scientific understandings lead to new conclusions about how to achieve the moral goals of each system. Because there are few clear ethical judgments, each of us needs to take ownership of our ethical beliefs—sometimes referred to as first-person ethics (Elliott 2006).
In Western philosophy, three traditions dominate ethical reasoning: virtue theory, deontological or duty-based theories, and teleological or consequentialism. Here I summarize these, in addition to ethical pragmatism and ethics of caring. The three schools are virtue ethics, consequentialist ethics, and deontological or duty-based ethics. Virtue ethics can be traced to Aristotle (384–322 BCE) and involves aspiring to a set of virtues, avoiding vices, and finding the right balance among values.
Duty-based ethics (deontological) asks “What are my duties and obligations regarding the treatment of others?” Kant’s (1787, 1998) categorical imperative held that the rightness or wrongness of actions does not depend on their consequences but on whether they fulfill our duty. Duties are obligatory. Common duties include “respect for humanity,” because persons have intrinsic value and should not be treated as things merely to be used for the benefit of others.
Consequentialist ethics can be traced to David Hume, Jeremy Bentham (1789), and John Stuart Mill (1863). There are two types of consequentialist schools of thought: ethical egoism, which treats self-interest as the foundation, and utilitarianism. Utilitarianism aims to bring about the greatest good for the greatest number of people or the greatest balance of good over evil. Actions are right if they tend to promote happiness (more formally, well-being), wrong if they tend to produce the reverse of happiness. Unfortunately, much critique of Mill did not recognize that his utilitarianism also profoundly advocated that individual liberty and strong government to promote education and culture were the foundation to promoting well-being, and that he was a strong abolitionist and suffragist (Mill 1859, 1975; Eggleston and Miller. 2014).
The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. (Mill 1859, 10)
The needs of the many outweigh the needs of the few. (Spock, Star Trek: The Wrath of Khan)
Moral relativism is the view that judgments are true or false only relative to some standpoint (for instance, that of a culture or a historical period) and that no standpoint is uniquely privileged over all others. Although the public may understand the concept, moral relativism is discredited among philosophers.
Pragmatic ethics was developed by William James and John Dewey at the turn of the 20th century to synthesize the best of prior ethical theories and to approach ethics more scientifically. From virtue theory, it recognized that character was very important; from duty-based theory it drew the importance of gradually changing society by keeping the best of the old and improving with new understandings. From utilitarianism, it focuses on the actual consequences of our actions. It emphasized the use of emotion, evidence, and reason when individuals were confronted with an actual situation that required a moral choice. Pragmatism focused on guiding people to consider the real choices that were possible to them and the impacts those choices would have on other people (Dewey 1932). The moral rule can be summed up as making sure you take the time to gather evidence, reflect, and take actions that improve the good in a specific situation, including consideration of the long-term impacts of that action.
Each school of ethics has advantages and disadvantages. We must consider these when choosing the school of ethics we will use to help us make ethical decisions (Table 4.2).
Question to ponder
Which ethical system (Table 4.2) do you prefer? Why?
Type of theory Advantages Disadvantages
Consequence-based
(Utilitarian)
Stresses promotion of happiness and utility Permits “tyranny of the majority,“ Mill (1859, 1975; p. 6) which ignores concerns of justice for the minority population
Duty-based (Deontology) Stresses the role of duty and respect for persons Underestimates the importance of happiness and social utility between different people
Feminist ethics of caring Stresses caring in personal relationships, for animals and the environment Unequal moral consideration of others (friends and family cared for more than others)
Pragmatism Simple moral rule—improve individual and social well-being, use science to achieve Requires individuals to take responsibility for moral reasoning
Contract-based (rights) Provides a motivation for morality Emphasized individualism, offers only a minimal morality
Character-based (virtue) Stresses moral development and moral education Depends on homogeneous community standards for morality
Ethics of caring Highlights the differences between men’s and women’s situations in life Differs from most Western traditions and many may not relate to orientation of caring
Table 4.2: Advantages and disadvantages of six types of ethical theories.
4.8 Comparing Ethical Theories and Their Use
The ethical theories developed and modified over time have been used and abused in many ways. As noted above, their abuse does not prohibit their proper use. Like the physical and biological sciences, doing ethics well requires study and practice. In this section I briefly address which ethical theories are in common use in the last one hundred years and how they have been used or abused.
Figure 4.3 provides another way to understand the relationship of ethical theories. It makes no judgment as to which is better or worse.
On the left side of the figure is ethical egoism, a form of consequentialism. Ethical egoism is widely regarded as a very weak ethical theory, antithetical to ethics, since it does not guide action to consider others. In short, any ethical theory that argues that it is good to be inconsiderate of others doesn’t seem to be very ethical.
Utilitarianism is applied frequently in fish conservation and dominates the public policy arena. Utilitarianism is the basis of contemporary economic theories, which commonly hold or assume that individuals are best served when they are able to pursue and satisfy their preferences within a free market. Utilitarianism is often justified because (1) happiness does matter, (2) flexibility is important, (3) it appeals to our commonsense intuitions, and (4) it ensures equal consideration of all interests. Utilitarianism, like most ethical theories, is not a practical approach when individuals differ in how they measure utility or happiness, in identifying duties in a specific situation, or on what is virtuous (pluralism). As an example of how consequentialism is often misinterpreted, John Rawls, one of the most famous and influential political philosophers in the 20th century, did not recognize utilitarianism’s founding principle of the need to respect individual liberties. Rawls (1971) and Cochrane (2000) criticized utilitarianism for not considering how in many fisheries, justice, fairness, and rights may be more important than consequences.
Utilitarians may recognize human rights of those who fish (Ratner et al. 2014) and private ownership of fishing rights. Conservationist Roderick Haig-Brown (1939, 135) recognized that “When angling rights are privately owned, the owners spend a great deal of money on the preservation of value and restrict themselves and their friends to catches and practices that will ensure preservation.” In practice, in regulating harvest of fish, it is difficult to predict future responses to reduced harvest, and harvesters often adopt the “if-I-don’t-get-’em-somebody-else-will” philosophy.
Duty-, rights-, and responsibility-based ethics tend to ignore crucial ethical questions, such as: “What is the best life for me?” “How do I go about living?” or “What actions will make a better society?” These questions are the focus of ethics of character, or virtue ethics. Proponents of virtue ethics focus on actions and character (Taylor 2002; Sandler and Cafaro 2005; Westra 2005). A virtue ethics approach can and often does inform best practices for welfare in aquariums and fish farms and in codes of angler ethics. It does so by guiding us to ask what a virtuous person would do in various situations. In ordinary situations, like whether or not we should treat animals and fish well, it and most other ethical theories agree that yes, we should treat them well.
In contrast to the Western philosophies of moral reasoning, ethics of indigenous peoples and ecological feminism focus on ethics of caring. Many indigenous peoples follow an ethic of care for all kinds of others, as well as the complex value of ecological interdependencies (Figure 4.3; Gilligan 1982; Whyte 2015; Whyte and Cuomo 2016). Ecological feminism often focuses on the ethics of care and links their analysis to beliefs about gender roles in patriarchy (Gilligan 1988). Gilligan argues that many commercial and subsistence fisheries are based on male-dominated decision making, and the role and contributions of females in the fisheries is undervalued (Thompson 1985; Frangoudes and Gerrard 2018). Care ethics maintains that ethical living depends on mutually beneficial caring relationships that do not exploit the caregivers and value animals and dependencies (Gaard and Gruen 1993).
4.9 Ethics and the Expanding Moral Circle
Over the course of human history, more and more beings in the world have been deemed to be worthy of serious moral consideration (Singer 2011a). The boundary drawn around those entities in the world deemed worthy of moral consideration, referred to as the moral circle, has expanded (Figure 4.4). Many people think that sentience, the ability to feel sensations like pain and pleasure, determines membership in our moral circle. If that’s the case, we need to ask what degree of sentience is required to make the cut?
Your personal beliefs about membership in the moral circle are likely a product of your culture. Use your reasoning to think beyond your inherited biases. For example, those raised in the Jain religion have always included all animals and all of nature in the circle. Extending the moral circle led to concerns for animal welfare and a code of conduct in use of animals to reduce suffering of people and animals. Singer’s notion of the expanding circle proposes that our moral sense, though shaped by evolutionary forces to overvalue self, kin, and clan, can propel us on a path of moral progress, as ethical reasoning will force us to include larger circles of sentient beings in our ethical deliberations.
Question to ponder:
Consider who is part of your moral circle of consideration. Yourself, your family, and your siblings are at the center of the circle. Draw multiple circles around the center and describe considerations you use to consider whether humanity, members of your group, your neighborhood, the nation, mammals, birds, fish, insects, plants, ecosystems, and future human generations should be included. What ethical theories do you find to be most applicable in defining your moral circle of consideration?
4.10 Model of Ethical Reasoning
Moral education involves improving the ability to identify ethical issues and then make a justified choice of how to act. There are many ways to organize our ethical reasoning. Sternberg (2012) identified eight sequential steps that are involved in ethical reasoning:
1. Recognize that there is an event to which to react,
2. define the event as having an ethical dimension,
3. decide that the ethical dimension is of sufficient significance to merit an ethics-guided response,
4. take responsibility for generating an ethical solution to the problem,
5. figure out what abstract ethical rule(s) might apply to the problem,
6. decide how these abstract ethical rules apply to the problem so as to suggest a concrete solution,
7. prepare for possible repercussions of having acted in what one considers an ethical manner, and
8. act.
This model will be adopted in discussion of case studies described in subsequent chapters.
Your moral argument uses both normative and descriptive language and is organized as (1) premises, (2) general moral principle, and (3) conclusion. The premises on which you base your argument will be descriptive, factual statements, whereas the other parts of the moral argument are normative statements. Ethical reasoning assists us in participating in debates and policy deliberations as an individual or as members of a group. Adopting the ethical reasoning model in a formal way helps us prevent ethical drift—that is, the gradual erosion of standards when there is competition for time and resources or an organizational culture that tolerates ethical lapses.
Question to ponder
Consider the many decisions related to fish and wildlife that are made by the Board of Game and Inland Fisheries in Virginia (see Virginia Code, Title 29.1 – Game, Inland Fisheries and Boating). Can you imagine any regulations regarding one of these articles having a significant ethical dimension? If so, what?
4.11 Ethical Perspectives Relevant to Fish and Fishing
Six perspectives consider common notions underlying ethical approaches to wild animals:
1. A contractarian perspective. In this view, wild animals fall outside the moral circle and are viewed as a resource for human use.
2. A utilitarian perspective. This view is a form of consequentialism taking into account everyone affected by decisions. Fish and wildlife can suffer, so they are inside the moral circle. Consequently, their welfare is taken into account in management decisions.
3. An animal rights perspective. This view maintains that certain animals share similarities with humans that underpin moral rights, such as the ability to suffer, or for some, the fact that they are alive. Consequently, there are some things we may never do to them. We should not kill, confine, or otherwise interfere in the lives of wild animals unless necessary. It is neither our right nor our duty to cull or in other ways to manage wild animals. These are very complex theories with many variations.
4. Respect for nature perspectives. This is an overlapping group of views on protecting values of naturalness itself, including whole species, ecosystems, and biodiversity. It was popularized by writings of Aldo Leopold (1949). The moral importance of individual animals depends on whether they promote or threaten environmental values. Keystone species are to be protected, while invasive species should be removed or killed. A popular quote from this perspective is, “Examine each question in terms of what is ethically and esthetically right, as well as what is economically expedient. A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise” (Leopold 1949).
5. A contextual (or relational) view. This view emphasizes the nature of the human-animal relationships. For example, there are different relations, and therefore different moral obligations, to wild animals than there are to domestic animals (Palmer 2010).
6. Hybrid or pluralist view. This view argues for creating a pragmatic and pluralistic ethical framework from which scientists and conservation managers can draw when complex moral questions arise. This pluralistic ethical framework incorporates different approaches to environmental and animal ethics (Minteer and Collins 2005; Norton 2005). In a pluralistic society, we can’t expect to persuade others on fundamental questions of the good and the right. We can, however, attempt to persuade them to adopt our views on policy by offering arguments that appeal to their fundamental values, even if we don’t share them.
The hybrid view may be considered practical ethics, which is ethics developed in the religious, legal, and medical arenas and focuses on the full range of moral values that inform our lives, such as what is right, good, just, and caring. Practical ethics looks to these and other moral concepts, as well as the empirical reality of individual cases, for guidance in making ethical decisions. By honoring the insights of many moral ideas and not a single ethical theory, practical ethics has a deep reservoir of concepts available to triangulate on the best understanding of a moral problem. These cases were described in three editions of Peter Singer’s Practical Ethics (2011b).
Question to ponder
Among the six ethical perspectives described above, which are you most likely to agree with and which ones do you disagree with? Why?
Moral pluralism is the view that acknowledges the existence of multiple values (Marrietta 1993). There are different ways to think about and judge what is moral, especially including other voices that are often marginalized, (e.g., indigenous peoples and women [Warren 1982]). Callicott (1990) argues that personal worldviews must be challenged and, if needed, abandoned. In this way, we make moral progress and are not guilty of moral relativism. Recognition of moral pluralism is one of the founding principles in the United States, particularly Virginia, where the individual’s right to have their own religious and moral systems is part of the Constitution. Respecting other’s views provides the start to respectful discussion between people about what actions and policies we agree are right. Then we can either try to make those agreements in moral norms, or pass programs or laws to help enact them.
Clearly, some cultural practices may be wrong. The ancient ritual in which Buddhists free captive animals to generate positive karma through an act of kindness (i.e., compassionate release of prayer fish) has been changed over time to become a commercial enterprise in which people buy animals specifically to release them. For example, the practice of compassionate release of captive animals may not serve the needs of the animals released nor the receiving ecosystem (Actman 2017). This well-intended practice may, in fact, be a threat to many species (Everard et al. 2019).
Ethical reasoning is helpful as we identify our values, others’ values, and what ethical system is preferred. Many ethical systems have very similar recommendations for what to do in common situations. The public and professionals in fish and wildlife management and other professions can increase the good when they help themselves and others find agreement on what actions to take. Recognizing that the ethical theories that other people hold have useful views can help unravel moral questions and bring people into agreement by recognizing their contributions to solving ethical questions.
Relying on a utilitarian principle for managing a fish or wildlife population to maximize human welfare is unworkable without also considering the principle of justice or other theories of ethics that require us to ensure rights of others. For yourself, I suggest that what you think, say, and do are in sync so that your values and actions are consistent. In addition, we should seek ways to respect the views of others and improve our ability to find agreement on how to protect people and fisheries.
4.12 Codes of Ethics
Ethical codes are specific codes of ethics adopted by or on behalf of professions (e.g., psychologists, doctors, wildlife professionals) or other practitioners to guide the behavior of members, interactions among members, and interactions between members and the public. In the context of a code adopted by a profession or by a governmental or quasi-governmental organization to regulate that profession, an ethical code may be styled as a code of professional responsibility, which informs about difficult issues of what behavior is “ethical.”
There are many forms of fishing practiced worldwide and, consequently, many ethical codes. Similarly, ethical codes exist for recreational anglers (http://www.ethicalangler.com/the-code-of-ethical-angling.html), fly fishers (https://flyfishersinternational.org/Resources/Educational-Resources/Code-of-Angling-Ethics), and commercial fisheries (FAO 2010–2020). The Association of Zoos and Aquariums (AZA) adopted a Code of Professional Ethics that includes mandatory standards and an Ethics Board that reviews complaints (AZA 2017). Aquarium and pond keepers in Australia abide by a code of conduct.
Question to ponder
What ethical codes have you learned or are expected to follow in your professional discipline or avocations? What difficulties do you anticipate regarding following these codes? What ethical theories provide the basis for the code of conduct for your discipline? You may wish to review ethical theories in Table 4.2 or online.
NOAA’s Fisheries Service (NMFS) adopted the following “Code of Angling Ethics” in cooperation with marine recreational fishing groups to implement the public education strategy (NOAA 1999).
The Ethical Angler:
• Promotes, through education and practice, ethical behavior in the use of aquatic resources.
• Values and respects the aquatic environment and all living things in it.
• Avoids spilling, and never dumps, any pollutants, such as gasoline and oil, into the aquatic environment.
• Disposes of all trash, including worn-out lines, leaders, and hooks, in appropriate containers, and helps to keep fishing sites litter-free.
• Takes all precautionary measures necessary to prevent the spread of exotic plants and animals, including live baitfish, into non-native habitats.
• Learns and obeys angling and boating regulations, and treats other anglers, boaters, and property owners with courtesy and respect.
• Respects property rights, and never trespasses on private lands or waters.
• Keeps no more fish than needed for consumption, and never wastefully discards fish that are retained.
• Practices conservation by carefully handling and releasing alive all fish that are unwanted or prohibited by regulation, as well as other animals that may become hooked or entangled accidentally.
• Uses tackle and techniques which minimize harm to fish when engaging in “catch-and-release” angling.
4.13 Management of Invasive Fishes
Often because of human modifications of waterways or intentional and accidental releases, many fish species develop large populations and cause excessive damage to ecosystems of native fish communities. These species are referred to by many terms, including invasive, introduced, translocated, exotic, alien, or pest. Debates persist on the need and approach to manage invasive fish. Invasive species cause harm as defined by human interests and/or ecosystems, and these harms must overwhelm rights of individual animals for control measures to be initiated. In two of three examples, the harm was high enough to result in large-scale destruction programs. Many species of carp of China were introduced to North America and expanded in population size and range, competing with native fish (Reeves 2019). Harvesting to reduce populations and electric and physical barriers to limit migration are two strategies employed to reduce populations of carp. When the Sea Lamprey entered the upper Great Lakes, the added mortality caused native lake trout populations to drop 98% in a few decades (Brant 2019). Large-scale poisoning of streams occupied by juveniles was initiated and continues annually to depress populations of the Sea Lamprey in order for native fish to recover. Recent research on pheromones revealed an approach to attract spawning Sea Lampreys so they could be trapped and removed, rather than using poisons. The Northern Snakehead, which was established in many waterways by intentional releases followed by population expansion, has been both reviled and targeted by recreational anglers. Researchers have failed to document significant harm that the Northern Snakehead causes to native fishes or economies. Rather, local recreational anglers found it to be another sportfishing target, despite regulations in Virginia and Maryland calling for anglers to kill any Northern Snakehead caught (Orth 2019). In October 2019, one Snakehead was found in Georgia. “Kill it immediately” was the initial advice to anglers, even those who practice catch and release and never kill their catch.
The Northern Snakehead case raised the ethical question of whether a state agency can require an angler to kill a fish. In the present day, a reconceptualization of the relationships between humans, translocated species, and ecosystems is warranted. In a reversal of past practice, the National Park Service has a program of killing for conservation in Yellowstone National Park. In this case, Lake Trout were introduced to Yellowstone Lake and threaten populations of native fish, including Yellowstone Cutthroat Trout (Koel 2017). We will see more cases in which humans must manage novel combinations of fish in ecosystems.
4.14 Ethical Fisheries
Fish are the last wild animals harvested commercially, and the importance of fish for providing essential protein for people around the world is substantial. Fisheries employ 260 million people, and fish are the primary protein source for ~ 40% of the world’s population (FAO 2018). Fisheries are managed by actions and interactions of government bodies, the market, and civil society (Lam and Pauly 2010). Government policies and the market seldom consider ethical issues unless they come up within public involvement processes in civil society and nongovernmental organizations. Consequently, many large fisheries are managed with the belief in the right of individuals to maximize their profits through their own initiative with minimum government interference. However, in an open fishery there are never enough fish for everyone to have all they can catch, and if fishers act independently in their own self-interest, the fishery will collapse.
The Code of Conduct for Responsible Fisheries sets out principles and international standards of behavior for responsible practices with a view to ensuring the effective conservation, management, and development of living aquatic resources, with due respect for the ecosystem and biodiversity (FAO 2010–2020, Pitcher et. al. 2009). The code recognizes the nutritional, economic, social, environmental, and cultural importance of fisheries and the interests of all stakeholders of the fishing and aquaculture industries. It considers the biological characteristics of the resources and their environment and the interests of consumers and other users.
For example, the management of many fisheries around the world is complicated by a complex global supply chain and, in some nations, weak governance. Government subsidies, bycatch, and employment vary greatly between commercial or large-scale fisheries and subsistence or small-scale management (Table 4.3; Lam 2016). Fisheries are sometimes managed by providing harvesters with individual transferable quotas or shares of the allotted catch. While this strategy provides for more efficient fisheries, the quotas are often unfairly distributed based on historical catches, which disadvantages small, subsistence coastal fishers. Yet small-scale, artisanal and subsistence fisheries generate about one-third to one-half of the global catch that is used for direct human consumption, and they employ more than 99% of the world’s 51 million fishers (Pauly and Zeller 2016; Jones et al. 2018).
Fisheries Benefits Large-scale Small-scale
Annual landings for human consumption ~ 60 million tonnes ~ 27 million tonnes
Annual catch discarded at sea 9 million tonnes Almost none
Annual catch for industrial reduction to fishmeal & fish oil
26 million tonnes
Almost none
Fuel used per tonne of fish for human consumption 10–20 million tonnes 2–5 million tonnes
Number of fishers employed 0.5 million ~ 12 million
Government subsidies 25–30 billion US \$ 5–7 billion US \$
Table 4.3: Comparison of benefits for large- and small-scale fisheries. From Pauly and Zeller (2016).
Canned tuna may be a cheap, nutritious, and healthy protein, but the activities along the global supply chain are often hidden from consumers. Some harvest methods are unsustainable and include government subsidies, high levels of illegal, unreported, and unregulated fishing, and in some cases forced labor aboard fishing vessels (Couper et al. 2015; Urbina 2019). These hidden costs of canned tuna or other seafood products are not considered unless the product contains appropriate labeling (Fishwise 2015). Seafood certification, or ecolabeling, provided by third parties, such as the Marine Stewardship Council and Seafood Watch, attempt to certify ethical fisheries based on a variety of goals, including fair trade, worker welfare, habitat, and bycatch (Kittinger et al. 2017; Lam 2019).
Intensive and participatory management of fisheries dominates in many developed nations, which have the resources to invest in scientific data collection and stock assessment. Many previously overfished fish stocks subjected to low fishing pressure are now rebuilding in regions where fisheries are intensively managed (Hilborn et al. 2020). However, fisheries in developing countries are under intense pressure from increasing human populations, overharvest, and conflicts over access. Typically, there are too many small-scale fisheries, weak governments, and poor fisheries management.
Comanagement involves a shared management responsibility among government, fishing communities, and other stakeholders to develop a shared knowledge base and democratic decision making (Berkes et al. 2000; Viswanathan et al. 2003; Defeo and Castilla 2005; Gelcich et al. 2005; Armitage et al. 2009; Lam and Pauly 2010; Villanueva-Poot et al. 2017). When fishers facing common dilemmas form cooperative communication ties with direct resource competitors, they may achieve positive gains (Barnes et al. 2019). Comanagement is still in its infancy in the United States, although the Magnuson-Steven Act includes few barriers to it in developing fishery management plans (Emmett Environmental Law & Policy Clinic and Environmental Defense Fund 2016.). Organized opposition from agencies and special interests and difficulties in consensus building must be overcome to implement comanagement (Ayers et al. 2017). Comanagement is a gradual process that relies on voluntary involvement of diverse stakeholders, but the sharing of responsibilities can make fisheries more sustainable if benefits are greater than the costs to change (Arlinghaus et al. 2019; Hoefnagel et al. 2006). Collaborative governance is becoming more politically feasible as emerging social norms consider a broader range of values (Lam and Pauly 2010). Creating a social network of fishers with authority to comanage fisheries may lead to solutions to many problems, including the following:
• Tyranny of scale, which means that too many small fisheries spread over a wide geographic area and cannot be monitored at these small scales by a single management entity (Prince 2010).
• The integration of fishers’ knowledge and practices inform fishery management plans and research.
• Coordination and negotiation of agreements with wealthy nations and nations that subsidize fishing have more fleet capacity and dominate the fisheries.
• Reduction in unreported and illegal fish harvests occurs from efforts at self-enforcement.
• Fishing income is more equitably distributed among participants in the fishery.
• Reduce marginalization of subsistence fishers, thereby enhancing livelihoods and reducing behaviors that degrade the local environment (Robbins 2012).
• Fishing boats from wealthy nations are kept out of the country’s exclusive economic zone (EEZ), reducing the stealing of fish from the poor (McCauley et al. 2018).
• People of small island states are most vulnerable to sea level rise and storm surges and depend entirely on fish for their protein. Yet, the USA and European Union contribute disproportionately to greenhouse gas emissions.
• Managing recreational fishing is tailored to specific anglers who have both catch- and noncatch-related motivations.
Effective public participation requires deliberation on issues by all those affected by a decision (Dewey 1927; Barber 2003), yet most fisheries’ management deliberations are done by governing boards. Board members are often appointed rather than elected and serve out of duty rather than interest. When the governing board is not forced to decide what is best for the whole, individuals may lapse into self-interest. In participatory comanagement, all stakeholders, not only harvesters, are present for discussing ethical issues of public trust, intergenerational equity, fishing rights, human welfare, social justice (exclusion), and freedoms (Lam and Pauly 2010; Lam and Pitcher 2012). This deliberative, democratic approach ensures that ethical issues along with economic factors, social policies, and political decisions are considered, as well as the condition of relevant ecosystems. In this way, environmental values and basic human interests (welfare, freedom, and justice) are considered (Lam 2016, 2019). Therefore, the ethical management of fisheries must address five moral imperatives:
• Avoid overexploitation and ensure long-term conservation in a just manner that enhances all people’s well-being;
• Allocate allowable harvest in a fair and equitable manner;
• Minimize restricted access to fishing areas;
• Enforce regulations with reasonable consequences; and
• Minimize or avoid fish welfare impacts of fishing practices and behaviors.
Requirements for ethical fisheries are summarized in Table 4.4 by components of the fishery and major ethical principles. Social justice is justice in terms of transparent decision making regarding the distribution of wealth and opportunities and privileges for fishers, other stakeholders, and consumers. Ecological justice requires putting the economy in its place as a subsystem within society and the wider natural world. Consideration of ecological justice recognizes that there are many more indicators of well-being beyond gross national product (Smith et al. 2013). The term distributive justice refers to fairness in the distributing benefits from a fishery and ecosystem.
Subject Objectives related to welfare (well-being) Objectives related to freedom (autonomy) Objectives related to justice
The ecosystem Ecosystem integrity; habitat and biodiversity protection Maintenance of capacity to change; resilience Stewardship and interests represented by human institutions
Fish stocks Stock and genetic conservation; animal welfare No barriers to migration Fair conditions for reproduction
Fisheries Economic viability; sustainable development; safety on board Conditional freedom to act Cross-sectoral equity (in taxes and law); access to tribunals
Fishers and their communities Adequate income and working conditions; poverty eradication; cultural diversity Freedom to change or not; empowerment; cultural identity Fair treatment in trade and law; equitable access to resources; compensation
Other stakeholders No or reduced externalities from fishing Freedom to compete Equitable share of resources; dispute resolution
Consumers Safe, nutritious, affordable food; societal efficiency Availability of choice (e.g. labelling) Equitable access to food; no barriers to trade; cross-sectoral equity
Politicians Availability of alternative policy choices Capacity to decide; free participation in public deliberation Transparency; accountability; liability; public oversight
Table 4.4: Ethical matrix for the ethical analysis of fisheries. Source: FAO.
Examination of the ethical matrix forces a fuller dialogue of the ethical principles important for different stakeholders (Lam and Pitcher 2012, Lam 2016, 2019). For example, government proposals to designate no-take marine reserves are intended to protect ecosystem integrity and the well-being or recovery of fish stocks. These benefits must be considered in the context of freedom and justice for fishers and fishing communities that are most affected by the designation (Jones 2009). Fishers will respond to such proposal with statements such as “Fishing is our way of life and our way of earning a living—it’s not just about money,” or “It’s not just the loss of an individual business if a fisherman leaves the industry, it’s the loss of the fishing culture, on which whole villages are dependent.” Another example includes proposals to grant property rights to fish stocks or fishing grounds. In these proposals, the consumer may benefit from a more efficient fishery and more affordable seafood. However, the freedom of certain fishers to fish will be lost, and equitable distribution of a quota must be considered. In developing countries, commonly needed fisheries reforms include justice issues, such as the evictions for coastal development, child labor, forced labor, unsafe working conditions, gender-based violence, and loss of fishing rights (Ratner et al. 2014). In small-scale, subsistence fisheries, governance systems that give fishers access rights provide strong incentives to engage in processes of data collection, assessment, and management (Prince 2010). Furthermore, the difficult tradeoffs can be made more easily in a collaborative, comanagement governance where stakeholders share knowledge and develop trusting relationships (Armitage et al. 2009).
Question to ponder
The justice ethical principle states that decision makers should focus on actions that are fair to those involved. In most developed countries, about 1 in 10 people are recreational anglers. Should those individuals who are not recreational anglers be involved in policies related to fishing? License fees and excise taxes on equipment and motorboat fuels fund sportfishing programs. Faced with declining revenues, how should state agencies fund fish conservation?
4.15 Concluding Thoughts
To ensure that fish practitioners are aware of ethical principles that guide their actions, ethical reasoning should be incorporated into all curricula, major meetings, and conferences, and state and federal agencies should establish ethics components in agency operations and procedures (Hadidian et al. 2006). Teaching should focus on being ethical and not simply knowing ethical principles (Kretz 2015). Ethics of caring has yet to gain widespread acceptance for fish conservation. Other concepts, such as social justice, distributive justice, and ecosystem justice, rarely enter into the policy-making process. The capacity to make genuine moral judgments is grounded in emotional attachments (Andreou 2007) that are engaged by making deliberations with others who have opposing sentiments. Recognizing the role that emotions play permits us to involve both hearts and minds in deciding right actions.
Young students in particular are prone to be pessimistic and despair over the daunting challenges in fish conservation. We need to avoid both pessimism and idealistic optimism. Being optimistic about the strategies used will allow us to persist in difficult circumstances. As Clayton and Myers (2005, 206) put it, “Sometimes the fear that we can never make enough of a difference—ecosystems will perish anyway—prevents us from making the attempt.” If we continue to ignore discussing ethical concerns with all interested stakeholders, we risk alienating a large segment of the populace. Not all members of the public value fish or fishing in the same way as you might. Ignoring ethical issues will further erode the credibility and efficacy of management agencies, forcing citizens to adopt the public ballot initiative process to be heard (Loring 2017; Manfredo et al. 2017). Emerging global threats to biodiversity and shifts in distributions of many marine fish will necessitate new, more responsive models of governance (Holling and Meffe 1996; Knight and Meffe 1997; Free et al. 2020).
Profile in Fish Conservation: Mimi E. Lam, PhD
Mimi E. Lam is a researcher and Marie Skłodowska-Curie Alumna at the University of Bergen.
Mimi E. Lam (https://www.uib.no/en/persons/Mimi.E..Lam) studied theoretical chemistry and physics in university, earning a BSc honors degree at the University of British Columbia and a PhD from Dalhousie University. This academic background gives her unique analytical insights and methods to examine the complex interactions and underlying mechanisms governing both physical and human-natural systems. She tackles “wicked” societal problems in fisheries and marine governance, where a plurality of values prevents a unique problem definition or solution, with collaborative teams drawn from the academic and non-academic sectors. She examines how human values, beliefs, attitudes, perceptions, and behaviors influence our interactions with nature. Consequently, her investigations at the science-policy-society interface inform the decision-making of individuals, communities, and society in “post-normal” situations, where facts are uncertain, values are in dispute, stakes are high, and decisions are urgent. Mimi Lam’s innovation is designing deliberation and decision-support tools that promote both scientific and ethical reflection, evaluation, and analysis to inform robust policy decisions.
In her transdisciplinary approach to fisheries, Mimi Lam works across disciplines, sectors, and cultures, routinely engaging scholars from fisheries ecology, psychology, and philosophy, as well as stakeholders and citizens from local and indigenous communities, fishing industries, nongovernmental agencies, and governments. Past research papers have established Mimi as a leader in the transdisciplinary study of the ethics of seafood, value chains, and fisheries governance. She co-led an interdisciplinary team elucidating the diverse values and ecology of herring to help reconcile the Pacific herring fishery conflict in Haida Gwaii, British Columbia, Canada. At conflict were herring’s cultural value as traditional food for coastal indigenous peoples, socio-economic value in the commercial roe fishery, and ecological value as forage fish for predatory fish, marine mammals, and seabirds. Stakes were high and facts were contested when the federal government decided whether or not to reopen the herring fishery. Her team’s novel value- and ecosystem-based management approach combined practical ethics to elicit values with ecological modeling to evaluate impacts and risks to open conflicting stakeholders to dialogue and to inform a compromise on a feasible management strategy.
Currently Dr. Lam is leading a project in Norway called Managing Ethical Norwegian Seascape Activities (https://mensa.w.uib.no/), which focuses on how to reconcile the inherent value trade-offs and ethical dilemmas involved in managing seascape activities that encompass not only fisheries, but also aquaculture, oil and renewable energy production, shipping, transportation, tourism, and recreation. Seascape activities are diverse, complex, and dynamic human enterprises that may intersect spatially and/or temporally in the coasts and oceans. Different ways of knowing and valuing coexist, which can lead to management and policy conflicts that must be understood from numerous perspectives in order to effectively govern the marine resources and activities. Dr. Lam’s approach in managing fisheries and other seascape activities fosters the extremely difficult consideration of values and deliberations for improved understanding and trust among different participants (for example, among disciplinary experts, fisher and non-fisher, policy-maker and activist, male and female, and wealthy and poor). Her transdisciplinary approach recognizes and offers ethical deliberation and decision-support tools to reconcile the plurality of values and worldviews that exists in modern society and among individuals and cultural groups.
In summary, Mimi Lam champions scientific and ethical approaches to complex environmental and societal challenges that bring diverse parties and perspectives together to develop dialogue and trust, by accepting differences and embracing tolerance for other values and ways of knowing. She received the Conservation Beacon Award from the Society for Conservation Biology for “pioneering an ethical approach to the conservation of marine resources, both natural and cultural, through interdisciplinary research and community engagement at the science-policy interface.” The legacy of her influence will be to promote a more sustainable and ethical future by informing policies that support diverse voices and sustain the ways of life of indigenous peoples and local communities, productive fisheries, and resilient ecosystems.
Key Takeaways
• Ethical reasoning deals with values and whether actions are right or wrong.
• Ethical arguments consist of premises, moral principles, and conclusions.
• Success or failure in environmental problem solving is often determined by the way a problem is formulated and discussed in public discourse.
• Five approaches for ethical thinking that may guide decision making include (1) virtue theory, (2) deontological or duty-based theories, (3) teleological or consequentialism, (4) ethical pragmatism, and (5) ethics of caring.
• Ethical reasoning assists us in participating in debates and policy deliberations as an individual, member of a group, and as a member of society.
• Codes of ethics for fishing have been developed to encourage ethical behavior.
• Ethical fisheries can evolve only with dialogue and consideration of principles of freedom, equity, fairness, and justice.
• Collaborative governance is necessary for developing trust among stakeholders.
• When fishers facing common dilemmas form cooperative communication networks with direct resource competitors, they may achieve positive gains.
This chapter was reviewed by Mimi E. Lam and Dennis Scarnecchia.
URLs
Virginia Code, Title 29.1 – Game, Inland Fisheries and Boating: https://law.justia.com/codes/virginia/2014/title-29.1
Ethical theories: https://www.youtube.com/watch?v=Uw7W1PpnbZQ
Long Descriptions
Figure 4.1: Arrow diagram showing that burden of proof is on conservationists when fish are instrumentally valuable and on developers when fish are intrinsically valuable. Jump back to Figure 4.1.
Figure 4.2: 1) Christianity, simple 2 line drawing of outline of a fish; Ichthys is an important identification symbol in Christianity; 2) Judaism, a painting of fish with other cooking ingredients; in Judaism, fish is a symbol of fertility and luck, and gefilte fish is a traditional dish; 3) Hinduism, a giant gray fish is larger than the boat it swims alongside filled with people; in Hinduism, Matsya, a fish is the first supreme god; 4) Islam, an older man stands atop a large fish, holding his hands in prayer; In Islam, fish is a symbol of eternal life and of knowledge. The mythical Al-Khidr is depicted here standing on the fish and using it to travel; 5) Buddhism, painting of 2 golden fish; in Buddhism, the golden fish are one of eight auspicious symbols; Daoism, drawing of 2 koi fish; in Daoism, the yin and yang is often illustrated with two koi fish. Jump back to Figure 4.2.
Figure 4.3: Ethical theories organizational chart; 1) Center line: Ethics of character; what sort of people should we be? leads to Aristotelianism, virtue is a mean between extremes of action and passion; 2) Left line: Ethics of conduct; what sort of actions should we perform? branches out to Consequentialism; the right action is the one that produces the most intrinsic good; Deontology; the good is defined independently of the right. Consequentialism branches out to for the agent: ethical egoism and for everyone affected: utilitarianism. Deontology leads to Kantianism; actions must satisfy the categorical imperative. 3) Right line: Ethics of caring branches out to ecological feminism and Indigenous peoples ethics. Jump back to Figure 4.3.
Figure 4.4: A circle made up of dashes encompasses human icons within it (adult male, adult female, male child and female child). on top of the dashes and outside the circle are a pig, an ant, a fish, and a tree. Jump back to Figure 4.4.
Figure 4.5: Three overlapping circles: 1) Fair Trade, no forced or child labor; 2) Local, reduced carbon footprint; 3) Eco-label, reduced habitat destruction. Where fair trade and local overlap, socioeconomic development and diversification. Where Eco-Label and Local overlap, improved stock status and reduced bycatch. Where all overlap, traceability. Jump back to Figure 4.5.
Figure References
Figure 4.1: Burden of proof as it relates to instrumental and intrinsic value systems. Kindred Grey. 2022. CC BY 4.0.
Figure 4.2: Religious symbols associated with fish and fishing. Kindred Grey. 2022. CC BY 4.0. Includes “Ichthus,” by Fibonacci, 2006 (public domain, https://commons.wikimedia.org/wiki/File:Ichthus.svg), Still life “Tor Marancia Vatican,” by Sconosciuto, 1506 (public domain, https://it.Wikipedia.org/wiki/File:Still_life_Tor_Marancia_Vatican.jpg), “The fish avatara of Vishnu saves Manu during the great deluge,” by unknown author, acquired in 1965 (public domain, https://commons.wikimedia.org/wiki/File:The_fish_avatara_of_Vishnu_saves_Manu_during_the_great_deluge.jpg), “Khizr,” by unknown author, mid-17th century (public domain, https://commons.wikimedia.org/wiki/File:Khizr.JPG), “Eight Auspicious Symbols,” wall mural, Tibetan Buddhist symbols; vase, flower, infinity knot, wheel, fish, banner, umbrella, shell, hotel, Boudha, Kathmandu, Nepal, by Wonderlane, 2007 (CC BY 2.0, https://flic.kr/p/8kaZV9), and koi, by kareemov, 2022 (Noun Project license, https://thenounproject.com/icon/koi-4630545/).
Figure 4.3: Hierarchical relationships among traditional Western ethical theories and ethics of caring. Kindred Grey. 2022. Adapted under fair use from Ethics: A Pluralistic Approach to Moral Theory, 2nd ed., by L. M. Hinman, 1998 (https://www.brainkart.com/article/Ethical-Theories_11639/).
Figure 4.4: A moral circle encompasses those we consider worthy of moral consideration. Kindred Grey. 2022. CC BY 4.0. Includes Pig by Adindar, 2020 (Noun Project license, https://thenounproject.com/icon/pig-3362726/), Family by Gan Khoon Lay, 2017 (Noun Project license, https://thenounproject.com/icon/family-1245000/), Ant by Cédric Stéphane Touati, 2015 (Noun Project license, https://thenounproject.com/icon/ant-93320/), Fish by Sari, 2018 (Noun Project license, https://thenounproject.com/icon/fish-2099999/), and Tree by Misru, 2019 (Noun Project license, https://thenounproject.com/icon/tree-3369293/).
Figure 4.5: Goals used for three types of certification for fisheries. Kindred Grey. 2022. Adapted under fair use from Fair Trade Fish: Consumer Support for Broader Seafood Sustainability, by Loren Mcclenachan and Sahan T. M. Dissanayake, 2016 (DOI:10.1111/faf.12148).
Figure 4.6: Mimi E. Lam, PhD. Used with permission from Mimi E. Lam. Photo by Tony J. Pitcher. CC BY-ND 4.0.
Text References
Actman, J. 2017. A Buddhist tradition to save animals has taken an ugly turn. National Geographic. January 23 2017. Available at https://www.nationalgeographic.com/news/2017/01/wildlife-watch-mercy-release-buddhist-china-illegal-trade/. Accessed 26 May 2020.
American Association of Zoos and Aquariums (AZA). 2017. Code of professional ethics. Available at https://www.aza.org/code-of-ethics. Accessed 12 June, 2020.
Andreou, C. 2007. Morality and psychology. Philosophy Compass 2:46–55.
Arlinghaus, R., J. K. Abbott, E. P. Fenichel, S. R. Carpenter, L. M. Hunt, J. Alós, T. Klefothh, S. J.Cooke, R. Hilborn, O. P.Jensen, M. J.Wilberg, J. R. Post,and M. J. Manfredo. 2019. Governing the recreational dimension of global fisheries. Proceedings of the National Academy of Sciences 116:5209–5213. https://www.pnas.org/content/116/12/5209.
Armitage, D. R., R. Plummer, F. Berkes, R. I. Arthur, A. T. Charles, I. J. Davidson-Hunt, A. P. Diduck, N. C. Doubleday, D. S. Johnson, M. Marschke, P. McConney, E. W. Pinkerton, and E. K. Wollenberg. 2009. Adaptive co-management for social-ecological complexity. Frontiers in Ecology and Environment 7:95–102. doi:10.1890/070089.
Ayers, A. L., J. N. Kittinger, M. T. Imperial, and M. B. Vaughan. 2017. Making the transition to co-management governance arrangements in Hawai‘i: a framework for understanding and transformation costs. International Journal of the Commons 11:388–421.
Barber, B. R. 2003. Strong democracy: participatory politics for a new age. University of California Press, Berkeley.
Barnes, M. L., Ö, Bodin, T. R. McClanahan, J. N. Kittinger, A. S. Hoey, O. G. Gaoue, and N. A. J. Graham. 2019. Social-ecological alignment and ecological conditions in coral reefs. Nature Communications 10:2039.
Bauman, W. A., R. Bohannon, and K. J. O’Brien, editors. 2017. Grounding religion: a field guide to the study of religion and ecology. 2nd ed. Routledge, Taylor & Francis, London and New York.
Bentham, J. 1789 [1879]. An introduction to the principles of morals and legislation. Clarendon Press, Oxford.
Berkes, F., J. Colding, and C. Folke. 2000. Rediscovery of traditional ecological knowledge as adaptive management. Ecological Applications 10(5):1251–1262.
Brant, C. 2019. Great Lakes Sea Lamprey: The 70 year War on a Biological Invader. University of Michigan Press, Ann Arbor.
Callicott, J. B. 1990. The case against moral pluralism. Environmental Ethics 12:99–124.
Callicott, J. B. 2005. Conservation values and ethics. Pages 111–135 in M. J. Groom, G. K. Meffe, and C .R. Carroll, editors, Principles of Conservation Biology, 3rd ed., Sinauer, Sunderland, MA.
Chengzhong, P. 2014. Ethical treatment of animals in early Chinese Buddhism: beliefs and practices. Cambridge Scholars, Newcastle, UK.
Clayton, S., and G. Myers. 2015. Conservation psychology: understanding and promoting human care for nature. Wiley Blackwell, Oxford.
Cochrane, K. L. 2000. Reconciling sustainability, economic efficiency and equity in fisheries: the one that got away? Fish and Fisheries 1:3–21.
Couper, A., H. D. Smith, and B. Ciceri. 2015. Fishers and plunderers: theft, slavery and violence at sea. Pluto Press, London.
Crabtree, V. 2014. Do we need religion to have good morals? The Human Truth Foundation website. Available at http://www.vexen.co.uk/religion/ethics.html#BI_011. Accessed 29 May 2020.
Cuomo, C. 1998. Feminism and ecological communities: an ethic of flourishing. Routledge, New York.
Defeo, O., and J. C. Castilla. 2005. More than one bag for the world fishery crisis and keys for co-management successes in selected artisanal Latin American shellfisheries. Reviews in Fish Biology and Fisheries 15:265–283.
Dewey J. 1932 [1976–1988]. The middle works. 14 vols. J. A. Boydston, editor. Southern Illinois University Press, Carbondale.
Dewey, J. 2016. The public and its problems: an essay in political inquiry. Edited and with an introduction by M. L. Rogers. Swallow Press, Ohio University Press, Athens.
Eggleston, B., and D. E. Miller. 2014. The Cambridge companion to utilitarianism. Cambridge University Press, New York and Cambridge.
Elliott, D. 2006. Ethics in the first person: a guide to teaching and learning practical ethics. Rowman & Littlefield, Lanham, MD.
Emmett Environmental Law & Policy Clinic and Environmental Defense Fund. 2016. Fisheries co-management in the United States: incentives, not legal challenges, key. Available at https://clinics.law.harvard.edu/environment/files/2019/09/EDF-ELPC-Coop-Fisheries-FINAL-3-18-16.pdf.
Everard, M., A. C. Pinder, R. Raghavan, and G. Kataria. 2019. Are well-intended Buddhist practices an under-appreciated threat to global aquatic biodiversity? Aquatic Conservation Marine and Freshwater Ecosystems 29:136–141.
FAO. 1995. Code of Conduct for Responsible Fisheries. Food and Agricultural Organization of the United Nations, Rome.
FAO. 2005. Ethical issues in fisheries. Ethics Series. Food and Agricultural Organization of the United Nations, Rome.
FAO. 2010–2020. Implementation of the 1995 FAO Code of Conduct for Responsible Fisheries. FI Institutional Websites. FAO Fisheries and Aquaculture Department, Rome. Updated 30 May 2018. http://www.fao.org/fishery/.
FAO. 2020. The state of world fisheries and aquaculture. 2020. Sustainability in action. Food and Agricultural Organization of the United Nations, Rome. Available at http://www.fao.org/publications/sofia/en/. Accessed 12 June 2020.
Fishwise. 2015. The hidden costs of canned tuna. Available at https://fishwise.org/the-hidden-costs-of-canned-tuna/. Accessed 27 May 2020
Frangoudes, K., and S. Gerrard. 2018. (En)gendering change in small-scale fisheries and fishing communities in a globalized world. Maritime Studies 17:117–124.
Free, C. M., T. Mangin, J. G. Molinos, E. Ojea, M. Burden, C. Costello, and S. D. Gaines. 2020. Realistic fisheries management reforms could mitigate the impacts of climate change in most countries. PLoS ONE 15(3):e0224347. https://doi.org/10.1371/journal.pone.0224347.
Friedman, R. S., E. A. Law, N. J. Bennett, C. D. Ives, J. P. R. Thorn, and K. A. Wilson. 2018. How just and just how? A systematic review of social equity in conservation research. Environmental Research Letters 13. https://doi.org/10.1088/1748-9326/aabcde.
Gaard, G., and L. Gruen. 1993. Ecofeminism: toward global justice and planetary health. Society and Nature 2:1–35.
Gelcich, S., G. Edwards-Jones, and M. J. Kaiser. 2005. Importance of attitudinal differences among artisanal fishers toward co-management and conservation of marine resources. Conservation Biology 19:865–875.
Gilligan, C. 1982. In a different voice. Harvard University Press, Cambridge, MA.
Gilligan, C. 1988. Mapping the moral domain: a contribution of women’s thinking to psychological theory and education. Harvard University Press, Cambridge, MA.
Guglielmo, S. 2015. Moral judgment as information processing: an integrative review. Frontiers in Psychology 6:1637.
Hadidian, J., C. H. Fox, and W. S. Lynn. 2006. The ethics of wildlife control in humanized landscapes. Proceedings of the Vertebrate Pest Conference 22:500–504.
Haig-Brown, Roderick. 1939. The Western angler. Vol. 2. Derrydale Press, New York.
Hilborn, R., R. O. Amoroso, C. M. Anderson, J. K. Baum, T. A. Branch, C. Costello, C. L. de Moor, A. Faraj, D. Hively, O. P. Jensen, H. Kurota, R. Little, P. Mace, T. McClanahan, M .C. Melnychuk, C. Minto, G. C. Osio, A. M. Parma, M. Pons, S. Sequrado, C .S. Szuwalski, J. R. Wilson, and Y. Ye. 2020. Effective fisheries management in improving fish stock status. Proceedings of the National Academy of Sciences 117:2218–2224. https://doi.org/10.1073/pnas.1909726116.
Hinman, L. M. 1998. Ethics: a pluralistic approach to moral theory. 2nd ed. Harcourt Brace, New York.
Hoefnagel, E., A. Burnett, and D. C. Wilson. 2006. The knowledge base of co-management. Developments in Aquaculture and Fisheries Science 36:85–108.
Holling, C. S., and G. K. Meffe. 1996. Command and control and the pathology of natural resource management. Conservation Biology 10:328–337.
Hume, D. 2007. A treatise of human nature. Ed. David Fate Norton and Mary J. Norton. Clarendon Press, Oxford. Originally published in 1739.
Johnson, D. S., A. Lalancette, M. E. Lam, M. Leite, and S. K. Pálsson. 2018. The value of values for understanding transdisciplinary approaches to small-scale fisheries. Pages 35–54 in R. Chuenpagdee and W. Jentoft, editors, Transdisciplinarity for small-scale fisheries governance, MARE Publication Series, vol. 21. Springer, Cham, NY.
Jones P. J. S. 2009. Equity, justice and power issues raised by no-take marine protected area proposals. Marine Policy 33(5):759–765. http://dx.doi.org/doi:10.1016/j.marpol.2009.02.009.
Jones, B .L., R. K. F. Unsworth, S. Udagedara, and L. C. Cullen-Unswrorth. 2018. Conservation concerns of small-scale fisheries: by-catch impacts of a shrimp and finfish fishery in a Sri Lankan lagoon. Frontiers in Marine Science 5:52. https://doi.org/10.3389/fmars.2018.00052.
Kant, I., P. Guyer, P., and A. W. Wood. 1998. Critique of pure reason. Cambridge University Press, Cambridge and New York.
Kittinger, J. N., L. C. L. Teh, E. H. Allison, N. J. Bennett, L. B. Crowder, E. M. Finkbeiner, C. Hicks, C. G. Scarton, K Nakamura, Y. Ota, J. Young, A. Alifano, A. Apel, A. Arbib, L. Bishop, M. Boyle, A. M. Cisneros-Montemayor, P. Hunter, E. le Cornu, M. Levine, R. S. Jones, J. Z. Koehn, M. Marschke, J. G. Mason, F. Micheli, L. McClenachan, C. Opal, J. Peacey, S. H. Peckham, E. Schemmel, V. Solis-Rivera, W. Swartz, and T. ‘A. Wilhelm. 2017. Committing to socially responsible seafood. Science 356(6342):912–913.
Koel, T., P. White, M. Ruhl, J. Arnold, P. Bigelow, C. Detjens, P. Doepke, and B. Ertel. 2017. An approach to conservation of native fish in Yellowstone. Yellowstone Science 25(1):4–12.
Kokotovich, A. E., and D. A. Andow. 2017. Exploring tensions and conflicts in invasive species management: the case of Asian Carp. Environmental Science and Policy 69:105–112. https://doi.org/10.1016/j.envsci.2016.12.016.
Kretz, L. 2015. Teaching being ethical. Teaching Ethics 15:1. DOI: 10.5840/tej2014111311.
Lam, M. E. 2016. The ethics and sustainability of capture fisheries and aquaculture. Journal of Agricultural and Environmental Ethics. 29 (1):35-65. DOI:10.1007/s10806-015-9587-2.
Lam, M. E. 2019. Seafood ethics: reconciling human well-being with fish welfare. Pages 177–197 in B. Fischer, editor, The Routledge handbook of animal ethics. Routledge, New York. https://www.uib.no/sites/w3.uib.no/files/lam_2019_routledge_handbook.pdf.
Lam, M. E., and D. Pauly. 2010. Who is right to fish? Evolving a social contract for ethical fisheries. Ecology and Society 15(3):16. http://www.ecologyandsociety.org/vol15/iss3/art16/.
Lam, M. E., and T. J. Pitcher. 2012. The ethical dimensions of fisheries. Current Opinion in Environmental Sustainability 4:364–373. https://doi.org/10.1016/j.cosust.2012.06.008.
Loring, P. A. 2017. The political ecology of gear bans in two fisheries: Florida’s net ban and Alaska’s salmon wars. Fish and Fisheries 18:94–104.
Lynch, A. J. 2014. Finding fish in faith. The Fisheries Blog. Available at https://thefisheriesblog.com/2014/04/21/finding-fish-in-faith/. Accessed 14 April, 2021.
Manfredo, M. J., T. L. Teel, L. Sullivan, and A. M. Dietsch. 2017. Values, trust, and cultural backlash in conservation governance: the case of wildlife management in the United States. Biological Conservation 214:303–311.
Marietta, D. E., Jr. 1993. Pluralism in environmental ethics. Topoi 12:69–80.
McCauley, D. J., C. Jablonicky, E. H. Allison, C. D. Golden, F. H. Joyce, J. Mayorga, and D. Kroodsma. 2018. Wealthy countries dominate industrial fishing. Science Advances 4(8). DOI: 10.1126/sciadv.aau2161.
Mehlich, J. 2017. “Is, ought, should”—scientists’ role in discourse on the ethical and social implications of science and technology. Palgrave Communications 3:17006. DOI: 10.1057/palcomms.2017.6 | www.palgrave-journals.com/palcomms.
Meyers, R. B. 2002. A heuristic for environmental values and ethics, and a psychometric instrument to measure adult environmental ethics and willingness to protect the environment. PhD diss., Ohio State University, Columbus.
Mill, J. S. 1859 [1975]. On liberty. W.W. Norton, New York.
Mill, J. S. 1863. Utilitarianism. Parker, Son, and Bourn, London.
Minteer, B. A. 2012. Refounding environmental ethics: pragmatism, principle, and practice. Temple University Press, Philadelphia.
Munk-Madsen, E. 2000. Wife the deckhand, husband the skipper: authority and dignity among fishing couples. Women’s Studies International Forum 23:333–342.
Murray, G., and A. Agyare. 2018. Religion and perceptions of community-based conservation in Ghana, West Africa. PLoS ONE 13(4):e0195498. https://doi.org/10.1371/journal.pone.0195498.
NOAA. 1999. Recreational fishing: angling code of ethics. National Atmospheric and Oceanic Administration. Federal Register 64(32):8067–8068. (Notice of final code of angling ethics, February 17).
Norton, B. G. 2005. Sustainability: A philosophy of adaptive ecosystem management. University of Chicago Press.
Olden, J. D., J. R. S. Vitule, J. Cucherousset, and M. J. Kennard. 2020. There’s more to fish than just food: exploring the diverse ways that fish contribute to human society. Fisheries 45(9):453–464.
Orth, D. J. 2019. Socrates opens a Pandora’s box of Northern Snakehead issues. Pages 203–221 in D. Chapman and J. Odenkirk, editors, First International Snakehead Symposium, American Fisheries Society Symposium 89. Bethesda, MD.
Ostrom, E., J. Burger, C. B. Field, R. B. Norgaard, and D. Policansky. 1999. Revisiting the commons: local lessons, global challenges. Science 284:278–282.
Palmer, C. 2010. Animal ethics in context. Columbia University Press, New York.
Pauly, D., and D. Zeller. 2016. Catch reconstructions reveal that global marine fisheries catches are higher than reported and declining. Nature Communications 7:10244.
Pitcher, T., Kalikoski, D., Pramod, G., and Short, K. Not honouring the code. Nature. 457, 658–659 (2009). https://doi.org/10.1038/457658a.
Prince, J. 2010. Rescaling fisheries assessment and management: A generic approach, access rights, change agents, and toolboxes. Bulletin of Marine Science 86:197–219.
Raman, S., P. Hobson-West, M. E. Lam, and K. Millar. 2018. “Science Matters” and the public interest: the role of minority engagement. Pages 230–250 in B. Nerlich, S. Hartley, S. Raman, and A. Smith, editors, Science and the politics of openness: here be monsters, Manchester University Press, UK.
Ratner, B. D., B. Åsgård, and E. H. Allison. 2014. Fishing for justice: human rights, development, and fisheries sector reform. Global Environmental Change 27:120–130.
Rawls, J. 1971. A theory of justice. Oxford University Press.
Reeves, A. 2019. Overrun: dispatches from the Asian Carp crisis. ECW Press, Toronto.
Robbins, P. 2012. Political ecology: a critical introduction. 3rd ed. Wiley-Blackwell, New York.
Sandler, R., and P. Cafaro, editors. 2005. Environmental virtue ethics. Bowman and Littlefield, Lanham, MD.
Schaefer, J. 2017. New hope for the oceans: engaging faith-based communities in marine conservation. Frontiers in Marine Science 4:62. https://doi.org/10.3389/fmars.2017.00062.
Singer, P. 2011a. The expanding circle: ethics, evolution, and moral progress. Princeton University Press, Princeton, NJ.
Singer, P. 2011b. Practical ethics. 3rd ed. Cambridge University Press.
Smith, L. M., J. L. Case, H. M. Smith, L. C. Harwell, and J. K. Summers. 2013. Relating ecosystem services to domains of human well-being: foundation for a U.S. index. Ecological Indicators 28:79–90.
Sternberg, R. J. 2012. A model for ethical reasoning. Review of General Psychology 6:319–326.
Taylor, R. 2002. Virtue ethics. Humanity Books, Amherst, NY.
Thompson, P. 1985. Women in the fishing: The roots of power between the sexes. Comparative Studies in Society and History 27:3–32.
Urbina, I. 2019. The outlaw ocean: journeys across the last untamed frontier. Alfred A. Knopf, New York.
Villanueva-Poot, R., J. C. Seijo, M. Headley, A. M. Arce, E. Sosa-Cordero, and D. B. Lluch-Cota. 2017. Distribution performance of a territorial use rights and co-managed small-scale fishery. Fisheries Research 194:135–145.
Viswanathan, K. K., J. R. Nielsen, P. Degnbol, M. Ahmed, M. Hara and N. M. Raja Abdullah. 2003. Fisheries co-management policy brief: findings from a worldwide study. WorldFish Center Policy Brief 2. Available at https://pdfs.semanticscholar.org/7426/79ddd9912aa5b2822fd91042f1b8a05cefb1.pdf.
Weaver, J. 1996. Defending mother earth: Native American perspectives on environmental justice. Orbis Books, Maryknoll, NY.
Westra, L. 2005. Virtue ethics as foundational for a global ethic. Pages 79–91 in R. Sandler and P. Cafaro, editors, Environmental virtue ethics, Bowman and Littlefield, Lanham, MD.
Whyte, K. P. 2019. How similar are indigenous North American and Leopoldian environmental ethics? In W. Forbes and T. Trusty, editors, Revisiting Aldo Leopold’s land ethic: emerging cultures of sustainability, Stephen F. Austin University Press, Nacogdoches, TX. Available at http://dx.doi.org/10.2139/ssrn.2022038.
Whyte, K. P., and C. J. Cuomo. 2016. Ethics of caring in environmental ethics: indigenous and feminist philosophies. Pages 234–247 in S. M. Gardiner and A. Thompson, editors, The Oxford handbook of environmental ethics, Oxford University Press.
Wilson, K. A., and E. A. Law. 2016. Ethics of conservation triage. Frontiers in Ecology and Evolution 4:112. http://dx.doi.org/10.3389/fevo.2016.00112.
1. Much research has been done on why people act for the short term, finding a range of explanations. Hardin (1968) argued that the Tragedy of the Commons drives people to do this because the lack of a management system encourages individuals to overexploit the resource. Hardin also explained that people in poverty need to prioritize short-term survival over long-term planning, so they overexploit resources.
2. Correct translation from Hebrew means “to take responsibility for meaning that humans were created by God . . . to exercise responsibility for the well-being of the garden Earth”. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.04%3A_Ethical_Reasoning_and_Conservation_Planning.txt |
Learning Objectives
• Describe the nervous system components involved in the perception of pain in fish.
• Apply criteria for pain to assess whether an animal perceives pain.
• Describe different criteria used to judge sentience.
• Create and critique ethical arguments for the treatment of fish.
• Judge conditions that are most likely to cause fish pain and suffering and actions to alleviate pain and suffering.
• Distinguish between three alternative views on animal welfare.
• Describe specific actions that can be taken to improve welfare of fish.
5.1 Relevant Questions
Fish are not stupid creatures. In fact, fish are socially complex, with highly developed learning abilities (Brown 2015). Fish feel pain and suffer as a consequence, and we must carefully examine welfare, use, and fishing practices. Scientists have questioned the outdated perspective that fish cannot have consciousness as their brain morphology is too simple and lacks the cerebral cortex present in humans. Yet, denial of fish pain perception prevails despite many recent, fascinating discoveries that demonstrate that fish do experience and remember exposures to noxious stimuli in a fashion that is far more complex than mere reflex. Consequently, there are many lively discussions on how we should treat fish.
Think of all the ways that you use fish in your life. Perhaps you enjoy sportfishing or keep tropical fish in aquariums. Maybe you harvest live fish for bait fishing. You may prefer to purchase fresh fish from the local seafood market. You may enjoy watching fish in public aquariums or by SCUBA diving. Or perhaps you identify with Santiago, the aging fisherman in The Old Man and the Sea, who struggles to reel in a giant marlin. Humans use fish for sport, food, pets, business, education, scientific research, and many other purposes (Olden et al. 2020). Whenever we use fish for any reason, we need to ask certain questions: How might our actions influence fish? Do fish feel pain? Do fish suffer? Are fish aware of their actions? Do fish in captivity have what they want? Is the fish healthy? How can we balance fish welfare with the benefits humans get from fish?
Although anglers and others have long pondered these questions, scientists began systematic investigations of these questions only within the last 50 years (Vettese et al. 2020). According to the International Association for the Study of Pain, pain is “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage” (Raja et al. 2020). What causes “unpleasant” and “emotional” responses in fish is a difficult scientific question to answer, long neglected by researchers. Early laws that regulated how animals are used in experiments excluded cold-blooded animals. The Health Research Extension Act of 1985 (PL 99-158, 1985) and the Animals (Scientific Procedures) Act (1986) gave protections to fish and further stimulated the science of animal suffering to include fish (Dawkins 2008; Braithwaite 2010). After the first study investigating whether fish feel pain was published (Sneddon 2002; Sneddon et al. 2003a), many strong feelings and debates emerged (Figure 5.1). This chapter presents the factual evidence and philosophical views and practices related to minimizing pain and suffering in fish.
Our personal decision making about how to treat fish involves reflecting on facts, intuitions, and moral principles about pain and suffering in fish. As such, we judge the relevance of both factual or descriptive statements as well as relevant moral principles. In practice, these reflections are difficult and demand that we participate in dialogue and debate with others who may disagree with our views. Disagreements may be over acceptability of moral principles or over the facts about consequences of different welfare measures on fish consciousness and suffering. Ethical considerations of fish involve application of existing normative theories (Meijboom and Bovenkerk 2013; Michel 2019; Veit and Huebner 2020), resulting in alternative perspectives (List 1997; Allen 2013; Rose et al. 2014; Key 2015, 2016a, b). If this was easy, someone would have done it already.
Who hears the fishes when they cry?
―Henry David Thoreau, A Week on the Concord and Merrimack Rivers, 1849
5.2 Pleasure and Pain Perception
Jeremy Bentham was one of the great thinkers in moral philosophy. He developed the theory of utilitarianism as the basis for law in 18th century England. In Bentham’s view, laws should serve to maximize the interests and preferences of all individuals. The foundation of utilitarianism held that pleasure is the only good, and pain, without exception, is the only evil. In response to creating a penal code regarding cruelty to animals, Bentham wrote, “The question is not, Can they reason? nor, Can they talk? but, Can they suffer?” This proposition formed the beginnings of utilitarian arguments for the ethical treatment of animals (Singer 1975).
Until recently, few scientists asked the question, “Do fish feel pain?” Here I highlight some key findings from studies on fish pain that asked three questions: (1) Do fish have the necessary receptors and nerve fibers to detect painful events? (2) Did a potentially painful stimulus trigger activity in the nervous system? (3) How did the experience of a potentially painful event affect the behavior of fish and decisions made? (Sneddon et al. 2003a; Braithwaite 2010).
Do fish have receptors to detect painful events? Nociceptors, the sensory receptors to detect noxious stimuli, are present in mammals, birds, reptiles, amphibians, lampreys, and bony fish. Even far distant animal groups, such as leaches, sea slugs, and fruit flies, have nociceptors (Whitear 1971; Matthews and Wickkelgren 1978; Sneddon 2002; Smith and Lewin 2009). Strangely, a few studies suggest that sharks and rays seem ill equipped to detect noxious stimuli, although more studies are needed (Snow 2003). The first descriptions of pain receptors in bony fish revealed that they were similar in size and structure to those observed in birds and mammals (Schnitzler and Ploner 2000; Sneddon 2002; Sneddon et al. 2003a, 2003b, 2018; Sneddon 2019). Nociceptors mapped on the head of Rainbow Trout indicate where pressure and chemical stimuli are detected (Figure 5.2).
Does the painful stimulus trigger activity of the nervous system? Scientists measure the electrical signals in nerves to determine if they respond to stimuli. They also use a technique called electroencephalography (EEG) to record electrical activity of the brain. For example, EEG was used to determine loss of and return of consciousness following stunning in studies designed to discover the quickest methods for killing fish (Robb et al. 2000). When the pain receptors in trout were stimulated by mechanical means, heat, or acid, activity in nerve fibers was recorded (Ashley et al. 2007). The painful stimulus triggered a quick reflex reaction. The second response to the painful stimulus requires processing in the brain and leads to the third question.
How did the experience of a potentially painful event affect the behavior of fish and decisions made? Think about pain that you have experienced. Minor pain may be tolerated without much affect. However, chronic or intense pain will be a priority concern and cause you to change your behavior. Therefore, the third question asks whether behavior or decision making changes after a potentially painful event. Trout responded to acid or bee venom applied to the lips by rubbing their lips against the gravel at the bottom of the holding tank (Sneddon et al. 2003a, 2003b). In other experiments in which Rainbow Trout were exposed to noxious stimuli, they stopped feeding and showed lower antipredator behaviors and lowered aggression with other Rainbow Trout (Ashley et al. 2009). The adverse effects were relieved by painkillers, such as aspirin, morphine, and lidocaine (Lopez-Luna et al. 2017; Sneddon 2015, 2019; Sneddon et al. 2018a).
Question to ponder
What is the principal evidence for concluding that fish can experience pain? Explain the questions and methods for the scientific studies. Would you expect all types of fish to have the same types, locations, and number of pain receptors? Why?
5.3 Are Fish Sentient?
In judging whether an animal deserves respect or protection, what matters morally is whether an animal is sentient and can be benefited or harmed by our actions (Singer 1975, 2010, 2011; Horta 2018). A sentient being can detect and sense external stimuli and is aware of how this perception alters its mental status. The concept of sentience provides the foundation for the animal welfare and animal rights movements (Regan 1983). The moral reasoning follows the argument: (1) If a being is sentient, then it deserves serious moral consideration; (2) fish are likely to be sentient; (3) therefore, fish deserve serious moral consideration (Lund et al. 2017). Whether an animal is sentient is based on the following five capabilities (Figure 5.3; Broom 2014).
Evaluate the actions of others in relation to itself and third parties (i.e., form relationships within and between species).
Anyone who has ever kept fish in aquariums knows that fish will quickly remember who feeds them and gradually habituate to the presence of the person doing the feeding. Fish develop relationships with their aquarium feeder. Fish develop relationships with other fish. We see behavioral displays and dominance in a small group of fish, especially when fish are in captivity. Cooperative relationships are observed in breeding cichlid fish, which care for their young offspring. Even different species, such as moray eels and grouper, may form cooperative hunting behaviors to enhance feeding success (Bshary et al. 2006). They can evaluate hierarchies from a third-part perspective through transitive inference.
Remember some of its own actions (the cognitive ability to learn and recall those memories that should influence future behavior).
In captivity, fish will quickly learn where the food is coming from; if the location changes, fish will learn a new location. In fish farms, fish learn to operate demand feeders. Fish also learn by watching each other (social learning) and avoid fighting with larger, stronger individuals. Many species of fish will return to their home after being experimentally displaced. They learn spatial arrangements in the environment and can remember the whereabouts of different locations and learn migration routes from watching other more experienced fish. Fish learn to avoid nets and hooks and retain that memory for almost a year. They also learn the location of dangerous places and avoid them. More studies on fish learning are highlighted in section 5.6.
Assess risks and benefits (make decisions based on the information available externally and its own subjective state).
Fish in the wild are always at risk of being eaten by a larger predator. If all behaviors were instinctive, the amount of risk-taking behavior would be constant, but that is not the case. In a controlled experiment, juvenile sea bass with higher metabolic demands were more likely to take risks after being deprived of food (Killen et al. 2011). Their behavior changed because the motivation (and benefits) of feeding when very hungry outweighed the potential risk of predation (i.e., they prioritized food over predation risk). Therefore, the risk taking depended on the relative benefits and was not a simple stimulus-response reflex. Fish behavior is often guided by the risk sensitivity: they are constantly attempting to balance the risk of certain behaviors (such as exposure to predators while feeding) with the expected benefits (increased feeding leads to growth and reproduction).
Have some feelings (positive or negative affective states such as pain, fear, and pleasure).
We understand and regularly speak of human emotions, such as fear, anxiety, grief, love, happiness, and pain. We can see these emotions in the faces of other humans. The idea that fish have feelings is often met with a response of disbelief. Whether fish have feelings or emotions was not studied because most behaviorists believed responses to stimuli, such as presence of a predator, was instinctive and not related to the emotion of fear. Discerning whether a fish has feelings is challenging, in part because fish live in environments that make it difficult to observe. Yet, fish need to experience pain, fear, and other feelings in order to respond effectively to their environment and survive (Darwin 1872; Millot et al. 2014; Cerqueira et al. 2017).
Fear is a feeling that protects animals from danger. The flight or fright physiological response is a conservative trait in vertebrates. Brains of fish and mammals have homologous structures that process fear stimuli and cause consistent responses. Fish such as Siamese Fighting Fish and zebra fish respond to antidepressant drugs by reducing aggression (Dzieweczynski and Hebert 2012; Theodoridi et al. 2017). These studies demonstrate that fish exhibit responses similar to those observed in humans and that these responses are controlled by the same neurotransmitters.
In addition to fear, fish are capable of positive and negative moods. Recently, ethologists tested whether Convict Cichlid fish, a monogamous fish, showed a negative mood (pessimistic) when partnered with a nonpreferred mate (Laubu et al. 2019). These findings demonstrated that fish experience similar emotions to humans. Serotonin plays a role in emotions in all vertebrates; zebra fish are extensively used to test new medications for anxiety and depression (Pittman and Lott 2014). Play behavior was long deemed to be a trait only exhibited in mammals. To study play in fishes, play was defined as “repeated, seemingly non-functional behavior differing from more adaptive versions structurally, contextually, or developmentally, and initiated when the animal is in a relaxed, unstimulating, or low stress setting.” Behaviors of fish that fit the definition of play include leapfrogging, balancing twigs, batting around balls, jumping into the air, and striking a self-righting thermometer (Burghardt et al. 2015).
Have some degree of awareness (often termed consciousness).
The ability to recognize oneself in a mirror is a rare capacity, once believed to be restricted to great apes, elephants, dolphins, and magpies (Gallup 1970; Plotnick et al. 2006; Prior et al. 2008; Reiss 2012). If an animal recognizes that the image in the mirror is its own, it will cease to respond to the reflection socially and will recognize changes over time. The mirror test is a long-standing test of self-awareness (Gallup 1970), and until recently, few studies tested self-recognition in fish. When manta rays were exposed to the mirror test, they spent more time when a mirror was present in their holding tank, especially in the first ten minutes of the experiment. While visually oriented to the mirror, manta rays made unusual or repetitive behavior, including bubble blowing and atypical social behaviors (Ari and de Agostino 2016). When exposed to a mirror, the Cleaner Wrasse (Labroides dimidiatus) first interacted aggressively as if seeing a rival, but aggressive reactions decreased over time. Instead, it showed atypical behaviors. After individuals were given a visible mark, they would posture in front of the mirror in order to view the location of the mark. Compared to controls with marks that were not visible, marked Cleaner Wrasse spent significantly longer in postures that would allow them to observe color-marked sites in the mirror reflection (Kohda et al. 2019). These findings that fish “passed” the mirror test were surprising to most scientists. It is still unclear whether scientists will accept the findings or question the mirror test and seek alternative tests for cognitive abilities of fish (de Waal 2019; Vonk 2020).
It is difficult to characterize what nonhuman animals are thinking about in relation to others, feelings, or awareness because they do not use a language that humans understand. Therefore, the evidence of sentient abilities in fish often comes from studies of fish behavior (Brown 2015; Sneddon and Brown 2020). In the study of fish behavior, scientists attempt to understand the thoughts of fish from manipulative studies that provide fish with choices and rewards. It’s a neat way of allowing fish behavior to tell scientists what the fish is thinking. From many recent studies of fish cognition, patterns are emerging to support the five criteria for sentience in fish (Sneddon and Brown 2020).
Question to ponder
Think about a fish species for which you have some familiarity. Does this fish exhibit some or all of the five capabilities that are criteria for sentience? If you are uncertain, how might you test the fish for one or more of these capabilities? Link to https://scholar.google.comand search for “fish_name” AND “pain” to see if any scientific studies have been published.
5.4 Skeptics and the Pursuit of Empathy
Since the first studies of fish pain, many skeptics have questioned the finding that fish feel pain and suffer and have opposed the need for regulations governing the welfare of fish (Rose 2002; Rose et al. 2014; Key 2015; Diggles and Browman 2017; Browman et al. 2019). Unlike certain mammals, fish lack a familiar face and voice that reveals emotional cues, and they lack nonhuman charisma that motivates advocates (Lorimer 2007). In response to the arguments of skeptics, Sneddon et al. (2018b) note that (1) “Skeptics still deny anything beyond reflex responses in fishes and state that they are incapable of complex cognitive abilities”; (2) “Processing is not restricted to hindbrain and spinal reflexes as skeptics have suggested”; and (3) “Widespread calls for use of the precautionary principle have been called into question by skeptics”—for example, “We should abandon the precautionary principle because the costs to industry would be too high.”
The “no cortex, no cry” argument, the dominant argument of the skeptics (Smith 1968; Rose 2002; Key 2016a; Dinets 2016), maintains that (1) If x feels pain, then x has a neocortex; (2) Fish do not have a neocortex; (3) Therefore, fish do not feel pain.
The counterargument postulates that fish depend on different neural pathways for pain processing that closely parallel those of the amygdala and hippocampus in mammals (Agetsuma et al. 2010; Michel 2019). Basic features of the forebrain (i.e., basal ganglia) involved in decision making, behavior, and rewards are similar in mammals and lampreys, a vertebrate lineage that diverged 560 million years ago (Grillner and Robertson 2016). While the brain of fish is smaller and less structured than the brain of mammals, there is high variation in brain structure among different fish species. Brain functions and neural circuits in fish, though not homologous to the mammalian brain, are complex enough to support phenomenal reasoning and consciousness (Brown et al. 2011; Woodruff 2017).
Charles Darwin first explored the notion of evolutionary continuity and emotions and believed that if humans feel emotions and can suffer, then so too can other animals, but their feelings are not necessarily identical (Darwin 1872). Although scientists have accumulated much evidence that fish fulfill Brown’s criteria for sentience, denial of sentience in fish persists. At the risk of oversimplifying the many writings by those denying sentience in fish, I offer two views often presented. First, many criticize the experiments and argue that scientists have yet to falsify the null hypothesis that “fish do not feel pain” or claim that pain is fundamentally different in nonhuman animals (Key 2016b; Browman et al. 2019). The other common argument is often a “slippery slope” fallacy that asserts that relatively small steps in protecting animals will culminate in significant restriction or bans in certain fishing sectors.
With the emergence of studies on fish consciousness, scientists have questioned whether there is a distinctive line between sentient and nonsentient animals (de Waal 2019; Vonk 2020). Studies of behavior and cognition in fish point to the need for more valid tests for cognitive abilities of fish. Sentience is typically treated as a property that organisms either have or do not have. Alternatively, organisms may possess varying degrees of sentience (Figure 5.4) that influence moral considerability (Veit and Huebner 2020). The controversy over sentience opens a new challenge of understanding the basis for empathy across different species. As a human society, we are struggling to understand what knowledge may lead to actions of care for others (Adriaense et al. 2020).
Question to ponder
Regarding pain and sentience in fish, do you feel empathy for fish? Does your need for seafood to eat eclipse sentience? How do you reconcile findings about fish sentience and your sense of moral obligation to making a difference in lives of fish?
5.5 Learning in Fish
Numerous studies support the hypothesis that fish are intelligent, highly social animals. As expected, fish show variation in learning abilities. Fish are capable of learning because they have high-order capabilities, including awareness, reasoning, and consciousness. Yet, popular media are not kind to fish. Dory, the regal Blue Tang in the movie Finding Nemo, is a caricature of the forgetful fish with a short-term memory. In contrast, recent studies tell us that certain fish have long-term memories comparable to other vertebrates (Brown 2001; Brown and Laland 2003, 2011). Fish can recognize one another, learn from dominance relations, use tools, cooperate with other fish, develop cultural traditions, and even have distinctive personality traits. Examples from a few significant experiments reveal impressive memory and abilities to learn.
Behaviors observed in fish reveal their memory and learning. Transitive inference is the ability to infer a relationship between items that have not been previously directly compared. In humans, children around the age of five can infer that if John is taller than Mary, and Mary is taller than Sue, then John is taller than Sue. In one experiment, a male cichlid fish, which is aggressive with other males, was able to observe fights between pairs of male cichlids. Let’s assume the individual cichlid watches as combatant A beats combatant B, B beats C, and C beats D. If the cichlid is now placed in a chamber with A and D, would it avoid either cichlid? If the cichlid avoided A more than D, it has deduced the dominance relationship, even though it never observed the two fish together. This is an example of transitive inference, which requires conscious awareness of the relationships (Grosenick et al. 2007).
In another experiment, rainbow fish learned to escape from a net trawled through an experimental tank and remembered the information for 11 months (Brown and Warburton 1999; Brown 2001). This length of memory was similar to that observed by Common Carp. After capture by hook and line, Common Carp learned to avoid baits presented on hooks and remembered this experience for many months. When foraging in food patches where previous hooking events took place, carp change behavior and spit out baited hooks without being hooked (Klefoth et al. 2013). Common Carp do not have to be captured in order to learn this lesson. Individuals that observed the hooking, struggle, and release of other carp, avoided baits on hooks seven days after the experience (Wallerius et al. 2020).
Tool use was long considered a defining feature separating humans from all other species. Our human perception of “tools” creates difficulty for fish, which have no grasping appendages. Furthermore, the watery environment is more viscous and buoyant, which restricts the mechanical forces involved in operating a “tool.” Studies on cognition in nonhumans necessitated a new definition of tool use that required that the animal “must directly handle an agent to achieve a goal.” Suddenly, many behaviors indicated that some fish were tool users (Keenleyside and Prince 1976; Keenleyside 1979; Coyer 1995; Bshary et al. 2002; Paśko 2010; Jones 2011; Bernardi 2012; Brown 2012). Brown Hoplo Catfish (Hoplosternum thoracatum) glues its eggs to a leaf and carries it like a tray (tool) to the safety of a foam nest. South American cichlids also lay eggs on leaves and will move the eggs on leaves to protected locations. The Sixbar Wrasse, when presented with food pellets too large to swallow, used a rock held in its mouth as a tool to batter the food pellet. Archerfish learn to shoot a stream of water at terrestrial insects above the water. Damselfish clean a vertical rock face by gathering sand in their mouth and sandblasting (Keenleyside 1979). Damselfish also maintain desirable algal patches by weeding out other algal species.
Fish recognize each other, which allows for cooperative behavior, social learning, and signaling (Griffiths and Ward 2011). Fish can recognize familiar individuals by their unique odor or visual cues. They can also identify close kin. Recognition provides fish with the ability to form large shoals of similar fish, thereby creating safety in numbers. Migrating Steelhead Trout, for example, form associations that persist during their long-distance migrations. Constant associations may lead to formation of social networks among individuals (Krause et al. 2017) and enhance social learning pathways. Social learning was previously thought to be restricted to birds and mammals. However, experiments with fish demonstrate numerous situations where individual fish learn from others (Brown and Laland 2011). For example, fish can learn about risky habitats from their own experience or from the reactions of other fish. Human fishing activities may influence fish learning. Removal of more knowledgeable individuals may disrupt social transmission of information, such as location and routes to feeding or spawning grounds. Furthermore, the improved effectiveness of fishing gears may at some point overcome the ability of fish to learn (Ferno et al. 2011), which means fish can no longer adapt their behavior to avoid being caught. Understanding how fish learn has important and unexplored applications, such as training of fish before conservation restocking.
Question to ponder
International Association for the Study of Pain (IASP) states that “activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state.” Pain requires a state of consciousness, which is processed in the cortex in humans. Do we know where fish consciousness resides? How do we know fish are aware? Are you convinced that fish can and do experience pain?
5.6 Welfare and Well-Being
The emerging picture informs our understanding of the intelligence, learning, and memory of fish. Evidence that fish are sensitive to pain and are self-aware is sufficient to lead many to conclude that fish exhibit relevant, morally significant capacity to suffer. Animals that are intelligent have greater capacity to suffer, and people are more likely to show empathy toward fish that they believe are intelligent (Bekoff 12014; Brown 2015). Fish are popular pets—only cats and dogs are more popular (Iwama 2007). Fish caught by global fisheries number in the trillions, and fish farming kills billions each year, more than the number of chickens killed for human consumption. Yet, wild fish are hardly as visible to us and do not share a common environment. This separation creates a challenge for questions of animal welfare (Meijboom and Bovenkerk 2013).
The term “welfare” addresses the physical and mental health and well-being of a fish or group of fish. Scientists and ethicists differ on how to approach animal welfare. For example, the animal welfare views held by individuals may be based on
• Function, that is, indicative of growth or fecundity;
• Nature, which relates to the ability to lead a natural life in the wild; or
• Feelings, which focuses on mental states rather than physical health and emphasizes not only the avoidance of stress or fear, but also the opportunity to experience positive feelings (Fraser 1995).
The function-based approach is advocated by recreational angling interests (Arlinghaus et al. 2007). The third view is advocated by animal welfare advocates. Good animal welfare practices mean fish “are healthy and have what they want” (Dawkins 2008). This statement obliges us to determine animals’ wants and presupposes that we can determine positive states of emotion. However, the scientific findings regarding pain and consciousness are now being filtered through ethical disputes between anglers, fishing and fish farming industries, and animal-rights advocates to develop norms and legal protections for fish. As expected, the animal rights advocates stress that the lives of fish are valuable in and of themselves (intrinsic value) and not because of their utility to humans. The views of others who value fish for human uses are in conflict. Therefore, they may question whether it is relevant that fish feel pain and suffer or can feel pleasure and enjoyment.
The views of stakeholders and society at large about mental capacities of fish and their moral status have not been systematically examined, but welfare decisions will have to consider a plurality of moral views. Attempts to provide objective measures of welfare in captivity or during and after capture may not be easily determined from existing models of domestic livestock (McGreevy et al. 2018; Barrell 2019; Browning 2020). While some scientists reject the empirical evidence on fish sentience, animal welfare practices are costly, debatable, and engage numerous social values and novel questions (Jacquet 2018). Only in the context of different fishing practices does it make sense to engage in the debates over animal welfare. Behavioral and physiological assessment of fish can be conducted to determine if fish are relaxed, agitated, anxious, or distressed. For example, levels of cortisol in the blood are universally used to indicate stress, a negative welfare status.
Question to ponder
In the future, do you believe that fish will continue to be treated as commodities—that is, caught, farmed, and eaten without moral consideration? What moral status will fish occupy in the future? Which of the three views (feelings, nature, functions) would you adopt to decide how to address welfare of fish?
5.7 Fish as Research Subjects
Fish are used in a wide variety of research studies, and this use may cause suffering or death. Therefore, suffering or death of research animals must be justified by scientific or medical advances that could not be achieved in any other way. Any scientist planning to use animals in their research must first show why there is no alternative, and consider the three Rs in order to minimize numbers of fish suffering:
• Replace the use of animals with alternative techniques or avoid the use of animals altogether.
• Reduce the number of animals used to a minimum, to obtain information from fewer animals or more information from the same number of animals.
• Refine the way experiments are carried out, to make sure animals suffer as little as possible. This includes better housing and improvements to procedures that minimize pain and suffering and/or improve animal welfare.
From a risk-management perspective, the ethical costs of making an error in this judgment are huge given the massive number of fish that are involved in fisheries and scientific research (Brown 2015). Guidelines for the use of fish in research are most often informed by empirical evidence with regard to the capacity of animals to experience pain (Sneddon 2015; Message and Greenhough 2019). Scientific associations have developed ethical justifications for allowable use of fish in research (Metcalfe and Craig, 2011; AFS 2014; Elsevier 2012).
5.8 Fish as Pets
Although welfare of fish as pets has been historically ignored, recent findings on fish pain, aesthetic concerns, and higher costs among serious hobbyists have raised concerns. Fish, such as Goldfish, have feelings and perceive pain and are capable of learning. Pet fish owners who provide adequate environments will see healthy fish that display a broader array of behaviors in fish tanks. Some estimates suggest that the aquarium-keeping industry is worth between 15 and 40 billion U.S. dollars globally, with approximately 10% of the U.S. and U.K. populations already invested in aquarium keeping (Marchio 2018; Sneddon and Wolfenden 2019). Growing numbers of veterinarians are gaining clinical experience with pet fish (Hartman et al. 2006). Common welfare issues include purchasing fish that grow too large for aquariums, overstocking an aquarium, water quality, inadequate water filtration, poor diets, and mixing incompatible species. Many aquarium keepers have misconceptions regarding the lifespans of fish and the required level of care. Further, when individual fish are affordable, their perceived value and concern for welfare are very low. Many unique varieties of Goldfish are prone to medical conditions that affect their welfare in captivity (Brown et al. 2019). Other welfare issues relate to the conditions in the supply chain, which often includes harvesting from wild populations and little concern for welfare during transport. Because fish are often one of the first pets that children obtain and care for, there is great opportunity for education in welfare concerns and conservation via the aquarium-keeping industry (Marchio 2018). In the future, better education, veterinary care, and creating codes of practice should improve the welfare of ornamental fish in captivity (Walster et al. 2015).
5.9 The Angler’s Dilemma
Justification for other uses of fish often considers the type of benefits that humans derive and whether harm is intentional (Figure 5.5). When viewing fish, humans are not consuming or removing individuals and do not intend to harm them. Consequently, little attention is paid to welfare issues associated with viewing wild fish. However, recreational fish may be pursued for food, competition, trophies, or leisure (catch and release). Most recreational anglers practice a mix of these pursuits, which complicates the ethical considerations. Subsistence and commercial fishing and fish farming are responsible for the highest numbers of fish killed worldwide.
The angler’s dilemma about treatment and welfare of the fish captured has a long history. The utilitarian argument maintains that the only morally justifiable reason for catching fish is to kill and eat them. When assessing the consequences of our actions, it is necessary to take the interests of animals seriously and to weigh any adverse effects on those interests from human actions as part of the consequences of those actions (Singer 1975). Consequently, some anglers feel strongly that catching fish for mere sport, not for food, is objectional. British poet and fly angler John Gay (1685–1732) argued in favor of the moral superiority of fly-fishing over other forms of angling on the grounds that fly anglers did not mistreat worms, insects, small fish, and frogs as did bait fishers (Schullery 2008). The first fishing code of ethics that advised anglers on how to minimize cruelty to fish was published in 1876 (Raymond 1876). Despite the long history of concerns, the welfare concerns about recreational fishing are still hotly debated today.
“If a fish could scream, a lot of things would be different”—this statement was attributed to fly-fishing writer Charles Brooks (Schullery 2008). It is easier for us to discount the suffering of fish because they do not make the intensity of their suffering known to us in a way that evokes our emotional response. As such, we would never permit fly-fishing for songbirds. Roderick Haig-Brown, in “The People’s Right to Go Fishing” (1939, 162) wrote, “There can be no doubt that animals, birds and fish feel pain. . . . They feel pain; and they know fear—not fear of death or future suffering—but immediate fear of an immediate, visible threat to themselves, fear of present pain or present restraint, and ever fear of something directly associated with pain or restraint.” Apparently, Haig-Brown was decades ahead in refuting the long-held notion that fish lack the neurological mechanisms to feel pain or experience awareness.
Among the three perspectives on welfare with respect to recreational fishing, most angling interests have argued for the functions-based or feelings-based approaches, and not the nature-based approach. Feelings-based approaches sometimes critique fishing terms, such as “fighting” or “playing” the fish. Writer John McPhee (2002) considered “playing” a euphemism for “at best torturing and at worst killing a creature you may or may not eat.” And de Leeuw (1996) maintained that sportfishing involves (a) killing fish and (b) purposefully inflicting pain and suffering in them in order for anglers to have “sport” with them. This is sometimes referred to as the “sadistic” argument against sportfishing. If one holds true to the principle of avoiding all suffering in animals, then they must reject all sportfishing. Sport anglers value sport with fish more than they respect the lives of animals pursued (de Leeuw 1996). Participation in sportfishing requires justification for inflicting avoidable pain and suffering.
Participants will claim that the utilitarian benefits of sportfishing outweigh any harm to fish. If conservation does not arise from angling, then clearly one cannot justify angling (de Leeuw 1996). Anglers support conservation via license fees, excise taxes, support for conservation organizations, and participation in creel surveys and volunteer work. Do these efforts justify the avoidable pain and suffering? One must consider the activities supported and whether they create more fish in the future. Do these activities outweigh harm to fish? Answering that question is a very substantial task. The argument proposed by de Leeuw (1996) did precipitate other counterarguments (Chipaniuk 1997; List 1997). As outlined by Olsen (2003), the sadistic argument is as follows (note: I replaced “sport fisherman” with the gender-neutral term “angler”):
• Premise: if the angler deliberately inflicts pain on fish and the infliction of pain on fish is the source of enjoyment, then sportfishing is an activity that involves deliberate and excessive cruelty morbidly enjoyed;
• Premise: the angler deliberately inflicts pain on fish;
• Premise: the infliction of pain on fish is the source of enjoyment for anglers;
• Premise: all activities that involve deliberate and excessive cruelty morbidly enjoyed are sadistic;
• Premise: all sadistic activities are unethical activities;
• Conclusion: sportfishing is an unethical activity.
Indigenous people advocate for banning the practice of catch-and-release fishing. In Switzerland and Germany, catch-and-release fishing is considered inhumane and is now banned. In some cases, the acceptance of the pain and suffering argument has led to bans on competitive fishing, put-and-take fishing, and use of live baitfish. The sadistic argument has not persisted because in the mind of the angler, there is a disconnect between fish behavior and fish pain. It is not the infliction of pain in fish that the angler enjoys but the experience of enticing the fish to bite and retrieving the struggling fish. If the fish did not struggle on the line, it is unlikely that sport anglers would pursue fishing. To argue that all who participate in sportfishing are sadists is an attack on the person more than the argument. Argumentum ad hominem, which refers to an attack on the person and not the argument, is a weak form of argumentation. Sportfishing may be wrong, but those who participate in the activity need not be sadists.
Those who argue for welfare considerations for fish from a functions-based view recognize that angling induces stress and may cause injuries (Arlinghaus et al. 2007, 2009; Arlinghaus and Schwab 2011). For example, angling often causes injuries that may depress the ability of the fish to feed and survive after release (Thompson et al. 2018). The pragmatic argument maintains that recreational fishing is a legitimate leisure activity that also contributes to overall food security and personal nutrition (Cooke et al. 2018). Furthermore, fishing may serve as a therapeutic coping mechanism for distressed individuals (Craig et al. 2020). The pragmatic argument may or may not accept the existence of pain, suffering, and consciousness in fish. However, rather than applying a rigid egalitarian perspective that fish morally deserve equal status, the pragmatist adapts to the complexity of real-life tradeoffs (Crittendon 2003; Dawkins 2017). Hence, the focus is on the welfare of fish from measures of health and fitness of individuals and attempt to balance the interests of anglers with the interests of fish. Anglers and fisheries managers may implement regulations or recommendations for gear choice, landing nets, catch-and-release fishing, and other practices that minimize fish welfare impairments (Ferter et al. 2020).
In practice, the weighing of concerns of fish and humans has not been a routine activity (Sandøe et al. 2009), but it is obvious in some fishing codes of ethics. Cooke and Suski (2005) and Cooke and Sneddon (2007) suggested that there are specific actions that anglers could take to minimize negative consequences on fish.
• Minimize angling duration.
• Minimize air exposure and improve handling.
• Terminal tackle choices can affect fish.
• Avoid angling in extreme environmental conditions or habitats.
• Avoid angling during the reproductive period.
• Avoid tethering of live fish on stringers.
• All fish bleeding from hooked gills should be killed.
• Dispatching a caught fish should be undertaken quickly and humanely by a blow to the head or spiking through the brain just behind the eye.
Question to ponder
Consider the last time you went fishing for recreation. How did you handle your catch? Was it released? If you kept it, did you kill it in a humane way? Watch this video, “The Right Way to Kill a Fish.” The video demonstrates the use of ikejime for humane killing of recreationally caught tuna. Do you know how the fish you purchase to eat are caught and killed?
5.10 Commercial and Subsistence Fishing
Most discussions around commercial and subsistence fishing focus on conservation and maintenance of traditional fishing-based livelihoods and not on the emerging evidence of pain and suffering of fish. Suffering is caused to wild-caught fish throughout the process of capture until death. Yet, discussion of capture, landing, and killing practices in commercial fisheries is uncommon. However, advocates for animal welfare for commercially caught wild fish highlight the trillions of slow deaths (Mood 2010). Globally, 84 million tonnes of fish were harvested in 2019. In terms of numbers, between 0.8 and 2.3 trillion fish were killed each year by commercial fishing operations between 2007 and 2017 (based on registered landings only, not including all bycatch and discards; fishcount.org.uk). Observations of fishing at sea are difficult; but a few studies report that most fish were alive and conscious when landed and left to die of asphyxia or gutted alive. Death may typically take one hour (trawls), from one to four hours (seines), and from four to six hours (hooks), depending on the species, while nets may take up to 24 hours (Håstein et al, 2005). Moreover, the practice of placing live fish on ice merely prolongs the suffering.
Commercial and subsistence fishing provides food necessary for human sustenance, which would qualify as a reason for certain infringements on the interests of fish. However, the compromises that are morally acceptable depend on the philosophy being applied (Sandøe et al. 2003). If one argues that it is morally impermissible to harvest fish from the wild, and if it were to be prohibited, the lifestyle of many traditional and modern communities would be lost. Perhaps the moral benefit of preserving these communities and lifestyles outweighs the harm of at least certain kinds of fishing. The principle of cultural preservation would claim that fishing is a long-standing cultural practice that is central to a community’s way of life. The cultural preservation arguments would support claims for preserving fishing as a moral consideration to be weighed against other moral considerations. These arguments are especially relevant for small-scale artisanal or subsistence fishing.
Welfare of commercially caught and farmed fish from the wild is the last frontier for animal food production (Cook et al. 2018; Browman et al. 2019). These types of debates are inevitable, and guidelines for responsible fisheries were outlined in the Food and Agricultural Organization Code of Responsible Fisheries (FAO 1995). The FAO has no legislative authority, so the code is voluntary and depends on the willingness of the fishing industry, fishery managers, fishing communities, and peer pressure for adoption. Stakeholders in the commercial and subsistence fishing sectors must participate and raise concerns about the human interests to be balanced against interests of fish (Lam and Pitcher 2012; Lam 2019).
Question to ponder:
The largest fishery in the USA targets Alaska Pollock via midwater trawls. Vessels harvest, process, package, and freeze catch within hours of harvest to produce frozen fillets, fish sticks, and to supply McDonald’s Filet-O-Fish®. Learn more about this large commercial fishery by watching this video. How might you address fish welfare issues in this fishery?
5.11 Welfare Considerations in Fish Farming
Fishing farming is the fastest-growing animal producing sector in the world and plays an important role in global food security. Since the 1990s, most growth in fish production has come from aquaculture, which currently accounts for 49% of total fish production (FAO 2020). Many challenges face the fish farming sector as it grows (Klinger and Naylor 2012), and fish welfare has not been a priority concern. Between 48 and 160 billion farmed fishes were slaughtered in 2015 (fishcount.org.uk). Fish farmers understand the many benefits to improving animal welfare and know that improvements to food production systems that allow fish to thrive, grow, and stay healthy will result in higher-quality fish products. Although there are currently no laws providing protection of farm-raised fish in the United States or in the European Union, the emergence of animal welfare concerns led to criteria for feeding, housing, health, and emotional states for all captive animals, including farmed-fish criteria (Botreau et al. 2007; Levenda 2013). For example, Norway is the world’s leading exporter of salmon and trout, and the Norwegian Animal Welfare Act (passed in 2010, Olesen et al. 2011) protects all vertebrates raised for food. Salmon farming has grown in size and intensity, from net-pen culture to land-based salmon farms, some of which are capable of harvesting over 1,000 tonnes per year (https://salmonbusiness.com/these-are-the-leading-land-based-salmon-farms-in-the-world-right-now/).
Fish farming adopts welfare indicators to judge the state of the welfare of farmed fish. Prominent welfare standards exist for Atlantic Salmon and Rainbow Trout (Noble 2020). Welfare indicators include disease, parasites, wounds, anomalies, and behavior, which are each scored from good to bad. High-intensity, high-output fish farms have the greatest welfare concerns due to overcrowding, handling, transport, starvation, and slaughter (Ashley 2007; Santurtun et al. 2018). A global assessment of welfare of 41 farmed fish indicated that the majority of fish farms have poor welfare conditions (Saraiva et al. 2019).
Indicators of the welfare of fish may be used by fish farms to draw attention to early signs of problems related to captivity conditions and allow intervention before harmful states are reached (Arechavala-Lopez and Saraiva 2019). For example, the social environment for Nile Tilapia had negative effects on stress levels, growth, and aggression, all of which can be resolved with changes in lighting, environment color, and enrichment structures (Gonçalves-de-Freitas et al. 2019). The more intelligent an animal, the more cognitive stimulation it requires to avoid boredom and experience positive states such as pleasure and excitement. Changes in the design of fish farms that recognize the unique behavioral needs of the fish being raised may yield important benefits to fish welfare and farm yields (Fife-Cook and Franks 2019). Furthermore, Norwegian consumers are willing to pay more for improved welfare in farmed salmon (Grimsrud et al. 2013).
Question to ponder:
Watch “Rethink Fish” here. What questions or concerns do you have about how your farmed fish are raised?
5.12 Killing Fish
Fish slaughter is the process of killing fish, typically after harvesting at sea or from fish farms. Despite the trillions of fish slaughtered annually, they are excluded from the U.S. Humane Slaughter Act (P.L. 85-765; 7 U.S.C. 1901 et seq.). This means that fish are killed without regard to the suffering they endure before death.
In 2004, the European Food Safety Authority observed that “Many existing commercial killing methods expose fish to substantial suffering over a prolonged period of time.” The Aquatic Animal Health Code of the World Organisation for Animal Health considers the following slaughter methods inhumane: air asphyxiation, ice bath, salt or ammonia bath, and exsanguination without stunning. More humane killing methods include stunning, pithing, and electrical stunning, and inventors have filed dozens of patents for stunning devices (Lines et al. 2003). Percussive and electric stunning causes loss of consciousness, based on EEG correlations (Robb et al. 2000). While some ethicists have argued that there are no available humane slaughter methods for fish (Browning and Veit 2020), improvements in killing techniques are being adopted by some fisheries (Goldfarb 2019).
Recent discoveries demonstrate that the more humanely a fish is killed, the better it tastes (Bane 2015; Lefevre et al. 2016; Goes et al. 2019). The combination of stress and intense physical activity can increase the degree of protein denaturation, leading to faster muscle softening (Hultmann et al 2012). This discovery provides a utilitarian argument for humane killing. Humane slaughter has been adopted in some fish farms. Are consumers willing to pay? Some high-end restaurants purchase “Humane Harvest” cod for their menus, providing direct value for welfare of sentient animals (Carlier and Treich 2020).
Question to ponder:
Socrates, in Plato’s Republic, said, “Would this habit of eating animals not require that we slaughter animals that we knew as individuals, and in whose eyes we could gaze and see ourselves reflected, only a few hours before our meal?” (360 BC). How often have you looked into the eyes of an animal you were about to slaughter for a meal? Do you agree with Marc Bekoff (2018) that “It’s time to stop pretending that fish don’t feel pain.”
Watch “How to Kill a Fish” here.
If you had to kill an animal in order to eat it, would you eat less meat?
5.13 Closing Thoughts
The debates over pain in fish have illustrated the difficulty that people have in changing long-held views and behaviors. Scientists need to do more than provide evidence in scientific articles that test whether fish are sentient and emotional beings who feel pain. Dialogue about the issue has more frequently been presented at one-way arguments that were certain to be countered with alternative interpretations. Simply giving people more information does not necessarily change how people feel about an issue. This is referred to as the information deficit model, which attributes skepticism or hostility to a lack of understanding and a lack of information. Scientists who study the public understanding of science have concluded the information deficit model is an insufficient strategy for communication and changing people’s views. One alternative strategy for communicating in contentious situations involves making personal connections in ways that permit the participants to listen, share, and connect with others in order to understand the mental model(s) used by others (Crandall et al. 2020). The process of dialogue can build understanding of personal values, interests, ideology, worldviews, moral foundations, group identity, and religious background that contribute to disputes. Although disagreements will continue, the process permits all stakeholders in fish welfare issues to contribute to solutions.
Profile in Fish Conservation: Culum Brown, PhD
Culum Brown is Professor of Fish Behavioral Ecology at Macquarie University, where he directs research in the Behaviour, Ecology and Evolution Laboratory. His lab studies social learning and memory in a variety of fish. Some journalists refer to him as Dr. Fish Feelings in recognition of his expertise in fish feeling.
His research has revealed that many fish are sophisticated learners that can retain memories for months. His findings related to social learning in fish have direct implications for conservation and restoration of exploited fish. For example, if older, more experienced fish are preferentially harvested, the collective information on feeding and breeding grounds and migration routes may be lost, thereby reducing growth and survival. Also, widespread use of hatchery-reared fish is inefficient because of the high mortality they experience immediately after release. He developed protocols for life-skills training to improve performance of salmonids after release in the wild. Expanding our knowledge of the role of learning in fish behavior has direct applications to welfare of fish raised in captivity for release or human food. Understanding the behavioral preferences provides fish farmers with specific ways to enrich the environment.
Dr. Brown’s research asks basic questions about learning and memory in the natural environment. Fish have a richer visual and acoustic environment than humans can appreciate. Fish have advanced sensory capabilities for vision, hearing, and smell, that directly influence their abilities to learn about their environments and communicate with other fish. For example, most fish have four types of cones in their eyes, and therefore they see more colors and see them more vividly than humans can. The ability of some fish to detect polarized and ultraviolet light waves permits them to distinguish more from their environment than humans can see. In addition to vision, fish hear an amazing chorus from animals underwater and communicate with other fish by making all sorts of fishy sounds. Vision, smell, and hearing enable fish to orient in familiar locations and remember locations of food patches, shelter, and breeding sites.
Another character trait explored by Culum Brown’s lab is the notion of personality in fish. His lab has found that personality, laterality, and stress reactivity are all linked. Most humans are right-handed, and other vertebrates show lateral preferences in the brain that translate into sidedness. This question of left-right dominance was seldom studied in fish, until Culum Brown’s lab investigated whether native rainbow fish used one eye or both eyes while looking out for potential dangers. The rainbow fish showed differences in boldness, a personality trait, and their personality was linked to whether one eye or both eyes were dominant.
One of Dr. Brown’s popular research subjects is the Port Jackson Shark, which he calls the “puppies of the sea.” His research discovered the complex social structure and intelligence in the Port Jackson Shark, disputing the notion that sharks are robot-like, antisocial killers. Recent research reveals that Port Jackson Sharks show individual preferences for either left-eye or right-eye dominance, have personalities, and vary in how they respond to handling (docility). Following highly mobile sharks and rays, his research has demonstrated group formation and affiliation among social networks. The abilities to learn, remember, communicate, form relationships, and use tools are all characteristics of sentience.
Brown’s collective works in behavior and cognition have contributed to the formation of a new field of neuroethics of nonhuman animals. He released a collection of works in two books, entitled Fish Cognition and Behaviour, published in 2006 and 2011, and he has published more than 150 scientific articles on fish behavior. He is also Editor of the Journal of Fish Biology. His work on fish cognition is increasingly used as a basis for the justification of positive welfare for fish.
For more information, see https://www.thefishlab.com/PI.html.
Key Takeaways
• Humans use fish in a variety of ways, which may influence how they perceive the value of a fish’s life.
• Fish feel pain and suffer as a consequence, and we must carefully examine welfare, use, and fishing practices.
• Studies of pain in fish examined pain receptors, nerve activity, and behavior change.
• Whether an animal is sentient is based on five capabilities that have been studied scientifically.
• Scientists apply the three Rs—Replacement, Reduction, and Refinement—for consideration when minimizing pain and suffering in experiments.
• Actions to improve welfare in recreational and commercial fisheries and fish farms are part of lively debates.
This chapter was reviewed by Culum Brown.
URLs
Humane Harvest: https://www.hsa.org.uk/
Long Descriptions
Figure 5.1: Anti-fishing slogans “don’t let your kids become hookers,” “fishing hurts,” “Your daddy kills animals” rose in late 1980s and again from 2000-2010 and 2018 and on. Jump back to Figure 5.1.
Figure 5.2: Position of polymodal mechanoreceptors (or nociceptors), mechanothermal receptors, and mechanochemical receptors on the head and face of the rainbow trout. Pale yellow circles: polymodal nociceptor. Black circles: mechanothermal nociceptor. Green circles: mechanochemical receptor. Jump back to Figure 5.2.
Figure 5.3: These are the 5 factors that contribute to sentience in fish: 1. Evaluation behavior of others; form relationships, 2. Remember own actions’ use memory to inform future behavior, 3 . Assess risks and benefits to make decisions, 4. Positive or negative affective states such as pain, fear, pleasure, 5. Some degree or awareness. Jump back to Figure 5.3.
Figure 5.4: Line graph A) The binary model shows that canines, felines, most birds, fish, monkeys, and most other species have no self-awareness. Line graph B) The gradualist view shows a linear climb of self-awareness starting with smaller-brained animals, dogs, cats, pigs, monkeys, parrots, cleaner fish, elephants, dolphins, magpies, and doesn’t reach mirror self-recognition until Hominids. Jump back to Figure 5.4.
Figure 5.5: An arrow displays two categories with (left) consumptive, anthropocentric, harm to life, for human benefit and (right) non-consumptive, bicentric, no intentional harm to life. From left, motivations listed include, 1) fish farming (profit); 2) commercial fishing (profit); 3) subsistence fishing (livelihood); 4) recreational fishing (food); 5) recreational fishing (trophy); 6) recreational fishing (catch and release); 7) fish viewing. Jump back to Figure 5.5.
Figure References
Figure 5.1: Frequency of appearance of “pain in fish” in books since 1965 coincides with appearance of antifishing slogans after 1996. Kindred Grey. 2022. CC BY 4.0. Data from Google ngram viewer.
Figure 5.2: Sketch of Rainbow Trout with locations of nociceptors. Kindred Grey. 2022. Adapted under fair use from Do Fishes Have Nociceptors? Evidence for the Evolution of a Vertebrate Sensory System, by Lynne U Sneddon, Victoria A Braithwaite, and Michael J Gentle, 2003 (doi: 10.1098/rspb.2003.2349). Includes PSM V47 D194 Rainbow Trout Adult Salmo Mykiss Walbaum, by unknown author, 1895 (public domain, https://commons.wikimedia.org/wiki/File:PSM_V47_D194_Rainbow_trout_adult_salmo_mykiss_walbaum.jpg).
Figure 5.3: Diagrammatic representation of the five capabilities that make an animal sentient. Kindred Grey. 2022. Adapted under fair use from “Mental Capacities of Fishes,” by Lynne U. Sneddon and Culum Brown, 2020 (https://doi.org/10.1007/978-3-030-31011-0_4).
Figure 5.4: Two different perspectives on the evolution of self-awareness. Kindred Grey. 2022. CC BY 4.0. Adapted from “Fish, Mirrors, and a Gradualist Perspective on Self-Awareness,” by Frans B. M. de Waal, 2019 (CC BY 4.0, DOI:10.1371/journal.pbio.3000112).
Figure 5.5: Human motivations for types of fish and fish viewing. Kindred Grey. 2022. Adapted under fair use from Tourism and Animal Ethics, by David A. Fennell, 2012, 182 (ISBN 9781138081345).
Figure 5.6: Culum Brown, PhD. Used with permission from Culum Brown. CC BY 4.0.
Text References
Adriaense, J. E. C., S.E . Koski, L. Huber, and C. Lamm. 2020. Challenges in the comparative study of empathy and related phenomena in animals. Neuroscience & Biobehavioral Reviews 112:62–82.
AFS. 2014. Guidelines for the use of fishes in research. Use of Fishes in Research Committee (joint committee of the American Fisheries Society, the American Institute of Fishery Research Biologists, and the American Society of Ichthyologists and Herpetologists). American Fisheries Society, Bethesda, MD.
Agetsuma, M., H. Aizawa, T. Aoki, R. Nakayama, M. Takahoko, M. Goto, T. Sassa, K. Kawakami, and H. Okamoto. 2010. The habenula is crucial for experience-dependent modification of fear responses in zebrafish. Nature Neuroscience 13:1354–1356.
Allen, C. 2013. Ethics, law, and the science of fish welfare. Between the Species 16:68–85.
Appleby, M. C., and P. Sandøe. 2002. Philosophical debate on the nature of well-being: implications for animal welfare. Animal Welfare 11:283–294.
Ari, C., and D. P. D’Agostino. 2016. Contingency checking and self-directed behaviors in Giant Manta Rays: do elasmobranchs have self-awareness? Journal of Ethology 34:167–174.
Arlinghaus, R., S. J. Cooke, A. Schwab, and I. G. Cowx. 2007. Fish welfare: a challenge to the feelings-based approach, with implications for recreational fishing. Fish and Fisheries 8(1):57–71.
Arlinghaus, R., and A. Schwab. 2011. Five ethical challenges to recreational fishing: what they are and what they mean. American Fisheries Society Symposium 75:219–234.
Arlinghaus, R., A. Schwab, S. Cooke, and I. G. Cowx. 2009. Contrasting pragmatic and suffering-centred approaches to fish welfare in recreational angling. Journal of Fish Biology 75:2448–2463.
Ashley, P. J. 2007. Fish welfare: current issues in aquaculture. Applied Animal Behaviour Science 104:199–235.
Ashley, P. J., S. Ringrose, K. L. Edwards, E. Wallington, C. R. McCrohan, and L. U. Sneddon. 2009. Effect of noxious stimulation upon antipredator responses and dominance status in Rainbow Trout. Animal Behaviour 77: 403–410. https://doi.org/10.1016/j.anbehav.2008.10.015.
Ashley, P. J., L. U. Sneddon, and C. R. McCrohan. 2007. Nociception in fish: stimulus-response properties of receptors on the head of trout Oncorhynchus mykiss. Brain Research 1166:47–54. DOI: 10.1016/j.brainres.2007.07.011.
Bane, B. 2015. The more humanely a fish is killed, the better it tastes. Science. doi:10.1126/science.aad7558.
Barrell, G. K. 2019. An appraisal of methods for measuring welfare. Frontiers in Veterinary Science 6:289. https://doi.org/10.3389/fvets.2019.00289.
Bekoff, M. 2014. Rewilding our hearts: building pathways of compassion and coexistence. New World Library, Novato, CA.
Bekoff, M. 2018. It’s time to stop pretending fishes don’t feel pain. Psychology Today (January 7). Available at https://www.psychologytoday.com/us/blog/animal-emotions/201801/its-time-stop-pretending-fishes-dont-feel-pain. Accessed July 28, 2020.
Bernardi, G. 1912. The use of tools by wrasses (Labridae). Coral Reef 31:39. doi:10.1007/s00338-011-0823-6.
Beukema, J. J. 1969. Angling experiments with carp. Netherlands Journal of Zoology 20:81–92.
Botreau, R., I. Veissier, A. Butterworth, M. B. M. Bracke, and L. J. Keeling. 2007. Definition of criteria for overall assessment of animal welfare. Animal Welfare 16:225–228.
Bovenkerk, B., and F. J. B. Meijboom. 2012. The moral status of fish: the importance and limitations of a fundamental discussion for practical ethical questions in fish farming. Journal of Agricultural and Environmental Ethics 25:843–860.
Braithwaite, V. 2010. Do fish feel pain? Oxford University Press.
Broglio, C., F. Rodriguez, and C. Salas. 2003. Spatial cognition and its neural basis in teleost fishes. Fish and Fisheries 4:247–255.
Broom, D. M. 2014. Sentience and animal welfare. CABI, Boston, MA.
Browman, H. I., S. J. Cooke, I. G Cowx, S. W. G. Derbyshire, A. Kasumyan, B. Key, J. D. Rose, A. Schwab, A. B. Skiftesvik, E. D. Stevens, C. A. Watson, and R. Arlinghaus. 2019. Welfare of aquatic animals: where things are, where they are going, and what it means for research, aquaculture, recreational angling, and commercial fishing. ICES Journal of Marine Science 76:82–92.
Browman, H. I., and A. B. Skiftesvik. 2011. Welfare in aquatic organisms: is there some faith- based HARKing going on here? Diseases of Aquatic Organisms 94:255–257.
Brown, C. 2001. Familiarity with the test environment improves escape responses in the Crimson Spotted Rainbowfish, Melanotaenia duboulayi. Animal Cognition 4:109–113.
Brown, C. 2012. Tool use in fishes. Fish and Fisheries 13:105–115.
Brown, C. 2015. Fish intelligence, sentience and ethics. Animal Cognition 18:1–17.
Brown, C. 2016. Comparative evolutionary approach to pain perception in fishes. Animal Sentience 3(5). DOI: 10.51291/2377-7478.1029.
Brown, C. 2017. A risk assessment and phylogenetic approach. Animal Sentience 16(3). DOI: 10.51291/2377-7478.1219.
Brown, C., and C. Dorey. 2019. Pain and emotion in fishes: fish welfare implications for fisheries and aquaculture. Animal Studies Journal 8(2):175–201.
Brown, C., J. Krause, and K. Laland. 2011. Fish cognition and behavior. 2nd ed. Blackwell, Oxford.
Brown, C., and K. Laland. 2003. Social learning in fishes: a review. Fish and Fisheries 4:280–288.
Brown C., and K. Laland. 2011. Social learning in fishes. Pages 240–257 in C. Brown, J. Krause, and K. Laland, editors, Fish cognition and behavior, 2nd ed, Blackwell, Oxford.
Brown, C., K. Laland, and J. Krause. 2011. Fish cognition and behavior. Pages 1–9 in C. Brown, J. Krause, and K. Laland, editors, Fish cognition and behavior, 2nd ed., Blackwell, Oxford.
Brown, C., and K. Warburton. 1999. Differences in timidity and escape responses between predator-naïve and predator-sympatric rainbowfish populations. Ethology 105:491–502.
Brown, C., D. Wolfenden, and L. Sneddon. 2019. Goldfish (Carassius auratus). Pages 467–478 in J. Yeates, editor, Companion animal care and welfare: the UFAW companion animal handbook, John Wiley & Sons, Somerset, NJ.
Browning, H. 2020. Assessing measures of animal welfare. [Preprint] URL: http://philsci-archive.pitt.edu/id/eprint/17144. Accessed June 15, 2020.
Bshary, R., and C. Brown. 2014. Fish cognition. Current Biology 24(19):R947–R950.
Bshary R., S. Gingins, and A. L. Vail. 2014. Social cognition in fishes. Trends in Cognitive Science 18:465–471.
Bshary R., A. Hohner, K. Ait-el-Djoudi, and H. Fricke. 2006. Interspecific communicative and coordinated hunting between grouper and Giant Moray Eels in the Red Sea. PLoS Biology 4(12):e431. doi:10.1371/journal.pbio.0040431.
Bshary, R., W. Wickler, and H. Fricke. 2002. Fish cognition: a primate’s eye view. Animal Cognition 5:1–13.
Burghardt, G. M. 2015. Play in fishes, frogs and reptiles. Current Biology 25:R9–R10.
Burghardt, G. M., V. Dinets, and J. B. Murphy. 2015. Highly repetitive object play in a cichlid fish (Tropheus duboisi). Ethology 121:38–44.
Carlier, A., and N. Treich. 2020. Directly valuing animal welfare in (environmental) economics. International Review of Environmental and Resource Economics 14:113–152.
Cerqueira, M., S. Millot, M. F. Castanheira, A. S. Félix, T. Silva, G. A. Oliveira, C. C. Oliveira, C. I. M. Martins, and R. F. Oliveira. 2017. Cognitive appraisal of environmental stimuli induces emotion-like states in fish. Scientific Reports 7:13181. https://doi.org/10.1038/s41598-017-13173-x.
Chipeniuk, R., 1997. On contemplating the interests of fish. Environmental Ethics 19(3):331–332.
Clegg, I. L. K. 2018. Cognitive bias in zoo animals: an optimistic outlook for welfare assessment. Animals 8:104. doi: 10.3390/ani8070104.
Cook, K. V., A. J. Reid, D. A. Patterson, K. A. Robinson, J. M. Chapman, S. G. Hinch, and S. J. Cooke. 2018. A synthesis to understand responses to capture stressors among fish discarded from commercial fisheries and options for mitigating their severity. Fish and Fisheries 20:25–43.
Cooke, S. J., and L. U. Sneddon. 2007. Animal welfare perspectives on recreational angling. Applied Animal Behaviour Science 104:176–198.
Cooke, S. J., W. M. Twardek, R. J. Lennox, A. J. Zoldero, S. D. Bower, L. F. G. Gutowsky, A. J. Danylchuk, R. Arlinghaus, and D. Beard. 2018. The nexus of fun and nutrition: recreational fishing is also about food. Fish and Fisheries 19:201–224.
Coyer, J. A. 1995. Use of a rock as an anvil for breaking scallops by the Yellowhead Wrasse, Halichoeres garnoti (Labridae). Bulletin of Marine Science 57:548–549.
Craig, P. J., D. M. Alger, J. L. Bennett, and T. P. Martin. 2020. The transformative nature of fly-fishing for veterans and military personnel with posttraumatic stress disorder. Therapeutic Recreation Journal 54:150–172.
Crandall, C. A., M. C. Monroe, and K. Lorenzen. 2020. Why won’t they listen to us? Communicating science in contentious situations. Fisheries 45(1):42–45.
Crittenden, C. 2003. Pluhar’s perfectionism: a critique of her (un)egalitarian ethic. Between the Species 13:3.
Darwin, C. 1872. The expression of the emotions in man and animals. John Murray, London.
Dawkins, M. S. 1980. Animal suffering: the science of animal welfare. Dordrecht, Netherlands: Springer.
Dawkins, M. S. 2008. The science of animal suffering. Ethology 114:937–945. doi: 10.1111/j.1439-0310.2008.01557.x.
Dawkins, M. S. 2017. Animal welfare with and without consciousness. Journal of Zoology 301:1–10.
de Leeuw, A. D. 1996. Contemplating the interests of fish: the angler’s challenge. Environmental Ethics 18:373–390.
de Waal, F. B. M. 2019. Fish, mirrors, and a gradualist perspective on self-awareness. PLOS Biology 17(2):e3000112. https://doi.org/10. 1371/journal.pbio.3000112.
Diggles, B., and H. I. Browman. 2018. Denialism and muddying the water or organized skepticism and clarity? THAT is the question. Animal Sentience 21(10).
Dinets, V. 2016. No cortex, no cry. Animal Sentience 3(7): DOI: 10.51291/2377-7478.1027.
Dzieweczynski, T. L., and O. L. Hebert. 2012. Fluoxetine alters behavioral consistency of aggression and courtship in male Siamese Fighting Fish, Betta splendens. Physiology and Behavior 107:92–97.
Elder, M. 2018. Fishing for trouble: the ethics of recreational angling. Pages 277–301 in A. Linzey and C. Linzey, editors, The Palgrave handbook of practical animal ethics. The Palgrave Macmillan Animal Ethics Series. Palgrave Macmillan, London.
Elsevier. 2012. Guidelines for the treatment of animals in behavioural research and teaching. Animal Behaviour 83 301–309. doi:10.1016/j.anbehav.2011.10.031.
FAO. 1995. Code of Conduct for Responsible Fisheries. Food and Agriculture Organization of the United Nations, Rome.
FAO. 2020. The state of the world fisheries and aquaculture 2020: sustainability in action. Food and Agriculture Organization of the United Nations, Rome. Available at: http://www.fao.org/documents/card/en/c/ca9229en.
Fennell, D. A. 2012. Tourism and animal ethics. Routledge, London and New York.
Ferno, 2011. Fish behaviour, learning, aquaculture and fisheries. Pages 359–404 in C. Brown, K. Laland, and J. Krause, editors, Fish cognition and behavior, 2nd ed.. Blackwell, Oxford.
Ferter, K., S. J. Cooke, O-B. Humborstad, J. Nilsson, and R. Arlinghaus. 2020. Fish welfare in recreational fishing. Pages 463–485 in A. Fernö, A. Pavlidis, J. W. van de Vis, and T. S. Kristiansen, editors, The Welfare of Fish (Animal Welfare 20). Springer.
Fife-Cook, I., and B. Franks. 2019. Positive welfare for fishes: rationale and areas for future study. Fishes 4:31.
Fraser D. 1995. Science, values and animal welfare: exploring the inextricable connection. Animal Welfare 4:103–117.
Goes, E. S. R., M. D. Goes, P. L. de Castro, J. A. Ferreira de Lara, A. C. P. Vital, and R. R Ribeiro. 2019. Imbalance of the redox system and quality of tilapia fillets subjected to pre-slaughter stress. PLoS ONE 14(1):e0210742. https://doi.org/10.1371/journal.pone.0210742.
Goldfarb, B. 2019. How should we treat fish before they end up on our plates? High Country News, March 20, 2019. Available at: https://www.hcn.org/issues/51.6/fish-how-should-we-treat-fish-before-they-end-up-on-our-plates. Accessed August 6, 2020.
Gonçalves-de-Freitas, E., M. C. Bolognesi, A. C. dos Santos Gauy, M. L. Brandão, P. C. Giaquinto, and M. Fernandes-Castilho. 2019. Social behavior and welfare in Nile Tilapia. Fishes 4:23.
Gregory, N. 1999. Do fish feel pain? Australian and New Zealand Council of Animal Care Research and Teaching News 12:1–12.
Griffiths, S. W., and A. Ward. 2011. Social recognition of conspecifics. Pages 186–206 in C. Brown, K. Laland, and J. Krause, editors, Fish cognition and behavior, 2nd ed., Blackwell, Oxford.
Grillner, S., and B. Robertson. 2016. The basal ganglia over 500 million years. Current Biology 26:R1088–R1100.
Grimsrud, K. M., H. M. Nielsen, S. Navrud, and I. Olesen. 2013. Households’ willingness-to-pay for improved fish welfare in breeding programs for farmed Atlantic Salmon. Aquaculture 372–375:19–27.
Grosenick, L., T. S. Clement, and R. D. Fernald. 2007. Fish can infer social rank by observation alone. Nature 445:429–432.
Håstein, T., A. D. Scarfe, and V. L. Lund. 2005. Science-based assessment of welfare: aquatic animals. Revue scientifique et technique (International Office of Epizootics) 24(2):529–547.
Horta, O. 2018. Moral considerability and the argument from relevance. Journal of Agricultural and Environmental Ethics 31:369–388.
Hultmann L., T. M. Phu, T. Tobiassen, Ø. Aas-Hansen, and T. Rustad. 2012. Effects of pre-slaughter stress on proteolytic enzyme activities and muscle quality of farmed Atlantic Cod (Gadus morhua). Food Chemistry 134:1399–1408.
Huntingford, F. A., C. Adams, V. A. Braithwaite, S. Kadri, T. G. Pottinger, P. Sandøe, and J. F. Turnbull. 2006. Current issues in fish welfare. Journal of Fish Biology 68:332–372.
IASP. 2019. IASP terminology: pain terms. International Association for the Study of Pain, Washington, DC:. Available at https://www.iasp-pain.org/Education/Content.aspx?ItemNumber=1698. Accessed 15 June 2020.
Iwama, G. K. 2007. The welfare of fish. Diseases of Aquatic Organisms 75:155–158.
Jacquet, J. 2018. Defining denial and sentient seafood. Animal Sentience 21(8). DOI: 10.51291/2377-7478.1334.
Jones, A. M., C. Brown, and S. Gardner. 2011. Tool use in the Tuskfish Choerodon schoenleinii? Coral Reefs 30:865.
Keenleyside, M. H. A. 1979. Diversity and adaptation in fish behaviour. Springer-Verlag, Berlin.
Keenleyside, M. H. A., and C. E. Prince. 1976. Spawning-site selection in relation to parental care of eggs in Aequidens paraguayensis (Pisces: Cichlidae). Canadian Journal of Zoology 54:2135–2139. doi:10.1139/z76-247.
Key, B. 2015. Fish do not feel pain and its implications for understanding phenomenal consciousness. Biology and Philosophy 30:149–165.
Key, B. 2016a. Why fish do not feel pain. Animal Sentience 3(1). DOI: 10.51291/2377-7478.1011.
Key, B. 2016b. Falsifying the null hypothesis that “fish do not feel pain.” Animal Sentience 3(39). DOI: 10.51291/2377-7478.1070.
Killen, S. S., S. Marras, and D. J. McKenzie.2011. Fuel, fasting, fear: routine metabolic rate and food deprivation exert synergistic effects on risk-taking in individual juvenile European Sea Bass. Journal of Animal Ecology 80(5):1024–1033.
Klefoth, T., C. Skov, A. Kuparinen, and R. Arlinghaus. 2017. Toward a mechanistic understanding of vulnerability to hook-and-line fishing: boldness as the basic target of angling-induced selection. Evolutionary Applications 10:994–1006.
Klinger, D., and R. Naylor. 2012. Searching for solutions in aquaculture: charting a sustainable course. Annual Review of Environment and Resources 37:247–276.
Kohda, M., T. Hotta, T. Takeyama, S. Awata, H. Tanaka, J. Asai, and A. L. Jordan. 2019. If a fish can pass the mark test, what are the implications for consciousness and self-awareness testing in animals? PLOS Biology 17(2):e3000021. https://doi.org/10.1371/journal.pbio.3000021.
Krause, S., A. D. M. Wilson, I. W. Ramnarine, J. E. Herbert-Read, R. J. G. Clément, and J. Krause. 2017. Guppies occupy consistent positions in social networks: mechanisms and consequences. Behavioral Ecology 28:429–438.
Lam, M. E. 2019. Seafood ethics: reconciling human well-being with fish welfare. Pages 177–197 in B. Fischer, editor, The Routledge handbook of animal ethics. Routledge, New York.
Lam, M. E., and T. J. Pitcher. 2012. The ethical dimensions of fisheries. Current Opinion in Environmental Sustainability 4:364–373.
Laubu, C., P. Louâpre, and F-X. Dechaume-Moncharmont. 2019. Pair-bonding influences affective state in a monogamous fish species. Proceedings of the Royal Society B: Biological Sciences 286(1904):20190760.
Lefevre, F., I. Cos, T. G. Pottinger, and J. Bugeon. 2016. Selection for stress responsiveness and slaughter stress affect flesh quality in pan-size Rainbow Trout, Oncorhynchus mykiss. Aquaculture 464:654–664.
Levenda, K. 2013. Legislation to protect the welfare of fish. Animal Law 20:119–144.
List, C. J. 1997. On angling as an act of cruelty. Environmental Ethics 19:333–334.
Lopez-Luna, J., Q. Al-Jubouri, W. Al-Nuaimy, amd L. U. Sneddon. 2017. Activity reduced by noxious chemical stimulation is ameliorated by immersion in analgesic drugs in zebrafish. Journal of Experimental Biology 220:1451–1458. doi:10.1242/jeb.146969.
Lorimer, J. 2007. Nonhuman charisma. Environment and Planning D: Society and Space 25:911–932.
Lucon-Xiccato, T., and A. Bisazza. 2017. Individual differences in cognition among teleost fishes. Behavioural Processes 141:184–195.
Lund, V., C. M. Mejdell, H. Röcklingsberg, R. Anthony, and T. Håstein. 2007. Expanding the moral circle: farmed fish as objects of moral concern. Diseases of Aquatic Organisms 75:109–118.
Marchio, E. A. 2018. The art of aquarium keeping communicates science and conservation. Frontiers in Communication 3:17. doi: 10.3389/fcomm.2018.00017.
Matthews, G., and W. O. Wickelgren. 1978 Trigeminal sensory neurons of the Sea Lamprey. Journal of Comparative Physiology A 123, 329–333. doi:10.1007/BF00656966.
McGreevy, P., J. Berger, N. de Brauwere, O. Doherty, A. Harrison, J. Fiedler, C. Jones, S. McDonnell, A. McLean, L. Nakonechny, C. Nicol, L. Preshaw, P. Thomson, V. Tzioumis, J. Webster, S. Wolfensohn, J. Yeates, and B. Jones. 2018. Using the Five Domains Model to assess the adverse impacts of husbandry, veterinary, and equitation interventions on horse welfare. Animals 8(3):41. doi: 10.3390/ani8030041.
McPhee, J. 2002. The founding fish. Farrar, Straus and Giroux, New York.
Meijboom, F. L. B., and B. Bovenkerk. 2013. Fish welfare: challenge for science and ethics—why fish makes the difference. Journal of Agricultural and Environmental Ethics 26:1–6.
Message, R., and B. Greenhough. 2019. “But it’s just a fish”: understanding the challenges of applying the 3Rs in laboratory aquariums in the UK. Animals 9(12):1075.
Metcalfe, J. D., and J. F. Craig. 2011. Ethical justification for the use and treatment of fishes in research: an update. Journal of Fish Biology 78:393–394.
Michaelson, E., and A. Reisner. 2018. Ethics for fish. Pages 189–206 in A. Barnhill, M. Budolfson, and T. Dogett, editors, Oxford handbook of food ethics.
Michel, M. 2019. Fish and microchips: on fish pain and multiple realization. Philosophical Studies 176:2411–2428.
Millot, S., M. Cerqueira, M. F. Castanheira, Ø. Øverli, C. I. M. Martins, and R. F. Oliveira. 2014. Use of conditioned place preference/avoidance tests to assess affective states of fish. Applied Animal Behaviour Science 154:104–111.
Mood, A. 2010. Worse things happen at sea: the welfare of wild-caught fish. Report by FishCount.org. Available at http://www.fishcount.org.uk/published/standard/fishcountfullrptSR.pdf.
Mood, A., and P. Brooke. 2010. Estimating the number of fish caught in global fishing each year. Available from http://fishcount.org.uk/studydatascreens/frontpage.php.
Ng, Y-K. 2016. Could fish feel pain? A wider perspective. (Ng commentary on Key’s Why fish do not feel pain). Animal Sentience 19:1–3.
Noble, C., K. Gismervik, M. H. Iversen, J. Kolarevic, J. Nilsson, L. H. Stien, and J. F. Turnbull, editors. 2020. Welfare indicators for farmed Rainbow Trout: tools for assessing fish welfare. Fishwell Handbooks. Tromso, Norway.
Olden, J. D., J. R. S. Vitule, J. Cucherousset, and M. J. Kennard. 2020. There’s more to fish than just food: exploring the diverse ways that fish contribute to human society. Fisheries 45(9):453–464.
Olesen, I., A. I. Myhr, and G. R. Rosendal. 2011. Sustainable aquaculture: are we getting there? Ethical perspectives on salmon farming. Journal of Agricultural and Environmental Ethics 24:381–408.
Olsen, L. 2003. Contemplating the intentions of anglers: the ethicist’s challenge. Environmental Ethics 25:267–277.
Paśko, Ł. 2010. Tool-like behavior in the Sixbar Wrasse, Thalassoma hardwicke (Bennett, 1830). Zoo Biology 29:767–773.
Patton, B. W., and V. A. Braithwaite. 2015. Changing tides: ecological and historical perspectives on fish cognition. WIREs Cognitive Science 6:159–176. doi: 10.1002/wcs.1337.
Pittman J. T., and C. S. Lott. 2014. Startle response memory and hippocampal changes in adult zebrafish pharmacologically-induced to exhibit anxiety/depression-like behaviors. Physiology & Behavior 123:174–179.
Plotnik, J. M., F. B. M. de Waal, and D. Reiss. 2006. Self-recognition in an Asian elephant. Proceedings of the National Academy of Sciences USA 103:17053–17057.
Pouca, C. V., and C. Brown. 2017. Contemporary topics in fish cognition and behaviour. Current Opinion in Behavioural Sciences 16:46–52.
Prior, H., A. Schwarz, and O. Güntürkün. 2008. Mirror-induced behavior in the Magpie (Pica pica): evidence of self-recognition. PLoS Biology 6(8):e202. doi:10.1371/journal.pbio.0060202.
Raja, S. N., D. B. Carr, M. Cohen, N. B. Finnerup, H. Flor, S. Gibson, F. J. Keefe, J. S. Mogil, M. Ringkamp, K. A. Sluka, X-J. Song, B. Stevens, M. D. Sullivan, P. R. Tutelman, T. Ushida, and K. Vader. 2020. The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises. PAIN 161:1976–1982.
Regan, T. 1983. The case for animal rights. University of California Press, Berkeley.
Reilly, S. C, J. P. Quinn, A. R. Cossins, and L. U. Sneddon. 2008. Behavioural analysis of a nociceptive event in fish: comparisons between three species demonstrate specific responses. Applied Animal Behaviour Science 114:248–259. doi:10.1016/j.applanim.2008.01.016.
Reiss, D. 2012. The dolphin in the mirror: exploring dolphin minds and saving dolphin lives. Houghton Mifflin Harcourt, New York.
Robb, D. H. F., S. B. Wotton, J. L. Mckinstry, N. K. Sørensen, and S. C. Kestin. 2000. Commercial slaughter methods used on Atlantic Salmon: determination of the onset of brain failure by electroencephalography. Veterinary Record 147:298–303.
Rose, J. D. 2002. The neurobehavioral nature of fishes and the question of awareness and pain. Reviews in Fisheries Science 10:1–38.
Rose, J. D., R. Arlinghaus, S. J. Cooke, B. K. Diggles, W. Sawynok, E. D. Stevens, and C. D. L. Wynne. 2014. Can fish really feel pain? Fish & Fisheries 15:97–133.
Sandøe, P., S. B. Christiansen, and M. C. Appleby. 2003. Farm animal welfare: the interaction of ethical questions and animal welfare science. Animal Welfare 12:469–478.
Sandøe, P., C. Gamborg, S. Kadri, and K. Millar. 2009. Balancing the needs and preferences of humans against the concerns for fish: how to handle the emerging ethical discussions regarding capture fisheries. Journal of Fish Biology 75:2868–2871.
Santurtun, E., D. M. Broom, and C. J. C. Phillips. 2018. A review of factors affecting the welfare of Atlantic Salmon (Salmo salar). Animal Welfare 27:193–204.
Saraiva, J. L., and P. Arechavala-Lopez. 2019. Welfare of fish—no longer the elephant in the room. Fishes 4(3):39.
Saraiva, J. L., P. Arechavala-Lopez, M. F. Castanheira, J. Volstorf, and B. A. Heinzpeter Studer. 2019. Global assessment of welfare in farmed fishes: the FishEthoBase. Fishes 4(2):30.
Schnitzler, A., and M. Ploner. 2000. Neurophysiology and functional neuroanatomy of pain perception. Journal of Clinical Neurophysiology 17:592–603. doi: 10.1097/00004691-200011000-00005
Schullery, P. 2008. If fish could scream: an angler’s search for the future of fly fishing. Stackpole Books, Mechanicsburg, PA.
Schuster, S. 2007. Quick guide: archerfish. Current Biology 17:R494–R495.
Singer, P. 1975. Animal liberation: a new ethics for our treatment of animals. Random House, New York.
Singer, P. 2010. Fish: the forgotten victims on our plate. The Guardian, September 14. Available at: https://www.theguardian.com/commentisfree/cif-green/2010/sep/14/fish-forgotten-victims. Accessed March 16, 2023.
Singer, P. 2011. Practical ethics. 3rd ed. Cambridge University Press.
Sloman, K. A., I. A. Bouyoucos, E. J. Brooks, and L. U. Sneddon LU. 2019. Ethical considerations in fish research. Journal of Fish Biology 94:556–577. doi:10.1111/jfb.13946.
Smith, J. L. B. 1968. Our fishes. Voortrekkerpers, Johannesburg.
Sneddon, L. U. 2002. Anatomical and electrophysiological analysis of the trigeminal nerve in a teleost fish, Oncorhynchus mykiss. Neuroscience Letters 319:167–171.
Sneddon, L. U. 2011. Cognition and welfare. Pages 405–434 in C. Brown, J. Krause, and K. Laland, editors, Fish cognition and behavior. 2nd ed., Wiley-Blackwell, Oxford.
Sneddon, L.U. 2011. Pain perception in fish: evidence and implications for the use of fish. Journal of Consciousness Studies 18(9-10):209–229.
Sneddon, L. U. 2019. Evolution of nociception and pain: evidence from fish models. Transactions of the Royal Society B 374:20190290. https://doi.org/10.1098/rstb.2019.0290.
Sneddon, L. U., V. A. Braithwaite, and M. J. Gentle. 2003a. Do fishes have nociceptors? Evidence for the evolution of a vertebrate sensory system. Proceedings of the Royal Society of London B 270:1115–1121. doi:10.1098/rspb.2003.2349.
Sneddon, L. U., V. A. Braithwaite, and M. J. Gentle. 2003b. Novel object test: examining pain and fear in the Rainbow Trout. Journal of Pain 4:431–440.
Sneddon, L. U., and C. Brown. 2020. Mental capacities of fishes. Pages 53–71 in L. S. M. Johnson et al., editors. Neuroethics and nonhuman animals: advances in neuroethics. Springer, Cham, NY.
Sneddon, L. U., R. W. Elwood, S. Adamo, and M. C. Leach. 2014. Defining and assessing animal pain. Animal Behaviour 97:201–212.
Sneddon, L. U., J. Lopez-Luna, D. C. Wolfenden, M. C. Leach, A. M. Valentim, P. J. Steenbergen, N. Bardine, A. D. Currie, D. M. Broom, and C. Brown. 2018b. Fish sentience denial: muddying the waters. Animal Sentience 21(1):1–11.
Sneddon, L. U., and D. C. C. Wolfenden. 2019. Ornamental fish (Actinopterygii). Pages 440–466 in J. Yeates, editor, Companion animal care and welfare: the UFAW companion animal handbook. John Wiley & Sons, Somerset, NJ.
Sneddon, L. U., D. C. C. Wolfenden, M. C. Leach, A. M. Valentim, P. J. Steenbergen, N. Bardine, D. M. Broom, and C. Brown. 2018. Ample evidence for fish sentience and pain. Animal Sentience 21(17). DOI: 10.51291/2377-7478.1375.
Sneddon, L. U., D. C. C. Wolfenden, and J. S. Thomson. 2016. Stress management and welfare. Fish Physiology 35:463–539.
Snow, P. J., M. B. Plenderleith, and L. L. Wright. 1993. Quantitative study of primary sensory neurone populations in three species of elasmobranch fish. Journal of Comparative Neurology 334:97–103.
Sørensen, C., J. B. Johansen, and Ø. Øverli. 2013. Neural plasticity and stress coping in teleost fishes. General and Comparative Endocrinology 181:25–34.
Theodoridi, A., A. Tsalafouta, and M. Pavlidis. 2017. Acute exposure to fluoxetine alters aggressive behavior in zebrafish and expression of genes involved in serotonergic system regulation. Frontiers in Neuroscience 11:223. https://doi.org/10.3389/fnins.2017.00223.
Thompson M., S. Van Wassenbergh, S. M. Rogers, S. G. Seamone, and T. E. Higham. 2018. Angling-induced injuries have a negative impact on suction feeding performance and hydrodynamics in Marine Shiner Perch, Cymatogaster aggregata. Journal of Experimental Biology 221:jeb180935. doi:10.1242/jeb.180935.
Veit, W., and B. Huebner. 2020. Drawing the boundaries of animal sentience. Animal Sentience 29(13): 342.
Vettese, T., B. Franks, and J. Jacquet. 2020. The great fish pain debate. Issues in Science and Technology (Summer):49–53.
Vonk, J. 2020. A fish eye view of the mirror test. Learning & Behavior 48:193–194.
Walster, C., E. Rasidi, N. Saint-Erne, and R. Loh. 2015. The welfare of ornamental fish in the home aquarium. Companion Animal 20:302–306.
Whitear, M. 1971. The free nerve endings in fish epidermis. Journal of Zoology London 163:231–236.
Woodruff, M. L. 2017. Consciousness in teleosts: there is something it feels like to be a fish. Animal Sentience 13(1). DOI: 10.51291/2377-7478.1198. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.05%3A_Pain_Sentience_and_Animal_Welfare.txt |
Learning Objectives
• Explain the conservation mandate of public aquariums for research, conservation outreach, policy, and education.
• Summarize the motivational factors of visitors to public aquariums.
• Articulate the potential affects that visitation to public aquariums has on visitors.
• Describe new initiatives to propagate rare and endangered fish in partnerships with public aquariums.
• Examine the future challenges for public aquarium management.
6.1 Role of Public Aquariums
Public aquariums[1] are special places for people to learn about aquatic life. The number of public aquariums has grown since the opening of the first in Regent’s Park, London, in 1853 (Hillard 1995). Early aquariums were devoted to game fish and were auxiliary locations for hatchery-reared fish. Public aquariums have four aims today—aesthetic, educational, entertainment, and scientific—while introducing many people to fish, their adaptations, habitats, values, and human uses. Expansion of aquariums in many large urban centers was intended to enhance tourism and promote an “Age of Aquariums” (Murr 1988). Broad-based community support and high visitation rates make public aquariums among some of the most important places for public engagement in fish conservation to begin. More than 700 million people visited zoos and aquariums worldwide in 2008 (Gusset and Dick 2010). In the United States alone, over 183 million people visit zoos and aquariums annually—this is three times the number of recreational anglers in the country.
The World Association of Zoos and Aquariums defines conservation as “securing populations of species in natural habitats for the long term” (Barongi et al. 2015). As you read more about the roles and challenges of public aquariums, you should envision the future potential for public aquariums to become even more influential in fish conservation programs. Public aquariums strive to communicate the issues, raise awareness, change behaviors, and gain widespread public and political support for conservation actions (Reid et al. 2013). Aquariums are often the first place where aspiring young conservation champions are first exposed to aquatic animals. For example, pioneering ichthyologist Dr. Eugenie Clark first visited the New York Aquarium at age nine (Clark 1951).
Large public aquariums are accredited by the Association of Zoos and Aquariums. Accreditation is a process by which the aquarium is evaluated by experienced and trained experts in operations, animal welfare and husbandry, and veterinary medicine and is measured against the established standards and best practices of aquarium management. In accredited aquariums, the behavioral and physical needs of animals are being met by providing opportunities for species-appropriate behaviors and choices. Consequently, a reliable way to choose an aquarium for visitation is to look for the notice, “Accredited by the Association of Zoos and Aquariums.”
6.2 Education and Interpretation
Education and interpretation are both on-site and off-site programs for targeted audiences, such as school groups, teachers, and families. Educational programs are proven methods for increasing awareness and participation in aquatic conservation. Conservation education programs are designed to fulfill specific goals of each institution. Many types of interpretive methods may be employed, but they typically involve graphic and video displays, exhibits of live animals, ambassador animals, and talks by animal care and conservation specialists.
At a time when fish conservation needs are acute in marine and freshwaters, the tensions and tradeoffs are apparent for aquarium conservation programs. Animal welfare concerns must be balanced against educational values of displays (Maynard 2018). Built aquatic habitats vary greatly in their suitability for fish. Consequently, the displays offer the potential to explain unique requirements of the displayed animals. Increasingly, video displays have emerged for education that can be delivered at aquariums as well as online. For example, Shark Cams (explore.org) installed around the world provide a view of sharks in their underwater world.
While shark displays are very popular in public aquariums, they may invoke controversies. Some aquarium goers prefer sharks with a predatory appearance, with streamlined bodies that display strong swimming ability. These include Blacktip Shark, Grey Reef Shark, and Sandbar Shark. Such shark displays require enormous tanks and skilled and experienced caretakers who use feeding tongs to ensure proper nutrition, thereby minimizing sharks eating their tank mates. Large sharks are difficult to capture and transport from the wild to aquariums. Sharks have declined in many parts of the world (Dulvy et al. 2014), and displays must convey a strong conservation message to justify their captivity. Other sharks, such as the Zebra Sharks, nurse sharks, carpet sharks, and other skates and rays more readily adapt to life in captivity.
Ambassador animals provide a powerful catalyst for learning. These are select animals whose role includes handling and/or training by staff or volunteers for interaction with the public and in support of institutional education and conservation goals. They allow the public to observe and interact with an animal that they may never see otherwise (Spooner et al. 2021). Ambassadors are important advocates for the protection of habitats and animals in nature.
In the 1930s, the John G. Shedd Aquarium in Chicago displayed a Smalltooth Sawfish (Pristis pectinata, Figure 6.1) for the first time. Since that time, other public aquariums have connected visitors with these unique and endangered fish. Millions of visitors have enjoyed the experience of seeing a sawfish up close and wondering about their existence in the wild. Worldwide, the sawfish and rays are among the most endangered fish. The educational displays of sawfish create a common understanding of their plight as the first step in a multifaceted approach needed to conserve populations of sawfish.
In an age where children lack nature experiences, public aquariums, by providing access to live animals in natural-like settings, enable human-fish relationships to be developed (Miller 2004; Louv 2008; Bekoff 2014; Brown 2015). Visitation at public aquariums allows thoughtful people to build a common definition of the conservation problem and understanding of the essential planning process.
The education and interpretation missions are undoubtedly the most important. They connect people to animals that they may never see otherwise, and that connection is important in developing advocacy for protection of habitats and animals in nature. To expand their education impact, public aquarium staff often collaborate with community groups, school districts, local colleges, and universities to expand the reach of education and interpretation programs.
6.3 Connecting Aquarium Visitors to Biodiversity Conservation
How do we motivate people who do not fish to care about aquatic life? Millennials, people born between 1981 and 1997, are more likely to be concerned with animal welfare issues than environmental protection (Palmer et al. 2018). Millennials are also more likely to believe in individuals as the source of solutions and trust less in the effectiveness of governments or nongovernmental organizations (Dropkin et al. 2015). Public support for conservation depends on committed and engaged conservationists who work for or with public aquariums. Their actions flow from acceptance of wildlife values, beliefs that fish are under threat, and beliefs that personal actions can help alleviate the threat and restore values. Self-interest, altruism toward other humans, and altruism toward other species and the biosphere are value orientations linked to pro-environmental behavior (Stern et al. 1999). People can be subtly influenced to change their behavior (i.e., nudged) by using seemingly innocuous persuasion (Thaler and Sunstein 2008). Committed individuals move conservation forward via pro-environmental behavior, often in the face of inertial and active resistance (Ballantyne and Packer 2016).
All members of the World Association of Zoos and Aquariums have a goal of creating a strong connection between their resident animals and their counterparts in nature and integrated species conservation plans (Barongi et al. 2015). The educated public expects a strong conservation message from public aquariums. Some of the best public aquariums have dynamic educational programs as well as collaborative in situ conservation programs (Knapp 2018). Public aquariums train and support staff in accurately evaluating educational benefits of visitation via questionnaires and interviews (Falk et al. 2007; Marino et al. 2010; Mellish et al. 2019). Understanding and knowledge of biodiversity loss significantly increased after visits relative to previsit levels (Moss et al. 2015).
But do aquariums influence conservation actions? Empathy for the plight of animals is an emotional capacity that develops over time and is reinforced through interactions (Fennel 2012). Empathy relies on the ability to perceive, understand, and care about the experiences or perspectives of another person or animal. Empathy, an internal motivator toward acting, is elicited more by exposure to primates, elephants, and canines than to fish. Fish lack facial expressions and other cues for human empathy (Myers 2007; Webber et al. 2017). Motivating visitors to take action is a complex interplay among barriers, incentives, affective outcomes, and internal motivators (Young et al. 2018). Research studies support the idea that people who establish personal connections with nature are likely to value and protect elements of natural environments. Public aquariums play an essential role in providing opportunities for people to connect to fish and aquatic life and learn to care about conservation. Positive messaging, rather warnings about a coming apocalypse, are more likely to result in support for conservation actions (Jacobson et al. 2019).
Question to ponder
The following quote by Baba Dioum is often used in communications about conservation:
“In the end we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught.” Baba Dioum (1986, cited in Valenti et al. 2005)
Do you agree or disagree with this sentiment? What type of information is most relevant to you in supporting conservation practices?
6.4 Restorative Nature of Public Aquariums
Public aquariums are popular tourist attractions and are interested in the guests’ motivations and experiences. Many are interested in whether an aquarium visit provides humans benefits in terms of psychological well-being or relaxation. Humans benefit from interactions with companion animals, primarily cats and dogs. If you ever had a pet dog, you know dogs can relieve a sense of loneliness. Dogs seem to know when you are feeling down and provide emotional support. Studies show that interactions with nonhuman animals lowered blood pressure and reduced risk of heart disease (Levine et al. 2013; Stanley et al. 2014; Mubanga et al. 2017; Brooks et al. 2018). Is it possible our interactions with pets can lead to longer life spans? A review paper published by the American Heart Association concluded that (1) pet ownership, particularly dog ownership, may be reasonable for reduction in risk of cardiovascular disease; and (2) pet adoption, rescue, or purchase should not be done for the primary purpose of reducing risk of cardiovascular disease (Levine et al. 2013). The association of pet ownership and regular aerobic activity is likely related to the effects. Although the “pet effect” on physical and mental health remains a hypothesis that is routinely debated, therapeutic interventions with animals continue to be practiced.
Few systematic studies have measured the benefits of fish viewing. Those who keep fish as pets find that it provides purpose and enjoyment in life (Langfield and James 2009). Early observations in medical facilities suggested a link between viewing fish in aquariums and benefits such as reduced blood pressure and increased relaxation (Riddick 1985). In controlled, experimental settings, fish viewing improved mood and reduced anxiety (Wells 2005; Gee et al. 2019). In some cases, fish viewing reduced stress and anxiety in patients (Cracknell et al. 2018; Clements et al. 2019). It is difficult to design a study of the psychological or physiological responses of visitors to public aquariums because of the difficulty of isolating causal factors, such as what exhibits were viewed or the effects of social interactions during the aquarium visit. However, there are enough indications that aquarium visiting has a calming effect (Cracknell et al. 2018; Clements et al. 2019) to support the argument that biodiversity in aquariums may influence well-being outcomes for the visitors.
Question to ponder
Can you remember a visit to a public aquarium? In what ways were you affected by the visit? Can you describe the type of exhibit or experience that was most memorable? Does it matter to the visitors that the displays at public aquariums are built and not natural?
6.5 Conservation and Public Aquariums
The larger and more progressive public aquariums are expanding their missions and conservation portfolios to align with the World Zoo and Aquarium (WZ Conservation Strategy (Barongi et al. (2015), which calls for a more action-driven, field-based conservation. Many responsibilities are outlined here:
• Provide the highest-quality care and management of wildlife within and across institutions.
• Develop and adapt intensive wildlife-management techniques for use in protecting and preserving species in nature.
• Support conservation-directed social and biological research.
• Lead, support, and collaborate with education programs that target changes in community behavior toward better outcomes for conservation.
• Use zoological facilities to provide for populations of species most in need of genetic and demographic support for their continued existence in the wild.
• Promote and exemplify sustainable practices in the management of animal populations, our facilities, and the environment.
• Provide a public arena to discuss and debate the challenges facing society as extinction accelerates and ecosystem services are degraded.
• Act as rescue-and-release centers for threatened animals in need of immediate help, with the best knowledge and facilities to care for them until they are fit to go back to the wild.
• Be major contributors of intellectual and financial resources to field conservation.
• Provide ethical and moral leadership.
In 2014, the Association of Zoos and Aquariums developed a common approach for expanding the scope of field conservation called Saving Animals from Extinction (SAFE). The mission of SAFE is to “combine the power of zoo and aquarium visitors with the resources and collective expertise of AZA members and partners to save animals from extinction.” This mission is achievable because accredited zoos and aquariums are uniquely positioned to become a force for global conservation, with more scientists, more animals, and more ability to activate the public than any other nongovernmental institution. SAFE is built on aquarium and zoo’s 100-year track record of success in saving endangered species from extinction. SAFE uses the One Plan Approach, where management strategies and conservation actions are developed by those with responsibilities for all populations (Grow et al. 2018). Priorities for selecting conservation projects depend on location, expertise, collection composition, institutional culture, financial restrictions, and collaboration with stakeholders (Knapp 2018). Sharks and rays—which are decreasing at alarming rates along with many critically endangered species and lack sustainable captive populations—were the first group of fish to be selected for applying the AZA SAFE approach. Seattle Aquarium, Shark Trust, Point Defiance Zoo & Aquarium, North Carolina Aquariums, the Wildlife Conservation Society, and many others collaborate to leverage the large audiences of public aquariums to increase awareness.
In some cases, public aquariums have dedicated research institutes to lead research efforts. For example, the Monterey Bay Aquarium Research Institute is a world leader in deep-ocean science and technology and uses novel tools to monitor ocean change, carbon emissions, and harmful algal blooms. Public aquariums with a long history of focusing on discoveries have been instrumental in supporting explorers and scientists. Consider the inspirational story of Eugenie Clark, who became a world authority on sharks and fish and founded the Mote Marine Lab (Rutger 2015), which later added a public aquarium. Eugenie Clark’s first exposures to marine life, as noted earlier, were at the New York Aquarium at age nine. She made the first groundbreaking discovery that sharks could be trained to learn visual tasks as fast as some mammals, and she left a long legacy of shark research.
Large public aquariums are engaged in numerous partnerships for conservation. These partnerships require trust, a key driver for effective collaborations, conflict resolution, and performance in implementing conservation (Ostrom 2003; Fulmer and Gelfand 2012). Nonscientists form public opinions about conservation policy issues and rely on many sources. Scientific knowledge is only one source, but it enables citizens to engage in political decisions. Public aquariums, through their combined mission of conservation science and education, are a trusted source of science information and work on fish conservation through many partnerships (Rank 2018; Huber et al. 2019).
Many public aquariums also work to restore degraded local habitats and support ecosystem health. In these actions, they must partner with local volunteers in nearby waters, parks, forests, and preserves. Public aquariums in large urban centers work to install treatments that help reverse effects of polluted stormwater runoff for impervious surfaces, storm drains, cracked pipes, and more. The National Aquarium in Baltimore, Maryland, and the Shedd Aquarium in Chicago, Illinois, are installing floating wetlands to treat excess nitrogen and create fish habitat in the local waters. The plants on the wetlands grow hydroponically and take up nutrients directly from the water before they cause harmful algal blooms. In these highly modified, urban waters, the floating wetlands are planted with native plants and attract a variety of native species. The floating wetland prototype designed by the National Aquarium was recognized by the American Society of Landscape Architects.
Larger public aquariums, including the New England Aquarium, Monterey Bay Aquarium, and Shedd Aquarium, are global leaders in outreach and use a portion of their budgets to fund larger programs. Shedd Aquarium has focused on charismatic flagship species, such as seahorses, sharks, and Nassau Grouper in The Bahamas, Arapaima in Guyana, as well as less well-known species, such as Queen Conch in the Caribbean and suckers in the Great Lakes. These outreach programs follow naturally from a vibrant research program focused on marine species (corals, Queen Conch, Nassau Grouper, sharks, and rays) and freshwater species (amphibians, freshwater mussels, and a diverse array of Great Lakes fish).
The public aquariums have scientific expertise on their staffs that give these conservation initiatives strong scientific grounding. A recent decline in favorability toward zoos and aquariums (Bergl 2017) may suggest a concomitant decline in trust; however, there are numerous examples of productive fish conservation programs emanating from public aquariums. Some public aquariums have research in their mission statements and support their staff to do research with direct conservation benefits (Knapp 2018; Loh et al. 2018). Consequently, you will find public aquariums playing an essential role as a trusted resource on fish conservation partnerships throughout the world. Collaborative programs include numerous partnerships. For example, the World Fish Migration Day raises global awareness about free-flowing rivers and migratory fish. Global FinPrint unites collaborators around the world to study sharks, rays, and other marine life with baited remote underwater video.
Question to ponder:
Can you imagine ways in which aquarium visitation leads to the appreciation and conservation of the natural environments and life therein?
6.6 Partnerships to Propagate and Restore Rare Fish and Habitats
On any visit to a large public aquarium, you will learn about efforts to propagate and restore rare fish. You may even be able to view rare or extinct in the wild fish. Currently, aquariums hold four of the six fish species listed by the IUCN Red List as “Extinct in the Wild.” (Table 6.1; da Silva et al. 2019). Public aquariums often keep and breed threatened species in captivity until such time as suitable conditions exist for reintroduction to the wild. Many other species with conservation value are held and, in some cases, propagated by public aquariums. In fact, 9.3% of ray-finned fish species, 10.7% of sharks, skates, and rays, and 62.5% of all lobe-finned fish species are displayed in public aquariums (da Silva et al. 2019).
Conservation cannot be done in a vacuum. For example, the Tennessee Aquarium was part of a team that discovered the few remaining populations of the Barrens Topminnow (Fundulus julisia), an endangered fish that occurs only in isolated springs of Tennessee (George et al. 2013). The Barrens Topminnow is endangered because many spring ponds and runs were converted to livestock pastures or plant nurseries, and the introduced Western Mosquitofish (Gambusia affinis) eat their young. These findings naturally led to proposing actions in concert with other conservation partners. Aquariums are ideally placed to influence public opinion and policy makers so that more species threatened by international trade are included on the list in the multilateral treaty, Convention on International Trade in Endangered Species (CITES 1973).
Fish species on IUCN Red List
Potosi Pupfish Cyprinodon alvarezi
La Palma Pupfish Cyprinodon longidorsalis
Butterfly Splitfin Ameca splendens
Golden Skiffia Skiffia francesae
Table 6.1: Four fish species on IUCN Red List "Extinct in the Wild" held in public aquariums.
Public aquariums, because of their in-house expertise, can act quickly to collect and breed rare fish. Actions to prevent the extinction of the Barrens Topminnow include monitoring populations and propagating and stocking juveniles into existing or newly created spring habitats. The Tennessee Aquarium assisted with propagations and developed a program called “Keeper Kids,” where students on spring break help feed the Barrens Topminnows in a behind-the-scenes experience.
The breeding colonies of the Butterfly Splitfin (Figure 6.3) at the London Zoo and elsewhere serve as ark populations essential to the survival of this species. Butterfly Splitfins are endemic to the Río Ameca in western Mexico and almost extinct in the wild. Actions such as nonnative fish removal, stream restoration, and sanctuary designation may take decades before eventual introduction and survival in the wild. The Tennessee Aquarium is part of a large partnership to guide hatchery augmentation and recovery of the rarest darter in North America (U.S. Fish and Wildlife Service 2019). The Conasauga Logperch (Percina jenkinsi), a federally endangered darter (Percidae), is found only in a 30-mile (48 km) stretch of the Conasauga River in Georgia and Tennessee (Moyer et al. 2015).
The Banggai Cardinalfish (Pterapogon kauderni), a small, endangered tropical cardinalfish in the family Apogonidae, is now bred and displayed in numerous public aquariums after overharvest in the wild drove wild populations to near extinction. Consequently, most Banggai Cardinalfish sold to hobbyists in the United States and European Union today are captive bred. Finally, the expertise in husbandry has led to high standards for care of fish in captivity and numerous published husbandry manuals (Grassman et al. 2017).
The Saving the Sturgeon program is a collaborative effort to reintroduce Lake Sturgeon (Acipenser fulvescens, Figure 6.4) into the Tennessee River and surrounding waters (George et al. 2013). Lake Sturgeon, an important commercial species, was once abundant throughout the Great Lakes and Mississippi River drainages. It was overfished, and spawning migrations were blocked by construction of dams. By the 1970s it was extirpated from the Tennessee River. This collaborative program is a formal partnership of the Tennessee Aquarium, Tennessee Aquarium Conservation Institute, Tennessee Tech University, University of Tennessee, Tennessee Valley Authority, U.S. Geological Survey, U.S. Fish and Wildlife Service, World Wildlife Fund, Conservation Fisheries Inc., Tennessee Clean Water Network, and Wisconsin Department of Natural Resources. The working group raises Lake Sturgeon for release as juveniles and collaborates with commercial and recreational anglers to monitor their health. The Tennessee Aquarium raises awareness and money for the conservation initiative. It also maintains a sturgeon touch-tank display and teaches elementary schoolchildren about sturgeon rearing, life history, and conservation. Touch displays for sturgeon are popular, as visitors can feel the unique leathery texture of the sturgeon’s skin and the hard bony plates.
6.7 Seahorse Conservation
Public aquariums are places where people first encounter the fascinating seahorses. The family Syngnathidae includes seahorses, sea dragons, sea moths, and pipefish. Because these are not targets of commercial or recreational fisheries, public aquariums first introduced them to the public. The World Aquariums and Zoo Association and Project Seahorse have worked collaboratively to improve husbandry of seahorses in order to decrease pressure on wild populations (Lunn et al. 1999; Koldeway et al. 2015; Muka 2018). Currently, rearing techniques are available for a dozen seahorse species. Aquariums were integral to studying biology and behavior (discover), distributing captive-bred specimens (act), and educating about their conservation status (share; Figure 6.3). The Association of Zoos and Aquariums organizes experts regarding the husbandry, veterinary care, conservation needs/challenges, research priorities, ethical considerations, and other issues of seahorse conservation (AZA 2014). The attention we give to seahorses in captivity is a necessary condition for conservation since many seahorse species are classified as vulnerable or worse (IUCN 2020). Trade in seahorses is highly regulated, and seahorses in public aquariums must be legally sourced.
The ethics of caring is illustrated by many stories about the fish in captivity, and in particular stories about the seahorses. Part of caring about a being is to be (1) curious about it, (2) willing to learn about it, and (3) responsible for its well-being (Schmitt 2017). A thoughtful person, in learning about the breeding and care for seahorses, is impressed and fascinated by the story of the male seahorse providing parental care in a protective pouch and nutrients and ionic balance to ensure normal embryonic development (Figure 6.5). The normal function of a female’s uterus is provided by the male seahorse. In addition, the appearance of seahorses swimming upright with curved neck, long snout, and tail that curls around a blade of seagrass or coral makes them unique in the world of fish.
Seahorses may be one of the very few fish to possess nonhuman charisma and operate as flagship species for conservation (Lorimer 2007). Flagship species are popular, charismatic symbols, and they serve as rallying points to stimulate conservation awareness and action (Leader-Williams and Dublin 2000). Seahorses live in some of the world’s most threatened habitats, and their plight has led to creation of marine protected areas and restoration projects. Recently, the rare Weedy Seadragon (Phyllopteryx taeniolatus) was raised at the Birch Aquarium, California. Saving seahorses means saving our seas.
Question to ponder:
In what ways do public aquariums educate the public? View this one-minute videodeveloped by the Birch Aquarium to see how effective a short video can be for public education.
6.8 Efforts to Influence Seafood Choices
Marine environments are inaccessible to many due to simple facts of inland geographic locations or the lack of boats or equipment. Consequently, viewing displays at public aquariums is as close as most people come to experiencing marine life. One personal connection that even the inland residents have is our consumption of seafood. Consequently, public aquariums may educate visitors about challenges of providing sustainable seafood to consumers. In making personal choices about our seafood, we should ask: (1) Where did it come from? (2) Is it farmed or wild caught? And (3) If it’s wild, how was it caught? In 1999, in response to global overfishing, the Monterey Bay Aquarium began working to solve the most critical barriers to transitioning to sustainable seafood. Today, the aquarium staff reaches an online audience of over 3 million followers who regularly seek reliable, up-to-date information on sustainable seafood at the Seafood Watch® website, https://www.seafoodwatch.org/.
Seafood Watch summarizes information for seafood businesses, restaurants, and consumers by categorizing seafood choices as best choice, certified, good alternative, or avoid. Most fish on restaurant menus or in grocery stores do not mention source, so consumers are not able to make wise choices. Seafood Watch develops recommendations based on environmental protection, social responsibility, and economic viability. Best choice seafood would be grown or harvested in ways that protect the environment and maintain fish for the future. Three aquariums in France, Italy, and Spain launched a similar campaign, called Mr. Goodfish, www.mrgoodfish.com, to promote consumer awareness of sustainable seafood purchases.
Consumers in the United States import 90% of the seafood consumed, and a willingness to pay a premium to buy sustainable seafood has a global impact.
6.9 Ethical Considerations for Public Aquariums
Zoos and aquariums grapple with many conservation and welfare questions, such as, “What constitutes our conservation obligations? What is the moral and scientific basis of aquariums? And, Should aquariums exist at all?” (Mazur and Clark, 2001, 185). Where can we obtain live fish for displays? In captivity animals may be deprived of needed interaction. Some people may believe that deriving entertainment from sentient animals is wrong. Increasingly, aquariums are dealing with such questions about their ethical obligations to aquatic animals through AZA standards (Bekoff 2014).
Most public aquariums are not-for-profit organizations and seek grants and donations to maintain conservation and science programs and exhibits. Monterey Bay Aquarium was built and fully funded with a gift from David and Lucile Packard. Georgia Aquarium, the largest aquarium in the United States, was built in 2000 at a cost of \$290 million, most from donations. Promoters for new aquarium construction sell them as both conservation initiatives and as enterprises that bring jobs and revenues to revitalize distressed downtowns. Tax breaks and bonds often subside public aquarium construction. Most also charge a daily entrance fee and annual memberships. Aquarium professionals have seen great variation in attendance, with high attendance numbers in the first years followed by dramatic declines if new exhibits are not developed and promoted (Lindquist 2018). Funding to support research and conservation efforts must compete with funds for maintenance and operations. Georgia Aquarium’s international Whale Shark research and conservation program is funded in part by proceeds from sales of a Whale Shark IPA launched by the Atlanta Brewing Company. Other innovative funding solutions exist in many public aquariums.
Many have begun to question moral acceptability of keeping animals in captivity. Do the benefits of keeping fish in captivity accrue to the institutions more than to conservation in the wild? How can we justify our captive animal programs based on attention and protection of species in the wild? Animal rights advocates stress that fish are valuable in and of themselves (they have inherent value) and that their lives are not just valuable because of what they can do for humans (their utility). In their view, the right actions are not found by invoking utilitarianism, in which the general rule of thumb is that the right actions are those that maximize utility summed over all those who are affected by the actions. No matter what you believe, animal welfare concerns must be a priority for public aquariums that exhibit fish.
Principles of ethics, compassion, humility, respect, coexistence, and sustainability should guide us in our interactions with aquarium animals. As we learn more about inner workings of the mind of fish, societal forces will increasingly ask about the level of respect and moral consideration given to fish (Bekoff 2014). These are not new questions, and we don’t yet have satisfactory answers, but we should expect to engage in dialogue.
Public aquariums believe there should be no boundaries to visitation. Therefore, exhibits, restrooms, and parking are fully accessible, and public transportation is available. In addition, some visitors with sensory processing disorders or photosensitive considerations are accommodated by scheduling low-sensory presentations with reduced volume and dimmed lighting. Assisted-listening devices and American Sign Language interpreters are often available for the hearing-impaired visitors. Audio-described presentations and tactile models are provided for the vision-impaired visitors.
Public aquariums maintain large and diverse collections of live animals for display and are committed to sustainability of aquatic animal trade (Tlusty et al. 2013, 2017). Some collect their own specimens but also share and engage in ornamental trade. The accreditation of Association of Zoos and Aquariums (AZA) requires that suppliers do not cause environmental damage when collecting specimens and that they have all required legal permits. Consequently, they are interested in supporting sustainable trade by educating consumers and retail chains about best options for purchasing ornamental fish.
In addition, public aquariums encourage and communicate the examples of sustainable ornamental fish trade, such as the Rio Negro cardinal tetra fishery (Chao and Prang 1997). Nearly 20 million live fish are exported from the region annually, generating more than U.S. \$2 million annually for the local economy. In some cases, such as sharks and rays, captive populations are challenging to sustain. Therefore, public aquariums engage in comprehensive assessments of the sustainability of future harvests so they can protect wild populations and permit some harvest for live displays (Buckley et al. 2018). In other cases, aquariums may have enough captive-bred fish to permit sharing among other aquariums. Zebra Sharks (Stegostoma tigrinum)—commonly known as Leopard Sharks throughout the Indo-Pacific—have declined in the wild. Public aquariums are assisting in recovery via introduction of juveniles bred in managed care and hatched from eggs supplied by participating AZA–accredited facilities.
Displays are increasingly designed for immersive experience for public education. Not all species are suited or captivity and display. If an animal suffers from being on display, it will never be a good specimen (Leddy 2012; Semczyszyn 2013). If the visitor finds the display is undignified, then it will not be a good display for aesthetic, education, or scientific purposes. Public aquariums are getting larger; the Atlanta Aquarium’s largest tank is 23,850,000 liters (that’s 6.3 million gallons) (Lindquist 2018). Keeping some fish, such as Whale Sharks and Great White Sharks in captivity, is controversial due to their feeding and extensive movements (Bruce et al. 2019; Roy 2019).
While public aquariums are places where visitors go to appreciate aquatic environments, for many of us, they remain the only glimpse of the underwater world. Yet, aquarium displays are human-created artifacts and not natural. The rapidly changing ethical and social perspective means that issues of animal welfare, animal rights, climate change, captive breeding, and commercialization may create tensions. Built displays will always be different from appreciation of nature and the natural environment (Semczyszyn 2013). Therefore, in addition to meeting the life requirements of live specimens, the aquarium displays must pay attention to the aesthetic experience. One alternative display option is to create smaller, more interactive models (Lindquist 2018, 343), such as touch displays for stingrays and sturgeon. In other aquarium displays, the display tanks are designed as invisible to focus attention on the living specimens. Choices made about displays recognize that not all species are equally suited to life on display.
Energy demands of large aquariums are substantial, with vast quantities of water and air that must be heated or cooled and treated. Electricity production generates waste as carbon dioxide (CO2). Shedd Aquarium’s CO2 emissions were once compared with “an endless 2,200 car traffic jam” (Wernau 2013), before a major initiative to reduce energy consumption, reduce and reuse water, and reduce waste (Shedd Aquarium 2020). The Aquarium Conservation Partnership is a new initiative that shares best practices in conservation actions designed to make conservation a core business strategy of public aquariums.
Profile in Fish Conservation: Karen J. Murchie, PhD
Karen J. Murchie is the Director of Freshwater Research at Shedd Aquarium, where she oversees a team of biologists focused on freshwater biodiversity conservation in the Great Lakes region. Her early experiences spending much time outside, from exploring a local conservation area near her home to a summer experience in a ranger program, led to an appreciation for nature. The first time she donned a mask and snorkel in Jamaica, a small purple and yellow Fairy Basslet entered her view and hooked her on a career in fisheries. Her experiences allowed her to learn about fish and explore aquatic habitats in the Caribbean, the Arctic, the Amazon, and many other places. Her first fisheries jobs included some environmental consulting gigs examining stream crossings and also working with American Eels on the St. Lawrence River, and then longer-term positions with the Department of Fisheries and Oceans in the Great Lakes region, followed by an environmental consulting job in the Northwest Territories of Canada. After completing her PhD at Carleton University, she worked as an Assistant Professor at the College of The Bahamas (now University of The Bahamas), where she taught biology courses and did research on bonefish through engagement with local guides and fishing lodge owners.
In 2016, she joined Shedd Aquarium as research biologist and instructor, which exposed her to the important roles that public aquariums play in education and conservation. In addition to maintaining a rigorous research program focused on migratory fish in collaboration with other researchers and fisheries practitioners, she also instructed a yearly fall semester course in Freshwater Ecology to college students at Shedd, through the Associated Colleges of the Chicago Area. In this course, students are connected with many hands-on opportunities related to local conservation work in the greater Chicago area.
In 2019, Karen became the Director of Freshwater Research at Shedd and began to oversee a team of freshwater biologists, in addition to running the migratory fish conservation research program. Education and outreach, whether through collaborative programs with the Learning and Community Department at Shedd, engagement of the public in community science, or sharing knowledge through seminars, activities in the aquarium and via social media are all aspects of the position. Dr. Murchie enjoys highlighting the value of the often-overlooked freshwater fish through her fieldwork and various public engagement activities.
Key Takeaways
• Public aquariums have an important role in communicating the issues, raising awareness, changing behaviors, and gaining widespread public and political support for conservation actions.
• Conservation education and inspiration for their visitors are common missions of public aquariums.
• As people learn more about the things they care about, then they may act to protect and conserve the species and ecosystems that they are aware of and value.
• The restorative nature of visiting public aquariums is difficult to study, but an interest in therapeutic intervention with aquatic animals continues.
• Public aquariums are expanding conservation efforts via the SAFE program, for Saving Animals from Extinction and other outreach programs.
• Despite the broad base of support and interests, public aquariums continue to face challenges by welfare advocates, climate activists, and conservationists.
• Public perceptions of aquariums range widely, and some people are concerned about the benefits and morality of keeping animals in captivity.
• Aquariums engage with the ornamental fish trade by promoting market-based initiatives that link retailers to captive-bred rather than wild-caught fish.
• Immersive exhibits provide more opportunities for aquarium visitors to interact with displayed animals.
This chapter was reviewed by Anna L. George and Karen J. Murchie.
URLs
Accredited by the Association of Zoos and Aquariums: https://www.aza.org/inst-status
Figure References
Figure 6.1: Smalltooth Sawfish from public aquarium display. Simon Fraser University, Communications & Marketing. 2007. CC BY 2.0. https://flic.kr/p/nRQ4G5.
Figure 6.2: Floating wetland at Inner Harbor, Baltimore. Ron Cogswell. 2015. CC BY 2.0. https://flic.kr/p/vRqNqx.
Figure 6.3: Photo of the critically endangered Butterfly Splitfin (Ameca spendens). Przemysław Malkowski. 2008. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:Ameca_splendens.jpg.
Figure 6.4: Lake Sturgeon (Acipenser fulvescens). George Brown Goode. 1884. Public domain. https://commons.wikimedia.org/wiki/File:FMIB_51148_Lake_Sturgeon.jpeg.
Figure 6.5: Two pregnant Potbelly Seahorses at the Tennessee Aquarium, USA. Joanne Merriam. Unknown date. CC BY-SA 3.0. https://www.academia.edu/31808923/Interspecies_Care_in_a_Hybrid_Institution.
Figure 6.6: Karen J. Murchie, PhD. Used with permission from Karen J. Murchie. Photo by Shedd Aquarium/Brenna Hernandez. Use of the contribution is permitted at no cost in perpetuity in this and all future versions of this work.
Text References
AZA. 2011. The accreditation standards and related policies. Association of Zoos and Aquariums, Silver Spring, MD.
AZA. 2014. Taxon advisory group (TAG) handbook. Association of Zoos and Aquariums, Silver Spring, MD.
Ballantyne, R., and J. Packer. 2016. Visitors’ perceptions of the conservation education role of zoos and aquariums: Implication for the provision of learning experiences. Visitor Studies 19:193–21. doi:10.1080/10645578.2016.1220185.
Barongi, R., F. A. Fisken, M. Parker, and M. Gusset. 2015. Committing to conservation: the World Zoo and Aquarium conservation strategy. World Association of Zoos and Aquariums Executive Office, Gland, Switzerland.
Bekoff, M. 2014. Aquatic animals, cognitive ethology, and ethics: questions about sentience and other troubling issues that lurk in turbid water. Antennae: Journal of Nature in Visual Culture 28:5–22.
Bergl, R. 2017. Patterns and drivers of public favorability towards zoos and aquariums. Directors’ Policy Conference, Association of Zoos and Aquariums, 25 January, Corpus Christi, TX.
Brooks, H. L., K. Rushton, K. Lovell, P. Bee, L. Walker, and L. Grant, and A. Rogers. 2018. The power of support from companion animals for people living with mental health problems: a systematic review and narrative synthesis of the evidence. BMC Psychiatry 18(1):31.
Brown, C. 2015. Fish intelligence, sentience and ethics. Animal Cognition 18:1–17.
Bruce, B. D., D. Harasti, K. Lee, C. Gallen, and R. Bradford. 2019. Broad-scale movements of juvenile white sharks Carcharodon carcharias in eastern Australia from acoustic and satellite telemetry. Marine Ecology Progress Series 619:1–15.
Buckley, K. A., D. A. Crook, R. D. Pillans, L. Smith, and P. M. Kyne. 2018. Sustainability of threatened species displayed in public aquaria, with a case study of Australian sharks and rays. Reviews in Fish Biology and Fisheries 28:137–151.
Chao, N. L., and G. Prang. 1997. Project Piaba: towards a sustainable ornamental fishery in the Amazon. Aquarium Science and Conservation 1:105–111.
CITES. 1973. Convention on international trade in endangered species of wild fauna and flora. https://cites.org/eng/disc/text.php.
Clark, E. 1951. Lady with a spear. Harper and Brothers, New York.
Clements, H., S. Valentin, N. Jenkins, J. Rankin, J. S. Baker, and N. Gee, D. Snellgrove, and K. Sloman. 2019. The effects of interacting with fish in aquariums on human health and well-being: s systematic review. PLoS ONE 14 (7):e0220524. https://doi.org/10.1371/journal.pone.0220524.
Cracknell, D. L., S. Pahl, M. P. White, and M. H. Depledge. 2018. Reviewing the role of aquaria as restorative settings: how subaquatic diversity in public aquaria can influence preferences, and human health and well-being. Human Dimensions of Wildlife 23:446–460.
da Silva, R., P. Pearce-Kelly, B. Zimmerman, M. Knott, W. Foden, and D. A. Conde. 2019. Assessing the conservation potential of fish and corals in aquariums globally. Journal of Nature Conservation 48:1–11.
Dropkin, L., S. Tipton, and L. Gutekunst. 2015. American millennials: cultivating the next generation of ocean conservationists. Edge Research and David and Lucille Packard Foundation, Arlington, VA. Available at: https://www.packard.org/insights/resource/american-millennials-cultivating-the-next-generation-of-ocean-conservationists/. Assessed September 11, 2019.
Dulvy, N. K., S. L. Fowler, J. A. Musick, R. D. Cavanagh, P. M. Kyne, L. R. Harrison, J .K. Carlson, L. N. K. Davidson, S. V. Fordham, M. P. Francis, C. M. Pollock, C. A. Simpfendorfer, G. H. Burgess, K. E. Carpenter, L. J. V. Compagno, D. A. Ebert, C. Gibson, M. R. Heupel, S. R. Livingstone, J. C. Sanciangco, J. D. Stevens, S. Valenti, and W. T. White. 2014. Extinction risk and conservation of the world’s sharks and rays. eLife 3:e00590 DOI: 10.7554/eLife.00590.
Dwyer, J. T., J. Fraser, J. Voiklis, U.G. Thomas. 2020. Individual-level variability among trust criteria relevant to zoos and aquariums. Zoo Biology 39:297–303.
Falk, J. H., E. M. Reinhard, C. L. Vernon, K. Bronnenkant, N. L. Deans, and J. E. Heimlich. 2007. Why zoos & aquariums matter: assessing the impact of a visit to a zoo or aquarium. Association of Zoos and Aquariums, Silver Spring, MD.
Fennel, D. A. 2012. Tourism and animal ethics. Routledge, New York.
Fulmer, A. C., and M. J. Gelfand. 2012. At what level (and in whom) we trust: trust across multiple organizational levels. Journal of Management 38(4):1167–1230.
Gee, N. R., T. Reed, A. Whiting, E. Friedman, D. Snellgrove, and K. A. Sloman. 2019. Observing live fish improves perceptions of mood, relaxation and anxiety, but does not consistently alter heart rate or heart rate variability. International Journal of Environmental Research and Public Health 16(17):3113 https://www.mdpi.com/1660-4601/16/17/3113.
George, A. L., J. R. Ennen, and B. R. Kuhajda. 2019. Protecting an underwater rainforest: freshwater science in the southeastern United States. Pages 64–90 in A. B. Kaufman, M. J. Bashaw, and T. L. Maple, editors, Scientific foundations of zoos and aquariums: Their role in conservation and research, Cambridge University Press.
George, A. L., M. T. Hamilton, and K. F. Alford. 2013. We all live downstream: engaging partners and visitors in freshwater fish reintroduction programmes. International Zoo Yearbook 47:140–150.
Goode, G. B. 1884. Fisheries and fishery industries of the United States. Section I: Natural history of useful aquatic animals, plates. Government Printing Office, Washington, D.C.
Grassmann, M., B. McNeil, and J. Wharton. 2017. Sharks in captivity: the role of husbandry, breeding, education, and citizen science in shark conservation. Advances in Marine Biology 78:89–119. doi: 10.1016/bs.amb.2017.08.002. Epub 2017 Sep 15. PMID: 29056144.
Grow, S., D. Luke, and J. Ogden. 2018. Saving animals from extinction (SAFE): unifying the conservation approach of AZA-accredited zoos and aquariums. Pages 122–128 in B. Minteer, J. Maienschein, and J. P. Collins, editors, The ark and beyond: the evolution of zoo and aquarium conservation. University of Chicago Press.
Gusset, M., and G. Dick. 2011. The global reach of zoos and aquariums in visitor numbers and conservation expenditures. Zoo Biology 30:566–569.
Happel, A., K. J. Murchie, P. W. Willink, and C. R. Knapp. 2020. Great Lakes fish finder app; a tool for biologists, managers and educational practitioners. Journal of Great Lakes Research 46:230–236.
Hillard, J. M. 1995. Aquariums of North America: a guidebook to appreciating North America’s aquatic treasures. Scarecrow Press, Lanham, MD, and London.
Huber, B., M. Barnidge, and H. G. de Zúñiga. 2019. Fostering public trust in science: the role of social media. Public Understanding of Science 28:759–777.
IUCN. 2020. The IUCN red list of threatened species. Version 2020-2. International Union for Conservation of Nature, Gland, Switzerland. https://www.iucnredlist.org.
Jacobson, S. K., N. A. Morales, B. Chen, R. Soodeen, M. P. Moulton, and E. Jain. 2019. Love or loss: effective message framing to promote environmental conservation. Applied Environmental Education & Communication 18(3):252–265.
Knapp, C. R. 2018. Beyond the walls: applied field research for the 21st century public aquarium and zoo. Pages 286–297 in B. Minteer, J. Maienschein, and J. P. Collins, editors, The ark and beyond: the evolution of zoo and aquarium conservation. University of Chicago Press.
Koldeway, H. 2005. Syngnathid husbandry in public aquariums. 2005 manual. Project Seahorse and Zoological Society of London. Available at: https://static1.squarespace.com/static/55930a68e4b08369d02136a7/t/5602efcbe4b033fa74554e82/1443033035533/Syngnathid_Husbandry_Manual2005.pdf. Accessed February 2, 2021.
Langfield, J., and C. James. 2009. Fishy tales: experiences of the occupation of keeping fish as pets. British Journal of Occupational Therapy 72:349–356.
Leader-Williams, N., and H. Dublin. 2000. Charismatic megafauna as “flagship species.” Pages 53–81 in A. Entwistle and N. Dunstone, editors, Priorities for the conservation of mammalian diversity. Cambridge University Press.
Leddy, T. 2012. Aestheticisation, artification, and aquariums. Contemporary Aesthetics 4. Special vol. http://hdl.handle.net/2027/spo.7523862.spec.406.
Levine, G. N., K. Allen, L. T. Braun, H. E. Christian, E. Friedmann, K .A. Taubert, S. A. Thomas, D. L. Wells, and R. A. Lange. 2013. Pet ownership and cardiovascular risk: a scientific statement from the American Heart Association. Circulation 127(23):2353–2363.
Lindquist, S. 2018. Today’s awe-inspiring design, tomorrow’s Plexiglas dinosaur: how public aquariums contradict their conservation mandate in pursuit of immersive underwater displays. Pages 329–343 in B. Minteer, J. Maienschein, and J. P. Collins, editors, The ark and beyond: the evolution of zoo and aquarium conservation. University of Chicago Press.
Loh, T-L., E. R. Larson, S. R. David, L. S. de Souza, R. Gericke, M. Gryzbek, A. S. Kough, P. W. Willink, and C. R. Knapp. 2018. Quantifying the contributions of zoos and aquariums to peer-reviewed scientific research. FACETS 3:287–299. DOI: https://doi.org/10.1139/facets-2017-0083.
Lorimer, J. 2007. Nonhuman charisma. Environment and Planning D: Society & Space 25:911–932.
Louv, R. 2008. Last child in the woods. Algonquin Books, Chapel Hill, NC.
Lunn, K. E., J. R. Boehm, H. J. Hall, and A. C. J. Vincent, editors. 1999. Proceedings of the First International Aquarium Workshop on Seahorse Husbandry, Management, and Conservation. John G. Shedd Aquarium, Chicago.
Marino, L. S., O. Lilienfeld, R. Malamud, H. Nobis, and R. Broglio. 2010. Zoos and aquariums promote attitude change in visitors? A critical evaluation of the American Zoo and Aquarium study. Society and Animals 18:126–138.
Maynard, L. 2018. Media framing of zoos and aquaria: from conservation to animal rights. Environmental Communication 12:177–190.
Mazur, N. A., and T. W. 2001. Zoos and conservation: policy making and organizational challenges. Yale Forestry and Environmental Science Bulletin 105:185–201.
Mellish, S., J. C. Ryan, E. L. Pearson, and M. R. Tuckey. 2019. Research methods and reporting practices in zoo and aquarium conservation-education evaluation. Conservation Biology 33:40–52.
Miller, B., W. Conway, R. P. Reading, C. Wemmer, D. Wildt, D. Kleiman, S. Monfort, A. Rabinowitz, B. Armstrong, and M. Hutchins. 2004. Evaluating the conservation mission of zoos, aquariums, botanical gardens, and natural history museums. Conservation Biology 18:86–93.
Moss, A., E. Jensen, and M. Gusset. 2015. Evaluating the contribution of zoos and aquariums to Aichi Biodiversity Target 1. Conservation Biology 29:537–544.
Moyer, G. R., A. L. George, P. L. Rakes, J. R. Shute, and A. S. Williams. 2015. Assessment of genetic diversity and hybridization for the endangered Conasauga Logperch (Percina jenkinsi). Southeastern Fishes Council Proceedings 55. Available at: https://trace.tennessee.edu/sfcproceedings/vol1/iss55/6.
Mubanga, M., L. Byberg, C. Nowak, A. Egenvall, P. K. Magnusson, E. Ingelsson, and T. Fall. 2017. Dog ownership and the risk of cardiovascular disease and death—a nationwide cohort study. Scientific Reports 7(1):1–9. https://doi.org/10.1038/s41598-016-0028-x.
Muka, S. 2018. Conservation constellations: aquariums in aquatic conservation networks. Pages 90–103 in B. Minteer, J. Maienschein, and J. P. Collins, editors, The ark and beyond: the evolution of zoo and aquarium conservation, University of Chicago Press.
Murchie, K. J., C. R. Knapp, and P. B. McIntyre. 2018. Advancing freshwater biodiversity conservation by collaborating with public aquaria: making the most of an engaged audience and trusted arena. Fisheries 43(4):172–178.
Murr, A. 1988. The age of aquariums. Newsweek 112(20):26.
Myers, G. 2007. The significance of children and animals: social development and our connections to other species. 2nd ed. Purdue University Press, West Lafayette, IN.
Ostrom, E. 2003. Toward a behavioral theory linking trust, reciprocity, and reputation. Pages 19–79 in E. Ostrom and J. Walker, editors, Trust and reciprocity. Russell Sage Foundation, New York.
Palmer, C., T. J. Kasperbauer, and P. Sandøe. 2018. Bears or butterflies? How should zoos make value-driven decisions about their collections? Pages 179–191 in B. Minteer, J. Maienschein, and J. P. Collins, editors, The ark and beyond: the evolution of zoo and aquarium conservation, University of Chicago Press.
Rank, S. J., J. Volkis, R. Gupta, J. R. Fraser, and K. Flinner. 2018. Understanding organizational trust of zoos and aquariums. K. P. Hunt, editor. Understanding the role of trust and credibility in science communication. https://doi.org/10.31274/sciencecommunication-181114-16.
Reid, G. McG., T. C. MacBeath, and C. K. Csatádi. 2013. Global challenges in freshwater-fish conservation related to public aquariums and the aquarium industry. International Zoo Yearbook 47:6–45. DOI http://dx.doi.org/10.1111/izy.12020.
Riddick, C. C. 1985. Health, aquariums and the institutionalized elderly. Marriage and Family Review 8(3–4):163–173. https://doi.org/10.1300/J002v08n03_12.
Roy, I. 2019. The real reason aquariums never have Great White Sharks. Reader’s Digest, June 21, 2019. https://www.yahoo.com/lifestyle/real-reason-aquariums-never-great-172748770.html.
Rutger, H. 2015. Remembering Mote’s “Shark Lady”: the life and legacy of Dr. Eugenie Clark. Mote Marine Laboratory & Aquarium website. Available at: https://mote.org/news/article/remembering-the-shark-lady-the-life-and-legacy-of-dr.-eugenie-clark. Accessed February 2, 2021.
Schmitt, S. 2017. Care, gender, and survival: the curious case of the seahorse. In Troubling species: care and belonging in a relational world. RCC Perspectives: Transformations in Environment and Society 2(1)83–89. doi.org/10.5282/rcc/7778.
Semczyszyn, N. 2013. Public aquariums and marine aesthetics. Contemporary Aesthetics 11. http://hdl.handle.net/2027/spo.7523862.0011.020.
Shedd Aquarium. 2020. Sustainability at Shedd 2020: waste not. Available at: https://www.sheddaquarium.org/stories/sustainability-at-shedd-2020-waste-not. Accessed March 20, 2023.
Spooner, S. L., M. J. Farnworth, S. J. Ward, and K. M. Whitehouse-Tedd. 2021. Conservation education: Are zoo animals effective ambassadors and is there any cost to their welfare? Journal of Zoological and Botanical Gardens 2:41–65. https://doi.org/10.3390/jzbg2010004.
Stanley, I. H., Y. Conwell, C. Bowen, and K. A. Van Orden. 2014. Pet ownership may attenuate loneliness among older adult primary care patients who live alone. Aging and Mental Health 18(3):394–399. https://doi.org/10.1080/13607863.2013.837147.
Stern, M. J., and K. J. Coleman. 2015. The multi-dimensionality of trust: applications in collaborative natural resources management. Society and Natural Resources 28:117–132.
Stern, P. C., T. Dietz, T. Abel, G. A. Guagnano, and L. Kalof. 1999. A value-belief-norm theory of support for social movements: the case of environmentalism. Human Ecology Review 6:81–97.
Thaler, R. H., and C. R. Sunstein. 2008. Nudge: improving decisions about health, wealth, and happiness. Yale University Press, New Haven, CT.
Tlusty, M. F., A. L. Rhyne, L. Kaufman, M. Hutchins, G. M. Reid, C. Andrews, P. Boyle, J. Hemdal, F. McGilvray, and S. Dowd. 2013. Opportunities for public aquariums to increase the sustainability of the aquatic animal trade. Zoo Biology 32:1–12.
Tlusty, M. F., N. Baylina, A. L. Rhyne, C. Brown, and M. Smith. 2017. Public aquaria. Pages 611–622 in R. Calado, I. Olivotto, M. P. Oliver, and G. J. Holt, editors, Marine ornamental species aquaculture, John Wiley & Sons, Somerset, NJ.
U.S. Fish and Wildlife Service. 2019. Revised recovery plan for the Conasauga Logperch (Percina jenkinsi). U.S. Fish and Wildlife Service, Department of the Interior, South Atlantic-Gulf Region, Athens, Georgia. Available at: https://ecos.fws.gov/docs/recovery_plan/Conasauga%20Logperch%20Recovery%20Plan%20Signed_FINAL_2.pdf. Accessed February 1, 2021.
Valenti, J. M., and G. Tavana. 2005. Report: continuing science education for environmental journalists and science writers (in situ with the experts). Science Communication 27 (2):300–310.
Wells, D. L. 2005. The effect of videotapes of animals on cardiovascular responses to stress. Stress and Health 21:209–213.
Wernau, J. 2013. Shedd Aquarium looks to slice energy bill. Chicago Tribune, January 26. https://www.chicagotribune.com/business/ct-xpm-2013-01-26-ct-biz-0126-shedd-energy-20130126-story.html. Accessed February 2, 2021.
Young, A., K. A. Khalil, and J. Wharton. 2018. Empathy for animals: a review of the existing literature. Curator: The Museum Journal 61(2):327–343.
1. I use the term public aquarium to include institutions, such as aquariums and marine parks, open to the public that may be supported by private or public funds. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.06%3A_Public_Aquariums_and_Their_Role_in_Education_Science_and_Conservation.txt |
Learning Objectives
• Describe the roles that women play in fishing, fisheries, and aquaculture.
• Recognize the contributions of women to the science of managing fish and fishing.
• Explain the activities of governance where women’s issues are not recognized.
• Explore intersectionality as a starting point for discussions of human rights and social justice related to fish conservation.
7.1 Why Gender Is Relevant to Sustainable Fishing
The old axiom goes “Give a man a fish and he eats for a day. Teach a man to fish and he eats for a lifetime.” A feminist version of this would be, “Teach a woman to fish, and everyone eats for a lifetime” (Sharma 2014). Contributions of women in fishing and fisheries science have been historically invisible because someone else got credit for them. Furthermore, in scientific fields dominated by white males, harassment and other behaviors discourage participation by women. Women’s contributions to fishing communities may be direct or indirect, such as: (1) direct contribution of women’s labor in catching or processing operations; (2) creating the next generation by bearing and raising children; and (3) special responsibilities because of the absence of men away while fishing (Thompson 1985). In some fisheries, the catching of fish for sale is dominated by males, while the catching of fish for feeding the family is dominated by females (Bennett 2005; Santos et al. 2015; Ameyaw et al. 2020; Tilley et al. 2020).
Women hold knowledge, skills, and traditions relevant for fisheries management. However, despite the seemingly valuable contributions, women are often not paid for their work and, consequently, women’s fishing activities are not included in official statistics. Because of both diminished appreciation and differing roles, women in the fishing industry are likely to have a smaller role in governance and suffer disproportionately during difficult times. For example, the COVID-19 pandemic affected women fishers differently due to gender-based norms or restrictions (Lopez-Ercilla et al. 2021; Woskie and Wenham 2021). More inclusive consideration of gender in fishing should result in more sustainable fisheries, yet important obstacles remain.
Gender refers to a social construct based on how women and men relate. Thus, gender is expressed in behaviors, roles, social status, and rights of women and men as organized and justified by society on the basis of biological differences between the sexes. However, gender analysis in fisheries is impossible without observations and data by gender or sex. Categorization of gender and sex as binary (i.e., male or female) is not a full or accurate portrayal of the diversity of human behavior or biology. American adults identifying as lesbian, gay, bisexual, transgender, queer, intersexual, or asexual (LGBTQIA) rose to 5.6 percent in a 2021 Gallup poll (Jones 2021). LGBTQIA adults are unlikely to see themselves represented in fishing and fish conservation arenas and other groups.
Increasingly, we are examining gender differences in participation in different types of fishing. Much of this work has focused on small-scale subsistence fishing, where fisheries support the economy of local communities (Campbell et al. 2021). Contributions of women in all types of fisheries, as well as in fisheries science and management, are overlooked by society, industry, and policy makers. However, the premise and promise of sustainability is rooted in the belief that no effort to restore ecological balance and integrity will succeed if it does not also address the social inequities and human suffering in our communities.
In this chapter, I examine implicit biases related to gender and fishing and encourage you to consciously and explicitly consider gender and diversity of those engaged in fishing. A modern view of fisheries should begin with the assumption that women do fish, rather the inverse. When we take a gender perspective, we identify where there are differences that generate inequalities, vulnerabilities, fears, and exclusion. Transforming harmful social ideas and practices requires everyone’s collaboration, regardless of their gender. This more inclusive view will bring women and historically underrepresented groups into the management process and will provide the base for better governance and policy reform.
Question to ponder
What is gender? What gender-related information would you want to have in order to manage a fishery or conserve a threatened fish population?
7.2 Harmful Fishing Stereotypes
A stereotype is any overgeneralized, widely accepted opinion, image, or idea about a person, place, or thing. We use stereotypes to simplify our world and reduce the amount of thinking we have to do. You may have heard someone remark that “women are bad luck on boats,” “girls are bad drivers,” “women are too emotional,” “the humanities are useless,” or “males are better at math.” At a boat ramp or fishing pier, one might hear that “you did really well for a woman,” which leads to anger and hostility. Stereotypes are harmful because we don’t work to see or understand the person and their identity. Instead, we substitute the stereotype. Such stereotypes may serve as self-fulfilling prophecies and affected individuals are at risk of being marginalized. Stereotypes may also lead to hostility between groups. Imagine that you are being judged and labeled without sharing anything about your creativity and uniqueness.
Our language continues to support the stereotype that those who catch fish are males. The term “fishermen” dominated the scientific literature in fisheries during most of the 20th century. Attempts to use gender-neutral terms, such as fisher or fisherfolk, have been increasing to the point that fishers and fishermen occurred equally in the most recent literature (Branch and Kleiber 2015). According to Welch (2019), women do not consistently take offense from the term “fishermen.” Two quotes from females are instructive:
I enjoy the term fishermen. I’d much rather be called a fisherman than a fisher woman. I feel like it would separate me as crew. I don’t want to be treated like a woman on the boat. I want to be treated like a crew member.
As a woman I have always considered myself a fisherman. My dad taught me how to fish, and I feel like it is something that is important to many families. Especially father daughter relationships and I think it should stay the way that it is.
The way we govern fisheries is influenced by gender stereotypes. Holding a stereotypic view that only males do the fishing means that access to fishing grounds, ownership of fishing boats, and the rights to fish are considered the domain of males (Figure 7.1). Therefore, males often have greater support from governing bodies in controlling harvest and influencing decisions than do females. Unfortunately, this leads to poor management decisions and marginalizing the role of women in fishing communities.
Question to ponder
What familiar stereotypes have you encountered? Are they positive or negative? What gender-neutral term do you typically use to describe one who harvests fish? Why would you prefer to use a gender-neutral term?
7.3 Gender Issues That Prevent Gender Equality
Women are a minority in many male-dominated sectors of fishing value chains, fisheries management, and fisheries science. Gender equality is not only a basic human right, but its achievement has enormous socioeconomic ramifications. Creating a world without gender-based discrimination is a global priority. Therefore, the United Nations Food and Agriculture Organization (FAO) and others have encouraged the use of a gender lens to examine and promote fisheries sustainability (FAO 2015, 2017; Kleiber et al. 2017). Only by applying a gender lens can we identify and eliminate barriers that exclude women from equal access to fisheries jobs, markets, and fishing resources. Avoidance of gender discrimination requires each of us to speak up and oppose inappropriate sexist behaviors and policies.
Sexism refers to any prejudicial attitudes or discrimination against women on the basis of their sex alone. Sexism is evident in our (a) beliefs, (b) behaviors, (c) use of language, and (d) policies reflecting and conveying a pervasive view that women are inferior (Herbst 2001). Nine issues are so engrained in society that most people experience one of these at some point but may fail to identify or call it out:
• Gender stereotypes
• Unrealistic body standards
• Unequal pay
• Negative female portrayals
• Sexist jokes
• Shaming language
• Gender roles
• Sexual harassment
• Toxic masculinity
Gender stereotypes. Many cultures around the world adopt a patriarchy—that is, a hierarchical system of social organization in which cultural, political, and economic structures are controlled by men. Male hegemony refers to the political and ideological domination of women in society.
Among those who fish for sport, only 27% of U.S. anglers are female, and females appear on 10% of covers, in 9% of fishing images, and in 6% of hero images in sportfishing magazines. Only 1% of feature articles are authored by females (Carini and Weber 2017; Burkett and Carter 2020).
Unrealistic body standards. These unrealistic standards of beauty have psychological effects that lead to women fixating negatively on their weight and appearance. From an early age, girls are subjected to unrealistic body images. Fishing is an activity that should emphasize safety as a priority, not body image. Another unrealistic assumption is that females prefer pink and will buy pink-colored fishing attire (Merwin 2010).
Unequal pay. Globally, women represent about 50% of all seafood workers. Yet, female workers are consistently overrepresented in low-skilled, low-paid, low-valued positions, remaining mostly absent at the other end of the value chain (Briceño-Lagos and Monfort 2018). Women’s labor is likely to be viewed as being part of the household duties assisting their husbands, while the high-paid positions in fisheries are mostly occupied by men.
Negative female portrayals. While many women are experts in fishing, ecology, and conservation, this expertise is not reflected in media portrayals. Rather, media portrayals too often focus on the rarity of “females who fish,” rather than on the expertise these individuals possess. Males who fish are not judged by their appearance and neither should females.
Objectification. There are many examples of fishing cultures that sexually objectify women and seek and to share photos of scantily clad women showing off the fish they catch. Among the detrimental effects of sexual objectification (Miles-McLean et al. 2019; Sáez et al. 2019), we can expect that objectification is a barrier to participation.
Sexist comments and jokes. The purpose of sexist jokes or comments is to disparage women. For example, the sexist joke — “What do you call a woman with half a brain? Gifted”—conveys the notion that women as a group are not very smart. The use of humor decreases the perception that the speaker is sexist and ultimately decreases the probability that the listener will confront the perpetrator (Mallett et al. 2016). In male-dominated fields, such as fishing or fisheries science, the frequency of sexist jokes is likely higher. Sexist jokes result in stress and anxiety over how or whether to respond or confront. Furthermore, sexual jokes may increase tolerance of sexual harassment. Clearly, men view sexist humor as more humorous and less offensive than do women. In the workplace, women who experience sexual humor are less likely to be satisfied with their jobs and more likely to withdraw from the workplace. This inappropriate behavior continues until men are confronted about the unwelcome jokes. People often hesitate to confront sexism for fear of social repercussions. Women, in particular, may be accused of being overly sensitive when they confront the perpetrator.
Failing to call out the sexist joke teller is a tacit endorsement of inappropriate behavior and damages group culture. Confronting sexism means quickly expressing disapproval when a sexist comment or situation arises (Monteith et al. 2019; Woodzicka et al. 2020; Woodzicka and Good 2021). Direct responses to sexist jokes and comments using the following statements are most effective.
• That made me uncomfortable.
• That’s against our code of conduct.
• That wasn’t funny at all.
• I don’t get it, can you explain.
• Disrespectful words are not tolerated here.
Shaming language. Shaming or patronizing language toward women—for example, explaining unnecessary things (e.g., mansplaining)—can make it more difficult to build productive working relationships in a male-dominated field. “Mansplaining” refers to the tendency of men to explain things to women, whether they need them explained or not. In many cases, a man may assume that a female is unaware of tips for winterizing a boat motor, finer points of baitcasting, or when to drift a nymph versus a dry fly. Adding further insult, the man may interrupt or speak over women, a behavior sometimes referred to as “manterrupting.” Often, men may compliment women at the expense of other women. For example, if one says “Most women are terrible when it comes to navigating with maps,” they are implying that there is a rule that women are inferior or incompetent in some way. Also, men may use gendered language to imply what is right or good. For example, a male may refer to another male as a “pussy” or may urge him to “man up,” which perpetuates a myth that females are weak.
Gender roles. Many fishing communities and organizations reflect the culture of society, and males typically have greater access to power. Commonly the division of labor in fishing communities is based on gender, which leads to unequal access to benefits of fishing. Gender roles are a source of prejudice and place limits on individuals and their behavior. Rural women face obstacles emanating from a strong patriarchal culture, prejudice, and tyranny rooted in religious traditions, as well as limited control over economic resources and the decision-making process (Deb et al. 2015). In some fishing communities, women fish close to home with little costly equipment in places where fishing may be done in the company of children. In Ghana, women called “Big Mammies” play major roles financing the tuna trade (Drury O’Neill et al. 2018). Gender roles can and do change over time (Gustavsson 2020). For example, in North America, the latter half of the 20th century saw an increase in working wives and mothers and their struggle to balance work and family life.
Sexual harassment. Harassment includes unwanted sexual advances, requests for sexual favors, or other verbal or physical conduct of a sexual nature. The growing sexual harassment problem hinders women’s participation in male-dominated parts of the fisheries value chain as well as the management and science sectors. Many women have been the target of some form of harassment, especially those with less power in the workplace. In a 2013 global survey across scientific disciplines, 64% of respondents reported being subjected to sexual harassment during fieldwork and 20% to sexual assault (Clancy et al. 2014). Among female observers on Alaskan commercial fishing boats, roughly half said they had experienced sexual harassment aboard vessels (Gross 2019). Such inappropriate and sexist behavior and its aftermath can derail a career and close off opportunities for women (Nelson et al. 2017).
Toxic masculinity. The term “toxic masculinity” was coined in the 1980s by Shepherd Bliss to characterize his father’s authoritarian masculinity. Toxic masculinity, sometimes called harmful masculinity, involves cultural pressures for men to behave in a way that corresponds to an old idea of “manliness” that perpetuates dangerous societal standards, such as male domination, homophobia, and aggression. In conversation, a male might respond with “I’m a guy, what do you expect?” Toxic masculinity teaches men that aggression and violence are acceptable solutions to problems. Toxic masculinity is expressed in some connections between environmental degradation and sexual power (Voyles 2021).
Recognizing that these gender issues exist is the first step in examining fishing with a gender lens. It is unacceptable to assume that if I don’t see it, it must not exist. Codes of conduct and rules for enforcement are essential to equal opportunity for all participants. The pervasive nature of these gender issues means that many allies will be needed to support gender equity in fishing and fisheries. These allies recognize that “If I were to remain silent, I’d be guilty of complicity.” Therefore, the message to all is to “See it. Name it. Stop it.”
7.4 Foundational Gender Concepts Apply to Fishing
Many differences exist among individuals and how they fish or do not fish. The problems arise when individual differences translate to differing preferences, privilege, and power (Figure 7.2). Differences mean that individuals display preferences that lead to certain unearned privileges. These privileges of males in fishing and fisheries are often a result of patriarchy where men are dominant figures who hold power. In fishing communities, males have much greater power in the catching and management of fish and occupy positions of power. In these male-dominated situations, males have ready access to resources and maintain differential power, and females are oppressed or their roles discounted. Over time, the oppression is internalized in ways that members of marginalized groups may see themselves as less or inferior. Men—especially middle-aged, middle-class white ones—are lacking in self-awareness of unearned privilege because they have gone through life taking their privileged position for granted (Perry 2017).
In addition to gender, multiple forms of oppression and identity interact to create one’s experience and access to influence and power (Figure 7.3). Therefore, the term “intersectionality” is a useful construct here as it acknowledges that everyone has their own unique experience of discrimination and privilege. Intersectionality is a crucial starting point in discussions and is grounded in social justice (Crenshaw 1989, 1991). Fishing controversies are seldom single-issue struggles. For example, fishing access may be constrained by race, class, language, or disability. Numerous factors, including gendered stereotypes, pedagogy, and science curricula, all conspire against a young woman’s ability to develop a science identity. In small-scale fisheries, gender intersects with issues such as human rights, well-being, food security, and climate change.
Society traditionally regards women as dissimilar to men in most fishing contexts. The difference often leads to societal preferences for men in fishing and may limit participation by women. Women are a minority in many male-dominated sectors of fishing value chains, fisheries management, and fisheries science. Participation by females in sportfishing depends on local culture and its ideas about a woman’s place (Toth and Brown 1997).
Gender socialization refers to the learning of behavior and attitudes considered appropriate for a particular gender. The group’s beliefs, behaviors, language, and policies will influence an individual’s initial involvement, attachment, and commitment. Females in fishing groups were seeking social aspects of fishing, while males were more interested in sport-related aspects (Kuehn et al. 2006).
Question to ponder:
Individuals reveal their sexist attitudes in their beliefs, behavior, and language, whereas institutions reveal sexist biases in established policies. Can you think of sexist beliefs, behaviors, language, or policies related to fishing?
Ecological feminism considers several foundational beliefs to guide our viewing of fishing through a gender lens (Gilligan 1988; Gaard 1993; Gaard and Gruen 1993). Foundational beliefs of feminism include the following:
• Women are oppressed and mistreated.
• The oppression and mistreatment of women is wrong.
• The analysis and reduction of the oppression and mistreatment of women are necessary (but not sufficient) for the creation and maintenance of the kind of individual and communal lives that should be promoted within good societies.
• Because different forms of oppression are intermeshed, the analysis and reduction of any form of oppression, mistreatment, or unjustified domination is necessary for the creation and maintenance of the kind of individual and communal lives that should be promoted within good societies (Cuomo 1998).
Language, practices, and values that lead to oppression of women are similar to those leading to exploitation or degradation of nature. For example, consider the passage from Warren (1994, 37):
Women are described in animal terms as pets, cows, sows, foxes, chicks, serpents, bitches, beavers, old bats, old hens, mother hens, pussycats, cats, cheetahs, bird-brains, and hare-brains. . . . “Mother Nature” is raped, mastered, conquered, mined; her secrets are “penetrated,” her “womb” is to be put into the service of the “man of science.” Virgin timber is felled, cut down; fertile soil is tilled, and land that lies “fallow” is “barren,” useless. The exploitation of nature and animals is justified by feminizing them; the exploitation of women is justified by naturalizing them.
Systematic analysis of gender differences in fishing is lacking, leading to persistence of implicit biases. “Implicit bias” describes when we have attitudes toward people or associate stereotypes with them without our conscious knowledge. Further analysis may help us understand differences in behavior and reveal biases that persist. We must remember that just as all men are not alike, all women are not alike. Yet, the studies done thus far support the conclusion that women experience more constraints to their participation.
Author Ernest Hemingway wrote about the quintessentially masculine image in this story of big game fishing in The Old Man and the Sea. Santiago, the main character, says, “I’ll kill him and all his greatness and his glory. I will show him what a man can do and what a man endures.” This is clearly a male author using masculine language to communicate this—the struggle between him and the fish. Ernest Hemingway and other writers always promoted the idea when they’re fighting these big trophy fish, that they were males and they were referred to as males—an implicit bias. This male bias misinforms us about the biology of fish. Females are more likely to be the larger individuals in many big game species, such as swordfish.
Fishers are a socially and culturally diverse group of people. However, the privilege and power differentials often lead to poor representation of marginalized groups in decision making. Therefore, fishing policies are often inappropriate when viewed with a gender lens (Williams 2008). Fishing and aquaculture policies currently do not collect gender-disaggregated data and do not value all the forms of labor. This leads to gender-blind policies, which may be inappropriate because they do not recognize the difference in motivations or roles (Figure 7.4). Gender-aware policies that take into consideration the gender differences so that better outcomes are achieved use instrumental frames to promote gender equality, whereas other gender-aware policies rely on intrinsic frames of fairness and justice as primary outcomes.
7.5 Towards the Goal of Gender Equality
Dialogues on gender equality in the seafood and fishing industries should be stimulated to create consciousness, to bring information, to share good practices, and to stimulate progressive initiatives. When we take a gender perspective, we look at relationships between women and men to identify where there are differences that generate inequalities, vulnerabilities, fears, and exclusion. Transforming harmful social ideas and practices requires everyone’s collaboration, regardless of their gender.
What prevents women from entering sportfishing? It only takes a single barrier to prevent females from becoming regular participants in fishing. The list below, shared by Betty Bauman of Ladies, Let’s Go Fishing!®, is only a partial list.
Sample Barriers to Participation by Females in Recreational Fishing:
• Husband/boyfriend says fishing is for guys only, won’t take them
• Can’t learn from others on the boat—no time to instruct
• Want to take their kids fishing but nobody knows how
• They have to stay home with kids while husband fishes
• Too early in the morning
• No one else to fish with
• Don’t like touching slimy fish
• Seasickness
• Feeling like “the alien” when entering a tackle shop
• Lack of knowledge and confidence regarding fishing skills (being on the team when you don’t know the game)
• Unable to launch or drive a boat
• Yelling / condescending comments / afraid to ask stupid questions
To encourage participation by females in sportfishing, we need to understand that certain motivations are unique to females. In a survey of licensed anglers in Minnesota in 2000–2001,
1. Men reported higher involvement in fishing than women did.
2. Women rated motivations related to catching fish for food higher than men did.
3. Men rated developing skills and catching trophy fish higher than women did.
4. Men agreed more with ethics related to catch-and-release fishing (Schroeder et al. 2006).
Question to ponder
In your lifetime, who has had the greatest influence on your behavior and personality? Take the implicit assumption test https://implicit.harvard.edu/implicit/ , which is a free test designed to allow an individual to identify their own unconscious biases related to gender, race, ethnicity, and obesity. What privileges do you possess due solely to your individual characteristics?
7.6 Examples of Women’s Impact
Sportfishing. Among those who fish for sport, only 27% of U.S. anglers are female (Burkett and Carter 2020). Underrepresentation of females in sportfishing is ironic, as the first publication on fly-fishing, dating from the 15th century, was written by Dame Juliana Berners, entitled Treatyse of Fysshynge with an Angle, a publication that heavily influenced novelty of the sport for European enthusiasts. Though sometimes invisible, women are slowly changing the world of sportfishing by breaking stereotypes. Future growth of sportfishing will rely on female anglers, instructors, and guides. Here I share a few examples on women making a substantial impact through their passion toward fishing. These examples demonstrate women who loved and valued what they did. If the paucity of female role models discourages females from seeing the relevance of fishing to them, these examples should inspire.
Frederick Buller (2013) chronicled the very long list of large Atlantic Salmon caught by female anglers, which are outnumbered 200 to 1 by male salmon anglers. Georgina Ballantine holds the British record for a 64-pound rod-caught Atlantic Salmon from River Tay, Scotland, in 1922 (Figure 7.5). Joan Wulff was introduced to fly-fishing by her father when she was ten and won several fly-fishing accuracy championships before winning the 1951 Fishermen’s Distance competition against all-male competitors. She became the first female spokesperson for Garcia Corporation in 1959 and advocated for women anglers in her writings for Outdoor Life and Rod & Reel. Today, females make up 30% of participants in the sport of fly-fishing (Recreational Fishing and Boating Foundation 2021). Joan Wulff participated in many distance casting events and did trick casting. She snapped a cigarette from the mouth of Johnny Carson on the TV show “Who Do You Trust?” (Fogt 2017). Starting in 1978, Wulff opened a fly-casting school on the Upper Beaverkill River in New York. Her Fly-Casting Techniques, published in 1987, and New Fly-Casting Techniques, published in 2012, are classic guides to learning her techniques. When asked about her favorite fish, she would respond, “Whatever I’m fishing for,” and her favorite place to fish was “Wherever I am.”
Most avid bass anglers can identify Roland Martin, Bill Dance, and Jimmy Houston, who dominated competitive bass fishing in the first decade of Bass Anglers Sportsman Society (B.A.S.S.) and have had TV fishing shows for decades. Kim Bain-Moore began competing in bass tournaments at age 19 and in 2009 became the first woman to compete in the Bassmaster Classic tournament. Only three females have been inducted into the Bass Fishing Hall of Fame. The first was Christine Houston, who organized the first-ever all women’s bass club, the “Tulsa Bass Belles.” But female participation in competitive bass fishing never took off as expected. Fewer that one in five readers of Field & Stream, Outdoor Life, and Bassmaster magazines are female (Carini and Weber 2017).
There are signs of change since Betty Bauman, the founder and CEO of Ladies, Let’s Go Fishing!® created “The No-Yelling School of Fishing.” Baumann realized that women preferred a nonintimidating atmosphere where they could learn fishing techniques (Crowder 2002). Since the first program in 1997, over 8,000 participants have graduated from the Ladies, Let’s Go Fishing! Training. In 2018, the Lady Bass Anglers Association was formed to promote the Women’s Pro Bass Tour. Wild River Press released Fifty Women Who Fish, by Steve Kantner. Many female fishing guides are emerging, as well as fishing resources for female anglers. One indigenous fly-fishing guide, Erica Nelson, became an avid fly fisher, guide, and advocate for inclusive fishing (Aiken 2022).
Subsistence Fishing. Women make up a significant, yet hidden, portion of the subsistence fishing workforce (Ogden 2017). Many times the catches are taken along the shoreline, on foot, or from small nonmotorized boats (Figure 7.6). Yet recent estimates suggest that the catch by women is a substantial contribution, especially to local communities (Harper et al. 2020). According to the Food and Agriculture Organization (FAO), 47% of the 120 million people who earn money directly from fishing and processing are women, while women make up some 70% of those engaged in aquaculture (Montfort 2015).
Catches by women are partially for home consumption or sold to support the household and child-rearing expenses, they are not part of the measured economic output. The work of women in subsistence fishing helps improve their living conditions, educate children, and gain economic independence. In Asia and Africa, many small-scale fisheries also produce dried fish (Figure 7.7). Over 50% of the workforce in fish drying yards of Bangladesh are women from marginalized groups, such as lower castes and refugees (Belton et al. 2018). Women working to process and market dried fish are constrained by gender restrictions that influence their ability to purchase fresh fish (Manyungwa et al 2019). Policy makers and development practitioners throughout the world often overlook the women’s burdens that are not shared by her brothers (Sharma 2014). The hegemony of dominant male fishermen is slowly beginning to crack as contributions of women are demonstrated (Weeratunge et al. 2010; Harper et al. 2012, 2017; Branch and Kleiber, 2017; Frangoudes and Gerrard 2018; Smith and Basorto 2019). Yet, many changes are needed for gender equity in fishing.
Commercial Fishing. Earliest commercial fisheries in North America recruited migrants to work in seasonal fisheries. Only white men engaged in these fisheries, and violence was common as men sought their place or power in commercial fishing industries. In the salmon fisheries that developed on the Columbia River, the fishing culture shifted from a rough, violent masculinity of seasonal labor to one dominated by ethnic patriarchy that emphasized fishing as the principal work for family breadwinners. Women played important if unrecognized roles as bookkeepers, parts runners, and general hands. By the 1970s, technological advancements provided a few openings for women on the boats, but by that time the commercial fisheries had dramatically declined in scope (Friday 2006).
Today, commercial fishing fleets are overwhelmingly male dominated, with fewer than 4% of commercial fishing licenses issued to women in Oregon and Washington states. Yet women contribute to resilient communities by caring for family and maritime households, and increasingly women play a significant role in science, fisheries management, policy, and decision making (Calhoun et al. 2016). The following quote is from a participant in an oral history project:
I used to go to groundfish management team meetings 25 years ago, and if there was one woman scientist in the groundfish management team it was a big deal. And now you see women are the chairs of the groundfish management team. So seeing changes, growth of women in both management and in science. Although I know those areas are still a challenge too. And then the rise of women participating in the decision-making process. (Calhoun et al. 2016)
Fisheries Science. In the early 20th century, research universities were seldom willing to offer women academic positions and a lab of their own. However, some women prevailed despite the discrimination (Brown 1994). I describe experiences and influences of Eugenie Clark and Emmeline Moore, recognizing that there were many other female scientists who were inspirational figures.
Eugenie Clark (1922–2015) was a zoologist at a time when the field was male dominated. Her illustrious career accomplishments are even more impressive when one considers the blatant sexism early in her career. In her first book, Lady with a Spear, she wrote of her expeditions to the West Indies, Hawaii, Guam, Palau, and the Red Sea, as well as early research trials on vision and behavior in gobies, puffers, triggerfishes, and sharks. In an interview, she said, “We had to work extra hard, especially on field trips, to prove we could keep up with males.” Eugenie Clark became a self-taught expert in the art of throwing a cast net and catching fish with both wooden-handled harpoons and spearguns. She pioneered research on behavior of sharks, conducted numerous submersible dives around the world, and founded the Mote Marine Lab before becoming a professor at the University of Maryland. Clark was a productive researcher who made 71 research dives with submersibles, and her many awards and accolades include the Legend of the Sea Award (Staff 2015).
Emmeline Moore (1872–1963) was a pioneering researcher investigating lakes from an ecosystem and landscape perspective (Zatkos 2020). Moore was the first woman scientist employed by the New York Conservation Department (1920–1925) and later led the New York Biological Survey, the most comprehensive watershed study of aquatic resources at the time. She was Chief Aquatic Biologist for New York State from 1932 to her retirement in 1944. Moore was an active member and leader in the American Fisheries Society, being elected as first female president of the organization in 1927. Her research on pond plants, food web dynamics, pollution, and fish parasites helped change the way fish were managed.
7.7 Toward More Inclusive Public Participation in Fisheries
Conventional wisdom for managing fisheries has focused on employment and products that contribute to value of all goods and services. However, mainstream economists (mostly male) tend to focus only on those things measured in monetary terms. Yet, feminist economists argue that many measures of human well-being from fisheries are ignored by prevailing governance systems (Cohen et al. 2019). Furthermore, the “tragedy of the commons” maintained that in trying to serve their own self-interests, individuals end up hurting themselves—and the public good—in the long run. Consequently, government intervention was needed to prevent the collapse.
The pioneering work of Elinor Ostrom demonstrated that human cooperation, self-governance, and sharing allow people to overcome the tragedy of the commons (Ostrom 1990). She argued that there was “no reason to believe that bureaucrats and politicians, no matter how well meaning, are better at solving problems than the people on the spot, who have the strongest incentive to get the solution right.” Her research has led to management of natural resources via comanagement. FAO’s Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries in the Context of Food Security and Poverty Eradication (FAO 2015, 2017) is one of the few policy guidelines that addresses the role of gender in fisheries. These guidelines call for equal participation of women and men in organizations and in decision-making processes. Consider the following argument claim for comanagement of fisheries:
Premise: Historically, fisheries decision-making literature focused primarily on stakeholder groups who were mostly comprised of men.
Premise: Environmental knowledge is gendered.
Premise: Who has a voice in community conservation influences how well a group functions and who gains and loses from or is affected by interventions.
Premise: Omitting stakeholders may also obscure the difference between those who have a stake in fish conservation and those who have the ability to act on it.
Premise: Participatory approaches often aim to overcome stakeholder neglect by purposefully including diverse stakeholders.
Normative Claim: Solutions to problems should be built on shared negotiation processes with all stakeholders.
Comanagement of fisheries represents a wide spectrum of user participation. Consider the range of opportunities for participation illustrated (Figure 7.8). Management approaches that consciously and explicitly consider gender and diversity of actors may provide the basis for better fisheries governance (de la Torre-Castro 2019). In simpler cases, participation by fishers is limited and governments are able to effectively manage fisheries with minimal exchange of information. This is sometimes called Decide-Announce-Defend, or DAD for short. The DAD method is not suited for fisheries, where a wide range of technical, social, cultural, and economic factors are influencing the current situation and the various possible alternatives to it, and successful implementation involves a lot of people, and these people are not in an obvious command structure. Governments may provide opportunities for participants to provide input (consultative). Most believe comanagement requires at least a cooperative arrangement where participants are equal participants. In fisheries where staffs of small governments are overwhelmed by the number of fishers who are mobile and can select from many fishing opportunities within a region, governments may choose to allow groups to advise or make management decisions collectively. One example demonstrated that comanagement provided a new source of female income from fisheries and an unprecedented recognition of female participation in fishing activities (Freitas et al. 2020).
Today, there are organizations throughout the world to support equitable participation in fishing. A few examples are listed here:
1. Commercial and Subsistence Fishing
• Strength of the Tides: Community organization aiming to support, celebrate, and empower all women, trans, and gender queer people on the water.
• Dried Fish Matters: Goal is to identify the overall contribution of dried fish to the food and nutrition security and livelihoods of the poor and examine how production, exchange, and consumption of dried fish may be improved to enhance the well-being of marginalized groups and actors in the dried fish economy.
• Minorities in Aquaculture: Goal is to educate women of color on the environmental benefits of aquaculture and support them as they launch and sustain their careers in the field, growing the seafood industry and creating an empowering space for women along the way.
• Women in Fisheries Network and other initiatives support women fishing.
• Gender in Aquaculture and Fisheries: Addresses the data gaps and issues faced by women in fisheries.
2. Recreational Fishing
• Ladies Let’s Go Fishing: Dedicated to attracting women to fishing and to promoting conservation and responsible angling.
• Angling For All: Encourages fishing companies to sign the Angling for All Pledge that establishes a commitment to addressing racism and inequality throughout a pledgee’s internal culture, consumer-facing behaviors, and broader community.
• Brown Folks Fishing: Cultivates the visibility, representation, and inclusion of people of color in fishing and its industry.
• United Women on the Fly: Committed to building an inclusive community that educates, provides resources, encourages, and connects anglers from all backgrounds into the sport of fly-fishing.
Today we are regendering many types of work and leisure activities, including fishing. The significant challenges that we face in fish conservation at home and abroad will require input from all. Rather than propagating stereotypes of fishing activities, we need to explore the participation across gender and other differences so we can do a better job evaluating outcomes of conservation for the well-being of all humans.
Women and men have significantly different approaches and views on public policy issues, which means that women’s voices and those of minorities need to be heard.
—Janet Yellen
Profile in Fish Conservation: Danika L. Kleiber, PhD
Danika Kleiber is a fisheries social scientist for the National Oceanic and Atmospheric Administration (NOAA) based in Hawai‘i. She was always interested in blending her interests in fisheries biology and feminism and earned a degree in biology and women studies at Tufts University.
Today, her research specialty focuses on issues of equity and the intersection of gender and natural resources, in particular socioecological research approaches to small-scale fisheries management. Her research has uncovered some hidden relations between gender, food security, and participatory governance.
In a study for her dissertation, Kleiber characterized the participation of women in small-scale fisheries from 106 case studies from around the world. This landmark study revealed reasons why women are seldom adequately studied in fisheries. In some cases, it is considered culturally unacceptable for women to fish. In other cases, analysts used very limited definitions of what counts as fishing. In fact, in some languages, such as Greek and Greelandic, there is no female equivalent for the term “fishermen.” These and other gender biases reinforced the clear need for fisheries scientists to embrace gender approaches and appreciate women in fishing as parts of an interdisciplinary ecosystem approach.
Kleiber’s studies of small-scale fisheries demonstrated the scope and economic impact of women in a variety of roles. Gleaning was often overlooked by previous studies. But this hand collection of invertebrates from shallow intertidal water is the main livelihood for many rural women. To advance fisheries management, Kleiber is pioneering studies of social impacts of proposed fisheries management measures on fishing communities. Social impact assessment tracks many indicators beyond catch and revenues and recognizes that fishing also contributes to culture and social cohesion of island communities.
Key Takeaways
• Women are involved in all aspects of the fishing industry, including skinning, drying, curing, salting, processing, and marketing seafood.
• Rights, equity, and justice are mainstream principles of good fisheries governance.
• Women’s role in fishing or fisheries is often overlooked in decision making for cultural reasons.
• Foundational concepts of ecofeminism and intersectionality are useful constructs for analyzing fisheries gender issues.
• Fisheries management policies are set by governance bodies that exclude women.
• Intersectionality is a crucial starting point in all discussions and is grounded in social justice.
This chapter was reviewed by Kafayat Fakoya.
Long Descriptions
Figure 7.1: Government, Institutions, NGOs, & Donors, provide assets and services give support to fisheries governance. Chart splits showing, left: fisheries governance gives greater support in traditional roles to (male symbol) in access, ownership, rights; leads to control harvest, more influence in governance; right: fisheries governance gives less support in traditional roles (female symbol) with limited access, no ownership, limited rights; leads to conduct post harvest, less influence in governance. Both lines lead to lower representation in decision making increases community vulnerability. Jump back to Figure 7.1.
Figure 7.3: Intersectionality displays how social identities intersect with one another and are wrapped in systems of power with overlapping circles of a spirograph, including 1) race, 2) ethnicity, 3) gender identity, 4) class, 5) language, 6) religion, 7) ability, 8) sexuality, 9) mental health, 10) age, 11) education, 12) body size, and many more. Quote by Kimberle Crenshaw reads, “intersectionality is a lens through which you can see where power comes and collides, where it locks and intersects. It is the acknowledgement that everyone has their own unique experiences of discrimination and privilege.” Jump back to Figure 7.3.
Figure 7.8: Range of co-management arrangements from government-based management to user group-based management. From left, 1) instructive, minimal exchange of information between government and users; 2) consultative, mechanisms exist for government to consult with user groups, but all decisions are taken by government; 3) co-operative, government and users co-operate as equal partners in decision-making. For some this is the definition of co-management; 4) advisory, users advise government of decisions to be taken and government endorses these decisions; 5) informative, government delegates authority to make decisions to user groups, who are responsible for informing government on these decisions. Jump back to Figure 7.8.
Figure References
Figure 7.1: Conventional fisheries governance gives greater support for traditional roles of males leading to lower representation of females in decision making. Adapted under fair use from A Review of Women’s Access to Fish in Small-Scale Fisheries, by Angela Lentisco and Robert Ulric Lee, 2015 (https://www.fao.org/3/i4884e/i4884e.pdf). Includes “Male,” by Heri Sugianto, 2018 (Noun Project license, https://thenounproject.com/icon/male-1745485/), and “Female.” by Maurizio Fusillo, 2012 (Noun Project license, https://thenounproject.com/icon/female-3446/).
Figure 7.2: The progression of gender influences begins with difference and illustrates a common pattern by which power is accrued by individuals who embody certain characteristics. Kindred Grey. 2022. CC BY 4.0.
Figure 7.3: Intersectionality is a powerful framework that acknowledges that everyone has unique experiences of discrimination and privilege. Sylvia Duckworth. 2020. Used with permission from Sylvia Duckworth. CC BY 4.0.
Figure 7.4: Policies may be gender blind or gender aware, and gender-aware policies may be instrumental or intrinsic. Kindred Grey. 2022. CC BY 4.0.
Figure 7.5: Georgina Ballantine holds the British record for a 64-pound rod-caught salmon from River Tay, Scotland in 1922. Photo by Raeburn Studio. Illustrated London News, “A woman breaks the record for tay salmon: A 64-pounder.” 2022. Public Domain.
Figure 7.6: Rana Tharu women go fishing in southwest Nepal. Yves Picq. 2004. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:N%C3%A9pal_rana_tharu1818a_Crop.jpg.
Figure 7.7: Woman selling dried fish at fish market in Cambodia. McKay Savage. 2008. CC BY 2.0. https://commons.wikimedia.org/wiki/File:Cambodia_08_-_036_-_markets_-_dried_fish_for_sale_(3198824843).jpg.
Figure 7.8: Spectrum of comanagement showing increasing participation of users from government-based to user group–based management. Kindred Grey. 2022. Adapted under fair use from “Fisheries co-management: a comparative analysis,” by Sevaly Sen and Jesper Raakjaer Nielsen, 1996 (https://doi.org/10.1016/0308-597X(96)00028-0).
Figure 7.9: Danika L. Kleiber, PhD. Used with permission from Danika L. Kleiber. CC BY 4.0.
Text References
Aiken, M. 2022. “I identify as an angler”: meet Erica Nelson, a female, indigenous fly fishing guide. New York Times, February 19, 2022. https://www.awkwardangler.com/blog/nytimes.
Ameyaw, A. B., A. Breckwoldt, H. Reuter, and D. W. Aheto. 2020. From fish to cash: analyzing the role of women in fisheries in the western region of Ghana. Marine Policy 113. https://doi.org/10.1016/j.marpol.2019.103790.
Belton, B., M. A. R. Hossain, and S. H. Thilsted. 2018. Labour, identity and wellbeing in Bangladesh’s dried fish value chains. Pages 217–241 in D. Johnson, T. G. Acott, N. Stacey, and J. Urquhart, editors, Social wellbeing and the values of small-scale fisheries, Springer, New York.
Bennett, E. 2005. Gender, fisheries and development. Marine Policy 29:451–459.
Branch, T. A., and D. Kleiber. 2015. Should we call them fishers or fishermen? Fish and Fisheries 18(1):114–127. https://doi.org/10.1111/faf.12130.
Brown, P. S. Early women ichthyologists. Environmental Biology of Fishes 41:9–30.
Bull, J. 2009. Watery masculinities: fly-fishing and the angling male in the south west of England. Gender, Place & Culture 16(4):445–465.
Buller, F. 2013. A list of large Atlantic Salmon landed by the ladies. American Fly Fisher 39(4):2–21.
Burkett, E., and A. Carter. 2020. It’s not about the fish: women’s experiences in a gendered recreation landscape. Leisure Sciences 44(7):1013–1030. https://doi.org/10.1080/01490400.2020.1780522.
Calhoun, S., F. Conway, and S. Russell. 2016. Acknowledging the voice of women: implications for fisheries management and policy. Marine Policy 74:292–299.
Campbell, S. J., R.Jakub, A.Valivia, H. Setiawan, A. Setiawan, C. Cox, A. Kiyo, Darman, L. F. Djafar, E. de la Rosa, W. Suherfian, A. Yuliani, H. Kushardanto, U. Muawana, A. Rukma, T. Alimi, and S. Box. 2021. Immediate impact of COVID-19 across tropical small-scale fishing communities. Ocean & Coastal Management 200:105485. https://doi.org/10.1016/j.ocecoaman.2020.105485.
Carini, R. M., and J. D. Weber. 2017. Female anglers in a predominantly male sport: portrayals in five popular fishing-related magazines. International Review for the Sociology of Sport 52(1):45–60.
Clancy, K. B., R. G. Nelson, J. N., Rutherford, and K. Hinde. 2014. Survey of academic field experiences (SAFE): trainees report harassment and assault. PloS ONE 9(7):e102172.
Clark, E. 1951. Lady with a spear. Harper Brothers, New York.
Cohen, P. J., E. H. Allison, N. L. Andrew, J. Cinner, L. S. Evans, M. Fabinyi, L. R. Garces, S. J. Hall, C. C. Hicks, T. P. Hughes, S. Jentoft, D. J. Mills, R. Masu, E. K. Mbaru, and B. D. Ratner. 2019. Securing a just space for small-scale fisheries in the blue economy. Frontiers in Marine Science 6. https://doi.org/10.3389/fmars.2019.00171.
Crenshaw, K. 1989. Demarginalizing the intersection of race and sex: a black feminist critique of antidiscrimination doctrine, feminist theory and antiracist politics. University of Chicago Legal Forum 1989(1), Article 8. Available at: http://chicagounbound.uchicago.edu/uclf/vol1989/iss1/8.
Crenshaw, K. 1991. Mapping the margins: intersectionality, identity politics, and violence against women of color. Stanford Law Review 43:1241–1299.
Crowder, R. 2002. Check your fly: tales of a woman fly fisher. Canadian Woman Studies 21(3):162–165.
Cuomo, C. 1998. Feminism and ecological communities: an ethic of flourishing. Routledge, New York.
Deb, A. K., C. E. Haque, and S. Thompson. 2015. “Man can’t give birth, woman can’t fish”: gender dynamics in the small-scale fisheries of Bangladesh. Gender, Place & Culture 22(3):305–324.
de la Torre-Castro, M. 2019. Inclusive management through gender consideration in small-scale fisheries: the why and the how. Frontiers in Marine Science 6:156. https://doi.org/10.3389/fmars.2019.00156.
Drury O’Neill, E., N. K. Asare, and D. W. Aheto. 2018. Socioeconomic dynamics of the Ghanaian tuna industry: a value-chain approach to understanding aspects of global fisheries. African Journal of Marine Science 40:303–313.
Fogt, J. 2017. Virtuoso. Anglers Journal, May 12. Accessed June, 21, 2019, at https://www.anglersjournal.com/freshwater/virtuoso.
FAO. 2015. Voluntary guidelines for securing sustainable small-scale fisheries in the context of food security and poverty eradication. Food and Agriculture Organization of the United Nations, Rome.
FAO. 2017. Towards gender-equitable small-scale fisheries governance and development: a handbook. (In support of the implementation of the Voluntary guidelines for securing sustainable small-scale fisheries in the context of food security and poverty eradication, by Nilanjana Biswas.) Food and Agriculture Organization of the United Nations, Rome.
Frangoudes, K., and S. Gerrard. 2018. (En)Gendering change in small-scale fisheries and fishing communities in a globalized world. Maritime Studies 17:117–124.
Friday, C. 2006. White family fishermen, skill, and masculinity. The Oregon History Project. Available at: https://www.oregonhistoryproject.org/articles/white-family-fishermen-skill-and-masculinity/#.YhkBji-B1qs.
Freitas, C. T., H. M. V. Espírito-Santo, J. V. Campos-Silva, C. A. Peres, and P. F. M. Lopes. 2020. Resource co-management as a step towards gender equity in fisheries. Ecological Economics 176. https://doi.org/10.1016/j.ecolecon.2020.106709.
Gaard, G., editor. 1993. Ecofeminism: Women, animals, and nature. Temple University Press, Philadelphia.
Gaard, G., and L. Gruen. 1993. Ecofeminism: toward global justice and planetary health. Society and Nature 2:1–35.
Gilligan, C. 1988. Mapping the moral domain: a contribution of women’s thinking to psychological theory and education. Harvard University Press, Cambridge, MA.
Grace, R. NOAA is trying to encourage more observers to report sexual harassment. 2019. Alaska Public Media, June 5. Accessed January 12, 2023, at https://alaskapublic.org/2019/06/05/noaa-is-trying-to-encourage-more-observers-to-report-sexual-harassment/.
Gustavsson, M. 2020. Women’s changing productivity practices, gender relations and identities in fishing through critical feminization perspective. Journal of Rural Studies 78:36–46.
Harper, S., M. Adshade, V. W. Y. Lam, D. Pauly, and U. R. Sumaila. 2020. Valuing invisible catches: estimating the global contribution by women to small-scale marine capture fisheries production. PLoS ONE 15(3):e0228912. https://doi.org/10.1371/journal.pone.0228912.
Harper, S., C. Grubb, M. Stiles, and U. R. Sumaila. 2017 Contributions by women to fisheries economies: insights from five maritime countries. Coastal Management 45(2):91–106.
Harper, S., D. Zeller, M. Hauzer, D. Pauly, and U. R. Sumaila. 2012. Women and fisheries: contribution to food security and local economies. Marine Policy 39: 56–63. doi:10.1016/j.marpol.2012.10.018.
Herbst, P. H. 2001. Wimmin, wimps & wallflowers: an encyclopedic dictionary of gender and sexual orientation bias in the United States. Intercultural Press, Yarmouth, ME.
Jones, J. M. 2021. LGBT identification rises to 5.6% in latest U.S. estimate. Gallup, February 24. Available at: https://news.gallup.com/poll/329708/lgbt-identification-rises-latest-estimate.aspx.
Kleiber, D., K. Frangoudes, H. T. Snyder, A. Choudhury, S. M. Cole, K. Soejima, C. Pita, A. Santos, C. McDougall, H. Petrics, and M. Porter. 2017. Promoting gender equity and equality through the small-scale fisheries guidelines: experiences from multiple case studies. Pages 737–759 in S. Jentoft, R. Chuenpagdee, Barrag´an-Paladines, editors, The small-scale fisheries guidelines, Springer, Cham, NY.
Kleiber, D., L. M. Harris, and A. C. J. Vincent. 2015. Gender and small-scale fisheries: a case for counting women and beyond. Fish and Fisheries 16(4):547–562.
Kleiber, D., L. M. Harris, and A. C. J. Vincent. 2018. Gender and marine protected areas: a case study of Danajon Bank, Philippines. Maritime Studies 17(2):163.
Kolan, M., and K. S. TwoTrees. 2014. Privilege as practice: a framework for engaging with sustainability, diversity, privilege and power. Journal of Sustainability Education 7:1–13.
Kuehn, D. M., C. P. Dawson, and R. Hoffman. 2006. Exploring fishing socialization among male and female anglers in New York’s eastern Lake Ontario area. Human Dimensions of Wildlife 11(2):115–127.
Lawless, S., P. J. Cohen, S. Mangubhai, D. Kleiber, and T. H. Morrison. 2021. Gender equality is diluted in commitments made to small-scale fisheries. World Development 140:105348. https://doi.org/10.1016/j.worlddev.2020.105348.
Lopez-Ercilla, I., M. J. Espinosa-Romero, F. J. F. Rivera-Melo, S. Fulton, R. Fernández, J. Torre, A. Acevedo-Rosas, A. J. Hernández-Velasco, and I. Amador. 2021. The voice of Mexican small-scale fishers in times of COVID-19: impacts, responses, and digital divide. Marine Policy 131:104606. https://doi.org/10.1016/j.marpol.2021.104606.
Mallett, R. K., T. E. Ford, and J.A. Woodzicka. 2016. What did he mean by that? Humor decreases attributions of sexism and confrontation of sexist jokes. Sex Roles: A Journal of Research 75(5-6):272–284. https://doi.org/10.1007/s11199-016-0605-2.
Manyungwa, C. L., M. M. Hara, and S. K. Chimatiro. 2019. Women’s engagement in and outcomes from small-scale fisheries value chains in Malawi: effects of social relations. Maritime Studies 8:1–11.
Merwin, J. 2010. Merwin: study says most women don’t like pink fishing gear. Field & Stream, 24 May. Available at: https://www.fieldandstream.com/blogs/bass-fishing/2010/05/merwin-study-says-most-women-dont-pink-fishing-gear/. Accessed June 20, 2019.
Miles-McLean, H., M. Liss, M. J. Erchull, C. M. Robertson, C. Hagerman, M. A. Gnoleba, and L. J. Papp. 2015. “Stop looking at me!” Interpersonal sexual objectification as a source of insidious trauma. Psychology of Women Quarterly 39(3):363–374.
Monteith, M., M. Burnes, and L. Hildebrand. 2019. Navigating successful confrontations: What should I say and how should I say it? Pages 225–248 in R. K. Mallett and M. J. Monteith, editors, Confronting prejudice and discrimination: the science of changing minds and behaviors. Academic Press, Cambridge, MA.
Montfort, M. C. 2015. The role of women in the seafood industry. Globefish Research Program, vol. 119. FAO, Rome. http://www.fao.org/3/a-bc014e.pdf.
Nelson, R. G., J. N. Rutherford, K. Hinde, and K. B. Clancy. 2017. Signaling safety: characterizing fieldwork experiences and their implications for career trajectories. American Anthropologist 119(4):710–722.
Ogden, L. E. 2017. Fisherwomen—The uncounted dimension in fisheries management: shedding light on the invisible gender. BioScience 67(2):111–117.
Ostrom, E. 1990. Governing the commons: the evolution of institutions for collective action. Cambridge University Press.
Perry, G. 2017. The Descent of Man. Penguin, New York.
Recreational Fishing and Boating Foundation. 2020. 2020 Special report on fishing. Recreational Fishing and Boating Foundation, Alexandria, VA. Available at: https://www.takemefishing.org/getmedia/eb860c03-2b53-4364-8ee4-c331bb11ddc4/2020-Special-Report-on-Fishing_FINAL_WEB.pdf.
Sáez, G., M. Alonso-Ferres, M. Garrido-Macías, I. Valor-Segura, and F. Expósito. 2019. The detrimental effects of sexual objectification on targets’ and perpetrators’ sexual satisfaction: the mediating role of sexual coercion. Frontiers in Psychology 10. https://doi.org/10.3389/fpsyg.2019.02748.
Santos, A. 2015. Fisheries as a way of life: gendered livelihoods, identities and perspectives of artisanal fisheries in eastern Brazil. Marine Policy 62: 279–288.
Sarasota Herald-Tribune. 2015. Timeline: Eugenie Clark’s life and work. February 25. https://www.heraldtribune.com/story/news/2015/02/26/timeline-eugenie-clarks-life-and-work/29301086007/.
Schroeder, S. A., D. C. Fulton, L. Currie, and T. Goeman. 2006. He said, she said: gender and angling specialization, motivations, ethics, and behaviors. Human Dimensions of Wildlife 11(5):301–315.
Sharma, R. 2014. Teach a woman to fish: overcoming poverty around the globe. St. Martin’s Press, New York.
Smith, H., and X. Basurto. 2019. Defining small-scale fisheries and examining the role of science in shaping perceptions of who and what counts: a systematic review. Frontiers in Marine Science 6:236. doi: 10.3389/fmars.2019.00236.
Thompson, P. 1985. Women in the fishing: the roots of power between the sexes. Comparative Studies in Society and History 27:3–32.
Tilley, A., A. Burgos, A. Duarte, J. dos Reis Lopes, H. Eriksson, and D. Mills. 2020. Contribution of women’s fisheries substantial, but overlooked, in Timor-Leste. Ambio 50:113–124.
Toth, J. F., Jr., and R. B. Brown. 1997. Racial and gender meanings of why people participate in recreational fishing. Leisure Sciences 19:129–146.
Voyles, T. B. 2021. Toxic masculinity: California’s Salton Sea and the consequences of manliness. Environmental History 26:127–141.
Warren, K. J., editor. 1994. Ecological feminism. Routledge, New York.
Weeratunge, N., K. A. Snyder, and C. P. Sze. 2010. Gleaner, fisher, trader, processor: understanding gendered employment in fisheries and aquaculture. Fish and Fisheries 11(4):405–420.
Welch, L. 2019. Fisher vs. fisherman: What do they prefer to be called? Alaska Fish Radio, December 31. Available at: https://www.seafoodnews.com/Story/1204395/Fisher-vs-Fisherman-What-Do-They-Prefer. Accesssed May 31, 2023.
Williams, M. J. 2008. Why look at fisheries through a gender lens? Development 51:180–185.
Woodzicka, J. A., R. K.Mallett, and K. J. Melchiori. 2020. Gender differences in using humor to respond to sexist jokes. Humor 33(2):219–238. https://doi.org/10.1515/humor-2019-0018.
Woodzicka, J. A., and J. J. Good. 2021. Strategic confrontation: examining the utility of low stakes prodding as a strategy for confronting sexism. Journal of Social Psychology 161(3):316–330.
Woskie, L., and C. Wenham. 2021. Do men and women “lockdown” differently? Examining Panama’s COVID-19 sex-segregated social distancing policy. Feminist Economics 27(1-2):327–344.
Zatkos, L., C. A. Murphy, A. Pollock, B. E. Penaluna, J. A. Olivos, E. Mowids, C. Moffitt, M. Manning, C. Linkem, L. Holst, A. B. Cárdenas, and I. Arismendi. 2020. AFS roots: Emmeline Moore, all things to all fishes. Fisheries 45(8):435–443. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.07%3A_Gender_and_Fishing.txt |
Learning Objectives
• Explain the ancestral origins of primitive bony fishes of North America.
• Describe the major threats to Alligator Gar populations.
• Apply life history theory to explain the vulnerability of Alligator Gar to human activities.
• Describe habitat changes that strongly influence recruitment in Alligator Gar.
• Apply the concept of the values-beliefs-norms-actions causal chain to changes in human perceptions of gars.
8.1 The Primitive Bony Fish of North America
When the first flowering plants appeared on Earth and dinosaurs were the dominant large land animals, the ancestors of gars, bowfins, sturgeons, and paddlefish swam the waters of the ancient Tethys Sea. Hence, these primitive bony fish are often referred to as fishy dinosaurs. Paddlefish and sturgeon appeared in the fossil record 245 to 208 million years ago (Mya) near the end of the Triassic, making them among the most ancient of still-living ray-finned (actinopterygian) fish (Figure 8.1). These primitive fish groups survived the last major extinction on Earth (66 million years ago) and persisted throughout the second age of radiation of bony fish. With such a long history on Earth, one would assume that these fish are extinction proof. However, most populations of sturgeons and paddlefish are at risk of extinction (Boreman 1997; Pikitch et al. 2005), and the Chinese Paddlefish was recently declared extinct (Zhang et al. 2020). Overharvest and habitat change have influenced these primitive bony fish, and the success of conservation efforts depends, in part, on changes in human attitudes that will stimulate conservation actions.
Sturgeon and paddlefish are vulnerable to impacts from human activities, in particular fisheries. Paddlefish and sturgeons display strong spawning site fidelity, and large shoals of adults gather over clean gravel-cobble stream substrates for spawning. Females have late maturity and do not breed each year. Even though a large female may produce a million or more eggs, these big, old, fat, fecund, female fish (BOFFFF) are very rare in exploited populations. The North American Sturgeon and Paddlefish Society (NASPS), the North American affiliate of the World Sturgeon Conservation Society, is dedicated to promoting the conservation and restoration of sturgeon species in North America by developing and advancing research pertaining to their biology, management, and utilization (Bruch et al. 2016). Efforts to restore Lake Sturgeon in the Winnebago System has resulted in opening of a well-regulated winter spearing season (Bruch et al. 2007). Similarly, recreational harvest is permitted for the American Paddlefish (Polyodon spathula) in certain Oklahoma waters (Cha and Melstrom 2018) and White Sturgeon in the Columbia River (Beamesderfer et al. 1995).
Unlike the sturgeons and paddlefish, gars and Bowfins are among North America’s most disliked fish, largely because of concerns that they eat game fish. The gar (family Lepisosteidae) have been around since the Jurassic and Cretaceous Periods (~150 to 160 million years ago), long before game fish of today emerged. Gars and Bowfins are the sister group (i.e., the closest relatives) to other teleost fish (Figure 8.1) and, therefore, of interest to evolutionary biologists. The largest gars are in the genus Atractosteus — the three extant species are Alligator Gar (A. spatula or Catan in Mexico), the Cuban Gar (A. tristoechus) or Manjuari from western Cuba, and the Tropical Gar (A. tropicus) or Pejelagarto from southern Mexico and Central America. Among these three, the largest is the Alligator Gar, which is most imperiled (Figure 8.2).
Question to ponder
What types of fish were living on planet Earth in the age of dinosaurs (345 to 66 million years ago)? How did these fish survive and dinosaurs went extinct?
8.2 Life History of Gars
Gars have a long, flexible cylindrical body with a hard bony covering and pointed snout with many sharp teeth. This body form is extremely well adapted for a sit-and-wait, ambush predator and not for fast, sustained swimming. The hard bony protection provided by ganoid scales emerged at a time when very large toothy aquatic reptiles, the large pliosaurs and their relatives, were still around. This bony covering is extremely difficult to pierce, even with a sharp filet knife. Each ganoid scale is rhomboid in shape and has a dorsal peg that articulates with a ventral socket joint on the adjacent, dorsally placed scale. Ganoid scales have a bony basal layer, a layer of dentine, and an outer layer of ganoine (an inorganic bone salt). Ganoid scales in gars are tightly overlapping on all parts of the body, creating the diamond-shaped pattern and the rather inflexible body form. Ganoid scales can resist powerful bite forces of self-predation and attack by alligators (Sherman et al. 2017). This chapter focuses mostly on the largest of the seven species of gars, the Alligator Gar (Figure 8.2).
Populations of the gars in the genus Lepisosteus (Longnose Gar L. osseus, Shortnose Gar L. platostomus, Spotted Gar L. oculatus, and Florida Gar L. platyrhincus) remain stable throughout much of their North American ranges. Longnose Gar, Spotted Gar, and Shortnose Gar are easily distinguishable from other gars by snout length and pigment patterns (Orth 2015; David 2016). For example, the spots on the body of the Longnose Gar are smaller and generally less well developed than on Spotted Gar. The snout length of Longnose Gar is more than 13 times its narrowest width in specimens 50 mm long or larger (Figure 8.3). Juveniles have a shorter snout, which grows proportionally faster than the body.
The Alligator Gar is rare, endangered, and has been extirpated from many outer areas of its range. Historically, the Alligator Gar’s home range included the Mississippi River and its tributaries from the lower reaches of the Ohio and the Missouri rivers southward to the Gulf of Mexico. Today, Alligator Gars are primarily restricted to coastal rivers, with inland populations persisting not only in Oklahoma but also in Florida, Georgia, Alabama, Tennessee, Arkansas, and Texas.
The unique life history of the Alligator Gar makes it very susceptible to overharvest and habitat change. Alligator Gars and other gar species have been commercially fished in southern states, and in recent years it has become a target of recreational hook-and-line anglers as well as bowfishers. The large size of the Alligator Gar and its numerous sharp teeth mean that it can produce a serious bite wound to those who attempt to handle it. There are no verified reports of attacks on humans. Eggs of all gars are poisonous to humans and other mammals, birds, and crayfish (Ostrand et al. 1996).
How large can they get? That’s hard to know because large specimens are no longer present in exploited populations. A commercial fisherman, while fishing for buffalo fish, caught a large Alligator Gar from Lake Chotard, Mississippi, on February 14, 2011. He had never seen an Alligator Gar that big—over twice his weight. The fish was barely alive after being tangled in the fisherman’s gill net. The fisherman barely had any freeboard after loading the big gar into his 16-foot boat. After calling a game warden, he found metal yard that had a big enough scale. The fish proved to be the largest Alligator Gar that’s ever been officially measured. It was 8.5 feet long, 47 inches in girth, and weighed 327 pounds (Figure 8.4). According to the International Game Fish Association (IGFA), the world record Alligator Gar captured by hook and line weighed 279 pounds. Larger Alligator Gar may be swimming in the wild, but the official measurements confirm that the Alligator Gar is the second-largest freshwater fish in North America (second only to the White Sturgeon).
The Alligator Gar is a very long lived fish, although previous estimates of longevity have been underestimates. To accurately age an Alligator Gar, scientists must remove the inner ear bone (otolith), because other structures such as fin rays and scales provide underestimates of true age (Daugherty et al. 2020). The record 327-pound Alligator Gar was aged by scientists, who verified that the individual was 95 years old (Figure 8.5).
The Alligator Gar is typically a solitary fish that appears passive and barely moving while watching for potential prey. Gars may feed during the day or night and spend their time in a “lie-and-wait” position before ambushing. They are not fast swimmers, but prey capture involves a flex of their tail with mouth open to impale their target on the double row of super-sharp teeth. As adults they mostly feed on other fish but can consume waterfowl, turtles, mammals, and whatever’s most abundant.
What’s unique about the growth of Alligator Gars is their fast growth in the first years of life followed by slower growth (Figure 8.6; Figure 8.7). Juvenile Alligator Gars quickly transition to fish-eating habits (Butler et al. 2018). A fish diet means the juveniles grow at 4-5 mm per day in the first three months of life, so that by the end of the first growing season they may reach 1.5 to 2 feet in length (~40–70 cm) and 8–10 pounds in weight (Sakaris et al. 2019). Despite their fast growth, young Alligator Gars are preyed upon by many larger fish.
Addition of new individuals to a population depends on fish surviving to maturity, finding mates, and surviving and growing through many challenges in egg, larval, and juvenile stages. Although many eggs may be produced, survival to maturity is very low. In fact, recruitment failure is typical in Alligator Gar populations, with successful recruitment observed in only 3 of 10 years (Figure 8.8).
After the first year, very few predators threaten Alligator Gars. The only known predator is the American Alligator, and annual survival for adults may be as high as 91.5%. This means that only a few individuals in a population will survive to be trophy catch or BOFFFF, especially in populations that are heavily fished (Figure 8.9). BOFFFFs typically produce more and more viable eggs, are able to outlive unfavorable periods, and survive to spawn multiple times (Hixon et al. 2014). Unfortunately, in the case of Alligator Gars, the benefits are not fully realized because the large fish in the lower Trinity River, Texas, had high concentrations of mercury, polychlorinated biphenyls (PCBs), and organochlorine pesticides (Harried et al. 2020).
Long life, variable recruitment, and low juvenile survival lead to vulnerability to overfishing in Alligator Gars. Female Alligator Gars produce many small offspring, and tiny little eggs. Male Alligator Gars remain in shallow spawning areas longer, making them vulnerable to sight-fishing. And all those traits mean that these fish are vulnerable to overfishing without restrictions on daily harvest. Every loss of a mature Alligator Gar influences the total number of eggs that may be produced. The biggest gars are almost always female fish. The spawning potential ratio (SPR) measures the total output of eggs relative to that in an unfished population. SPR drops rapidly as the exploitation rate increases (Smith et al. 2018; Figure 8.10). Alligator Gar populations may be able to sustain annual harvests of only 5%. Thus, regulations in some trophy waters are set at only one fish per day bag limit (Binion et al. 2015; Buckmeier et al. 2016).
Question to ponder:
Describe aspects of the life history of Alligator Gar that makes them vulnerable to overfishing.
8.3 Mistreatment of Gars
Before European colonists came to North America, the gars were held in high status by indigenous peoples. Gars are still a popular food fish in various parts of Mexico and Cuba. In the southeast United States, indigenous people ate a variety of fish and mollusks, but gars were captured for food (Reitz et al. 2021). Native peoples did eat gar, and the scales were used to make arrow points, and the skins were used as breastplates. There is also evidence that ritual dances of Native American tribes were inspired by the gar.
European colonists did not give gars respect as a food fish or game fish. Instead, they were considered voracious pests based on misinformation. They were believed to be “responsible for the destruction of great numbers of useful and valuable fishes,” and that’s where the story of gar persecution begins (Caldwell 1913). The following quotes from so-called authorities at the time would eventually be proven incorrect:
• “Fishermen everywhere destroy it [the Longnose Gar] without mercy. Its flesh is rank and tough and unfit even for dogs” (Jordan 1905, page 30).
• “Certainly if our commercial fisheries are to be properly conserved, stringent measures will have to be taken against these ‘weeds’ and ‘wolves among fishes” (Richardson 1913, 407).
• Gars “are responsible for the destruction of great numbers of useful and valuable fishes” (Gowanloch 1933).
• “The time will doubtless come where thorough going measures will be taken to keep down to the lowest practicable limit the dogfish [bowfin] and the gars—as useless and destructive in our productive waters as wolves and foxes were in our pastures and poultry yards” (Forbes and Richardson 1920, 41).
• “First time I saw an alligator gar I damn near threw up. They ain’t natural anything get that big. It’s ten feet long and three feet at the girth. Not one of God’s creations like you and me. Some say they ain’t afraid of alligator gar fish. Bullshit. You look at that thing. It’s big and mean. Swallow both of us. Them people say they ain’t afraid tellin’ lies” (Bukka White, blues singer and guitarist).
• “Gars are highly predaceous animals, stealthy and persistent destroyers of a vast quantity of aquatic life” (Gowanloch 1940, 292).
The following poem was written by Missouri Assistant Attorney General Lovan, interpreting the state’s right to kill gars:
Mr. Deputy in charge of fish,
You are informed it is my wish,
That you take some dynamite in your flivver
And proceed to Jack’s Fork river,
And, standing on the gravelly bar
Cast in the shots to kill the gar.
But when you execute this command
Don’t forget the law will demand
That while killing a gar, you must not harass
A single sucker, catfish, or bass.
You must obey instructions without fail
Or run the risk of going to jail.
—State v. Freeland 1927, 627 (from Scarnecchia 1992)
Missouri Game and Fish and other agencies would target and kill large numbers of gars. In the April 1926 issue of Missouri Game and Fish News (Figure 8.11), we learn about law enforcement people in Missouri going out and destroying 5,000 gars because of the damage that they were believed to be causing. Many times, agencies directed efforts to exterminate gars, including the use of the Electrical Gar Destroyer deployed by the Texas Game Fish and Oyster Commission (Burr 1931). Up until recently, most states had no limits on harvesting gars.
During most of the twentieth century, gars were viewed as harmful by most anglers and even fisheries managers. Yet, the Richardson (1913, 407) warning of the need for stringent measures against these “weeds” and “wolves” was based only on visual observations of adult Shortnose Gar (Lepisosteus platostomus) and not on any scientific evidence of harm.
Scarnecchia (1992) reported that even by the late 1980s, it was not legal to release gar alive in Iowa. Section 109.114 stated, “It shall be unlawful for any person to place any gar pike in any waters of the state, and such fish when taken shall be destroyed.” Tarzwell (1945) explored the possibility of commercial fishing for rough fish in Tennessee Valley Authority reservoirs. Too often the gars were simply thought of as a rough fish problem to be solved and not a resource to protect and conserve. Ironically, today fish markets of Arkansas cannot supply the demand for gar meat, which fetches a price higher than catfish fillets. Researchers investigating feeding habits of gar support the view that consumption of game fish is minimal.
Catching an Alligator Gar (often referred to as “gator gar”) is not so easy. They are not abundant today and occur in large floodplain rivers of the delta region of Louisiana, Arkansas, Mississippi, and Texas. It is very hard to impale the toothy jaws with a barbed hook. Most gars are caught by accident by commercial fisheries or targeted by bowfishers. Unfortunately, those who learn to catch gator gar with bowfishing, trot lines, and heavy-duty equipment often leave them dumped by the truckload or turned into fertilizer. Today, some anglers are “hooked” on targeting the monster gator gar, or le poisson armé (the armored fish), as the French explorers referred to it. When author Mark Spitzer (2010, 2015) hooked his second monster gar, it was just as Jack Harper described in Outdoor Life (1950): “They call him gar. His mother is a hurricane and his father is a ring-tailed tornado, and when he’s mad he’s one fish wave of destruction.”
Question to ponder:
Describe the causal chain of influence from values, beliefs, norms, and actions as it applies to early actions of European colonists toward gars. Contrast that with values, beliefs, norms, and actions of modern conservationists.
8.4 Bowfishing Controversies over Ethics and Waste
Bow anglers are a growing and dedicated constituency with specialized boats and equipment. Bowfishers in Texas represented only 3% of Texas freshwater anglers, were primarily male (97%), and fished 46 days per year, reporting a success rate of 57% (Bennett et al. 2015). Bowfishing may account for the majority of recreational harvest of Alligator Gar in Texas (Buckmeier 2008).
Bowfishing has grown in popularity, despite controversies over ethics and waste. Unlike hook-and-line fishing, bowfishing means that Alligator Gar are captured and killed. There is no such thing as catch and release. Wanton waste laws can be applied to all fish caught, requiring anglers to either release them or eat them. For example, Virginia’s Wanton Waste Law holds that “No person shall kill or cripple and knowingly allow any nonmigratory game bird or game animal to be wasted without making a reasonable effort to retrieve the animal and retain it in their possession” (4 VAC15-40-250 Wanton Waste Virginia Law).
Also, because many bowfishers stalk fish at night in order to get close, the notion of fair chase has been questioned. Fair chase is the ethical, sportsmanlike, and lawful pursuit and taking of any free-ranging wild, native North American big game animal in a manner that does not give the hunter an improper advantage over such animals. Many dislike the idea of bowfishing because modern equipment and practices do not permit fair chase.
In response to criticisms, the Colorado Bowfishing Association (COBF) developed a member code of ethics (see below).
It is our responsibility, as sportsmen and members of the COBF, to act in a responsible, professional, and ethical manner when engaging in the sport of bowfishing. Our individual actions, both good & bad, can have an enormous impact on the sport of bowfishing for current and future generations of sportsmen.
This code provides a clear standard of conduct for a bowfisher and gives the public a clear indication of what to expect from a COBF member.
• As a member of COBF, I will subscribe to a higher standard of ethical and sportsmanlike conduct.
• I will not breach, encourage or condone any violation of the Colorado Division of Wildlife’s fishing regulations or local lake regulations. I will always be in possession of a valid fishing license when engaging in the sport of bowfishing and will only pursue and harvest those species deemed legal by the Colorado Division of Wildlife for take with archery equipment.
• I will always engage with a safety first policy when bowfishing which includes inspecting my equipment—bowstring, arrows, nocks, tips, reel and line—for unsafe wear or damage; keeping my bow pointed in a safe direction and being sure of my target—what is in front of it, to the side of it and behind it.
• I will be aware of others around me. If other fishermen are nearby I will keep a safe, courteous distance and will share the waters with my fellow sportsmen.
• I will take the time to answer questions about the sport of bowfishing and always represent the COBF in a professional and courteous manner.
• I will make good use of the fish I harvest and will never leave my fish on the public shoreline or within communal trash receptacles. Doing so is not only unethical but tarnishes the sport of bowfishing for all. If I do not have a plan to make good use of the fish I am about to harvest, I should not be bowfishing.
• I will make my best attempt to rotate where I bowfish so to not over fish a body of water. I will do this to help manage Colorado’s fisheries and hopefully ensure the preservation of the sport of bowfishing for current and future generations.
Scarnecchia and Schooley (2020) reported that only nine states surveyed had bowfishing education programs and none had articulated bowfishing management goals. Management agencies can examine how many native fish are currently being managed or not managed. Native fish advocates maintain that certain fish—including Alligator Gar, Bigmouth Buffalo, and paddlefish—should not be permitted targets of bowfishing, just as bowfishers may not shoot trout, bass, and other “game” species. With growing interest in bowfishing, the controversies will continue.
Question to ponder:
In your opinion, what are some key characteristics of responsible, ethical fishing for Alligator Gar?
8.5 Habitat Connection
Gars are fascinating and misunderstood creatures, and unfortunately, the influence of habitat restoration for them has not yet been fully explored. Can we save one of the largest fish in North America with floodwaters? Rivers in the range of Alligator Gar are highly altered due to dams, dikes, dredging, and other forms of habitat and flow alteration. Managers need to understand what drives populations of Alligator Gar if the species has any chance to be restored throughout its range (Buckmeier et al. 2017). Recently, investigators confirmed suspicions that Alligator Gars are dependent on seasonal flooding in large floodplain rivers (Robertson et al. 2018).
Efforts are now underway to restore these magnificent creatures via supplemental stocking. It will take up to 50 years for stocked Alligator Gar to reach the potential maximum sizes. Stocking is an expensive short-term strategy, which may be necessary until natural spawning and rearing habitats can be restored. Although the effects of hydrologic modification of rivers is well documented, the prevailing questions related to reestablishing ecologically sustainable flows, such as “How much?” and “How often?” remain unanswered. Fully mature Alligator Gars may produce 200,000 or more large eggs (2–4 mm in diameter). These BOFFFF need to be protected from harvest, and we also need to provide habitat so that they will spawn naturally.
What is suitable habitat for spawning? The life history of Alligator Gar is tuned to life in large floodplain rivers where spawning is synchronized with the high flow-pulse events (Buckmeier et al. 2017). Alligator Gar spawning habitat includes floodwaters between 0.2 and 2 meters deep over woody vegetation and open-canopy vegetation types. Spawning habitat increases as the river flow increases enough to spill onto the floodplains (Figure 8.12; Robertson et al. 2018). However, Alligator Gars must be able to access these newly flooded habitats. Dams can block migrations of these fish as they seek spawning habitats (Lochmann et al. 2021).
Alligator Gar congregate in newly flooded backwaters (Kimmel et al. 2014) when water temperatures exceed 20°C (68°F). Fertilized eggs are deposited on woody debris and vegetation and will hatch in two to four days. The larvae of all species of gars have an attachment organ on the head (Figure 8.13) to allow larvae to attach to vegetation, as the yolk sac is used for energy. Eggs of gars are toxic to birds, mammals, and crustaceans, thereby reducing some predation. Rapid growth of larvae and juveniles will permit large numbers to survive if floodwaters occur at the right time and persist during this vulnerable period for young gars (Allen et al. 2020; Schumann et al. 2020).
The lessons from the Trinity River study give us optimism for population restoration here and elsewhere. The demand for water from the Trinity River is growing from population centers of Dallas-Fort Worth and Houston, and flood-pulse management may provide for periodic strong Alligator Gar recruitment. While many are experimenting with spawning and stocking of Alligator Gar (Mendoza et al. 2008; Schmidt 2015; Frenette and Snow 2016; Snow et al. 2018; Porta et al. 2019; Long et al. 2020), the restoration of natural habitat when and where it is needed has the best likelihood for long-term sustainable populations. Therefore, we must maintain the periodicity of flood pulses that connect river channel habitats to backwater areas to ensure Alligator Gar recruitment. Maintenance of river flows will also be critical to the preservation of estuarine habitats used.
Alligator Gar habitat restoration is a “Field of Dreams” plan—If you build it, they will come. If we create large expanses of spawning habitat, breeding Alligator Gar may receive the cue to initiate the courtship and spawning behavior. However, if dam operations cut off the flood pulse after spawning, recruitment will be reduced. The longer duration of the flood pulse enhances nursery habitats for young Alligator Gar.
8.6 From Pest to the Target of Conservation
The history of fish management depicts eras of abundance and discovery, followed by exploitation, then protection and management, and eventually holistic environmental management. The changes in human attitudes are evident, as people shifted from viewing gars as pests to be destroyed to targets for ecosystem conservation. The values-beliefs-norms-actions causal chain explains human perceptions and actions relative to the gars. European colonists in North America had value orientations associated with dominion over living things. Many early fish biologists were misinformed about the role of gars and viewed them as indiscriminate predators who decimate the highly valued game fish. These early beliefs made the lack of control programs and fishing regulations for gar as norms and encouraged people to remove them (Scarnecchia 1992). Gars were considered undesirable “rough fish.”
“Rough fish” (or the slang, “trash fish”) is a term used in the United States to describe fish that are less desirable to sport anglers. Harriet Carlander, in History of Fish and Fishing, explained that the term “rough” was a term used for lower-valued fish that had only been partly processed during a busy day of fishing. These fish could not be sold for full price. In northern Europe, the term is “coarse fish.” Today, the term persists, but many types of rough fish (roughfish.com) are pursued by anglers interested in capturing the wide variety of species that exist in U.S. waters. The negative connotations of the term are unfortunate, and should be abandoned. Putting buffalo fish, carp, and gar in the same category for management makes no sense.
“What’s in a name? That which we call a rose, By any other name would smell as sweet.” Rough fish have value, and the terms we use should reflect that value. For example, the Common Carp and the four Asian carps all have demonstrated a high probability of causing ecological and economic effects where populations become established (Conover et al. 2007). Regulations on bowfishing should be liberal to encourage the take of these species so that they are turned into food or fertilizer. Bowfishing tournaments have partnered with organic fertilizer companies to utilize the harvest. Carpbusters Inc., a nonprofit, created the EcoCarp® project, which takes carp and makes nutritious, affordable food for zoos, sanctuaries, and other applications.
When recreational anglers did begin to target gars, they organized tournaments with bowfishing to remove undesirable fish. However, fish management agencies were slow to institute protective fishing regulations for gars. Alligator Gars were listed by experts as “vulnerable” (Jelks et al. 2008), prompting agencies to form the Alligator Gar Technical Committee and promote research and conservation for the species. Simultaneously, many recreational anglers got hooked on gar fishing. Television shows, such as National Geographic’s Monster Fish with Zeb Hogan and River Monsters with Jeremy Wade, demonstrated catch-and-release fishing for Alligator Gar. Today more fishing guides have converted to strict catch-and-release advocates. Captain Kirk, featured on River Monsters, is an Alligator Gar catch-and-release guide (he hates stupid bow hunters who dump their kill).
Those who value Alligator Gars for their role in the ecosystem believe in ethical, well-regulated fishing practices (Miller 2017; Blok 2021; Rypel et al. 2021). The status of the Alligator Gar is still vulnerable, but progress is evident (Smith et al. 2020):
• Five states classify the Alligator Gar as a “commercial/rough fish,” whereas Florida and Louisiana consider the species a “nongame fish.”
• Four states identify the species as a “sport fish/game fish.”
• Over half of the states (N = 7) in the species’ range classify Alligator Gar as a “Species of Greatest Conservation Need” or similar under State Wildlife Action Plans. This classification frequently allows for funding conservation efforts and research for nongame species through the U.S. Fish and Wildlife Service’s State Wildlife Grants program.
• Growing popularity of hook-and-line angling and bowfishing for Alligator Gar has prompted agencies to actively manage existing populations.
• Alligator Gar is now officially the State Primitive Fish of Arkansas.
• Illinois passed a resolution to protect gars in Illinois, justified based on the ecological importance of gars as apex predators.
• New regulations for the Trinity River, Texas, restrict taking Alligator Gar longer than 48 inches, bans nighttime bowfishing, and requires reporting Alligator Gar harvest in other Texas waters (Tompkins 2019).
• Minnesota has redesignated Shortnose and Longnose Gar as game fish and established bag limits for them.
The solutions suggested here are conceptually simple: manage gar and other “rough fish” the same as freshwater game fish and use science-based limits and regulations. Outdated notions that some fish are more valued and worthy of protection have been questioned (Rypel et al. 2021). The lack of bag limits on many “rough fish” encourages excessive kills and waste. A renewed focus on common fish is needed to understand the ecological role of species we take for granted (Frimpong 2018). We may find that the common species sustain the rare ones and even prevent more species from becoming vulnerable to extinction.
Question to ponder:
Why is the term “rough fish” not appropriate as a categorization for conservation purposes?
8.7 Concluding Thoughts
I argue that changes in human attitudes are happening and allowing changes in mortality on these long-lived creatures. The case studies of gar, sturgeon, and paddlefish further support the notion that ethical pragmatism[1] can play an important role in development of effective conservation programs. In the case of gars, anglers, bowfishers, and conservationists have examined the issues surrounding gars and have realized changes in norms and practices about gars and gar fishing.
Profile in Fish Conservation: Solomon David, PhD
Solomon David is currently an Assistant Professor at Nicholls State University in Thibodaux, Louisiana, where he runs the GarLab and teaches biology, evolution and ecology, and biology of fish. His origin story begins with as a kid reading Ranger Rick magazine. Like many young children, he was fascinated with dinosaurs. When he first read about an Alligator Gar, which coexisted when dinosaurs lived on Earth, he was hooked on gar for life. He claims that “My career, dedicated to prehistoric fish, began with Ranger Rick,” and he is still chasing his childhood fish fascination.
He earned a BS in biology from Ohio Northern University and an MS and PhD from the University of Michigan, where he studied the life history and genetic diversity of Spotted Gar across its range. David also worked as a research associate at Michigan State University on genomics of gar, before he began a joint position as research scientist with the USGS Great Lakes Science Center, and Research Associate at John G. Shedd Aquarium and the University of Wisconsin. At the Shedd Aquarium he had ready access to primitive bony fish on display and contributed to many educational efforts on gars and other primitive bony fish.
Dr. Solomon has published more than thirty publications on a variety of freshwater fish, from gars and Bowfins to bloaters, Lake Whitefish, Northern Pike, and Lake Trout. He is active in international networks for gar research and other freshwater fish and has organized special symposiums dedicated to biology and conservation of gars. In addition, he has written numerous articles targeted at a nonscience audience and has offered training for professionals interested in science communications.
Since reading an article about gars in Ranger Rick magazine as a kid, he has become one of the fish’s most vocal defenders and is quick to oppose any angler’s or bowhunter’s persecution of “trash” fish. Matt Miller’s book, Fishing through the apocalypse, describes how Miller and David fished with drones and large carp heads for gargantuan Alligator Gar in Texas (Miller 2019b). They adopted a strict catch-and-release practice.
Solomon David is a popular teacher. From Rate My Professors, a student writes, “Very passionate about his subject material, which makes classes very interesting! He was always very understanding when I had issues arise.” In what may be the first-ever gar-inspired romance, he met his future wife at the Shedd Aquarium. At the time, she thought the most charismatic and interesting creatures at the aquarium were the belugas, sharks, and penguins. But she was soon swept away by his enthusiasm for the African Lungfish, sturgeon, Arapaima, and, of course, the gars.
Solomon David is a charter member and former president of the Science Communication Section of the American Fisheries Society. He has a large following on Twitter (@SolomonRDavid), where he routinely builds enthusiasm and appreciation for primitive fish and debunks myths surrounding gar and other native fish. His work has influenced many new audiences to take another look at gar as a model for scientific studies or a target for recreational fishing. I must confess that he inspired me to write song lyrics for the parody The Accidental Gar. He is not one to avoid controversies. Those who follow him on social media will learn that he believes fish are better than birds, penguins are overhyped, and fish puns are fintastic.
Key Takeaways
• Sturgeons, paddlefish, gars, and Bowfins are old lineages whose ancestors were present on Earth over 150 million years ago.
• Sturgeons, Alligator Gars, and paddlefish were overexploited and extirpated from parts of their range due to habitat change.
• The gar family (Lepisosteidae) has been around since the Cretaceous Period (~100 million years ago).
• Success of gar recovery depends, in part, on changes in human beliefs, norms, and actions.
• Problems have been overharvest, persecution, and waste.
• Propensity for overfishing due to life history traits, including long life and delayed age of maturity.
• Habitats essential for spawning and early life were highly modified by dams, diversions, and floodplain draining.
• Shift in human values related to treating gars as game fish was a slow process.
This chapter was reviewed by Solomon David.
URLs
The Accidental Gar: https://vimeo.com/229492355
Long Descriptions
Figure 8.6: 1) 10 years, approx 60 in; 2) 25 years, approx 70 in; 3) 35 years, approx 80 in; 4) 50 years, approx 85 in, 5) 65 years, approx 90 in; 6) 80 years, approx 100 in. Jump back to Figure 8.6.
Figure 8.9: Decline in numbers of fish with age with 1,000 at age 1 and 0 at age 80; Fish are reproductively mature at age 12 and trophy size at age 23. Jump back to Figure 8.9.
Figure 8.11: Page from old Missouri Fish and Game News. Article titled, “Raids Waged by Deputies Resulted in Destruction of over 5,000 Gar: large schools dynamited by department- all former records shattered- officials received excellent co-operation from sportsmen”. Jump back to Figure 8.11.
Figure References
Figure 8.1: Phylogenetic tree depicting the accepted relationships between sturgeons and paddlefish, gars, Bowfins, and bony fish. Bowfins and gars are sister groups to all bony fish. Kindred Grey. 2022. CC BY 4.0.
Figure 8.2: Alligator Gar (Atractosteus spatula). Duane Raver. 2012. Public domain. http://www.publicdomainfiles.com/show_file.php?id=13483708812923.
Figure 8.3: Longnose Gar. USFWS Mountain-Prairie. 2019. CC BY 2.0. https://flic.kr/p/2fmqruA.
Figure 8.4: Largest Alligator Gar captured in 2011 weighed 327 pounds. Ricky Flynt—MS DWFP. 2011. Used with permission from Ricky Flynt. CC BY 4.0.
Figure 8.5: Processed otolith (sagittae magnified 12.5X) from the current world record Alligator Gar caught from the Mississippi River Basin in Mississippi on February 14, 2011. Otoliths were obtained by Mississippi Wildlife, Fisheries, and Parks, with age assessment and imaging by Texas Parks and Wildlife Department. Nathan G. Smith, Texas Parks and Wildlife Department. Used with permission from Nathan G. Smith. CC BY 4.0.
Figure 8.6: Growth in length of Alligator Gar in Texas. Kindred Grey. 2022. CC BY 4.0. Data from “Characteristics and Conservation of a Trophy Alligator Gar Population in the Middle Trinity River, Texas,” by Buckmeier et al., 2016. https://seafwa.org/journal/2016/characteristics-and-conservation-trophy-alligator-gar-population-middle-trinity-river.
Figure 8.7: Growth in weight of Alligator Gar in Texas. Kindred Grey. 2022. CC BY 4.0. Data from “Characteristics and Conservation of a Trophy Alligator Gar Population in the Middle Trinity River, Texas,” by Buckmeier et al., 2016. https://seafwa.org/journal/2016/characteristics-and-conservation-trophy-alligator-gar-population-middle-trinity-river.
Figure 8.8: Recruitment of two populations of Alligator Gar in Texas demonstrates variable recruitment. Kindred Grey. 2022. CC BY 4.0. Data from “Reproductive Ecology of Alligator Gar: Identification of Environmental Drivers of Recruitment Success,” by Buckmeier et al., 2017. https://seafwa.org/journal/2017/reproductive-ecology-alligator-gar-identification-environmental-drivers-recruitment.
Figure 8.9: Hypothetical decline in numbers of Alligator Gar with age, beginning with 1,000 individuals at the age of one year. Kindred Grey. 2022. CC BY 4.0.
Figure 8.10: Expected effects of fishing regulations on spawning potential ratio (SPR), with the percentage of spawning fish relative to the unfished state (SPR=100). Kindred Grey. 2022. CC BY 4.0. Data from “Modeling the Responses of Alligator Gar Populations to Harvest under Various Length-Based Regulations: Implications for Conservation and Management,” by Nathan Smith et al., 2018. https://doi.org/10.1002/tafs.10040.
Figure 8.11: Page from Missouri Game and Fish News article published in April 1926. Missouri Game and Fish Dept., Missouri Game and Fish News, 1926. Public domain. https://catalog.hathitrust.org/Record/100804086.
Figure 8.12: Spawning habitat suitable for Alligator Gar in the middle Trinity River, Texas, as related to river flow. Kindred Grey. 2022. CC BY 4.0. Data from “Development of a Flow-Specific Floodplain Inundation Model to Assess Alligator Gar Recruitment Success,” by Robertson et. al., 2018. https://doi.org/10.1002/tafs.10045.
Figure 8.13: Shortnose Gar larva with yolk sac and adhesive organ. Kindred Grey. 2022. CC BY 4.0. Includes a picture used with permission from Konrad Schmidt.
Figure 8.14: Solomon David, PhD, with the head of an Alligator Gar. Used with permission from Solomon David. Photo by Derek Sallman. CC BY 4.0.
Text References
Allen, Y., K. Kimmel, and G. Constant. 2020. Using remote sensing to assess Alligator Gar spawning habitat suitability in the lower Mississippi River. North American Journal of Fisheries Management 40:580–594. DOI: 10.1002/nafm.10433.
Beamesderfer, R. C. P., T. A. Rien, and A. A. Nigro. 1995. Differences in the dynamics and potential production of impounded and unimpounded White Sturgeon populations in the lower Columbia River. Transactions of the American Fisheries Society 124:857–872.
Bennett, D. L., R. A. Ott, and C. C. Bonds. 2015. Surveys of Texas bow anglers, with implications for managing Alligator Gar. Journal of the Southeastern Association of Fish and Wildlife Agencies 2:8–14.
Binion, G. R., D. J. Daugherty, and K. A. Bodine. 2015. Population dynamics of Alligator Gar in Choke Canyon Reservoir, Texas: implications for management. Journal of the Southeastern Association of Fish and Wildlife Agencies 2:57–63.
Blok, A. 2021. Gar-bage fish no more. it’s time to respect gar. Environmental Monitor, January 27. Available at: https://www.fondriest.com/news/gar-bage-fish-no-more-its-time-to-respect-gar.htm.
Boreman, J. 1997. Sensitivity of North American sturgeons and paddlefish to fishing mortality. Environmental Biology of Fishes 48:399-405.
Bruch, R. M. 2007. Management of Lake Sturgeon on the Winnebago System: long term impacts of harvest and regulations on population structure. Journal of Applied Ichthyology 15(4-5):142–152.
Bruch, R. M., T .J. Haxton, and H. Rosenthal. 2016. History of the founding and early years of the North American Sturgeon and Paddlefish Society (NASPS). Journal of Applied Ichthyology 32 (Supplement 1):11–14.
Buckmeier, D. L. 2008. Life history and status of the Alligator Gar Atractosteus spatula, with recommendations for management. Texas Parks and Wildlife Department. Available at: https://tpwd.texas.gov/publications/nonpwdpubs/media/gar_status_073108.pdf.
Buckmeier, D. L., N. G. Smith, D. J. Daugherty, and D. L. Bennett. 2017. Reproductive ecology of Alligator Gar: identification of environmental drivers of recruitment success. Journal of the Southeastern Association of Fish and Wildlife Agencies 4:8–17.
Buckmeier, D. L., N. G. Smith, and K. S. Reeves. 2012. Utility of Alligator Gar age estimates from otoliths, pectoral fin rays, and scales. Transactions of the American Fisheries Society 141:1510–1519.
Buckmeier, D. L., N. G. Smith, J. W. Schlechte, A. M. Ferrara, and K. Kirkland. 2016. Characteristics and conservation of a trophy Alligator Gar population in the middle Trinity River, Texas. Journal of the Southeastern Association of Fish and Wildlife Agencies 3:33–38.
Burr, J. G. 1931 Electricity as a means of garfish and carp control. Transactions of the American Fisheries Society 61(1):174–182.
Butler, S. E., L. M. Einfalt, A. A. Abushweka, and D. H. Wahl. 2018. Ontogenetic shifts in prey selection and foraging behaviour of larval and early juvenile Alligator Gar (Atractosteus spatula). Ecology of Freshwater Fish 28(3):385–395. DOI:10.1111/eff.12461.
Caldwell, E. E. 1913. The gar problem. Transactions of the American Fisheries Society 42:61–64.
Cha, W., and R. T. Melstrom. 2018. Catch-and-release regulations and paddlefish angler preferences. Journal of Environmental Management 214:1–8.
Conover, G., R. Simmonds, and M. Whalen, editors. 2007. Management and control plan for Bighead, Black, Grass, and Silver carps in the United States. Asian Carp Working Group, Aquatic Nuisance Species Task Force, Washington, D. C. Available at: https://invasivecarp.us/Documents/Carps_Management_Plan.pdf. Accessed May 30, 2017.
Daugherty, D. J., A. H. Andrews, and N. G. Smith. 2020. Otolith-based age estimates of Alligator Gar assessed using bomb radiocarbon dating to greater than 60 years. North American Journal of Fisheries Management 40:613–621.
David, S. R. 2016. The 7 wonderful gar of the world. The Fisheries Blog. September 6. Available at: https://thefisheriesblog.com/2016/09/06/the-7-wonderful-gar-of-the-world/.
David, S. R. 2018. Angling for ancient fish. American Scientist Blogs. August 17. Available at: https://www.americanscientist.org/blog/macroscope/angling-for-ancient-fish.
David, S. R., S. M. King, and J. A. Stein. 2018. Introduction to a special section: angling for dinosaurs—status and future study of the ecology, conservation, and management of ancient fishes. Transactions of the American Fisheries Society 147:623–625.
Forbes, S. A., and R. E. Richardson. 1920. Fishes of Illinois, vol. 1, 2nd ed. Illinois Natural History Survey, Springfield.
Frenette, B. D., and R. A. Snow. 2016. Natural habitat conditions in a captive environment lead to spawning of Spotted Gar. Transactions of the American Fisheries Society 145:835–838.
Frimpong, E. A. 2018. A case for conserving common species. PLoS Biology 16:e2004261. https://doi.org/10.1371/journal.pbio.2004261.
Gowanloch, J. N. 1933. Fishes and fishing in Louisiana. Department of Conservation, State of Louisiana, New Orleans.
Gowanloch, J. N. 1940. Control of garfish in Louisiana. Transactions of the North American Wildlife Conference 5:292–295.
Harried B. L., D. J. Daugherty, D. J. Hoeinghaus, A. P. Roberts, B. J. Venables, T. M. Sutton, and B. K. Soulen. 2020. Population contributions of BOFFFFs may be eroded by contaminant body burden and maternal transfer: a case study of Alligator Gar. North American Journal of Fisheries Management 40(3):566–579. DOI: 10.1002/nafm.10382.
Hixon, M. A., D. W. Johnson, and S. M. Sogard. 2014. BOFFFFs: on the importance of conserving old-growth age structure in fishery populations. ICES Journal of Marine Science 71:2171–2185.
Jelks, H. L., S. J. Walsh, N. M. Burkhead, S. Contreras-Balderas, E. Diaz-Pardo, D. A. Hendrickson, L. Lyons, N. E. Mandrak, F. McCormick, J. S. Nelson, S. P. Platania, B. A. Porter, C. B. Renaud, J. J. Schmitter-Soto, E. B. Taylor, and M. L. Warren. 2008. Conservation status of imperiled North American freshwater and diadromous fishes. Fisheries 33(8):372–407.
Jordan, D. S. 1905. A guide to the study of fishes, vol. 2. H. Holt, New York. Available at: https://www.gutenberg.org/files/51702/51702-h/51702-h.htm.
Kikugawa, K., K. Katoh, S. Kuraku, H. Sakurai, O. Ishida, N. Iwabe, and T. Miyata. 2004. Basal jawed vertebrate phylogeny inferred from multiple nuclear DNA-coded genes. BMC Biology 2:3. https://doi.org/10.1186/1741-7007-2-3.
Kimmel, K., Y. Allen, and G. Constant. 2014. Seeing is believing: Alligator Gar spawning event confirms model predictions. Landscape Conservation Cooperative Network, Falls Church, VA. Available at: https://lccnetwork.org/sites/default/files/Blog/Seeing%20is%20Believing-Kimmel.pdf.
Lochmann, S., E. L. Brinkman, and D. A. Hahn. 2021. Movements and macrohabitat use of Alligator Gar in relation to a low head lock and dam system. North American Journal of Fisheries Management 41:204–216.
Long, J. M., R. A. Snow, and M. J. Porta. 2020. Effects of temperature on hatching rate and early development of Alligator Gar and Spotted Gar in a laboratory setting. North American Journal of Fisheries Management 40:661–668.
Mendoza, R., C. Aguilera, and A. M. Ferrara. 2008. Gar biology and culture: status and prospects. Aquaculture Research 39:748–763.
Miller, M. L. 2019a. Afield with the gar professor. Cool Green Science blog. April 29. Available at: https://blog.nature.org/science/2019/04/29/afield-with-the-gar-professor/.
Miller, M. L. 2019b. Fishing through the apocalypse: an angler’s adventures in the 21st century. Lyons Press, Lanham, MD.
Miller, M. L. 2017. Gar wars: a fish force awakens. Cool Green Science blog. November 13. Available at: https://blog.nature.org/science/2017/11/13/gar-wars-a-fish-force-awakens/.
Orth, D. 2015. Such a long nose and such big teeth, it can only be the Longnose Gar. Virginia Tech Ichthyology Class blog. September 11. Available at: https://vtichthyology.blogspot.com/2015/09/such-long-nose-and-such-big-teeth-it.html.
Ostrand, K. G., M. L. Thies, D. D. Hall, and M. Carpenter. 1996. Gar ichthyotoxin: its effect on natural predators and the toxin’s evolutionary function. The Southwestern Naturalist 41:375–377.
Pikitch, E. K. P. Koukakis, L. Lauck, P. Chakrabarty, and D. L. Erickson. 2005. Status, trends and management of sturgeon and paddlefish fisheries. Fish and Fisheries 6:233–265.
Porta, M. J., R. A Snow, and K. G. Graves. 2019. Efficacy of spawning Alligator Gars in recreational-grade swimming pools. North American Journal of Aquaculture 81(2):126–129. https://doi.org/10.1002/naaq.10078.
Reitz, E .J., C. S. Hadden, G. A. Waselkov, and C. F. T. Andrus. 2021. Woodland-period fisheries on the north-central coast of the Gulf of Mexico. Southeastern Archaeology 40:135–155.
Richardson, R. E. 1913. Observations on the breeding habits of fishes at Havana, Illinois, 1910 and 1911. Bulletin of the Illinois State Laboratory of Natural History 9(1-12). Available at: https://www.biodiversitylibrary.org/item/35136#page/471/mode/1up.
Robertson, C. R., K. Aziz, D. L. Buckmeier, and N. G. Smith. 2018. Development of a flow-specific floodplain inundation model to assess Alligator Gar recruitment success. Transactions of the American Fisheries Society 147:674–686.
Rypel, A. L., P. Saffarinia, C. C. Vaughn, L. Nesper, K. O’Reilly, C. A. Parisek, M. L. Miller, P. B. Moyle, and N. A. Fangue. 2021. Goodbye to “rough fish”: paradigm shift in the conservation of native fishes. Fisheries 46(12):605–616.
Sakaris, P. C., D. L. Buckmeier, N. G. Smith, and D. J. Daugherty. 2019. Daily age estimation reveals rapid growth of age-0 Alligator Gar in the wild. Journal of Applied Ichthyology 35(6):1218–1224.
Scarnecchia, D. L. 1992. A reappraisal of gars and Bowfins in fisheries management. Fisheries 17(5):6–12.
Scarnecchia, D. L., and J. D. Schooley. 2020. Bowfishing in the United States: history, status, ecological impact, and a need for management. Transactions of the Kansas Academy of Science 123:285–338.
Schmitt, K. 2015. Gar farming. American Currents 40(4):3–9.
Schumann, D. A., M. E. Colvin, L. E. Miranda, and D. T. Jones-Farrand. 2020. Occurrence and co-occurrence patterns of gar in river–floodplain habitats: leveraging species coexistence to benefit distributional models. North American Journal of Fisheries Management 40:622–637. DOI: 10.1002/nafm.10402.
Sherman, V. R., H. Quan, W. Yang, and M. A. Myers. 2017. A comparative study of piscine defense: the scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula. Journal of the Mechanical Behavior of Biomedical Materials 73:1–16. DOI: 10.1016/j.jmbbm.2016.10.001.
Smith, N. G., D. J. Daugherty, E. Brinkman, M. Wegener, B. R. Kreiser, A. Ferrara, K. Kimmel, and S. David. 2020. Advances in conservation and management of the Alligator Gar: a synthesis of current knowledge and introduction to a special section. North American Journal of Fisheries Management 40(3):527–543.
Smith, N. G., D. J. Daugherty, J. W. Schlechte, and D. L. Buckmeier. 2018. Modeling the responses of Alligator Gar populations to harvest under various length-based regulations: implications for conservation and management. Transactions of the American Fisheries Society 147:665–673.
Snow, R. A., M. J. Porta, R. W. Simmons, and J. B. Bartnicki. 2018. Early life history characteristics and contributions of stocked juvenile Alligator Gar in Lake Texoma, Oklahoma. Proceedings of the Oklahoma Academy of Science 98:46–54.
Spitzer, M. 2015. Return of the gar. University of North Texas Press, Denton.
Spitzer, M. 2010. Season of the gar: adventures in pursuit of America’s most misunderstood fish. University of Arkansas Press, Fayetteville.
Tarzwell, C. 1945. The possibilities of a commercial fishery in the TVA impoundments and its value in solving the sport and rough fish problems. Transactions of the American Fisheries Society 73:137–157.
Tompkins, S. 2019. Texas hunters and anglers in for big rule changes. Houston Chronicle, August 14.
Zhang, H., I. Jarić, D. L. Roberts, Y. He, H. Du, J. Wu, C. Wang, and Q. Wei. 2020. Extinction of one of the world’s largest freshwater fishes: lessons for conserving the endangered Yangtze fauna. Science of the Total Environment 710:136242. https://doi.org/10.1016/j.scitotenv.2019.136242.
1. View that we can and should carry on our practice of moral deliberation without reference to moral truths | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.08%3A_Angling_and_Conservation_of_Living_Fishy_Dinosaurs.txt |
God never did make a more calm, quiet, innocent recreation than angling.
—Izaak Walton (1808)
Learning Objectives
• Examine the history of fly-fishing and early influencers on conservation on cold-water fishes, with emphasis on the Rocky Mountain west.
• Identify the four past eras of fly-fishing and describe their unique characteristics, and analyze change in fly-fishing over time.
• Recognize fly-fishing as a specialized fishing endeavor that led to early development of an angling code of ethics.
• Evaluate the historical significance of fly-fishing and cold-water conservation organizations in the development of conservation programs.
• Identify issues and conflicts of stocking nonnative trout and preserving wild trout.
• Understand future challenges for preserving cold-water fish in response to global change.
9.1 Introduction
Imagine the frustration of being surrounded by fish and casting to them, only to have them ignore or be spooked by all your offerings. Anglers learned long ago to imitate the same food that fish were eating and place the imitation fly without spooking the fish. While fishing can use a wide range of gears and baits, fly-fishing refers specifically to the sport of fishing using a long rod and an artificial fly. This form of fishing has been around for at least 1,800 years, based on writings from Eastern Europe, and may have been practiced earlier (Hoffman 2016). Fly-fishing initially focused on trout and salmon, but now it is widely used to catch other fresh- and saltwater fish.
Fly fishers targeting trout had an important influence in developing and sustaining conservation programs, although they were sometimes criticized for exclusive or single-interest advocacy. Here I review the history of trout fishing and fly-fishing with special focus on the Rocky Mountain West, where fly fishers first exerted their influence on conservation ethics and sportfishing policy. Although many individuals and organizations played roles, I concentrate on only two: Fly Fishers International (FFI) and Trout Unlimited (TU). These two organizations had similar interests in conservation, but important differences prevented them from working together on a unified goal of conservation. The legacy of fly-fishing demonstrates the importance of passion, persistence, and partnerships in fish conservation.
Trout and salmon are the only sport fish native to the Western states, and fly-fishing here became more than a leisure activity. Norman Maclean’s novel, A River Runs through It (1976), begins, “In our family there was no clear line between religion and fly fishing.” Later Maclean writes that “Something within fishermen[1] tries to make fishing into a world perfect and apart.” The iconography of Western fly-fishing that Maclean and others wrote about was created by anglers, fisheries managers, tourists, guides, businesses, and region promoters. The history of Rocky Mountain fly-fishing parallels the history of the expansion of our Western frontier as well as fisheries management (Brown 2015). Although Henry David Thoreau (1862) maintained that “In wildness is the preservation of the world,” humans are part of the trout fishing system and helped create, destroy, maintain, and restore the trout fishing we have today.
The first trout fishers were Native Americans. Native Americans used a variety of fishing methods, including weirs, spears, nets, traps, baskets, hook-and-line methods, and baits. They also caught fish by hand via tickling. Tickling for trout involves rubbing the underbelly of a trout with fingers to get the trout to go into a trance, after which they can then easily be thrown onto the bank (Martindale 1901). Native Americans were more patient than others. This method is different from noodling for catfish, where the noodler uses fingers as bait and grabs the catfish by its mouth. Native Americans also caught fish by fly-fishing with deer-hair flies, according to the writings of early American naturalist William Bartram (1739–1823) (Monahan, no date).
The story of Rocky Mountain trout fishing begins with displacement of Native Americans from their historical fishing and hunting grounds. Uninhabited wilderness had to be created through the dispossession of Native people before it could be preserved (Spence 1999). Explorers, trappers, pioneers, soldiers, and homesteaders brought fishing gear to frontier outposts. The Lewis and Clark Expedition (1804–1806) included a designated angler named Silas Goodrich. The expedition first described several new species of fish, including the Yellowstone Cutthroat Trout and Westslope Cutthroat Trout, caught by Goodrich. Later military expeditions spent time trout fishing in addition to fighting Native Americans. Custer’s Last Stand at Little Bighorn might have been avoided if he’d joined a column of reinforcements under General George Crook. Crook’s soldiers were comfortably camped close by on Goose Creek near the Tongue River—fishing, not fighting (Monnett 1993; Owens 2002a; Lessner 2010).
The history of fly-fishing’s legacy in the American West is organized in four overlapping historical eras. The history highlights changing values as well as the changing scientific understanding of complex topics, such as phylogeny and competitive displacement of trout species. Deciding what are right or wrong actions involves consideration of values as well as scientific findings. We use “ought” to reflect ethical norms, whereas “is” refers descriptive statements. David Hume (1711–1776) articulated the “is-ought” fact-value gap, which maintains that one cannot make statements about what ought to be based on statements about what is. The NOFI (No-Ought-From-Is) idea that one cannot deduce an “ought” from an “is” means that we can make no logically valid arguments from the nonmoral to the moral.
These eras (with approximate dates) are reflective of the shifting value systems of fishers and fish managers (Snyder 2016):
1. Era of Rugged Individualism 1730–1880
2. Era of Hubris and Hatcheries 1880–1970
3. Era of Wild Trout 1970–2000
4. Era of Restoration of Native Trout 2000–present
Values shifted from resource exploitation for food to concerns for overharvest, followed by attempts to fix trout overharvest with hatchery production. While the legacy of fishing for stocked trout remains today, values shifted toward appreciation of native trout and recognition of the need for restoration. The era of restoration of native trout arose as important influencers began to engage in these value arguments as the world changed and scientific understanding expanded.
9.2 Era of Rugged Individualism
A rugged individual is someone totally self-reliant and independent from outside assistance, including from government entities. “Rugged individualism” is a term closely associated with the Western expansion. Frontier settlers were disproportionately male, prime age, illiterate, and foreign born (Buzzi et al. 2017). A sense of Manifest Destiny, or the idea that settlers were destined by God to expand throughout the continent, led to widespread fishing for subsistence during westward expansion. Westward expansion was furthered by the Homestead Act of 1862, which provided adult citizens who had never borne arms against the U.S. government with 160 acres of surveyed government land.
Settlers did not want government interference with their freedom to follow the frontier road to riches. By the 1890s, loggers were removing timber, trappers were removing beavers, farmers were irrigating arid lands for agriculture, and some were buying land for fishing in remote areas of the Rocky Mountains. Miners and railroad workers introduced fishing with dynamite. The early settlers had little time for leisure activities nor the patience of tickling for trout.
When did rugged individualists become elitist fly fishers? The first fly fishers who visited the West wrote for outdoor magazines and popularized the notion of the Rocky Mountains as a paradise for fly-fishing. One of these was Thaddeus Norris, “Uncle Thad” (1811–1877), who published The American Angler’s Book in 1864 (Figure 9.1). The American Angler’s Book was the first comprehensive account of sportfishing at the time. Norris was racist and criticized indigenous fishing methods: “For the red man . . . was a destructive fisher; his weirs and traps at the time of their autumnal descent, the spear on the spawning beds, and his snare or loop, were murderous implements” (Norris 1864). Settlers also used nets, traps, seines, weirs, and dynamite to catch fish. Fly-fishing at the time was a luxury and a leisure pursuit of only the wealthy in the United States, whereas most other people fished for subsistence purposes. There was a social class, and “fly fishing in the USA retained a sense of masculine individualism . . .where the angling tourist exercised power over local land and people” (Mordue 2009).
Tourism led to a second wave of Western expansion by those who argued that fly-fishing was more ethical than either the spearfishing methods used by Native Americans or fishing with hook and line to feed the homesteader’s family. Whether real or imagined, fly-fishing in America developed a distinctive imagery, ethos, and subculture (Schullery 1987, 246). Boston physician and author of “The Fishes of Massachusetts” Jerome V. C. Smith described fly-fishing in 1833 as the “perfection of fishing” (Washabaugh and Washabaugh 2000, 56). However, I see a paradox of simplicity and complexity. Angling writer John Gierach wrote, “I love the simplicity and the surroundings. Fly fishing is a breath of fresh air amid your busy lives.” Yet, the zealous fly fisher seems to defy this simplicity. Cold-water streams are loaded with a variety of trout foods, such as different stages of insects, and fly fishers attempt to imitate natural insects with hand-tied artificial flies in order to fool fish. The technique of “matching the hatch” in different seasons and waters demands a mix of special knowledge on aquatic entomology, fish behavior, and fluid dynamics. It is much easier to fish with live bait. The use of artificial flies instead of mistreating worms or other live baits is one reason why fly fishers have perceived themselves as more ethical and, therefore, better people.
This second wave included many writers who waxed poetic when it came to fly-fishing. Some writers—who were also fly fishers—claimed that “fly fishers are better people all around” (Soos 1999). After the Civil War, fly-fishing grew in popularity, spurred by the writings of popular authors like Thaddeus Norris and others. Fly-fishing became distinctly American with creation of fishing retreats, fishing clubs, lodges, specialty magazines, and fly-fishing organizations (Washabaugh and Washabaugh 2000). And Western fly-fishing was “a shiny badge of regional authenticity—of a person’s westernness” (Schullery 2006). Fly fishers toward the end of this era were tied to particular places and environments that they would eventually protect. Fly-fishing, and by extension fishing tourism, enlisted and promoted certain codes of practice and being that connected fly-fishing tourists to places.
At some point, the frontier trout anglers began to notice widespread declines in the rich abundance of trout. Methods other than hook and line for catching trout were outlawed in most states and territories by late 19th century. Early ichthyologists Barton Evermann (1891, 1894) and David Starr Jordan (1890) surveyed fish in the Rocky Mountain streams. In his 1889 surveys, Jordan commented on the many trout entrained in irrigation ditches and “left to perish in the fields.” He also commented on the many surveyed waters where eastern Brook Trout were introduced and doing well. Declines in numbers of trout were inevitable and had many causes, including fishing, mining, overgrazing, water diversion, dams, logging, and removal of woody cover. The ironic move of rugged individuals asking for government assistance in building federal and state trout hatcheries led to the next era.
Question to ponder:
The 19th-century movement of settlers into the American West began with the Louisiana Purchase and was fueled by the Gold Rush, the Oregon Trail, and a belief in “Manifest Destiny.” In what ways was manifest destiny apparent among fly fishers during this period?
9.3 Era of Hubris and Hatcheries
Trout populations were declining, while a new scientific technology was developing that might reverse the decline. Seth Green, the father of fish culture, developed the first private fish hatchery in North America in Caledonia, New York, primarily to provide Atlantic Salmon and Brook Trout for food fish markets (Figure 9.2). Green’s comprehensive work, Trout Culture (1870), was used by hatchery managers throughout the continent. Soon Green’s hatchery was also producing American Shad, Brown Trout, and Rainbow Trout for stocking. More than any other individual, he is credited with introducing Rainbow Trout east of the Continental Divide, Brook Trout to Western states, and Brown Trout from Eurasia throughout the United States (Karas 2002; Halverson 2010; Newton 2013).
Before scientists understood the evolutionary history of the native trout and char of North America (Fausch et al. 2019; Trotter et al. 2018), hatcheries were built, eggs were taken, and millions of fish were stocked to provide trout fishing. Before the end of the 19th century, Rainbow Trout were propagated and widely introduced outside their range by the Ornithological and Piscatorial Acclimatizing Society of California. Seth Green was shipping eggs and fry of salmon and Rainbow Trout across the continent (Halverson 2010). Fish culturists and the New York Fish Commission promoted the superiority of the Rainbow Trout for their hardiness, ease of hatching, game qualities, ease of capture, and fighting qualities. Soon U.S. Fisheries Commissioner Spencer Fullerton Baird instructed Livingston Stone to build another hatchery devoted to Rainbow Trout on the McCloud River, California. The eastern Brook Trout, no longer thriving in their native range due to logging, sedimentation, and warming, were deemed superior for streams of Colorado and were widely planted on top of native Cutthroat Trout. Since that time, the National Fish Strain Register has described 64 strains and even more broodstocks of Rainbow Trout (Kincaid et al. 2001). Despite lessons learned from unrestrained carp plantings as a food-fish-turned-pest species (Bartlett 1910), all reports on nonnative trout were positive, until many decades later.
Trout hatcheries were a distinctly American invention that led to the formation of the American Fish Culturists’ Association in 1870 (now recognized as the American Fisheries Society). The first federal fish hatchery, known as the Baird Hatchery, was established in 1872 on the McCloud River in California (Figure 9.3). Soon it was shipping eggs of trout and salmon throughout the United States and the world (Stone 1897). Other federal hatcheries were soon built in Leadville, Colorado (1889), Bozeman, Montana (1892), and Spearfish, South Dakota (1896), to stock Cutthroat Trout, Brook Trout, Rainbow Trout, and Brown Trout.
Many millions of trout were produced and stocked each year to meet the demand for trout fishing. Stocking catchable-sized trout provided higher returns and angler satisfaction than fry stocking (Wiley et al. 1993). But it is an expensive undertaking, and biosecurity and fish health concerns require substantial infrastructure improvements as well as feed and personnel costs. While fly fishers brought notions of fishing for sport, not subsistence, and concern for angler ethics, they also lobbied for regulation changes that set aside more waters for fly-fishing only.
Scientists investigating trout waters soon revealed the fallacy of hatchery solutions over a long period of reckoning with hatchery plantings and their effect on aquatic ecosystems and fishing culture. I call it the “reckoning” because indirect effects of hatchery plantings (Table 9.1) and narrow emphasis on game species ignored needed efforts at ecosystem protection. The actions of the hatchery era are irreversible, eliminating options and choice for future generations.
Indirect effects of stocking nonnative trout
Hatchery effluents
Competition with native fish
Predation on native fish
Hybridization with native trout
Table 9.1: Indirect effects of stocking nonnative trout. Hatchery effluents refers to waste discharged from fish hatchery.
Since the beginnings of hatchery plantings of trout and salmon, scientists and anglers have debated both the harms and triumphs of planted trout and salmon. Native trout that were replaced with nonnative trout and any fish that was not a trout were automatically viewed as trash fish (Hoffman 2016). This derogatory term was unfortunate, as it influenced the actions of many anglers toward “trash fish.”
During the postwar era, most states developed wide-scale fisheries by planting catchable-size Rainbow Trout, which were quickly removed by anglers. Rainbow Trout were selected because at the time they were considered to be easier to raise in hatcheries, they fought and jumped better, and they were well known by anglers. Spinning fishing gear began to be mass-produced at this time and made trout fishing with spinners and bait widely available. The postwar era also saw the emergence of fishing tackle manufacturers, such as Garcia Mitchell, Zebco, and others. And trout stamps—an actual stamp sold by fish and wildlife agencies in addition to a fishing license—contributed to commodifying trout fishing, as all revenues went to raising trout for stocking. In response to intense and widespread angler demand, nonnative stocked trout overpowered any concern for wild trout, or any other wild fish, at the time.
Fish and game laws defined fish as game fish or coarse fish. One by one, the coarse fish species were labeled as enemies because of presumed deleterious effects on game fish, in this case trout and salmon. Numerous species of chub, minnows, sculpins, suckers, and whitefish were labeled as “trash fish” and killed when inadvertently captured. Sculpins are often abundant in riffles where salmon and trout are spawning and in areas where salmonid fry are abundant. Early fisheries managers expressed concern that sculpins might decimate trout and salmon populations via predation on the eggs and fry and through competition for benthic invertebrates. Research suggests that only under exceptional or artificial conditions can sculpins severely limit salmonid populations (Moyle 1977).
Similarly, suckers were thought to be harmful to trout because of predation on eggs and fry and from competition for food. This influenced fisheries management programs in many states. Wisconsin passed a state law in 1973 requiring that “All rough fish taken in nets or on set lines shall be brought to shore and buried, sold, or otherwise lawfully disposed of, but no rough fish shall be returned to any waters.” While evidence exists demonstrating that many species of suckers do prey on eggs when they have an opportunity, the evidence does not support the notion that sucker removals benefit trout population (Holey et al. 1979).
Mountain Whitefish (Figure 9.4) represent one of the most abundant native salmonid species in the Rocky Mountain West, yet they remain an “afterthought for most fisheries research and management programs in western North America” (Meyer et al. 2009). Mountain Whitefish were harvested by indigenous people and the non-elite during the 19th and 20th centuries. They survived the long period of mistreatment by anglers who considered them trash fish. Yet, Mountain Whitefish also declined, as did trout, salmon, and char in response to dams, excessive irrigation withdrawals, and other insults. Mountain Whitefish provided fishing opportunities in the past and will in the future without investment in hatcheries. The prejudice against any fish that was not trout or salmon influenced investments in hatcheries and fishing regulations. Consequently, conflicts still remain on the values of coarse or rough fish. The primacy of trout in the minds of fly fishers led to trout fisheries in unusual places and unjustified removals of native fish (Brown and Moyle 1981) and planting of nonnative trout.
The hatchery era also coincided with the development of major dams built by the Bureau of Reclamation, U.S. Army Corps of Engineers, and the Tennessee Valley Authority, which created additional opportunities for planting nonnative trout in tailwaters below dams. Deepwater releases of cold, oxygenated, nutrient-rich, and sediment-free water from dams displaced native fish and created opportunities for supporting “large numbers of trout that generally grow far faster, bigger, and fatter than trout in western freestone rivers without high dams” (Owens 2002b). The Bighorn River and Beaverhead River in Montana, Green River in Wyoming and Utah, Fryingpan River in Colorado, and South Platte River in Colorado are just a few of these unique tailwaters that produce exceptional growth rates for trout (Gebhards 1971;Wiley and Mullan 1975). Many new trout fisheries were established in cold tailwaters via stocking fingerling trout (Pfitzer 1975). Wild trout were often limited in tailwaters from lack of spawning habitat, high fishing pressure, fluctuating water levels due to hydropower generation, presumed competition with native species, and in some cases water temperature. Fly fishers adapted to fishing these special waters by mimicking the unique fauna. Simple, tiny black midges and amber scuds mimicked the dominant prey and resulted in catches of lunker trout by many fly fishers.
The hubris of the hatcheries era coincided with massive ecosystem change, dam construction with hatchery supplementation, environmental degradation, haphazard transplanting of nonnative trout, and lack of regard for any fish that was not a trout. The legacies of the hatchery era remain, and a broader ecosystem perspective would be needed for successful cold-water fish conservation.
Question to ponder
Can you recall your parents or grandparents talking about trout fishing in the past? How did they view trout fishing at the time?
9.4 Era of Wild Trout
The fundamental salvation of trout fishing in the west, or anywhere, lies in the maintenance of environment.
—Arthur Carhart (1950)
Hatchery stocking masked a long legacy of detrimental effects of mining, dewatering, overgrazing, and other forms of stream degradation on wild trout populations. Yet, it took many years to convince fisheries managers to quit heavy stocking in Western rivers. Roderick Haig-Brown preached earlier to “just protect the habitat, the rest will take care of itself” (Sloan and Prosek 2003). Two organizations, Trout Unlimited and Federation of Fly Fishers (Brown 2015), played key roles in advocating policies emphasizing wild trout, ethical fishing, and healthy habitat. Although its members included many fly fishers, Trout Unlimited did not consistently advocate for policies that favored fly-fishing–only regulations.
Trout Unlimited is the largest and certainly most prominent cold‐water fishery conservation association in the United States. This nonprofit organization has 300,000 members and supporters dedicated to conserving, protecting, and restoring North America’s cold-water fisheries and their watersheds. The philosophy of Trout Unlimited includes the following beliefs:
• Trout Unlimited believes that trout fishing isn’t just fishing for trout.
• It’s fishing for sport rather than food, where the true enjoyment of the sport lies in the challenge, the love and the battle of wits, not necessarily the full creel.
• It’s the feeling of satisfaction that comes from limiting your kill instead of killing your limit.
• It’s communing with nature where the chief reward is a refreshed body and a contented soul, where a license is a permit to use—not abuse, to enjoy—not destroy our trout waters.
• It’s subscribing to the proposition that what’s good for trout is good for trout fishermen and that managing trout for the trout rather than for the fisherman is fundamental to the solution of our trout problems.
• It’s appreciating our trout, respecting fellow anglers, and giving serious thought to tomorrow.
Trout Unlimited (TU) was started in 1959 by 16 fly fishermen who met on the banks of the famous AuSable River in Michigan. The organization was the brainchild of George Mason, president of American Motors, and George A. Griffith, a commissioner with the Michigan Department of Natural Resources (Griffith 1993; Ross 2016). Trout Unlimited did not claim to be a flies-only club, though they advocated flies-only regulations in Michigan the year before they incorporated. Trout Unlimited members had two common interests: the love of trout and a desire to improve trout stream habitat. They saw weaknesses of bureaucratic systems in most fisheries departments and failures to consult with fisheries scientists. Trout Unlimited was guided by the principle that if we “take care of the fish, then the fishing will take care of itself.” TU’s first president, Dr. Casey E. Westell Jr., said, “In all matters of trout management, we want to know that we are substantially correct, both morally and biologically.” TU relied on the best available science and included scientists on its Board of Directors. Membership grew from a local organization into many local chapters, state councils, and a national presence. Through the efforts of local chapters, TU focused on sustaining rural quality of life in watersheds, promoted economic activities compatible with local watersheds, protected and advocated for water rights or instream flows for trout, and promoted habitat restoration (Munday 2002; Owens 2002b). Today, the National Conservation Strategy of Trout Unlimited is set by its leadership council, a body of volunteers and grassroots leaders (Trout Unlimited 2016).
Fly Fishers International (formerly Federation of Fly Fishers) was founded in 1965 with a dual mission to educate fly fishers and promote conservation through advocacy. Its founding was motivated by concern for a decline in fishing quality in many well-known trout and salmon rivers. Founding members, Bill Nelson and Gene Anderegg, were driving forces behind recruiting members and developing a national meeting. Fly Fishers International (FFI) was organized as a federation of local fly-fishing clubs, loosely tied to a national office. FFI has over 11,000 members in 37 countries organized into over 200 clubs. The vision of FFI was to develop in fly fishers a conservation conscience and promote activism (Williams 2016). Early leaders included Ted Trueblood, editor of Field and Stream, and Lee Wulff. Lee Wulff and Roderick Haig-Brown were early advocates for the concept of catch and release in North American fisheries. Wulff wrote the aphorism, “gamefish are too valuable to be caught only once” (Wulff 1939). Catch-and-release regulations, first implemented in 1970, have become widespread in managing game fish. TU and FFI played key advocacy and advisory roles in supporting national conservation legislation, including the Clean Water Act (1972), the Endangered Species Act (1970), and the Wild and Scenic River Act (1968), as well as policies restoring native fish (Williams et al. 2011).
The first code of fly-fishing ethics was written in 1939 by Roderick Haig-Brown (1939), in “Limits and ethics” in The Western Angler. Haig-Brown and other FFI members were instrumental in educating and promoting fly-fishing ethics and ethical codes. The Fly Fishers International Code of Angling Ethics (Fly Fishers International 2002) asserts the following:
• Fly anglers understand and obey laws and regulations associated with the fishery.
• Fly anglers believe fly-fishing is a privilege and a responsibility.
• Fly anglers conserve fisheries by limiting their catch.
• Fly anglers do not judge fellow anglers and treat them as they would expect to be treated.
• Fly anglers respect the waters occupied by other anglers so that fish are not disturbed.
• When fishing from a watercraft, fly anglers do not crowd other anglers or craft or unnecessarily disturb the water.
• Fly anglers respect other angling methods and promote this Code of Angling Ethics to all anglers.
Beginning in 1974, Trout Unlimited and others sponsored a series of symposia on Wild Trout to exchange technical information on wild trout management. Held every three years, the Wild Trout Symposium brings together anglers, writers, students, and professionals from every trout region in the United States and Canada. The issue of stocking trout on top of wild trout populations was the hot topic at the first symposium. Willis King proposed that “wild trout are members of a naturally produced and maintained population, in a natural setting” (King 1975, 99). Based on studies by Dick Vincent, the Montana Fish and Game Department stopped stocking trout in streams and rivers that supported wild trout populations (Zachheim 2006). The new strategy was based on a concept of self-propagating fisheries, catch and release, fly only, barbless hooks, fly-fishing only, special regulations, and limited hatchery supplementation.
TU’s National Leadership Council (NLC) passed a resolution in 2011 that states, “Resolved, that the NLC is opposed to Chapters or Councils stocking of non-native hatchery trout on top of native trout populations” (Trout Unlimited 2011). Other states began to debate the meaning of “wild” and to initiate restoration projects to focus on habitat protection and restoration to restore wild trout. Numerous restoration methods are needed for trout stream restoration, including enhancing instream flows in trout-rearing areas, preventing fish loss in irrigation canals, reconstructing altered streams to naturalize channel form and function, and fencing livestock from riparian areas (Pierce et al. 2019). To avoid the polarizing native-nonnative debates, TU often emphasized that “We just focus on the habitat.”
The future of wild trout and wild trout fishing is threatened by a legacy of nonnative fish introductions, beaver extirpation, logging, wood removal, dams, irrigation withdrawals, and climate change. Popular game fish, such as Walleye and Northern Pike (McMahon and Bennett 1996) and nonnative trout (Dunham et al. 2002; Dunham et al. 2004; Quist and Hubert 2004; Budy and Gaeta 2018) displace native trout in the Rocky Mountain region. Whirling disease introduced from infected trout has the potential to reduce wild trout populations. But the threat of climate change on wild trout, especially Bull Trout and Cutthroat Trout, may be most difficult to mitigate because these species are already constrained to high elevations and latitudes, limiting their ability to adapt (Figure 9.5; Isaak et al. 2015; Hansen et al. 2019). The management with wild trout restoration and nonnative trout suppression will dominate the actions of fisheries and land managers for the next generation.
Question to ponder
Why do you suppose there are still two large conservation organizations, Fly Fishers International and Trout Unlimited? Would it make more sense for the two organizations to merge into one larger, influential organization? What were the most significant influences these organizations had on conservation?
9.5 Era of Restoration of Native Trout
I know that neither hatcheries, nor biologists, nor all the thought and ingenuity of man can put them back when once they’ve gone.
—Roderick Haig-Brown, Fisherman’s Spring (1951)
Many thought they were doing the right thing for the world at the time of indiscriminate and inconsiderate stocking of nonnative trout. Stockings supported a subsistence fishery, diversified fishing opportunities, and engaged more anglers. Yet, these decisions were irreversible, eliminating choice and options for future generations. Stocking nonnative fish outside their native range is passing through a door that goes in one direction—there’s no going back. Once introduced, the consequences are uncertain and cannot be reversed except in the most special circumstances.
We understand values of fish for fishing and food. Trout provided for the well-being of trout anglers were of cultural importance to settlers of the frontier and provided direct financial gains for trout guides and private hatcheries. All of these were instrumental values, but other values of trout may be intrinsic or relational. The more we study trout in a variety of settings, the more diverse the set of values held will be. Conflicts over values affect decision making, and the stocking of nonnative trout only considered a narrow set of instrumental values. Nature’s gifts (or nature’s contributions) to well-being broaden the values perspectives (Pascual et al. 2017). Is stocking nonnatives right or wrong? What values are harmed with stocking? The answers to such questions depend on the value argument (Zablocki 2019). Consider the intrinsic values of protecting unique and irreplaceable evolutionary lineages of native trout. Instrumental values arguments would focus on the value of encouraging a vibrant economy based on abundant, catchable trout. Relational values arguments would focus on a unique way of life harmed by introduction of nonnatives.
Three voices—Aldo Leopold, James A. Henshall, and Edwin “Phil” Pister—were influential in early critiques of indiscriminate trout stocking. They advocated for recognizing values of native fish at a time when state and U.S. governments were investing heavily in trout hatcheries. It’s taken a century of scientific investigations into indiscriminate, inconsiderate, and often planned trout plantings to develop a scientific basis for conservation actions to restore native fish.
Aldo Leopold, after completing a master of forestry at Yale University, worked at the Apache National Forest in the Arizona Territory, Carson National Forest in New Mexico, and regional headquarters in Albuquerque, New Mexico (Figure 9.6). In this region, Leopold would be familiar with the endemic Apache Trout (Oncorhyncus gilae apache), Gila Trout (Oncorhynchus gilae gilae), and Rio Grande Cutthroat Trout (Oncorhynchus clarkia virginalis). Based on his observations on trout in these waters, Leopold presented a paper on “Mixing Trout” (Leopold 1918; Warren 2010). He wrote that “Nature, in stocking trout waters, sticks to one species.” And Leopold recommended that to “Restock with the best adapted species, the native species [is] always preferred” (Leopold 1918, 102). Furthermore, in restocking empty waters, “ordinarily native and indigenous species are preferable.” It would be years later that he reconstituted these ideas in these famous words:
The last word in ignorance is the man who says of an animal or plant: “What good is it?” If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of eons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering. (Leopold 1993, 145–146)
James A. Henshall, while best known for his Book of the Black Bass, was the first superintendent of the Bozeman National Fish Hatchery from 1897 until 1909 (Figure 9.7). The Bozeman Hatchery produced Brook Trout and Rainbow Trout for Colorado and Montana. Henshall described the accidental release of Brook Trout and Rainbow Trout into Bridger Creek. Noting pristine conditions prior to this, he wrote, “If depleted waters had been stocked with native fish, this happy and natural condition of affairs might have continued for many years to come” (Henshall 1919).
Edwin “Phil” Pister read the works of Aldo Leopold while in graduate school. He worked as fisheries biologist with the California Department of Fish and Game during the height of the hatchery era. Hatchery trout and trophy fishing fueled a tourist economy in the High Sierra mountains of California. License buyers who funded most agency programs also overwhelmingly viewed trout as a commodity. Only one game species managed for fishing was native and that was the California Golden Trout (Onchorhynchus mykiss aguabonita), which is the State Freshwater Fish of California. Other species that were not managed were on the verge of extinction. In fact, one of the desert fish, the Ash Meadows Poolfish (Empetrichthys merriami), went extinct before the Ash Meadows Wildlife Refuge was established. On a visit to speak to Virginia Tech students after his retirement in 1991, Pister told the story of how in 1969 he scooped rare Owens Pupfish (Cyprinodon radiosus) out of a shoe-deep slough sure to dry (Figure 9.8). That day he literally saved the last population of Owens Pupfish—moving 800 fish in two buckets—away from certain destruction. The Owens Pupfish persists today and is classified as an endangered species.
Pister worked tirelessly to establish and maintain the Desert Fishes Council. This group’s mission is to “preserve the biological integrity of desert aquatic ecosystems and their associated life forms, to hold symposia to report related research and management endeavors, and to effect rapid dissemination of information concerning activities of the Council and its members.” His work on Golden Trout began in 1959 when it was apparent the state fish was at risk of extinction (Figure 9.9). In the 1970s, he sided with the National Park Service against his agency directive. Park Service policy directed that since “Trout are not indigenous to the lakes of the High Sierra, they would no longer be planted in park waters.” Nonnative trout stocking in fishless lakes led to near extinction of the Sierra Nevada Yellow-Legged Frog (Rana sierrae). Since the practice was eliminated in 1991, frog abundances have increased to levels similar to those in never-stocked lakes (Knapp et al. 2016).
Phil Pister also worked to reduce threats to the rare and threatened subspecies of Golden Trout in high-elevation streams of California. Pister liked to quote Stephen Jay Gould: “We are trapped in the ignorance of our own generation.” The move from wild trout to native trout has been underway for nearly 100 years. Paul Schullery, in Cowboy Trout, explained it as follows:
Most recently, it wasn’t all that big a step from preferring wild fish to preferring wild native fish, which are now seen by many as providing a more authentic angling experience in nature. A fish that actually evolved over many millennia in the water has certain aesthetic advantages over a fish that only arrived a few decades ago. (Schullery 2006)
Today, many Western states have a “native trout challenge” that encourages anglers to seek out various species/subspecies of (mostly native) trout and the places they inhabit as a way to get the public to appreciate the value of natives.
My role as a scientist is not to make a choice for all people about which trout to stock where. We all have many differences in attitude and outlook regarding restoration of trout. These are mostly cultural, not scientific differences. As a scientist, I can advocate for application of best science available, while recognizing that value arguments about nonnative trout stocking matter. The “No Ought From Is” idea should remind us to take time and slow down decision making so that the public develops trust and feels engaged in the process of fish conservation and management. Hatcheries have adapted over time because of public input, and today many hatcheries raise rare fish for introduction into their native habitats.
Conservationists are notorious for their dissensions. . . . In each field one group (A) regards the land as soil. And its function as commodity-production; another group (B) regards the land as a biota, and its function as something broader.
—Aldo Leopold (1947)
Question to ponder
In the 21st century, do you consider stocking nonnative trout as right or wrong? What values are harmed with stocking? When you think about fishing in cold-water streams, do you value wild more than native fish? Can you distinguish between native and naturalized fish?
9.6 Closing
The legacy of fly-fishing is important and has multiple dimensions. The popularity of fly-fishing for trout led to extensive planting of nonnative trout outside their range, including the continents of South Africa, Australia, New Zealand, and South America. Consequently, throughout the world managers deal with native trout restoration and nonnative trout suppression. The first code of fly-fishing ethics was traced to early writings of “Limits and Ethics” (The Western Angler), and fly-fishing organizations educate their members in the code of fly-fishing ethics (Ross 2008). Fly fishers were responsible for many of the first efforts at habitat restoration and protection, including the proposals of Native Fish Conservation Areas designed to protect entire watersheds and aquatic communities. Special fishing regulations, such as flies only and catch and release, were advocated by fly fishers, which led to declines in fishing by bait anglers who were displaced from local trout fisheries (Traver 2017). Importantly, fly fishers were some of the first anglers to support evidence-based fishery management programs. The fly-fishing literature is rich with stories as well as evidence to support the notion of sense of place influenced by trout and trout fishing. Robert Traver, in Trout Magic, wrote, “I fish because I love to. Because I love the environs in which trout are found, which are invariably beautiful, and hate the environs where crowds of people are found, which are invariably ugly” (Traver 1974). And David Quammen wrote, in Wild Thoughts from Wild Places, that “Trout were the indicator species for a place and a life I was seeking” (Quammen 1998). Strong conservation initiatives often start from grassroots action that taps into people’s sense of place (Brown et al. 2019).
Exceptional (perhaps oversold) trout fisheries of the Western United States are neither totally wild nor natural; instead, they exist because of drastic and complicated environmental and social changes. The history of fly-fishing reveals the change in anglers’ values from utilitarian self-interest toward biocentric, ecosystem-based conservation (Hoffman 2016). None of these changes were without conflict, and the political battles among anglers with differing values and different notions of how trout should be managed continue today. Having strong grassroots support from users, as well as a strong organizational structure, allows Trout Unlimited and the International Federation of Fly Fishers to lead conservation efforts. Climate change is the greatest threat to the viability of fisheries, and cold-water fish in streams are particularly at risk (Kunkel et al. 2013; Isaak et al. 2015). Restoration efforts can work toward mitigating expected effects of climate change (Williams et al. 2015).
Perhaps fishing is, for me, only an excuse to be near rivers. If so, I’m glad I thought of it.
—Roderick Haig-Brown (1974)
Profile in Fish Conservation: Daniel C. Dauwalter, PhD
Daniel C. Dauwalter is the Fisheries Research Director for Trout Unlimited in Boise, Idaho, and a Certified Fisheries Professional. He was born in Minnesota and earned a BA in biology and environmental studies from Gustavus Adolphus College (St. Peter, Minnesota), an MS in fisheries and aquaculture from the University of Pine Bluff, Arkansas, and a PhD in fisheries and wildlife ecology from Oklahoma State University.
After investigating aquatic monitoring protocols during his postdoctoral research at the University of Wyoming, he began his current position. His current work is focused mostly on aquatic conservation planning at the scale of large landscapes. In addition, he studies stream restoration science, effectiveness monitoring, habitat selection, and population viability of rare fish. His work directly benefits many species of trout and char, which are some of the more culturally, economically, and ecologically important taxa of freshwater fish worldwide. Nearly half of the world’s trout and char are imperiled or at risk of global extinction, and conservation of native trout depends on progressive solutions focused on the root causes of imperilment. For Trout Unlimited, he helps identify where conservation programs may have the greatest influence on persistence of at-risk species of trout and supports management of trout fisheries.
Dauwalter has researched fish conservation and management across the country, ranging from broad-scale, spatial conservation assessments for native aquatic species to inform conservation programs, understanding the impacts of land management on and habitat requirements of fish at multiple spatial scales, and implementation of angler-based water quality programs using mobile applications in the Midwest. His wide-ranging work on fish communities and habitat selection has demonstrated that many recognizable stream features have direct ties to active and passive instream habitat restoration techniques. Consequently, restoration efforts that enhance habitat complexity may benefit many more species beyond trout.
He provides leadership in advocating for improved long-term monitoring programs for trout. In addition, he supports the profession as President of the Western Division of the American Fisheries Society and as Associate Editor of the North American Journal of Fisheries Management.
Dauwalter believes that trout are sentinels that depend on healthy watersheds that support clean and cold-water lakes and streams. Consequently, they are useful indicators of effects of global climate change, and the long-term prognosis for cold-water specialists is not good. Further, trout attract a large number of vocal advocates for new regulations that may squeeze out non–fly fishers. These advocates may also support large-scale efforts to build climate resilience. Many people are familiar with trout in artificial hatchery environments where they become domesticated and associate people with food. However, in the wild, trout quickly adapt to changes and human conditions and learn to avoid what anglers repeatedly throw at them. Through long time periods, unique locally adapted trout develop, and new species evolved over many millennia. Many unique trout species teach us important lessons of persistence and local adaptation to harsh environments. These include the Redband Trout, Lahontan Cutthroat Trout, Apache Trout, Gila Trout, Mexican Golden Trout, and several undescribed species of trout in Mexico. These species will become even more valuable under changing climate conditions.
Key Takeaways
• Fly-fishing is a highly specialized form of fishing.
• Nonnative trout were transplanted throughout North America in the 19th century, often threatening viability of native trout.
• Fly fishers played an important role in the 19th and 20th centuries in introducing trout on other continents, advocating for catch and release, and promoting a fly-fishing code of ethics.
• The history of fly-fishing reveals the change in anglers’ values from utilitarian self-interest toward biocentric, ecosystem-based conservation.
• Fly Fishers International and Trout Unlimited are two organizations committed to conserving favored species and habitats.
• The folly of transplanting trout has shifted to “just protect the habitat, the rest will take care of itself.”
• Furthermore, the legacy of exceptional (perhaps oversold) trout fisheries of the Western United States is neither wild nor natural, but rather they exist because of drastic and complicated environmental and social changes.
This chapter was reviewed by Daniel C. Dauwalter and Shannon L. White.
URLs
Trout Unlimited: https://www.tu.org/about/
Figure References
Figure 9.1: The American Angler’s Book: Embracing the Natural History of Sporting Fish, and the Art of Taking Them, by Thaddeus Norris. Valerie F. Orth. Unknown date. CC BY 4.0.
Figure 9.2: The father of fish culture, Seth Green, from Trout Culture (1870). Seth Green, 1870. Public domain. https://commons.wikimedia.org/wiki/File:Seth_Green_from_Trout_Culture_(1870).JPG.
Figure 9.3: Baird Hatchery Station on McCloud River, California, with Mount Persephone in background (1897). Livingston Stone, 1897. Public domain. https://commons.wikimedia.org/wiki/File:FMIB_39938_Baird_Station_The_McCloud_River_in_the_foreground;_in_the_background_the_limestone_rocks_of_Mount_Persephone_Engine_house_and.jpeg.
Figure 9.4: Mountain Whitefish (Prosopium williamsi) (16 inches) was caught and released in the McKenzie River near the town of Blue River, Oregon. Woostermike, 2007. Public domain. https://commons.wikimedia.org/wiki/File:Prosopium_williamsoni.jpg.
Figure 9.5: Westslope Cutthroat Trout (Onchorhynchus clarkii lewisi). USFWS Mountain-Prairie, 2011. CC BY 2.0. https://flic.kr/p/9Mfg9G.
Figure 9.6: Leopold’s trips to the Rio Gavilan region of the northern Sierra Madre in 1936 and 1937 helped to shape his thinking about land health. Pacific Southwest Forest Service, USDA, 2010. CC BY 2.0. https://flic.kr/p/9hS1XD.
Figure 9.7: Illustration of James A. Henshall, author of Book of the Black Bass (1881). J. A. Henshall, 1881. Public domain. https://commons.wikimedia.org/wiki/File:Book_of_the_black_bass_(Frontispiece-_J._A._Henshall)_BHL8568061.jpg.
Figure 9.8: Owens Pupfish (Cyprinodon radiosus), Fish Slough Ecological Reserve. California Department of Fish and Wildlife, 2011. CC BY 2.0. https://commons.wikimedia.org/wiki/File:Owens_pupfish_(Cyprinodon_radiosus).jpg.
Figure 9.9: California Golden Trout. Jordan, David Starr, 1907. Public domain. https://jenikirbyhistory.getarchive.net/amp/media/fmib-51959-golden-trout-of-soda-creek-f7d177.
Figure 9.10: Daniel C. Dauwalter, PhD. Used with permission from Daniel Dauwalter. CC BY 4.0.
Text References
Bartlett, S. P. 1910. The future of the carp. Transactions of the American Fisheries Society 39(1):151–154.
Brown, J. C. 2015. Trout culture: how fly fishing forever changed the Rocky Mountain West. Center for the Study of the Pacific Northwest. University of Washington Press, Seattle.
Brown, J. C., K. H. Lokensgard, S. Snyder, and M. Draper. 2019. The social currents and social values of trout. Pages 65–93 in J. L. Kershner, J. E. Williams, R. E. Gresswell, and J. Lobón-Cerviá, editors, Trout and char of the world. American Fisheries Society, Bethesda, MD.
Brown, L. R., and P. B. Moyle. 1981. The impact of squawfish on salmonid populations: a review. North American Journal of Fisheries Management 1:104–111.
Budy, P., and J. W. Gaeta. 2018. Brown Trout as an invader: a synthesis of problems and perspectives in North America. Pages 525–543 in Javier Lobón-Cerviá and Nuria Sanz, editors, Brown Trout: biology, ecology and management, 1st ed., John Wiley & Sons, Somerset, NJ.
Buzzi, S., M. Fiszbein, and M. Gebreskilasse. 2017. Frontier culture: the roots and persistence of “rugged individualism” in the United States. NBER Working Paper No. 23997. Available at: https://www.nber.org/papers/w23997.
Carhart, A. H. 1950. Fishing in the West. Macmillan, New York.
Dunham, J. B., S. B. Adams, R. E. Schroeter, and D. C. Novinger. 2002. Alien invasions in aquatic ecosystems: toward an understanding of Brook Trout invasions and potential impacts on inland Cutthroat Trout in Western North America. Reviews in Fish Biology and Fisheries 12:373–391.
Dunham, J. B., P. S. Pilliod, and M. K. Young. 2004. Assessing the consequences of nonnative trout in headwater ecosystems in Western North America. Fisheries 29(6):18–26.
Evermann, B. W. 1891. A reconnaissance of the streams and lakes of western Montana and northwestern Wyoming. Fishery Bulletin 11(1):1–60.
Evermann, B.W., and C. Ritter. 1894. The fishes of the Colorado Basin. Fishery Bulletin 14(1):473–486.
Fausch, K. D., J. Prosek, and K. R. Bestgen. 2019. Standing on the shoulders of giants: three trout biologists who shaped our understanding of trout and trout streams. Pages 41–64 in J. L. Kershner, J. E. Williams, R. E. Gresswell, and J. Lobón-Cerviá, editors, Trout and char of the world. American Fisheries Society, Bethesda, MD.
Fly Fishers International. 2002. Code of angling ethics. Available at: https://flyfishersinternational.org/Portals/0/Documents/FFFGeneral/FFI_Code_of_Angling_Ethics_2002.pdf.
Gebhards, S. 1975. Wild trout: not by a damsite. Pages 31–33 in W. King, editor, Wild trout management: proceedings of the Wild Trout Symposium. Bozeman, MT. Available at: https://wildtroutsymposium.com/proceedings-1.pdf.
Griffith, G. A. 1993. For the love of trout. George Griffith Foundation, Grayling, MI.
Haig-Brown, R. 1951. Fisherman’s spring. William Morrow, New York.
Haig-Brown, R. 1939. The Western angler: an account of Pacific Salmon and Western trout in British Columbia. William Murrow, New York.
Halverson, A. 2010. An entirely synthetic fish: how Rainbow Trout beguiled America and overran the world. Yale University Press, New Haven, CT.
Hansen, M. J., C. S. Guy, P. Budy, and T. E. McMahon. 2019. Trout as native and nonnative species: a management paradox. Pages 645–684 in J. L. Kershner, J. E. Williams, R. E. Gresswell, and J. Lobón-Cerviá, editors, Trout and char of the world, American Fisheries Society, Bethesda, MD.
Henshall, J. A. 1919. Indiscriminate and inconsiderate planting of fish. Transactions of the American Fisheries Society 48:166–169.
Hoffman, R. C. 2016. Trout and fly, work and play, in medieval Europe. Pages 27–45 in S. Snyder, B. Borgelt, and E. M. Tobey, editors, Backcasts: a global history of fly fishing and conservation, University of Chicago Press.
Holey, M., B. Hollander, M. Imhof, R. Jesien, R. Konopacky, M. Toneys, and D. Coble. 1979. “Never give a sucker an even break.” Fisheries 4(1):2–6.
Isaak, D., M. Young, D. Nagel, D. Horan, and M. Groce. 2015. The cold-water climate shield: delineating refugia for preserving salmonid fishes through the 21st century. Global Change Biology 21:2540–2553.
Jordan, D. S. 1890. Report of explorations in Colorado and Utah during the summer of 1889, with an account of the fishes found in each of the river basins examined. Nineteenth Century Collections Online, https://www.biodiversitylibrary.org/item/148425#page/7/mode/1up. Accessed 22 July 2019.
Karas, N. 2002. Brook Trout: a thorough look at North America’s great native trout—its history, biology, and angling possibilities. Revised ed. Lyons Press, New York.
Kincaid, H. L., M. J. Gray, L. J. Mengel, and S. Brimm. 2001. National fish strain registry: trout species tables of reported strains and broodstocks. U.S. Fish and Wildlife Service, U.S. Geological Survey, 98-032/NF. https://archive.org/details/nationalfishstra02kinc/page/n1.
King, W., editor. 1975. Wild trout management: proceedings of the Wild Trout Symposium. Bozeman, MT. Available at: https://wildtroutsymposium.com/proceedings-1.pdf.
Knapp, R. A., G. M. Fellers, P. M. Kleerman, D. A. W. Miller, V. T. Vredenburg, E. B. Rosenblum, and C. J. Briggs. 2016. Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors. Proceedings of the National Academy of Sciences 113:11889–11894.
Kunkel, K.E., Stevens, L.E., Stevens, S.E., Sun, L., et al. 2013. Regional Climate Trends and Scenarios for the U.S. National Climate Assessment Part 5. NESDIS 142‐5, NOAA Technical Report.
Leopold, A. 1918. Mixing trout in Western waters. Transactions of the American Fisheries Society 47(3):101–102.
Leopold, A. 1993. Round River. Oxford University Press, New York.
Leopold, A. 1947. A Sand County almanac. Oxford University Press.
Lessner, R. 2010. How Meriwether Lewis’s Cutthroat Trout sealed Custer’s fate at the Little Bighorn. American Fly Fisher 36(4):17.
Martindale, T. 1901. Sport, indeed. George W. Jacobs, Philadelphia. Reprinted by BiblioLife in 2017.
McMahon, T. E., and D. H. Bennett. 1996. Walleye and Northern Pike: boost or bane to Northwest fisheries? Fisheries 21(8):6–13.
Meyer, K. A., F. S. Elle, and J. A. Lamansky Jr. 2009. Environmental factors related to the distribution, abundance, and life history characteristics of Mountain Whitefish in Idaho. North American Journal of Fisheries Management 29:753–767.
Monahan, P. N. D. 2011. Did Native Americans invent fly fishing for bass? Midcurrent website. Available at: https://midcurrent.com/history/did-native-americans-invent-fly-fishing-for-bass/.
Monnett, J. H. 1993. Mystery of the Bighorns: did a fishing trip seal Custer’s fate? American Fly Fisher 19(4):2–5.
Mordue, T. 2009. Angling in modernity: a tour through society, nature and embodied passion. Current Issues in Tourism 12(5):529–552.
Moyle, P. B. 1977. In defense of sculpins. Fisheries 2(1):20–23.
Munday, P. 2002. “A millionaire couldn’t buy a piece of water as good”: George Grant and the conservation of the Big Hole watershed. Montana: The Magazine of Western History 52(2):20–37.
Newton, C. 2013. The trout’s tale: the fish that conquered an empire. Medlar Press, Ellesmere, Shropshire, UK.
Norris, T. 1864. The American angler’s book: embracing the natural history of sporting fish, and the art of taking them. E. H. Butler, Philadelphia.
Owens, K. 2002a. While Custer was making his Last Stand: George Crook’s 1876 war on trout in the Bighorn Country. Montana: The Magazine of Western History 52(2):58–61.
Owens, K. N. 2002b. Blue ribbon tailwaters: the unplanned role of the U.S. Bureau of Reclamation in creating prime sites for recreational fly fishing for trout in Western America. Symposium on the History of the Bureau of Reclamation. Available at: http://www.riversimulator.org/Resources/USBR/ReclamationHistory/OwensKenneth.pdf.
Pascual, U., Balvanera, P., Díaz, S., Pataki, G., Roth, E., Stenseke, M., et al. 2017. Valuing nature’s contributions to people: the IPBES approach. Current Opinion in Environmental Sustainability 2:7–16. doi: 10.1016/j.cosust.2016.12.006.
Pierce, R., W. L. Knotek, C. Podner, and D. Peters. 2019. Blackfoot River restoration: a thirty-year review of a wild trout conservation endeavor. Pages 649–682 in D. C. Dauwalter, T. W. Birdsong, and G. P. Garrett, editors, Multispecies and watershed approaches to freshwater fish conservation, American Fisheries Symposium, Bethesda, MD.
Pfitzer, D. 1975. Tailwater trout fisheries with special reference to the Southeastern states. Pages 23–27 in W. King, editor, Wild trout management: proceedings of the Wild Trout Symposium. Bozeman, MT. Available at: https://wildtroutsymposium.com/proceedings-1.pdf.
Quammen, D. 1998. Wild thoughts from wild places. Scribner, New York.
Quist, M. C., and W. A. Hubert. 2004. Bioinvasive species and the preservation of Cutthroat Trout in the Western United States: ecological, social, and economic issues. Environmental Science and Policy 7:303–313.
Ross, J. 2016. It takes a river: Trout Unlimited and coldwater conservation. Pages 274–296 in S. Snyder, B. Borgelt, and E. Tobey, editors, Backcasts: a global history of fly fishing and conservation, University of Chicago Press.
Ross, J. 2008. Rivers of restoration: Trout Unlimited’s first 50 years of conservation. Skyhorse, New York.
Schullery, P. 1987. American fly fishing: a history. Nick Lyons Books. American Museum of Fly Fishing, Manchester, VT.
Schullery, P. 2006. Cowboy trout: Western fly fishing as if it matters. Montana Historical Press, Helena.
Sloan, S., and J. Prosek. 2003. Fly fishing is spoken here: the most prominent anglers in the world talk tactics, strategies, and attitudes. Lyons Press, Guilford, CT.
Snyder, S. 2016. A historical view: history of angling’s evolving ethics. Pages 1–14 in S. Snyder, B. Borgelt, and E. Tobey, editors, Backcasts: a global history of fly fishing and conservation, University of Chicago Press.
Soos, F. 1999. Bamboo fly rod suite: reflections on fishing and the geography of grace. University of Georgia Press, Athens.
Stone, L. 1897. Artificial propagation of salmon on the Pacific Coast of the United States, with notes on the natural history of the Quinnat Salmon. Bulletin of the United States Fish Commission, vol. 16. Washington, DC: Government Printing Office
Spence, M. D. 1999. Dispossessing the wilderness: Indian removal and the making of the national parks. Oxford University Press, New York.
Thoreau, H. D. 1862. Walking. Atlantic Monthly 9:657–674.
Traver, R. (pen name of J. D. Voelker). 1974. Trout magic. Simon & Schuster, New York.
Traver, T. 2017. Lost in the driftless: trout fishing on the cultural divide. Crooked River Press, Taftsville, VT.
Trotter, P., P. Bisson, L. Schultz, and B. Roper. 2018. Cutthroat Trout: evolutionary biology and taxonomy. American Fisheries Society, Special Publication 36, Bethesda, MD.
Trout Unlimited. 2011. Guidance document for NLC resolution on stocking nonnative hatchery trout over native trout populations. Website. Available at: https://www.tu.org/wp-content/uploads/2019/07/Stocking_Guidance_Resolution_2011.pdf.
Trout Unlimited. 2016. National conservation agenda. Website. Available at: https://www.tu.org/get-involved/volunteer-tacklebox/council-leader-resources/national-leadership-council/national-conservation-agenda/.
Walton, I. 1808. The complete angler; or, contemplative man’s recreation being a discourse on rivers, fish-ponds, and fishing. Printed for Samuel Bagster, London.
Warren, J. L. 2010. Weaving a wider net for conservation: Aldo Leopold’s water ethic. Organization and Environment 23(2):220–232.
Washabaugh, W., and C. Washabaugh. 2000. Deep trout: angling in popular culture. Berg, New York.
Wiley, R. W., and J. W. Mullan. 1975. Philosophy and management of the Fontenelle Green River tailwater trout fisheries. Pages 28–31 in W. King, editor, Wild trout management: proceedings of the Wild Trout Symposium, Bozeman, MT. Available at: https://wildtroutsymposium.com/proceedings-1.pdf.
Wiley, R. W., R. A. Whaley, J. B. Satake, and M. Fowden. 1993. Assessment of stocking hatchery trout: a Wyoming perspective. North American Journal of Fisheries Management 13:160–170.
Williams, J. E., H. M. Neville, A. L. Haak, W. T. Colyer, S. J. Wenger, and S. Bradshaw. 2015. Climate change adaptation and restoration of Western trout streams: opportunities and strategies. Fisheries 40(7):304–317.
Williams, J. E., R. N. Williams, R. F. Thurow, L. Elwell, D. P. Philipp, F. A. Harris, J. L. Kershner, P. J. Martinez, D. Miller, G. H. Reeves, C. A. Frissell, and J. R. Sedell. 2011. Native fish conservation areas: a vision for large-scale conservation of native fish communities. Fisheries 36(6):267–277.
Williams, R. 2016. The origin, decline, and resurgence of conservation as a guiding principle in the Federation of Fly Fishers. Pages 252–273 in S. Snyder, B. Borgelt, and E. Tobey, editors, Backcasts: a global history of fly fishing and conservation, University of Chicago Press.
Wulff, L. 1939. Handbook of freshwater fishing. Frederick A. Stokes, New York.
Zablocki, J. 2019. A stream of action: a blueprint for conserving the world’s trout and char diversity. Pages 777–781 in J. L. Kershner, J. E. Williams, R. E. Gresswell, and J. Lobón-Cerviá, editors, Trout and char of the world, American Fisheries Society, Bethesda, MD.
Zackheim, H. 2006. A history of Montana Fish, Wildlife and Parks Fisheries Division, 1901–2005. Montana Department of Fish, Wildlife and Parks, Helena. Available at: https://archive.org/details/historyofmontana2005zack.
1. Although Maclean and other writers use the term fishermen, women are active anglers and contribute significantly to the sport. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.09%3A_Fly-Fishings_Legacy_for_Conservation.txt |
Learning Objectives
• Describe the types of benefits provided by recreational fishing to the economy.
• Classify individual motivations for recreational fishing.
• Review options for maintaining satisfactory recreational fishing.
• Explain the basis for therapeutic value from recreational fishing.
• Understand the types of impacts that recreational fishing may have on fish, populations, and ecosystems.
• Explain how science can inform responsible fishing practices.
• Apply the Keep Fish Wet principles to minimize postrelease stress or mortality of released fish.
• Apply principles of behavior change to nudge recreational anglers to adopt responsible fishing practices.
10.1 Recreational Fishing and Its Importance
Recreational fishing is fishing for fun or sport, or fishing that “does not constitute the individual’s primary resource to meet essential physiological needs” (Arlinghaus and Cooke 2009). While subsistence fishing has a longer history, the first recreational fishing began at different times in different regions of the world. A Treatyse of Fysshynge with an Angle, by Dame Juliana Berners (1496), was the first book written about recreational fishing. Today, recreational fishers dominate many freshwater and marine fisheries. At least 220 million recreational fishers use a variety of gear, including rod and line, handlines, spears, bow and arrow, traps, and nets, to catch fish while engaged in a leisure activity (Arlinghaus et al. 2015; Cooke et al. 2018). In this chapter, I refer to recreational fishers as anglers. The term “angler” has been used since the mid-15th century to refer to those who “fish with a hook.”
Although commercial fishers have taken the brunt of the blame for fisheries depletions in the ocean, restrictive fishing regulations are often implemented for recreational fishing to prevent decline in catch rates (Lewin et al. 2006). In some freshwater lakes and streams, recreational fishing may be the only source of fishing mortality and may lead to collapse of important freshwater fisheries (Post et al. 2002). A major constraint in preventing overexploitation in recreational fisheries is the diffuse and open-access nature of the activity, making it very difficult to monitor the status of all fished populations (Arlinghaus and Cooke 2009). Privatization of recreational fisheries exists in only limited situations (Olausen and Block 2014), while many commercial fisheries have adopted individual transferable quotas.
The economic impact of recreational fishing is substantial, valued at U.S. \$190 billion globally (World Bank 2012). However, the economic value of recreational fishing is often underappreciated, as is the secondary value of recreational catch as a source of food. In Wisconsin alone, recreational harvest from lakes amounts to ~4,200 metric tons and an estimated annual angler consumption rate of ~1.1 kg, nearly equal to the total estimated U.S. per capita freshwater fish consumption (Embke et al. 2020). The annual economic impact of trout fishing in Georgia alone is U.S. \$130.3 million, which amounts to between \$60 to \$165 per trout angler (TenHarmsel et al. 2021). Although recreational fisheries have a greater importance in developed countries, as incomes rise in developing countries more opportunities arise to develop recreational fisheries and their links to tourism.
Approximately 11% of individuals fish for recreation in industrialized countries, although participation decreases in industrialized and urbanized regions where fishing has a reduced cultural importance (Arlinghaus et al. 2015). In the United States, 54.7 million Americans fished at least once during 2020, with a participation rate of 18%. Freshwater fishing attracts more participants than saltwater fishing, largely due to access constraints. Time spent inside and more hours watching television, playing digital games, and following social media compete with nature-based activities in young people (Larson et al. 2019). In larger cities, fishing is one of the last remaining ways in which people connect with nature. In order for future fishing participation to increase or even remain the same, it is important to introduce children to fishing at a young age. Many (88%) of the current fishing participants first fished before the age of 12 (Figure 10.1).
In addition to the concern that recreational fishing can deplete fish populations, many of today’s anglers are concerned about the welfare of fish that they catch, as well as noncompliance with fishing regulations by others. From the second a fish is hooked, they experience stress, and playing the fish has physiological effects. Fortunately, studies have revealed the following three key principles for releasing captured fish with minimal harm (Danylchuk et al. 2018): (1) eliminate air exposure; (2) eliminate contact with dry surfaces; and (3) reduce handling time. Numerous programs have developed to educate and promote a catch-and-release ethic that limits the effects on the captured fish. Many fishing groups have formulated and promoted the development of an angler’s ethic for conservation of many marine and freshwater fish populations. Education about good angling practices may provide the best approach for improving the welfare of recreational fish.
10.2 Motivations for Recreational Fishing
We fish to be outdoors, to relax, and to experience the thrill of the catch. When we look more closely, these motivations vary among anglers. The five most common types of motivations include the following:
1. Enhancing psychological and physiological well-being,
2. Experiencing the natural environment,
3. Experiencing social connections,
4. Connecting to the fisheries resource, and
5. Improving fishing skills and equipment. (Fedler and Ditton 1994)
Catching fish is only one of many components of the angling experience. Some anglers may rank eating fish high, while others rate catching fish to eat lower, emphasizing the experience of nature. Making a connection to the environment was the most common motivation for recreational fishers (Figure 10.2; Young et al. 2016). Thirty-four percent of fishing participants said that getting away from the usual demands of life was one of the best things about fishing. Motivations are highly complex and changeable over time (Schramm and Gerard 2004; Young et al. 2016). Both catch-related factors (i.e., catch rate, size of caught fish, fish harvest) as well as non-catch-related components, such as sociability and crowding, influence angler satisfaction (Birdsong et al. 2021). Some degree of aggregation of anglers may be important, perhaps for social reasons, though further increase in crowding reduces satisfaction (Schuhmann and Schwabe 2004; Olaussen 2010). Not all anglers share similar interests in catching fish, as it depends on the value individuals place on these factors:
1. Catching something,
2. Retaining fish,
3. Catching large-sized fish, or
4. Catching large amounts of fish. (Anderson et al., 2007)
Over time, an angler’s motivation may change from a catch orientation to emphasize noncatch motivations, such as being outdoors or passing on their passion for fishing (McKenna 2013). The progression often follows these stages:
• Stage 1: I just want to catch a fish!
• Stage 2: I want to catch a lot of fish!
• Stage 3: I want to catch big fish.
• Stage 4: I’m just happy to be out fishing.
• Stage 5: I want to pass on my knowledge and passion for fishing.
Studies of angler characteristics confirm that there is no such thing as an “average” angler. Rather, anglers are a heterogeneous and changing group. Therefore, we can segment anglers in distinct categories for analysis (Bryan 1977; Kyle et al. 2007; Beardmore et al. 2013; TenHarmsel et al. 2019). For example, Magee (2018) categorized recreational anglers into five distinct fisher classes with differing motivations (Table 10.1).
Type of angler Motivation Illustrative quote
Social fishers Motivated by noncatch-related aspects of fishing, particularly socialization and escapism. “We'll keep them live in a big tank, but if we don't catch many then I'll say let's put them back because there's no point. If we're not going to feed the whole family, then forget it.”
Trophy fishers Motivated primarily by challenge and mastery aspects of fishing, including catching large fish. “It's purely… for catching the fish, the fight of the fish and yeah, obviously at the top our mind, is the personal best I guess… It's the size of the fish that's most important.”
Outdoor enthusiasts Tend to fish primarily for the opportunity for escapism and being outdoors. “I always fish primarily by myself; it's the challenge of looking at the conditions, working out what's my best chance, where I should go, what lure I should use… and just the satisfaction of actually getting the fish.”
Generalists A mix of fishing motivations. Individuals in this class rated escapism as an important aspect of fishing. “The relaxing part of it is a big motivator, especially with the stresses of work… If the tide is right the anticipation of nailing a couple of big fish is pretty cool. That can be with friends or on my own.”
Hunter gatherers A mix of different motivations, and a comparatively large percentage of individuals who gave neutral responses to each item. “I'm part of a fishing club and there are a lot of guys in that I think are artists, whereas I'd probably use dynamite if I was allowed….I'm certainly more of a skull dragger than a finesse fisherperson.”
Table 10.1: Five distinct classes of recreational anglers.
Why do we need to know so much about angler motivations? If we ignore angler motivations, we risk providing the wrong mix of angling opportunities that fully meet public needs. This is a fundamental principle of fisheries management. With the many distinct types of anglers, the fisheries manager has many opportunities to improve fishing opportunities through stocking, regulations, access improvements, or habitat enhancements. The wrong choices will reduce angler satisfaction and the likelihood of returning. For example, more restrictive fishing regulations allowed Bull Trout numbers and average catch rates to increase dramatically, yet resulted in dramatic declines in participation by traditional anglers who did not favor the new regulation (Johnston et al. 2011). In addition to considering motivations of anglers, managers must also examine motivations and interests of the nonparticipating anglers and consider lost opportunities, or what economists call “opportunity costs.” Only 18% of the U.S. population fishes in any given year, leaving one to ask what we can do to allow the other 82% to fish.
Declining participation, stakeholder conflicts, regulations on harvest, and angler behavior and compliance are common concerns that can dramatically influence how satisfied an angler is with a fishing trip (Arlinghaus and Cooke 2009). Declining participation is associated with demographic shifts to urban living. Anglers choose fishing locations based on expected catch, but environmental and facility quality are also important determinants (Hasler et al. 2011; Hunt et al. 2019; Birdsong et al. 2021). How quickly a new fishing hole gets fished out depends on suitable regulations to avoid the phenomenon of an invisible collapse by highly mobile and successful anglers (Post et al. 2002; Post 2013).
As anglers become progressively diverse, fisheries managers need ways to satisfy users with different preferences while concurrently conserving a limited resource (TenHarmsel et al. 2019). Each angler group has differing views on the importance of fishing attributes, such as catch rate, fish size, or the environment. From the field of marketing, we can apply a framework that analyzes both the importance and satisfaction with each attribute of fishing. The framework reveals guidance for needed actions and recognizes that a “one size fits all” management approach is not optimal for large, complex fisheries with a heterogeneous mix of anglers (Ward et al. 2013).
The importance and satisfaction ratings for anglers can be displayed in a two-dimensional graph that shows importance versus satisfaction (Figure 10.3). The x-axis represents attribute satisfaction and the y-axis represents attribute importance, both ranging from low to high. Each of the four quadrants corresponds with management priorities. For example, trophy anglers who rate size of catch as most important would be dissatisfied with many small fish in their daily creel. This combination fits the upper-left quadrant, which indicates that fisheries managers should concentrate on improving the size of fish caught. High importance and low satisfaction means “concentrate here.” The ideal combination is high importance and high satisfaction, which means fisheries managers should “keep up the good work.” The case of low importance and high satisfaction means “possible overkill.” Finally, the lower-left quadrant of both low importance and low satisfaction means “low priority.”
Question to ponder
Many people love to fish, and perhaps you are one of these people. What are your primary motivations for fishing? Do you know any anglers who fit one of the categories defined in Table 10.1? If you do not fish, what alternative leisure time activities are you engaged in?
10.3 Therapeutic Benefits of Recreational Fishing
Recreational fishing reflects both cultural and emotional aspects of our relationships with places, fish species, and individual fish. Experienced anglers have memories of important places to fish, fishing partners, types of fish caught, and even individuals captured even if not landed. The positive influences of fishing create positive feedback, so that good fishing encourages more fishing. By making connections with nature via fishing, people feel better (McManus et al. 2011). In fact, Australia’s national recreational fishing policy maintains that “Recreational fishing is a legitimate activity that contributes to Australians’ health and well-being at individual, family and community levels” (Griffiths et al. 2017). In the United States, fly-fishing has been adopted as a therapy for treating combat-related post-traumatic stress disorder and improving the quality of life for women with breast cancer (Hildreth et al. 2019).
Casting for Recovery (2022) was formed in 1996 to introduce the benefits of fly-fishing to women with breast cancer. Approximately 200,000 new cases of breast cancer are diagnosed each year, and more than 2.9 million breast cancer survivors are living in the United States. Retreats organized by Casting for Recovery provide opportunities for breast cancer patients to escape to a safe space in nature while learning to fly-fish (Weston 2016). Participants in weekend retreats report a high degree of satisfaction, healing, and learning (Henry 2017).
Post-traumatic stress disorder (PTSD) is a mental disorder originating from experiencing a traumatic event (e.g., witnessing a violent act, sustaining a debilitating physical injury, combat). PTSD symptoms make it difficult for individuals to relax, enjoy, and participate in activities with others due to the fear of triggering symptoms. Approximately one in five of the 2.4 million troops who served in Iraq and Afghanistan meet the diagnostic criteria for PTSD or depression. Since 2005, Project Healing Waters Fly Fishing (PHWFF) began treating wounded military service members returning from combat in Iraq and Afghanistan. Participants learn fly-fishing through outings, insect identification, flytying, and rod-building classes. Project Healing Waters accommodates fly-fishing for clients with physical limitations or mobility issues.
Does fly-fishing work as a therapy? Few randomized controlled experiments by licensed mental health professionals have been done to answer this question. However, much has been learned from efforts by trained therapists to use fly-fishing to resolve trauma even when there is no control group used for comparison. Participants learn that it is not about the fish but the activities that assist in forming new memories while decreasing the intensity of traumatic memories (Parmenter 2022).
Fly-fishing can create a healing environment that can promote a return to healthy activity and personal transformation for veterans and military personnel with PTSD, and it facilitates a positive mood in individuals suffering from PTSD (Bennett et al. 2017; Hildreth et al 2019; Craig et al. 2020). The calming effect of sharing natural environments with other like-minded companions in pursuit of elusive wild fish was also alluded to in earlier writings about fishing. Author and ecologist Carl Safina (2011) likened fishing to meditation when he wrote, “Fishing in a place is a meditation on the rhythm of a tide, a season, an arc of a year, and the seasons of life.”
Therapeutic fly-fishing programs can improve quality of life for veterans with combat-related disabilities. Participants demonstrated reduced symptoms of PTSD, depression, stress, and functional impairment in the immediate response to the program and increased leisure satisfaction even after three months (Bennett et al. 2017; Parmenter 2022). Interviews with participants in the Project Healing Waters Fly Fishing program demonstrated that the program facilitates positive mood, generates motivation for coping, provides hope for the future, and contributes to post-traumatic growth (Craig et al. 2020). However, the fact that fishing and other recreation therapy provides health and well-being benefits is underappreciated (Kemeny et al. 2020).
Benefits of fly fishing Representative quotes
Positive mood - “It helps you relax, to unwind…it puts you in a better frame of mind…it’s just tranquil.”
- “It’s hard to explain to people the tranquility of just being on a stream. It doesn’t matter if I’m fishing, or just trying to see what kind of bugs are on the water; it’s just that feeling of peace and quiet.”
- “It definitely helps me with my anxiety; just casting, alone in itself. And, just knowing, I’ve got to get better, I’ve got to go further … it’s a soothing thing, it helps you just calm down within because you don’t have to rush it.”
Motivation for coping - “When I first got back from Iraq, I didn’t have any patience at all, my concentration wasn’t there…I couldn’t tie a fly. Now, with fly-fishing, I’m probably more patient than I have been in a long time."
- “Because of PHWFF, I get out of bed.”
Hope for the future - “Fly-fishing breaks down a lot of barriers, and makes you feel like you’re not alone…it’s a big network, and a mentorship. For me, it’s not about the fishing at all. I love to catch fish, but I don’t go to fish at all, I go to see everybody.”
- “Everything about it is so—I’m not going to say divine—but it’s just natural, just being around the water and the trees. And it helps you cope even when you’re stuck. I was so stuck.”
- “I may have a bad week or two, but tell myself Friday is a casting session which helps me get through the day. I can deal with a few bad days because there is going to be one day I can go fishing.”
Post-traumatic growth - “I feel like I do love myself. I love fishing and I just feel happy and relaxed and peaceful. I got one thought in my head, not a million.”
- “With flyfishing, you have something you take on forever, you can take it with you. They don’t come and feed you but teach you how to fish and feed yourself.”
- “It ain’t about the fishing. It’s about where it takes you and how it can reform you and make you over and help you get out of a rut, and just try. It’ll transform you. It helped me to be more complete.”
Table 10.2: Benefits of fly-fishing and representative quotes by participants (from Craig et al. 2020).
10.4 Conservation Issues Facing Recreational Fishing
In North America and other areas, fisheries are a public resource, and open access may lead to overfishing. Recreational fishing often truncates the natural age and size structure, resulting in fewer older larger fish (Figure 10.4). Recent studies also reveal that high fishing pressure may reduce genetic variability or influence evolutionary pressures (Sutter et al. 2012). Fishing may also alter aquatic food webs. A third effect relates to loss of fishing gear and lures that result in unintended ecosystem consequences. Habitat modifications to improve access for boats may make habitats less hospitable for fish (Lewin et al. 2006). The loss of bigger and older individuals in a population is a common influence of unrestricted recreational fishing. Even at a modest rate, fishing can greatly reduce the number of older fish in a population, resulting in catch dominated by small fish (Figure 10.4). Recreational fishing is facing a number of conservation challenges, including high exploitation, selective harvest, fishing and boating during spawning, pollution and contaminated fish, stocking, sublethal effects, fish welfare and antifishing sentiments, and community and ecosystem influences (Cooke and Cowx 2006; Lewin et al. 2006; Arlinghaus and Cooke 2009).
High exploitation is a prominent conservation issue in recreational fishing, particularly in highly valued species. For example, recent studies show that approximately 40% of recreational Walleye fisheries of Wisconsin were overharvested (Embke et al. 2019). Other assessments indicated that a collapse of recreational fisheries may be more widespread than previously assumed (Simonson and Hewett 1999; Post et al. 2013; Rypel et al. 2016). Numerous technological innovations, such as social media, fish finders, drones, and underwater cameras, have greatly increased anglers’ ability to locate and catch fish (Cooke et al. 2021). Such developments in fishing technologies have so greatly influenced success in finding and catching fish that we need to revisit questions of what constitutes “fair play” in recreational angling and what limitations, if any, should be imposed. Because these new technologies are cost prohibitive for some participants, an uneven playing field exists.
Recreational fishing is highly selective. Anglers have favorite species to target, and regulations are often needed to protect spawning or trophy-sized fish. Targeting rare trophy individuals of fish species that are late maturing or with variable recruitment may have effects on population viability. The International Game Fish Association continues to certify the world record size fish, even for species that are at risk of extinction (Shiffman et al. 2014; Cooke et al. 2016). If we continue to certify records for endangered fish species, we must ensure that the role of anglers in conservation exceeds the risk of population collapse. Some sportfishing-based conservation projects focus on at-risk fish species, including the mahseers, Taiman, Murray Cod, White Sturgeon, Atlantic Bluefin Tuna, Arapaima spp., and coastal sharks (Cooke et al. 2016; Gallagher et al. 2017). In these and other cases, anglers can promote conservation in a number of ways by raising funds, monitoring catch, and implementing guidelines for responsible angling practices (Schratwieser 2015).
Question to ponder:
Should we permit recreational fishing on fish that are at risk of extinction?
Recreational anglers learn the patterns of the fish they target and adopt fishing practices to increase the odds of success. For example, bass anglers soon learn that fishing during spawning season when males are creating and defending nest sites can be highly effective. In particular, parental males of black bass (Micropterus spp.) are highly vulnerable to angling while guarding nests in shallow water. Even temporary removal of guarding males may lead to predation on offspring or even male abandonment of the nest (Suski and Philipp 2004). Fishing may also influence fish populations indirectly via habitat disturbance. Boat noise near nesting bass may also reduce nest success (Mueller 1980; MacLean et al. 2020), and wading by anglers can kill developing trout eggs (Roberts and White 1992). Construction of moorings for recreational boating reduces aquatic vegetation, important habitat for juvenile fish (Hansen et al. 2019). Planning for quality recreational fishing requires that we minimize the indirect effects of recreational fishing.
Water pollution has reduced availability of fishable waters as well as eliminated the aesthetic quality of fishing experiences. Although water pollution laws have benefited recreational fishing tremendously (Vaughan and Russell 2015), consumption advisories for contaminated fish are commonplace, often eliminating the benefits of fishing for food (Cole et al 2004; Westphal et al. 2008). Pregnant women and young children are the most at risk fish consumers. Some anglers are not aware of the fact that contaminants bioaccumulate up the food chain from sediments to plants to fish. Fishing also generates litter from discarded fishing line, hooks, and lures that may result in injury to wildlife. The deposition of lead from fishing sinkers can lead to poisoning and death when ingested by waterfowl.
Stocking is an important tool for recreational fisheries management. It may supplement heavily fished populations, and in certain cases, nonnative fish stocking may cause problems for native populations. Stocking on top of native trout populations has been discontinued in many states, as noted earlier in Chapter 9 Fly Fishing’s Legacy for Conservation. Introduction of species from outside their range may cause unintended consequences or may be beneficial. Throughout much of the industrialized world, novel ecosystems are increasingly widespread; there are no pristine environments and no species assemblages unaltered by human activity. For example, the unintentional introduction of the Sea Lamprey into the Great Lakes had profound consequences to all large-bodied fishes, such as Lake Trout, Burbot, and Lake Whitefish (Brant 2019). This introduction plus others so greatly changed the Great Lakes that an intentional creation of put-grow-take salmon and steelhead fisheries resulted in a world-renowned biologically and economically valuable fishery in the Great Lakes (Tanner 2019). These introductions are well managed and considered to be beneficial. However, several species of Asian carp, introduced in Arkansas in the 1970s, have expanded their range and are considered ecologically destructive. Asian carp are now a threat, as their expansion continues into the Great Lakes (Reeves 2019).
Most fisheries management agencies categorized fish as threatened or endangered (all take is restricted), game (harvest is regulated), or nongame (harvest may be regulated). Unfortunately, many species are perceived to have low fisheries values and are referred to as “rough fish.” As noted earlier, Rypel et al. (2021) argued for dropping the term “rough fish” because it is pejorative and reflects a cultural problem of viewing these fish as nuisances. The term was first used in the late 1800s to refer to fish that were gutted but not filleted. Often these “rough-dressed” fish were discarded when other higher-valued species were caught. Referring to fish as “rough” is not helpful or informative and obscures the unappreciated benefits of native species. Furthermore, the daily harvest or possession limits for these and nonnative fish are unlimited in many states. The use of the term “rough fish” was recently eliminated by one state (Minnesota), which has substituted the term “underused fish.” With a growing demand for alternative fishing adventures, agencies need to create scientifically based fishing regulations for the undermanaged and underused fish.
Question to ponder:
What descriptive name(s) would you suggest we adopt for nongame fish to better reflect their values?
10.5 Challenges in Managing Recreational Fishing
Management agencies often hear anglers express their concern that “fishing is not what it used to be.” Anglers are relaying their experience in personal success rate, measured as either catch rates or size of catch. Maintaining high levels of fishing satisfaction is a challenge for a number of reasons. First, angler trip success and catch rates are dependent upon a fish’s vulnerability to angling gear and often decline with increased fishing effort (Shaw et al. 2021). Second, access to innovative technology and specialized information increases vulnerability to capture and loss of harvestable-size fish. Although fishing success may be enhanced by hiring a fishing guide, the additional cost is often prohibitive for many anglers. Finally, the paradox of satisfaction is a common pattern where improved fish populations lead to higher expectations and, therefore, not higher fishing satisfaction.
Recreational fishing is also challenging to manage because of the ability of anglers to easily change target species or target fishing spots. Most anglers (86%) reported that other species would be acceptable substitutes for their preferred species (Sutton and Ditton 2005). As anglers become more experienced, they learn about fishing sites and social media, and other fishing communities provide access to changes in fishing success. Consequently, fishing effort can rapidly change in response to expected catch rates. For a region with multiple species and locations, angler behaviors of choosing fishing opportunities appear to be driven primarily by expenses and less by specialization (Shelby and Vaske 1991; Beardmore et al. 2013; Sutton and Oh 2015). If fishing regulations are uniform within a region, anglers will fish down stocks closest to home and then substitute more distant locations as catch quality declines close to home (Carpenter and Brock 2004). This creates a leapfrog exploitation pattern that spreads across a region. The substitutability problem means that management regimes must be flexible enough to avoid such cascades of fishery impacts across patchy environments.
Recreational anglers have dealt with animal welfare concerns and antifishing sentiments in recent years (Arlinghaus et al. 2012; Muir et al. 2013). (Chapter 5 discusses personal decision making about minimizing pain and suffering in recreationally caught fish.) The term “welfare” addresses physical and mental health and well-being of a fish or group of fish. Scientists and ethicists differ on how to approach animal welfare. For example, the animal welfare views held by individuals may be any of the following:
• Function-based, that is indicative of growth or fecundity,
• Nature-based, which relates to the ability to lead a natural life in the wild, or
• Feelings-based, which focuses on mental states rather than physical health and emphasizes not only the avoidance of stress or fear but also the opportunity to experience positive feelings.
Recreational anglers practice a mix of pursuit of fish for food, competition and trophies, leisure, and catch and release. The pain and suffering of fish are not the only morally relevant criteria considered. Recreational anglers may claim that the utilitarian benefits of sportfishing exceed any harm. Typically, they consider welfare considerations for fish from a functions-based view, which recognizes that angling induces stress and may cause injuries, but responsible fishing practices can minimize injuries.
Responsible fishing practices should be actively debated by recreational anglers so that values, beliefs, norms, and personal actions drive decisions rather than ill-advised policies. For example, the Swiss Animal Welfare Act makes voluntary catch and release of legally harvestable fish an offense. This act, passed in 2008, is based on the belief that the only valid reason to go fishing is to harvest fish. In Germany, fishing tournaments with voluntary catch and release are banned. Five ethical viewpoints are common in many parts of the world (Table 10.3; Arlinghaus et al. 2007; Arlinghaus and Schwab 2011).
Viewpoint Description
Animal welfare Focuses on how recreational fishing impacts the well-being, health, and fitness of individual fish and actions to minimize impairments.
Animal liberation Takes a utilitarian view to weigh the benefits of recreational fishing to individual anglers and society against the pain and suffering of individual fish.
Animal rights Holds that animals have an intrinsic right to life and a right not to be harmed. Therefore, recreational fishing is unethical.
Angler motivation Examines intention of the recreational angler to either meet essential survival needs (i.e., food) or fish for fun. Angler’s motive is what counts most in judging ethical permissibility. Therefore, catch-and-release fishing is unethical, whereas fishing for food is acceptable.
Biocentrism and ecocentrism Recreational angling is a threat to natural wilderness processes and biological integrity and should be avoided.
Table 10.3: Five ethical viewpoints applied to recreational fishing.
Of these five viewpoints, only the animal welfare and ecocentric views do not involve the total abolition of recreational angling. Responsible angling requires better information on technologies to improve fish care (Cooke et al. 2021). Laws and policies that follow other viewpoints may greatly limit availability of conservation practices. In response to animal rights activists, 23 of the 50 states of the United States have passed constitutional amendments proclaiming a right to hunt and fish, subject to reasonable regulations and restrictions (Ballotpedia 2022).
Question to ponder
Which of the five viewpoints are you likely to adopt to decide how to address welfare of fish caught by recreational anglers? Which of these viewpoints represent the biggest threat to the future of recreational angling?
10.6 Options for Regulating Recreational Fishing
Costs of enforcement of regulations of harvest and gear restrictions can be substantial. Therefore, voluntary adoption of fishing restrictions via promoting changes in behavior is preferable (Cooke et al. 2013). The most commonly employed regulations for recreational fishing include creel (or bag) limits, closed seasons, and length limits. Over time, these regulations have become more restrictive in response to increasing fishing.
Creel limits are simple and easy to understand and enforce. They restrict angler harvest per fishing event or day. Creel limits are widely applied to distribute the finite harvest among more anglers and reduce the harvest by more experienced anglers. These limits have historically been higher than the daily angler catch of most anglers (Cook et al. 2001; Radomski et al. 2001). For example, the Yellow Perch daily creel limit in Minnesota was once 100 fish. With high daily creel limits, few anglers harvest the daily limit. Often only “10% of the anglers harvest 50% of the fish” (Snow 1978). There are two reasons for the highly skewed distribution of success (Figure 10.5). One is that not all days are equally good for fishing. The second is the great variation in skill level among anglers (Wagner and Orth 1991).
Creel limits are one of many elements that may be used by anglers to define fishing success. When more fish are harvested per trip, anglers rate fishing higher. High creel limits may cause anglers to have unrealistic expectations about the potential supply of fish compared to the demand (Cook et al. 2001). Creel limit reductions may be unsuccessful in reducing angler harvest or affecting fish populations. The hypothetical angler success graph (Figure 10.5) demonstrates that a reduction in creel from 8 to 4 would affect only a few trips and result in a small harvest reduction. Furthermore, creel limits are applied on a per-angler basis, so they cannot control total harvest if total fishing effort increases or if noncompliance is high. Finally, since anglers have a variety of motivations, they likely respond differently to regulation changes (Beard et al. 2011).
The ethic of fairness is involved in setting creel limit regulations because many anglers do not harvest a single fish during an angling trip. In Wisconsin lakes, Walleye harvest was not equally distributed. Only 7.4% of Walleye angler trips were successful in harvesting at least one Walleye, and <1% harvested a limit during a fishing trip (Staggs 1989). In Minnesota, anglers were slightly more successful, where 27.2% of angler trips ended with a harvest of at least one Walleye and about 1% harvesting a limit. The ideal creel limit would distribute the catch among more anglers and prevent overuse by a few individuals.
Long-term trends in panfish populations (i.e., Bluegill, Yellow Perch, Black Crappie, Pumpkinseed, and Rock Bass) in Wisconsin lakes showed significant declines due to overfishing (Rypel et al. 2016). The daily limit for panfish was 50 aggregate per day from 1967 through 1998, which was reduced to 25 in 1998. Further reduction in daily limits for panfish (10) to improve undesirable small sizes of Bluegill populations increased both mean length and mean maximum length relative to sizes in control lakes (Jacobson 2005; Rypel et al. 2015).
Recreational fishing is often regulated with a variety of length-based regulations, based on the assumption that population size structure and trophy potential will improve as a result (Figure 10.4). Most common are minimum length limits; however, maximum length limits and protected and harvest slot limits are also very common. Minimum length limits are adopted to avoid growth overfishing, where the fish are removed before they attain quality size for anglers. Maximum length limits are adopted to protect the big, old, fat, fertile, female fish (BOFFFFs). A protected slot limit is designed to allow anglers to keep up to the daily creel limit of fish smaller than slot. This regulation has the dual purpose of allowing balance of harvest of small pan-size fish and trophy fish.
The big old fat fertile female fish hypothesis considers the many ways that the BOFFFFs benefit the long-term productivity of fish populations (Hixon et al. 2014). Often the larger fish in a population are more valuable economically (as trophies), and there are potential trade-offs between harvesting these fish or implementing management measures to protect them. There are five hypothesized effects of BOFFFFs on population productivity (Figure 10.6). Large females produce far more eggs than small females. Natural mortality of large females is low, meaning that the BOFFFFs will survive long periods of conditions unfavorable for reproduction. Larger females often produce larger eggs with higher amounts of yolk, thereby allowing the offspring to grow faster and survive better. Larger fish typically spawn earlier in the year and at different places than younger females. To the extent these relationships hold, recreational fishing tends to differentially remove BOFFFFs because fishing both elevates mortality and changes the age/size-selective pattern of mortality within fished populations.
Fishing regulations may also close certain areas or locations to fishing. Closed seasons or catch-and-release fishing seasons during spawning are sometimes implemented. Protected areas refer to implementing some level of exclusion from the use of fish resources. Attempts to establish “no-take” marine reserves in Hawaii, California, and the Florida Keys have engendered strong opposition from sportfishing groups (Salz and Loomis 2004), which limits the use of the regulatory strategy. There tends to be more support for protected areas that for banning commercial fishing but allowing catch-and-release recreational fishing (Bartholomew and Bohnsack 2005). Marine protected areas (MPAs) are most effective when (1) MPAs are large, old, and isolated, (2) all fishing is prohibited, and (3) enforcement is strong (Edgar et al. 2014). Some anglers argue that if nonextractive activities, such as SCUBA diving and snorkeling, are allowed within no-take reserves, then catch-and-release angling should be permitted because it is not extractive. Consequently, best practice includes the recreational anglers in the design and implementation of protected areas to ensure that recreational values are incorporated into the management strategies (Danylchuk and Cooke 2011).
Catch-and-release practices have increased to reduce the effects of angling on fish populations, particularly where angler motivations are less harvest oriented (Arlinghaus et al. 2007). Voluntary release of Largemouth Bass exceeds 90% in certain waters and effectively “recycles” fish, thereby improving fishing quality (Myers et al. 2008). These trends reflect the values, beliefs, norms, and action causal change of influence (Figure 10.7). This theory helps to explain choices of actions based on habits and complex motives. At the core of the theory are notions of values and norms. Values are general principles that provide standards for assessing actions. These core values rarely change over a short time span. For example, one may value being active in the outdoors for feelings of relaxation and enhancing a sense of personal well-being. Both emotions and rational thinking lead to beliefs about best practices for recreational fishing. Beliefs in turn affect personal norms and action in a sequential fashion.
Many avid catch-and-release anglers begin by nudging others with the simple message, “You should release your catch.” For example, fishing buddies had the largest effect on catch-and-release behaviors (Stensland et al. 2013). Norms are important because they are standards that serve to motivate individual behavior based on a sense of obligation rather than punishment. As such, norms become informal rules enforced by informal sanctions or internalized by the individual.
However, the benefits of catch and release are not guaranteed because angler behavior and gear choice can affect its success. Often, the responses to catch-and-release fishing on fishing mortality are species-specific (Allen et al. 2008; Sass and Shaw 2020). Success of this practice depends on reducing air exposure, hooking injury and mortality, and handling time. Implementing fishing regulations that require anglers to release fish are also associated with recommendations for use of differing gears, such as circle hooks, barbless hooks, or certain types of landing nets (Brownscombe et al. 2018).
Reliance on voluntary norms of proper behavior among anglers facilitates achieving management objectives (e.g., development of voluntary release of fish to reduce fishing mortality). Fly fisher Lee Wulff actively promoted voluntary catch-and-release fishing even when regulations allowed harvest, and his name continues to stand for catch-and-release fishing and the concept that “game fish are too valuable to be caught only once.” In his biography of Wulff, Jack Samson (1995) wrote that “The father of catch-and-release angling and a pioneer in the conservation of Atlantic salmon, Lee Wulff may have been America’s greatest fly-fisherman.” Voluntary release of Largemouth Bass has become a commonplace norm that often aligns with management objectives of trophy and competitive tournament fishing (Siepker et al.; 2007; Myers et al. 2008). Ray Scott, the founder of the Bass Anglers Sportsman Society, introduced the catch-and-release ethic to bass fishing and was a staunch advocate for boating safety. At the time, Scott wrote that the “notion of releasing a bass was about as common as giving a steak back to the butcher after you’d bought it. In bass fishing, success was measured in numbers of fish on the dock.” Ray Scott’s persistent message was “Don’t Kill Your Catch” in order to nudge bass fishing tournaments to adopt codes of conduct (i.e., social norms) that drive compliance (Boyle 1999; Thomas et al. 2016).
Raising angler awareness about the practice resulted in catch and release becoming a pervasive “social norm” for a variety of recreational fisheries (Stensland et al. 2013; Sass and Shaw 2019). Wisconsin’s Muskellunge fishery management has focused on catch-and-release fishing due to low creel limits and restrictive length limits. Numbers of musky anglers have never been higher as catch and release has become a norm for Muskellunge anglers. In Wisconsin and elsewhere, the release rate for Largemouth Bass and Muskellunge often exceeds 90% in recent times, reflecting the current social norm. As release rates increased over time, the catch rates for Largemouth Bass have increased (Sass and Shaw 2019); however, the responses to catch and release are species specific, and promotion of the practice should not assume that “one size fits all” fisheries. Walleye fishing attracts many harvest-oriented anglers, and therefore catch and release has limited benefits over size limits.
How can we influence the behavior of recreational anglers? Fisheries management generally relies on deterrence via restrictive regulations. The low probability of being caught is one of the key drivers of noncompliance in recreational fisheries. Yet, nudges based on social norms may be more cost effective (Mackay et al. 2021). A nudge is an aspect of the choice that alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives. To count as a mere nudge, the intervention must be easy and cheap to avoid. Nudges are not mandates. For example, “Putting fruit at eye level counts as a nudge. Banning junk food does not” (Thaler and Sunstein 2021).
Not all nudges will work, and therefore we must consider opportunities for changing norms in fishing practice. The theory of planned behavior models explains an individual’s behavioral intentions as influenced by three questions: (1) Do I have the right skills to do this? (capability); (2) Do I like it? (motivation); and (3) What do others think of this? (opportunity or norm) (Figure 10.8; Ajzen 2005). Among the many behaviors that might be promoted as new social norms are more effective and less-harmful lures and hooks, use of landing nets, choice of fishing time or seasons, and reduced handling and air exposure. In an evaluation of the use of venting tools and descender devices to minimize barotrauma (injury resulting from changes in barometric pressure) in released reef fish, Crandall et al. (2018) found that the influence of others via social norms had the greatest influence on adopting new barotrauma mitigation tools.
Efforts to implement large-scale and long-term behavioral intervention strategies for recreational angling should include following simple steps (Geller 1989). These are Selection, Intervention, Evaluation, and Dissemination (Figure 10.9). Step one (Selection) is to identify the target behavior that is desired. Step two is Intervention. Change agents should apply Benjamin Franklin’s principle, “Tell me and I forget, teach me and I remember, involve me and I learn,” to their intervention communications. To encourage adoption of a new behavior, it should be Easy, Attractive, Social, and Timely (remember: EAST). Verbal and written messages alone are not sufficient. Rather the use of local, credible anglers to demonstrate the new behaviors is preferred. Conducting these demonstrations in pleasant, outdoor surroundings will increase participation by anglers. Step three is Evaluation, during which observations of baseline and after-intervention behaviors are compared to evaluate the effectiveness of the intervention on target behaviors. Step three may indicate the intervention was not effective and a new behavior is selected for change. If the intervention was effective, that leads to step four, Dissemination. Here the benefits of adopting the new behavior are shared with recreational anglers. Much can be learned from social marketing to make the target audience aware of the benefits of the behavioral change. For example, social marketing uses market segmentation to divide a market into small units with common characteristics. In promoting behavior change in recreational fishing, segmenting the angling population into different motivations (see Table 10.1) will help define different strategies appropriate for the target group of anglers.
Recreational fishing regulations via creel limits, length limits, and catch and release are still evolving as new research explores angler behavior and consequences of catch-and-release fishing. Ice fishing is a popular winter sport in northern climates; however, more detailed information is needed to develop fishing regulations for ice fishing that properly consider the effects of air exposure, freeze damage, and temperature shock on the fate of fish released (LaRochelle et al. 2021; Lawrence et al. 2022). Microfishing is a growing form of fishing where the angler is motivated by catching many species of fish with small hooks. Few appropriate studies have been conducted to inform fishing regulations suitable for microfishing (Cooke et al. 2020). Learning how to understand and influence behavior of recreational anglers remains a high priority.
10.7 Responsible Recreational Fishing and Keep Fish Wet Principles
Recreational anglers are important and effective conservation partners who may influence the behavior of other anglers (Granek et al. 2008; Cooke et al. 2019). Depending on the fishing gear used, the angler’s skill and intentions, and environmental conditions, hooking mortality of released fish ranges from ~1% to over 90% (Bartholomew and Bohnsack 2005). Therefore, modifying angler choices and behavior may greatly reduce mortality of released fish (Arlinghaus et al. 2007). Keep Fish Wet is one program designed to encourage anglers to adopt strategies to minimize stress in hooked fish. Three Keep Fish Wet Principles address actions that are most under the angler’s control and backed by scientific evidence.
• Principle 1: Minimize air exposure
• Principle 2: Eliminate contact with dry surfaces
• Principle 3: Reduce handling time
Additional tips provide simple and easy actions that every angler can do (Table 10.4). Proper use of tools and related tactics may include terminal tackle, retrieval tools, landing nets, unhooking tools, measuring devices, holding and recovery nets, and livewells (water tanks used to keep fish alive). Keep Fish Wet is an organization that works to build relationships with anglers who will rely on the organization to provide practical guidance for catch-and-release fishing. As such, it is a recognizable brand with the potential to influence angler behavior.
The general tips provided are generally applicable to recreationally caught species. However, there are differences among fishing locations and game species that require further species-specific studies (Cooke and Suski 2005; Kerr et al. 2017; Browncombe et al. 2017, 2019a, 2019b). For example, use of circle hooks when fishing for sailfish and coral reef fish reduced lethal injuries (Prince et al. 2002; Sauls and Ayala 2012), and replacing treble hooks with single barbless hooks reduced unhooking time (Trahan et al. 2021).
When Tip
Before you go fishing - Follow local regulations
- Think twice before going after spawning fish
- Be wary of warm water
Before your first cast - Use barbless hooks
- Consider using artificial baits
- Use rubber nets
- Limit use of lip grippers
- Carry hook removal devices
When you hook a fish - Limit fight time
- Hold fish in or over water
- Grip fish carefully
- Photograph wet fish
- Only revive fish that cannot swim
Table 10.4: "Keep Fish Wet" tips.
The claim that minimizing air exposure of caught fish enhances postrelease survival is supported by credible and authoritative scientific evidence (Figure 10.10). The scientific evidence comes from a number of studies that reveal the levels of stress, gill damage, and reduced recovery time induced by increased air exposure. In a study of Rainbow Trout, one minute of air exposure following exhaustive exercise promotes more severe acid-base disturbances than does exercise alone (Ferguson and Tufts 1992). One minute of air exposure is much shorter than the time most anglers take to admire the catch and pose for a photograph.
After catching a fish, it should be released as soon as possible to ensure survival. However, the angler can quickly test the reflexes of the fish with a few simple tests. These signs of impairment in the reflexes of captured fish are correlated with mortality and stress indicators, such as elevated cortisol and lactate levels (Davis 2010; Raby et al. 2012). Anglers who wish to release caught fish should learn to follow the steps for determining reflex action mortality predictors (Brownscombe 2018). If fight times are short and air exposure is minimized during handing, then one should expect the fish to show a strong escape response (Figure 10.11). If the angler grabs the tail of the fish with the fish submerged in water, an unimpaired fish will immediately attempt to swim away and the angler will feel the muscles flex. Additionally, if the fish is held out of water using two hands wrapped around the middle of the body, the unimpaired fish will actively attempt to struggle free. If a fish passes the escape response test, it should immediately be released to reduce any further handling. If it fails, the angler tests the righting response. Here, the fish is placed upside down in the water just below the surface and should right itself in a few seconds. If it passes the righting response, it should be immediately released. If a fish fails both the escape and right response tests, the angler checks for normal gill ventilation. Hold the fish in the water, observe for regular, consistent ventilation (opening and closing) of the operculum (gill covers). If a fish isn’t ventilating at regular intervals, it fails this test, and is highly impaired and at high risk for mortality. Therefore, the fish should be held until it can be reassessed for the righting response and ventilation responses (Figure 10.11). In the final test, the angler holds the fish in water and rolls the fish side to side. If the eye remains level instead of rolling it with the body, the fish passes the test. With either outcome of the eye test, the fish should be held until it can be reassessed and released only after passing the righting response.
Even shark anglers have become strong allies for the development, dissemination, and adoption of specific best practice catch-and-release guidelines. Ninety-three percent of recreational anglers from the United States have caught a shark at least once while fishing (Press et al. 2016). However, many lack knowledge of sharks and how to enhance their survival after capture, and guidelines from the National Marine Fisheries Service (NMFS) were not consistently applied. NMFS recommends that recreational anglers who catch and release sharks (1) use nonoffset circle hooks; (2) set the hook immediately in the lip or jaw to avoid gut hooking; (3) reduce fight times by using heavy tackle; (4) minimize handling of the animal, including not landing the shark; (5) use a dehooker to remove the hook; and (6) revive the shark if it is fatigued or near death. These guidelines must be better disseminated.
To increase the awareness of the important role we all play in protecting our fisheries, anglers are asked to embrace a Code of Angling Ethics to serve as a reminder of their stewardship role.
In one example Code of Angling Ethics, anglers make the following pledges:
• Have a valid fishing license for all members of your party.
• Understand and follow state and lake-specific regulations. Compliance to regulations directly plays a role in sustaining a healthy recreational fishery and benefits fishing for the future.
• Strive to keep the watershed clean and minimize the impact you may have when fishing. Avoid degrading stream and lake banks and properly dispose of debris and trash, including monofilament line.
• Respect property and share waters respectfully with others.
• Avoid the introduction of aquatic nuisance species to protect the integrity of Illinois lakes and streams. Prevent the transport of unwanted plants, fish, and other aquatic animals by thoroughly cleaning all recreational equipment and disposing of live bait in the trash.
• Practice best handling guidelines for catch-and-release fishing. Fish should be released with minimal harm to help ensure post-release survival and promote healthy fish populations.
• Keep no more fish than needed for consumption.
• Take care when anchoring to minimize damage to the aquatic environment. Be aware that there may be nesting fish close to the shore during the spawning season.
• Preserve the sportfishing tradition by sharing knowledge, skills, techniques, and ethics. Help others to understand sound fisheries conservation practices. (Illinois DNR, no date)
Adoption of any new fishing practice behavior does not happen simultaneously among all participants. Rather, some people are more apt to adopt the innovation than others. When promoting a new behavior, it is important to understand the target population to help or hinder adoption of the innovation. Innovators are eager to try new ideas and demonstrate their effectiveness before early adopters eventually adopt them (Figure 10.12). Later, the early majority and late majority may learn and adopt the new practice, and the last group, called the laggards, applies the practice only if it is the only remaining method. According to adoption-diffusion theory, the greatest impact in implementing innovative fishing practices will come from seeking out and educating the innovators and early adopters (Rogers and Shoemaker 1971). The Keep Fish Wet brand uses ambassadors who serve as innovators and can demonstrate the correct application of Keep Fish Wet principles so that the new behaviors become new social norms.
Question to ponder:
Can you think of “brands” that help foster social change?
10.8 Governing Conflict and Challenges
Management of recreational fishing has a strong moral dimension, while relying on scientific studies in informing responsible fishing practices. The ethical decisions deal with values, rules, duties, and virtues of relevance to both human well-being and ecosystems. Guidance on recreational fisheries recognizes that the right to fish carries with it the obligation to do so in a responsible manner so as to ensure effective conservation and management of the living aquatic resources (FAO 2012). Consequently, to govern fisheries we must engage all stakeholders and their potentially diverse views in decision making (Arlinghaus et al. 2005). Over time, if the recreational anglers form influential, conservation-conscious communities, they become a powerful force for the conservation of aquatic biodiversity. Boundary organizations can bring different people with variable backgrounds into routine contact. Examples include the Bonefish and Tarpon Trust in conserving flats habitats and fishing, Mahseer Trust supporting mahseer conservation in India, and Mongolia River Outfitters/Fish Mongolia for Taimen conservation in Mongolia (Adams et al. 2019; Brownscombe et al. 2019c; Cooke et al. 2016).
The number and catching capacity of recreational anglers globally are very substantial. Most recreational fisheries have no mechanism for limiting total fishing effort, which may result in negative effects on important fish populations and communities, in addition to traffic and congestion problems. Although some types of angling depend on group sociability (Olaussen 2010), excessive crowding at popular fishing locations, dubbed “combat fishing,” is undesirable (Figure 10.13). Crowds and conflicting actions by other anglers were two of the most significant factors influencing angler satisfaction (Tseng et al. 2009; Birdsong et al. 2021; TenHarmsel et al. 2021). Anglers seeking solitude while fishing may desire remote public lands to be physically and legally accessible. In many congested fishing locations, site improvements may help to reduce the negative effects of crowding on the fishing experience.
With increasing demands for recreational fishing, more conflicts are anticipated and should be addressed by management actions (Coleman et al. 2004; Elmer et al. 2017; Arlinghaus et al. 2019). It is not possible to maximize the quality of fishing experiences for trophy and more harvest-oriented anglers simultaneously. Similarly, it is not possible to maximize the harvest in a commercial fishery while providing quality recreational fishing. Making a choice among competing objectives requires a value judgment informed by societal preferences (Arlinghaus et al. 2019). Key questions to consider include these:
• What do stakeholders want?
• What can the target population provide?
• What can the ecosystem sustain?
The future of recreational angling depends on how well we foster sustainable use of species targeted by recreational anglers while minimizing conflicts. The challenges of maintaining sustainable recreational fishing into the future will require collaboration with multiple stakeholders and resolving multiple objectives. Collaborations are likely to enhance use of traditional ecological knowledge, leverage regional and local networks, and enhance sustainable fishing (Granek et al. 2008). People who fish develop an identity as an angler, which drives their engagement in conservation behavior and normative beliefs about responsible fishing (Mordue 2009; Landon et al. 2018). A more holistic engagement will contribute to making access to recreational fishing more equitable and responsive to changing motivations. Finally, there are many examples of interventions that have enhanced fishing satisfaction and provide for a more optimistic outlook for the future of recreational fishing (Elmer et al. 2017; Cooke et al. 2019). In the book Fishing Through the Apocalypse: An Angler’s Adventures in the 21st Century, Matthew Miller explores many nontraditional types of fishing that are changing the expectations of recreational angling.
Profiles in Fish Conservation: Sascha Clark Danylchuk and Andy Danylchuk, PhD
Sascha Clark Danylchuk and Andy J. Danylchuk might be called a power couple in the science of recreational fishing and the science of catch and release in particular. Both share a passion for fishing that drives their work and play. Sascha Clarke Danylchuk is the Executive Director of Keep Fish Wet, and Andy J. Danylchuk is Professor of Fish Conservation at the University of Massachusetts, Amherst. Both are fisheries scientists with strong credentials built upon their decades of innovative investigations that have informed the best practice for catch-and-release fishing. Together they taught themselves to fly fish and tie flies while living on a remote Caribbean island.
Sascha worked for a number of non-profit organizations before joining the Keep Fish Wet organization in 2016. As Executive Director, she works directly with anglers and conservation organizations. Keep Fish Wet promotes the use of science-based best practices to catch, handle, and release fish. Sascha says, “One of our goals is to unlock science and make it more accessible and understandable to all anglers.” Along with economic benefits that accrue from catch-and-release fishing, many anglers and organizations become influential in fish conservation. However, recreational anglers can learn much from scientists, and Keep Fish Wet helps make the science of recreational fishing accessible to a wide audience.
Andy J. Danylchuk focuses his research on many factors that influence the life history and ecology of fish and other aquatic organisms, as well as how disturbances can influence the dynamics of their populations. His work on stress physiology, behavioral ecology, spatial ecology, predator-prey interactions, and adaptations in life history traits as a response to disturbance has been often cited by other scientists. He has also collaborated with numerous stakeholder groups to develop best practices for the recreational angling community to avoid overfishing.
Both Sascha and Andy are acutely aware that many fish die due to recreational fishing, including catch-and-release fishing. Catch-and-release practice has been used a long time, but the science is very new. Sascha says, “Fishing is a blood sport.” Yet, the fate of landed fish is determined largely by angler behavior that determines the health of released fish. They both help develop and advocate for adoption of Keep Fish Wet principles and tips to reduce the number of fish that die from fishing.
The principles and tips they advocate are different from many other fishing tips in two important ways. First, the principles and tips were selected because they are backed by substantial scientific evidence. Second, the principles and tips recognize that the fate of fish after release is primarily determined by angler behavior. For example, simple advice such as avoiding fishing spawning fish, using barbless hooks, avoiding grippers, and keeping air exposure to ten seconds or less can be easily followed by anglers and will result in enhanced survival of released fish. Other advice may be more specific based on the fish and location. Sascha’s research on Bonefish demonstrated that air exposure and handling time influenced whether a landed fish will swim away after release. In The Bahamas, where there are numerous predators such as sharks and barracuda, her research guided anglers to avoid releasing Bonefish in areas where predation threat is high.
Andy Danylchuk has pioneered the use of telemetry, biologgers, accelerometers (i.e., motion detectors), underwater video cameras, and associated emerging technological aids in the study of recreational angling. He also investigated physiological disturbance of captured sharks and other fish by measuring stress indicators in blood samples. This type of research was essential to supporting the “reduce handling time” principle. Andy’s studies of movement of Bonefish led to learning the sites where spawning Bonefish aggregate.
Although many research studies on proper handling of released fish have occurred, anglers are largely unaware of the findings because they are written for other scientists and inaccessible to most anglers. Sascha has examined how best to encourage behavior change in anglers. Social media shaming does not work. Her work is done through education, outreach campaigns, partnerships with fishing industry’s biggest brands, and fishing demonstrations. Scientists talking to anglers and guides is a novel approach but directly benefits information transfer. Sascha has written a blog, Finsights for Keep Fish Wet Fishing, that translates the scientific journal articles to a form accessible to anglers. She is building a strong bridge between scientific findings and the practice of recreational angling. Keep Fish Wet recognizes that many of the best practices, such as learning how to hold a fish, take some proper on-water education and practice.
The outcome from releasing a landed fish is too often a sublethal or unrecognized effect, such as a wound from hooking or exhaustion. Recovery of the fish takes time, but the final fate is not known to the angler, and it may influence spawning success or cover-seeking behavior. Translating the scientific findings to simple memorable language, such as “minimize air exposure,” tells the angler how to treat the fish to avoid sublethal effects. In demonstrations to anglers, the Danylchuks emphasize desired behaviors, such as “no knuckles in photograph,” “no grip and grin,” “protect the slime,” and other essential actions for catch-and-release fishing.
Andy Danylchuk is a Patagonia fly-fishing ambassador where he has a direct influence on fly-fishing globally. As an award-winning professor, he is a strong proponent of experiential, hands-on opportunities that can enhance learning for students of all ages. And this philosophy extends to education of anglers. He is a scientific advisor to Keep Fish Wet and was awarded the Excellence in Public Outreach from the American Fisheries Society, a nonprofit organization whose mission is to improve the conservation and sustainability of fishery resources and aquatic ecosystems by advancing fisheries and aquatic science and promoting the development of fisheries professionals. He also received the Flats Stewardship Award and is a Member of the Circle of Honor for his significant contributions to the stewardship of flats species and habitats. He has strong collaborations with researchers globally and advised Bonefish & Tarpon Trust, Indifly Foundation, Patogonia, and Fish Navy Films, among others.
Together, Andy and Sascha have had major influence in developing and promoting the best practices for the conservation and management of recreational fisheries. Anglers can make small changes in how they catch, handle, and release fish to help fish return to normal behavior as quickly as possible after release. Advocates show their support and commitment by becoming advocates for Keep Fish Wet and pledge to use best practices for catch and release by minimizing air exposure, eliminating contact with dry surfaces, and reducing handling time. Take the pledge at https://www.keepfishwet.org.
Key Takeaways
• In inland waters, recreational fishing is often the dominant use of fish.
• Larger fish in a population are more valuable as trophies, but the big, old, fat, fecund, female fish in a population have a disproportionate effect on productivity.
• Catch-and-release fishing is a growing conservation strategy beyond the domain of fly-fishing.
• Our ability to achieve sustainable fisheries with a positive effect on environmental conservation is highly dependent on forming and promoting a conservation-minded angling culture.
• Solving problems in recreational fishing requires that we build trust in an accessible, reliable, and solution-oriented framework for changing social norms.
• Human behavior is a key source of uncertainty in recreational fisheries management.
• Keep Fish Wet principles are best practices for catch-and-release fishing that address the elements of the angling event that are most in an angler’s control.
• Technological innovations in recreational fishing have raised questions about “fair chase” and need for gear regulations.
This chapter was reviewed by Sascha Clark Danylchuk and Andy Danylchuk.
URLs
Keep Fish Wet: https://www.keepfishwet.org/
Keep Fish Wet Principles: https://www.keepfishwet.org/tips#keepemwet-tips
Long Descriptions
Figure 10.2: Catching my own food (12%); Reliving my childhood memories of going fishing (12%); Experiencing excitement/adventure (14%); Experiencing solitude (14%); The scenic beauty (16%); spending time with family or friends (29%); catching fish (31%); enjoying the sounds and smells of nature (32%); being close to nature (33%); getting away from the usual demands (34%). Jump back to Figure 10.2.
Figure 10.3: Four quadrants. Low priority: low satisfaction and low importance. Possible overkill: high satisfaction and low importance. Concentrate here: low satisfaction and high importance. Keep up the good work: high satisfaction and high importance. Jump back to Figure 10.3.
Figure 10.4: Vertical axis= number; horizontal axis= age (years); decline in number of fish and increase in weight in an unfished and fished population over time. Jump back to Figure 10.4.
Figure 10.5: Bar graph with catch per day on the x-axis and proportion of anglers on the y-axis. No daily limit and daily limit both increase as catch per day increases. Jump back to Figure 10.5.
Figure 10.6: BOFFFF: 1) more eggs; 2) outlive unfavorable environmental periods; 3) offspring grow faster and survive better; 4) spawn at different times and places than younger females. This leads to enhanced fish population productivity. Jump back to Figure 10.6.
Figure 10.7: 1) Values; values are the hardest thing to change; 2) beliefs; facts alone do not change beliefs; 3) norms; norms are more flexible; 4) actions; example actions: best practices for recreational fishing. Emotions and thinking apply here: Values and beliefs. Jump back to Figure 10.7.
Figure 10.8: 1) Capability; do I have the right skills to do this?; 2) motivation; do I like it?; 3) opportunity; what do others think of this. Arrows from each question directed to behavior. Jump back to Figure 10.8.
Figure 10.9: Steps: 1) Selection; what behavior is targeted for change?; 2) intervention; credible local peers introduce the intervention; 3) evaluation; did the intervention change the behavior? If yes, evaluation leads to 4) dissemination; inform audience through policymakers and grassroots agencies. If evaluation leads to no, arrow back to 1) selection. Jump back to Figure 10.9.
Figure 10.10: Top line connects 1) evidence; air exposure experiments show stress, gill damage, and reduced recovery time and 2) claims; minimized air exposure will enhance post-release survival. Claims leads to 1) rebuttals and 2) counter arguments. Line in between 1) evidence and 2) claims leads to 1) logic; reducing stress from air exposure will enhance survival, growth, and eventual reproduction and 2) support; theory of homeostasis, that is, a body’s need to maintain internal states such as temperature and energy levels at stable levels. Jump back to Figure 10.10.
Figure 10.11: Steps: 1) when you grab a fish by the tail does it flex its body and attempt to swim away?; 2) does the fish right itself in water when inverted? If no, fail; if yes, then release. 3) are gill coverings opening and closing at a normal rate?; 4) does the eye track normally as you roll the fish side to side? If no, fail; if yes retain with minimal handling and reassess with 2) does the fish right itself in water when inverted? Jump back to Figure 10.11.
Figure 10.12: Normal distribution showing variation from innovators (2.5%), early adopters (13.5%), early majority (34%), late majority (34%), laggards (16%) to show lag in adoption and diffusion of new behavior. Jump back to Figure 10.12.
Figure References
Figure 10.1: Two young recreational anglers using familiar spinning fishing gear. Florida Fish and Wildlife. 2012. CC BY-ND 2.0. https://flic.kr/p/bR2GSZ.
Figure 10.2: Positive attributes reported by recreational anglers in the United States. Kindred Grey. 2022. CC BY 4.0. Data from “Chasing the Thrill or Just Passing the Time? Trialing a New Mixed Methods Approach to Understanding Heterogeneity amongst Recreational Fishers Based on Motivations,” by Magee et al. 2018. https://doi.org/10.1016/j.fishres.2017.11.026.
Figure 10.3: Four quadrants of management priorities based on importance to anglers and angler satisfaction with fishing experience. Kindred Grey. 2022. CC BY 4.0.
Table 10.2: Benefits of fly-fishing and representative quotes by participants (from Craig et al. 2020). Data from “The Transformative Nature of Fly-Fishing for Veterans and Military Personnel with Posttraumatic Stress Disorder,” by Craig et al. 2020. https://doi.org/10.18666/TRJ-2020-V54-I2-9965
Figure 10.4: Theoretical comparison of number of fish in an unfished and fished age group through time. Kindred Grey. 2022. CC BY 4.0.
Figure 10.5: Frequency distribution displays the number of angler days resulting in differing catch per day for a hypothetical 8 fish per day creel limit and estimated change if creel limit is reduced to 4 fish per day. Kindred Grey. 2022. CC BY 4.0.
Figure 10.6: Hypothesized maternal effects of big, old, fat, fertile, female fish (BOFFFFs). Kindred Grey. 2022. Adapted under fair use from BOFFFFs: On the Importance of Conserving Old-Growth Age Structure in Fishery Populations, by Hixon et. al. 2014. https://sedarweb.org/documents/pw7-85-boffffs-on-the-importance-of-conserving-old-growth-age-structure-in-fishery-populations/.
Figure 10.7: Values, beliefs, norms, and action causal change of influence. Kindred Grey. 2022. CC BY 4.0.
Figure 10.8: Three questions that determine behavior intentions according to the theory of planned behavior. Kindred Grey. 2022. CC BY 4.0.
Figure 10.9: Steps in applied social marketing to change behavior of recreational anglers. Kindred Grey. 2022. Adapted under fair use from Applied Behavior Analysis and Social Marketing: An Integration for Environmental Preservation, by E. Scott Geller, 1989. https://doi.org/10.1111/j.1540-4560.1989.tb01531.x.
Figure 10.10: Structure of an argument supporting the premise that minimizing air exposure will reduce the mortality of released fish. Kindred Grey. 2022. CC BY 4.0.
Figure 10.11. Steps in determining the reflex response in order to minimize the risk of mortality of a released fish. Kindred Grey. 2022. CC BY 4.0.
Figure 10.12. Diffusion of innovations graph based on adoption-diffusion model. Kindred Grey. 2022. CC BY 4.0.
Figure 10.13: Combat fishing for king salmon near Montana Creek, Alaska. Frank Kovalchek. 2008. CC BY 2.0.
Figure 10.14: Sascha Clark Danylchuk. Used with permission from Sascha Clark Danylchuk. CC BY-ND 4.0.
Figure 10.15: Andy Danylchuk, PhD. Used with permission from Andy Danylchuk. Photo by Brian Irwin. CC BY 4.0.
Text References
Adams, A., J. S. Rehage, and S. J. Cooke. 2019. A multi-methods approach supports the effective management and conservation of coastal marine recreational flats fisheries. Environmental Biology of Fishes 102:105–115.
Ajzen, I. 2005. Attitudes, personality, and behavior. 2nd ed. Open University Press, New York.
Allen, M. S., C. J. Walters, and R. M. Myers. 2008. Temporal trends in Largemouth Bass mortality, with fisheries implications. North American Journal of Fisheries Management 28:418–427.
Anderson, D. K., R. B. Ditton, and K. M. Hunt. 2007. Measuring angler attitudes toward catch-related aspects of fishing. Human Dimensions of Wildlife 12:181–191.
Arlinghaus, R. 2005. A conceptual framework to identify and understand conflicts in recreational fisheries systems, with implications for sustainable management. Aquatic Resources, Culture and Development 1:145–174.
Arlinghaus, R., J. K. Abbottc, E. P. Fenicheld, S. R. Carpenter, L. M. Hunt, J.Alós, T.Klefothh, S. J. Cooke, R. Hilborn, O. P. Jensen, M. J. Wilberg, J. R. Post, and M. J. Manfredo. 2019. Governing the recreational dimension of global fisheries. Proceedings of the National Academy of Sciences 116:5209–5213.
Arlinghaus, R., J. Alós, B. Beardmore, K. Daedlow, M. Dorow, M. Fujitani, D. Hühn, W. Haider, L. M. Hunt, B. M. Johnson, F. Johnston, T. Klefoth, S. Matsumura, C. Monk, T. Pagel, J. R. Post, T. Rapp, C. Riepe, H. Ward, amd C. Wolter. 2017. Understanding and managing freshwater recreational fisheries as complex adaptive social-ecological systems. Reviews in Fisheries Science and Aquaculture 25:1–41. https://doi.org/10.1080/23308249.2016.1209160.
Arlinghaus, R., and S. J. Cooke. 2009. Recreational fisheries: socioeconomic importance, conservation issues and management challenges. Pages 39–58 in B. Dickson, J. Hutton, and W. M. Adams, editors, Recreational hunting, conservation and rural livelihoods: science and practice, Blackwell, Malden, MA.
Arlinghaus, R., S. J. Cooke , J. Lyman , D. Policansky, A. Schwab, C. Suski , S. G. Sutton, and E. B. Thorstad. 2007. Understanding the complexity of catch-and-release in recreational fishing: an integrative synthesis of global knowledge from historical, ethical, social, and biological perspectives. Reviews in Fisheries Science 15:75–167.
Arlinghaus, R., S. J. Cooke, A. Schwab, and I. G. Cowx. 2007. Fish welfare: a challenge to the feelings-based approach, with implications for recreational fishing. Fish and Fisheries 8:57–71.
Arlinghaus, R., and A. Schwab. 2011. Five ethical challenges to recreational fishing: what they are and what they mean. American Fisheries Society Symposium 75:219–234.
Arlinghaus, R., A. Schwab, C. Riepe, and T. Teel. 2012. A primer on anti-angling philosophy and its relevance for recreational fisheries in urbanized societies. Fisheries 37:153–164.
Arlinghaus, R., R. Tillner, and M. Bork. 2015. Explaining participation rates in recreational fishing across industrialised countries. Fisheries Management and Ecology 22:45–55.
Ballotpedia. 2022. Hunting and fishing on the ballot. Available at: https://ballotpedia.org/Hunting_and_fishing_on_the_ballot.
Bartholomew, A., and J. A. Bohnsack. 2005. A review of catch-and-release angling mortality with implications for no-take reserves. Reviews in Fish Biology and Fisheries 15:129–154.
Beard, T. D., S. P. Cox, and S. R. Carpenter. 2011. Impacts of daily bag limit reductions on angler effort in Wisconsin Walleye lakes. North American Journal of Fisheries Management 23:1283–1293.
Beardmore, B., W. Haider, L. M. Hunt, and R. Arlinghaus. 2013. Evaluating the ability of specialization indicators to explain fishing preferences. Leisure Sciences 35:273–292.
Bennett, J. L., J. A. Piatt, and M. Van Puymbroeck. 2017. Outcomes of a therapeutic fly-fishing program for veterans with combat-related disabilities: a community-based rehabilitation initiative. Community Mental Health Journal 53:756–765.
Berners, D. J. 1496. A treatyse of fysshynge with an angle. (Transcribed by Risa S. Bear, November 2002). Renascence Editions. Available at: http://www.luminarium.org/renascence-editions/berners/berners.html.
Birdsong, M., L. M. Hunt, and R. Arlinghaus. 2021. Recreational angler satisfaction: What drives it? Fish and Fisheries 22:682–706.
Boyle, R. H. 1999. Bass boss: the inspiring story of Ray Scott and the sport fishing industry he created. Whitetail Trail Press, Pintlala, AL.
Brant, C. 2019. Great Lakes Sea Lamprey: the 70 year war on a biological invader. University of Michigan Press, Ann Arbor.
Brownscombe, J. W. 2018. Fish reflex tests: a valuable tool for anglers. KeepEmWet Fishing. February 14. Website. Available at: https://www.keepfishwet.org/keepemwet-news-1/2018/2/14/fish-reflex-tests-a-valuable-tool-for-anglers.
Brownscombe, J. W., A. J. Adams, N. Young, L. P. Griffin, P. E. Holder, J. Hunt, A. Acosta, D. Morley, R. Boucek, S. J. Cooke, and A. J. Danylchuk. 2019a. Bridging the knowledge-action gap: a case of research rapidly impacting recreational fishing policy. Marine Policy 104:210–215.
Brownscombe, J. W., S. D. Bower, W. Bowden, L. Nowell, J. D. Midwood, N. Johnson, and S. J. Cooke. 2014. Canadian recreational fisheries: 35 years of social, biological, and economic dynamics from a national survey. Fisheries 39:251–260.
Brownscombe, J. W., A. J. Danylchuk, A. J. Adams, B. Black, R. Boucek, M. Power, J. S. Rehage, R. O. Santos, R. W. Fisher, B. Horn, C. R. Haak, S. Morton, J. Hunt, R. Ahrens, M. S. Allen, J. Shenker, and S. J. Cooke. 2019c. Bonefish in south Florida: status, threats and research needs. Environmental Biology of Fishes 102:329–348.
Brownscombe, J. W., A. J. Danylchuk, J. M. Chapman, L. F. Gutowsky, and S. J. Cooke. 2017. Best practices for catch-and-release recreational fisheries: angling tools and tactics. Fisheries Research 186:693–705.
Brownscombe, J. W., K. Hyder, W. Potts, K. L. Wilson, K. L. Pope, A. J. Danylchuk, S. J. Cooke, A. Clarke, R. Arlinghaus, and J. R. Post. 2019b. The future of recreational fisheries: advances in science, monitoring, management, and practice. Fisheries Research 211:247–255.
Bruskotter, J. T., and D. C. Fulton. 2013. The future of fishing: an introduction to the special issue. Human Dimensions of Wildlife 18:319–321.
Bryan, H. 1977. Leisure value systems and recreational specialization: the case of trout fishermen. Journal of Leisure Research 9:174–188.
Carpenter, S. R., and W. A. Brock. 2004. Spatial complexity, resilience, and policy diversity: fishing on lake-rich landscapes. Ecology and Society 9(1):8. https://www.jstor.org/stable/26267645.
Casting for Recovery. 2022. Casting for Recovery website. Available at: https://castingforrecovery.org.
Chiaramonte, L. V., K. A. Meyer, D. W. Whitney, and J. L. McCormick. 2018. Air exposure, fight times, and deep-hooking rates of steelhead caught in Idaho fisheries. North American Journal of Fisheries Management 38:1114–1121.
Cole, D. C., J. Kearney, L. H. Sanin, A. Leblanc, and J. P. Weber. 2004. Blood mercury levels among Ontario anglers and sport-fish eaters. Environmental Research 95:305–314.
Coleman, F. C., W. F. Figueira, J. S. Ueland, and L. B. Crowder. 2004. The impact of United States recreational fisheries on marine fish populations. Science 305:1958–1960.
Cook M. F. , T. J. Goeman, P. J. Radomski , J. A. Younk, and P. C. Jacobson. 2001. Creel limits in Minnesota: a proposal for change. Fisheries 26(5)19–26.
Cooke, S. J., and I. G. Cowx. 2004. The role of recreational fishing in global fish crises. BioScience 54:857–859.
Cooke, S. J., Z. S. Hogan, P. A. Butcher, M. J. W. Stokesbury, R. Raghavan, A. J. Gallagher, N. Hammerschlag, and A. J. Danylchuk. 2017. Angling for endangered fish: conservation problem or conservation action? Fish and Fisheries 17:249–265.
Cooke, S. J., R. J. Lennox, B. Cantrell, and A. J. Danylchuk. 2020. Micro-fishing as an emerging form of recreational angling: research gaps and policy considerations. Fisheries 45(10):517–521.
Cooke, S. J., and C. D. Suski. 2005. Do we need species-specific guidelines for catch-and-release recreational angling to effectively conserve diverse fishery resources? Biodiversity Conservation 14:1195–1209. https://doi.org/10.1007/s10531-004-7845-0.
Cooke, S. J., C. D. Suski, R. Arlinghaus, and A. J. Danylchuk. 2013. Voluntary institutions and behaviours as alternatives to formal regulations in recreational fisheries management. Fish and Fisheries 14:439–457. https://doi.org/10.1111/j.1467-2979.2012.00477.x.
Cooke, S. J., W. M. Twardek, R. J. Lennox, A. J. Zolderdo, S. D. Bower, L. F. G. Gutowsky, A. J. Danylchuk, R. Arlinghaus, and D. Beard. 2018. The nexus of fun and nutrition: recreational fishing is also about food. Fish and Fisheries 19:201–224.
Cooke, S. J., W. M. Twardek, A. J. Reid, R. J. Lennox, S. C. Danylchuk, J. W. Brownscombe, S. D. Bower, R. Arlinghaus, K. Hyder, and A. J. Danylchuk. 2019. Searching for responsible and sustainable recreational fisheries in the Anthropocene. Journal of Fish Biology 94:845–856.
Cooke, S. J., P. Venturelli, and A. J. Danylchuk. 2021. Technological innovations in the recreational fishing sector: implications for fisheries management and policy. Reviews in Fish Biology and Fisheries 31:253–288.
Craig, P. J., D. M. Alger, J. L. Bennett, and T. P. Martin. 2020. The transformative nature of fly-fishing for veterans and military personnel with posttraumatic stress disorder. Therapeutic Recreation Journal 54:150–172. https://doi.org/10.18666/TRJ-2020-V54-I2-9965.
Crandall, C. A., T. M. Garlock, and K. Lorenzen. 2018. Understanding resource-conserving behaviors among fishers: barotrauma mitigation and the power of subjective norms in Florida’s reef fisheries. North American Journal of Fisheries Management 38:271–280.
Danylchuk, A. J., and S. J. Cooke. 2011. Engaging the recreational angling community in the implementation and management of aquatic protected areas. Conservation Biology 25:458–464.
Danylchuk, A. J., S. C. Danylchuk, A. Kosiarski, S. J. Cooke, and B. Huskey. 2018. Keepemwet fishing: an emerging social brand for disseminating best practices for catch-and-release in recreational fisheries. Fisheries Research 205:52–56.
Danylchuk, S. E., A. J. Danylchuk, S. J. Cooke, T. L. Goldberg, J. Koppelman, and D. P. Philipp. 2007. Effects of recreational angling on the post-release behavior and predation of Bonefish (Albula vulpes): the role of equilibrium status at the time of release. Journal of Experimental Marine Biology and Ecology 346:127–133. https://doi.org/10.1016/j.jembe.2007.03.008.
Davis, M. W. 2010. Fish stress and mortality can be predicted from reflex impairment. Fish and Fisheries 11:1–11.
Edgar, G. J., R. D. Stuart-Smith, T. J. Willis, S. Kininmonth, S. C. Baker, and S. Banks, N. S. Barrett, M. A. Becerro, A. T. F. Bernard, J. Berkhout, C. D. Buxton, S. J. Campbell, A. T. Cooper, M. Davey, S. C. Edgar, G. Försterra, D. E. Galván, A. J. Irigoyen, D. J. Kushner, R. Moura, P. E. Parnell, N. T. Shears, G. Soler, E. M. A. Strain, and R. J. Thomson. 2014. Global conservation outcomes depend on marine protected areas with five key features. Nature 506:216–220.
Elmer, L. K., L. A. Kelly, S. Rivest, S. C. Steell, W. M. Twardek, A. J. Danylchuk, R. Arlinghaus, J. R. Bennett, and S. J. Cooke. 2017. Angling into the future: ten commandments for recreational fisheries science, management, and stewardship in a good Anthropocene. Environmental Management 60:165–175. https://doi.org/10.1007/s00267-017-0895-3.
Embke, H. S., T. D. Beard Jr., A. J. Lynch, and M. J. Vander Zanden. 2020. Fishing for food: quantifying recreational fisheries harvest in Wisconsin lakes. Fisheries 45(12):647–655. https://afspubs.onlinelibrary.wiley.com/doi/abs/10.1002/fsh.10486?campaign=wolearlyview.
Embke, H. S., A. L. Rypel, S. R. Carpenter, G. G. Sass, D. Ogle, T. Cichosz, J. Hennessy, T. E. Essington, and M. J. Vander Zanden. 2019. Production dynamics reveal hidden overharvest of inland recreational fisheries. Proceedings of the National Academy of Sciences 116(49):24676–24681. https://www.pnas.org/cgi/doi/10.1073/pnas.1913196116.
FAO. 2012. Recreational fisheries. FAO Technical Guidelines for Responsible Fisheries, no. 13. Rome, Food and Agriculture Organization of the United Nations.
Fedler, A. J., and R. B. Ditton. 2001. Dropping out and dropping in: a study of factors for changing recreational fishing participation. North American Journal of Fisheries Management 21:283–292.
Fedler, A. J., and R. B. Ditton. 1994. Understanding angler motivations in fisheries management. Fisheries 19(4):6–13.
Ferguson, R. A., and B. L. Tufts. 1992. Physiological effects of brief air exposure in exhaustively exercised Rainbow Trout (Oncorhynchus mykiss): implications for “catch and release” fisheries. Canadian Journal of Fisheries and Aquatic Sciences 49:1157–1162.
Fulton, E. A., A. D. M. Smith, D. C. Smith, and I. E. van Putten. 2010. Human behaviour: the key source of uncertainty in fisheries management. Fish and Fisheries 12:2–17.
Gallagher, A. J., N. Hammerschlag, A. J. Danylchuk, and S. J. Cooke. 2017. Shark recreational fisheries: status, challenges, and research needs. Ambio 46:385–398.
Geller, E. S. 1989. Applied behavior analysis and social marketing: an integration for environmental preservation. Journal of Social Issues 45:17–36.
Granek, E. F., E. M. P. Madin, M. A. Brown, W. Figueira, D. S. Cameron, Z. Hogan, G. Kristianson, P. de Villiers, J. E. Williams, J. Post, S. Zahn, and R. Arlinghaus. 2008. Engaging recreational fishers in management and conservation: global case studies. Conservation Biology 22:1125–1134.
Griffiths, S. P., J. Bryant, H. F. Raymond, and P. A. Newcombe. 2017. Quantifying subjective human dimensions of recreational fishing: Does good health come to those who bait? Fish and Fisheries 18: 171–184.
Gwinn, D. C., M. S. Allen, F. D. Johnston, P. Brown, C. R. Todd, and R. Arlinghaus. 2015. Rethinking length-based fisheries regulations: the value of protecting old and large fish with harvest slots. Fish and Fisheries 16:259–281.
Hansen, J. P., G. Sundblad, and J. S. Eklöf. 2019. Recreational boating degrades vegetation important for fish recruitment. Ambio 48:539–551.
Hasler, C. T., A. H. Colotelo, T. Rapp, E. Jamieson, K. Bellehumeur, R. Arlinghaus, and S. J. Cooke. 2011. Opinions of fisheries researchers, managers, and anglers towards recreational fishing issues: an exploratory analysis for North America. American Fisheries Society Symposium 75:51–74.
Henry, B. J. 2017. Quality of life and resilience. Clinical Journal of Oncology Nursing 21:E9–E14.
Hildreth, A., R. Poff, E. Knackmuhs, B. Schu, and L. Gardner. 2019. Fly fishing: one approach to assisting veterans. Kentucky SHAPE Journal 57(1):30–36.
Hixon, M. A., D. W. Johnson, and S. M. Sogard. 2014. BOFFFFs: on the importance of conserving old-growth age structure in fishery populations. ICES Journal of Marine Science 71:2171–2185.
Hunt, L. M., E. Camp, B. van Poorten, and R. Arlinghaus. 2019. Catch and non-catch-related determinants of where anglers fish: a review of three decades of site choice research in recreational fisheries. Reviews in Fisheries Science & Aquaculture 27:261–286.
Hunt, L. M., S. G. Sutton, and R. Arlinghaus. 2013. Illustrating the critical role of human dimensions research for understanding and managing recreational fisheries within a social-ecological system framework. Fisheries Management and Ecology 20:111–124.
Illinois Department of Natural Resources. No date. Illinois code of angler ethics. Available at: https://www.ifishillinois.org/catch_release/ethics.html.
Jacobson, P. C. 2005. Experimental analysis of a reduced daily bag limit in Minnesota. North American Journal of Fisheries Management 25:203–210.
Johnston, F. D., R. Arlinghaus, J. Stelfox, and J. R. Post. 2011. Decline in angler use despite increased catch rates: anglers’ response to the implementation of a total catch-and-release regulation. Fisheries Research 110:189–197.
Kemeny, B., H. Fawber, J. Finegan, and D. Marcinko. 2020. Recreational therapy: implications for life care planning. Journal of Life Care Planning 18:35–45.
Kerr S. M., T. D. Ward, R. J. Lennox, J. W. Brownscombe, J. M. Chapman, L. F. G. Gutowsky, J. M. Logan, W. M. Twardek, C. K. Elvidge, A. J. Danylchuk, and S. J. Cooke. 2017. Influence of hook type and live bait on the hooking performance of inline spinners in the context of catch-and-release Brook Trout Salvelinus fontinalis fishing in lakes. Fisheries Research 186:642–647.
Kyle, G., W. Norman, L. Jodice, A. Graefe, and A. Marsinko. 2007. Segmenting anglers using their consumptive orientation profiles. Human Dimensions of Wildlife 12:115–132.
Landon, A. C., G. T. Kyle, C. J. van Riper, M.A. Schuett, and J. Park. 2018. Exploring the psychological dimensions of stewardship in fisheries. North American Journal of Fisheries Management 38:579–591.
Landsman, S. J., H. J. Wachelka, C. D. Suski, and S. J. Cooke. 2011. Evaluation of the physiology, behavior, and survival of adult Muskellunge (Esox masquinongy) captured and released by specialized anglers. Fisheries Research 110:377–386. doi:10.1016/j.fishres.2011.05.005.
LaRochelle, L., A. D. Chhor, J. W. Brownscombe, A. J. Zolderdo, A. J. Danylchuk, and S. J. Cooke. 2021. Ice-fishing handling practices and their effects on the short-term post-release behaviour of Largemouth Bass. Fisheries Research 243:106084. https://doi.org/10.1016/j.fishres.2021.106084.
Larson, L. R., R. Szczytko, E. P. Bowers, L. E. Stephens, K. T. Stevenson, and M. F. Floyd. 2019. Outdoor time, screen time, and connection to nature: troubling trends among rural youth? Environment and Behavior 51:966–991.
Lawrence, M. J., K. M. Jeffries, S. J. Cooke, E. C. Enders, C. T. Hasler, C. M. Somers, C. D. Suski, and M. J. Louison. 2022. Catch-and-release ice fishing: status, issues, and research needs. Transactions of the American Fisheries Society DOI: 10.1002/tafs.10349.
Lennox, R. J., A. Filous, S. C. Danylchuk, S. J. Cooke, J.W. Brownscombe, A. M. Friedlander, and A. J. Danylchuk. 2017. Factors influencing postrelease predation for a catch-and-release tropical flats fishery with a high predator burden. North American Journal of Fisheries Management 37:1045–1053. https://doi.org/10.1080/02755947.2017.1336136.
Lewin, W-C., R. Arlinghaus, and T. Mehner. 2006. Documented and potential biological impacts of recreational fishing: insights for management and conservation. Reviews in Fisheries Science 14:305–367.
Mackay, M., S. Yamazaki, S. Jennings, H. Sibly, I. E. van Putten, and T. J. Emery. 2020. The influence of nudges on compliance behaviour in recreational fishing: a laboratory experiment. ICES Journal of Marine Science 77:2319–2332.
MacLean, K., T. S. Prystay, and S. J. Cooke. 2020. Going the distance: influence of distance between boat noise and nest site on the behavior of paternal Smallmouth Bass. Water, Air, & Soil Pollution 231, 151. https://doi.org/10.1007/s11270-020-04470-9.
Magee, C., M. Voyer, A. McIlgorm, and O. Li. 2018. Chasing the thrill or just passing the time? Trialing a new mixed methods approach to understanding heterogeneity amongst recreational fishers based on motivations. Fisheries Research 199:107–118.
Martilla, J. A., and J. C. James. 1977. Importance-performance analysis. Journal of Marketing 41:77–79.
McKenna, M. 2013. Five stages of a fisherman’s life. Sun Valley Magazine, March 18. Available at: https://sunvalleymag.com/five-stages-of-a-fishermans-life/.
McManus, A., W. Hunt, J. Storey, and J. White. 2011. Identifying the health and well-being benefits of recreational fishing. Report No. 2011/217, Curtin University of Technology, Centre of Excellence for Science, Seafood & Health. Available at: https://espace.curtin.edu.au/handle/20.500.11937/27359.
Meka, J. M., and S. D. McCormick. 2005. Physiological response of wild Rainbow Trout to angling: impact of angling duration, fish size, body condition, and temperature. Fisheries Research 72: 311–322.
Mordue, T. 2009. Angling in modernity: a tour through society, nature and embodied passion. Current Issues in Tourism 12:529–552.
Mueller, G. 1980. Effects of recreational river traffic on nest defense by Longear Sunfish. Transactions of the American Fisheries Society 109:248–251.
Muir, R., A. J. Keown, N. J. Adams, and M. J. Farnworth. 2013. Attitudes towards catch-and-release recreational angling, angling practices and perceptions of pain and welfare in fish in New Zealand. Animal Welfare 22(3):323–329. https://doi.org/10.7120/09627286.22.3.323.
Myers, R. M., J. B. Taylor, M. S. Allen, and T. F. Bonvechio. 2008. Temporal trends in voluntary release of Largemouth Bass. North American Journal of Fisheries Management 28:428–433.
Olausen, M., and W. E. Block. 2014. Privatizing recreational fisheries. Economics, Management, and Financial Markets 9:18–28.
Olaussen, J. O. 2010. Bandwagon or snob anglers? Evidence from Atlantic Salmon recreational fishing. Marine Resources Economics 24:387–403.
Parmenter, A. 2022. Treating combat-related posttraumatic stress disorder using therapeutic fly-fishing with EMDR (TF-EMDR). Journal of Military and Veteran’s Health 30:24–30.
Post, J. R. 2013. Resilient recreational fisheries or prone to collapse? A decade of research on the science and management of recreational fisheries. Fisheries Management and Ecology 20:99–110.
Post, J. R., M. Sullivan, S. Cox, N. P. Lester, C. J. Walters, E. A. Parkinson, A. J. Paul, L. Jackson, and B. J. Shuter. 2002. Canada’s recreational fisheries: the invisible collapse? Fisheries 27(1):6–17.
Press, K. M., J. Mandelman, E. Burgess, S. J. Cooke, V. M. Nguyen, and A. J. Danychuk. 2016. Catching sharks: recreational saltwater angler behaviours and attitudes regarding shark encounters and conservation. Aquatic Conservation: Marine and Freshwater Ecosystems 26:689–702.
Prince, E. D., M. Ortiz, and A. Venizelos. 2002. A comparison of circle hook and “J” hook performance in recreational catch-and-release fisheries for billfish. American Fisheries Society Symposium 30 66–79.
Raby, G. D., M. R. Donaldson, S. G. Hinch, D. A. Patterson, A. G. Lotto, D. Robichaud, K. K. English, W. G. Willmore, A. P. Farrell, M. W. Davis, and S. J. Cooke. 2012. Validation of reflex indicators for measuring vitality and predicting the delayed mortality of wild Coho Salmon bycatch released from fishing gears. Journal of Applied Ecology 49:90–98.
Raby, G. D., J. R. Packer, A. J. Danylchuk, and S. J. Cooke. 2014. The understudied and underappreciated role of predation in the mortality of fish released from fishing gears. Fish and Fisheries 15: 489–505.
Radomski, P. J., G. C. Grant, P. C. Jacobson, and M. F. Cook. 2001. Visions for recreational fishing regulations. Fisheries 26(5):7–18.
Recreational Fishing and Boating Foundation (RFBF). 2021. 2021 Special report on fishing. RFBF, Alexandria, VA. Available at: https://www.takemefishing.org/getmedia/5a424cb3-c67a-4f27-a24d-db143f84d896/2021-Special-Report-on-Fishing_WEB.pdf.
Reeves, A. 2019. Overrun: dispatches from the Asian carp crisis. ECW Press, Toronto.
Roberts, B. C., and R. G. White. 1992. Effects of angler wading on survival of trout eggs and pre-emergent fry. North American Journal of Fisheries Management 12:450–459.
Rogers, E. M., and F. F. Shoemaker. 1971. Communication of innovations: a cross-cultural approach. Free Press, New York.
Rypel, A. L. 2015. Effects of a reduced daily bag limit on Bluegill size structure in Wisconsin lakes. North American Journal of Fisheries Management 35:388–397. https://doi.org/10.1080/02755947.2014.1001929.
Rypel, A. J., J. Lyons, J. D. T. Griffin, and T. D. Simonson. 2016. Seventy-year retrospective on size structure changes in the recreational fisheries of Wisconsin. Fisheries 41(5):230–243.
Safina, C. 2011. The view from Lazy Point: a natural year in an unnatural world. Henry Holt, New York.
Salz, R. J., and D. K. Loomis. 2004. Saltwater anglers’ attitudes towards marine protected areas. Fisheries 29:10–17.
Samson, J. 1995. Lee Wulff. Frank Amato, Sante Fe, NM.
Sass, G. G., and S. L. Shaw. 2020. Catch-and-release influences on inland recreational fisheries. Reviews in Fisheries Science & Aquaculture. 27:211-227. DOI: 10.1080/23308249.2019.1701407
Sauls, B., and O. Ayala. 2012. Circle hook requirements in the Gulf of Mexico: application in recreational fisheries and effectiveness for conservation of reef fishes. Bulletin of Marine Science 88:667–679.
Schramm, H. L., and P. D. Gerard. 2004. Temporal changes in fishing motivation among fishing club anglers in the United States. Fisheries Management and Ecology 11:313–321.
Schratwieser, J. 2015. A rejoinder to Shiffman et al., Trophy fishing for species threatened with extinction: a way forward building on a history of conservation. Marine Policy 53:5–6.
Schuhmann, P. W., and K. A. Schwabe. 2004. An analysis of congestion measures and heterogeneous angler preferences in a random utility model of recreational fishing. Environmental and Resource Economics 27:429–450.
Shaw, S. L., K. M. Renik, and G. G. Sass. 2021. Angler and environmental influences on Walleye Sander vitreus and Muskellunge Esox masquinongy angler catch in Escanaba Lake, Wisconsin, 2003–2015. PLoS ONE 16(9):e0257882. https://doi.org/10.1371/journal.pone.0257882.
Shelby, B., and J. J. Vaske. 1991. Resource and activity substitutes for recreational salmon fishing in New Zealand. Leisure Science 13:21–32.
Shiffman, D. S., A. J. Gallagher, J. Wester, C. C. Macdonald, A. D. Thaler, S. J. Cooke, and N. Hammerschlag. 2014. Trophy fishing for species threatened with extinction: a way forward building on a history of conservation. Marine Policy 50:318–322.
Siepker, M. J., K. G. Ostrand, S. J. Cooke, D. P. Philipp, and D. H. Wahl. 2007. A review of the effects of catch-and-release angling on black bass, Micropterus spp.: implications for conservation and management of populations. Fisheries Management and Ecology 14:91–101.
Simonson, T. D., and S. W. Hewett. 1999. Trends in Wisconsin’s Muskellunge fishery. North American Journal of Fisheries Management 19:291–299.
Snow, H. E. 1978. A 15-year study of the harvest, exploitation, and mortality of fishes in Murphy Flowage, Wisconsin. Department of Natural Resources, Technical Bulletin 103, Madison.
Sovacool, B., and D. J. Hess. 2017. Ordering theories: typologies and conceptual frameworks for sociotechnical change. Social Studies of Science 47(5):703–750.
Spencer, P. D., and G. R. Spangler. 1992. Effect that providing fishing information has on angler expectations and satisfactions. North American Journal of Fisheries Management 12:379–385.
Staggs, M. 1989. Walleye angling in the ceded territory, Wisconsin, 1980–87. Bureau of Fisheries Management, Department of Natural Resources, Fish Management Report 144, Madison.
Statista. 2022. Recreational fishing in the U.S.: statistics & facts. Available at: https://www.statista.com/topics/1163/recreational-fishing/.
Stensland, S., Ø. Aas, and M. Mehmetoglu. 2013. The influence of norms and consequences on voluntary catch and release angling behavior. Human Dimensions of Wildlife 18:373–385.
Suski, C. D., and D. P. Philipp. 2004. Factors affecting the vulnerability of angling to nesting male Largemouth and Smallmouth Bass. Transactions of the American Fisheries Society 133:1100–1106.
Sutter, D. A. H., C. D. Suski, D. P. Philipp, T. Klefoth, D. H. Wahl, P. Kersten, S. J. Cooke, and R. Arlinghaus. 2012. Recreational fishing selectively captures individuals with the highest fitness potential. Proceedings of the National Academy of Sciences 109(51):20960–20965. doi:10.1073/pnas.1212536109.
Sutton, S. G., and R. B. Ditton. 2005. The substitutability of one type of fishing for another. North American Journal of Fisheries Management 25:536–546.
Sutton, S. G., and C-O. Oh. 2015. How do recreationists make activity substitution decisions? A case of recreational fishing. Leisure Sciences 37:332–353.
Tanner, H. A. 2019. Something spectacular: my Great Lakes salmon story. Michigan State University Press, East Lansing.
TenHarmsel, H. J., B. B. Boley, B. J. Irwin, and C. A. Jennings. 2019. An importance-satisfaction analysis of trout license holders in Georgia. North American Journal of Fisheries Management 39:1227–1241.
TenHarmsel, H. J., B. B. Boley, B. J. Irwin, and C. A. Jennings. 2021. Perceived constraints and negotiations to trout fishing in Georgia based on angler specialization level. North American Journal of Fisheries Management 41:115–129.
Thaler, R. H., and C. R. Sunstein. 2021. Nudge: the final edition. Penguin Books, New York.
Thomas A. S., T. L. Milfont, and M. C. Gavin. 2016. New approach to identifying the drivers of regulation compliance using multivariate behavioural models. PLoS One 11:1–12.
Trahan, A., A. D. Chhor, L. LaRochelle, A. J. Danychuk, and S. J. Cooke. 2021. Influence of artificial lure hook type on hooking characteristics, handling, and injury of angled freshwater gamefish. Fisheries Research 243:106056. https://doi.org/10.1016/j.fishres.2021.106056.
Tseng, Y-P., G. T. Kyle, and M. A. Schuett. 2009. Exploring the crowding-satisfaction relationship in recreational boating. Environmental Management 43:496.
Tufts, B. L., J. Holden, and M. DeMille. 2015. Benefits arising from sustainable use of North America’s fishery resources: economic and conservation impacts of recreational angling. International Journal of Environmental Studies 72:850–868.
Vaughan, W. J., and C. S. Russell. 1982. Freshwater recreational fishing: the national benefits of water pollution control. Routledge, London.
Wagner, B. K., and D. J. Orth. 1991. Use of the negative binomial distribution to characterize angler harvest in Smallmouth Bass fisheries. Pages 121–125 in D. C. Jackson, editor, First International Smallmouth Bass Symposium, American Fisheries Society.
Wallmo, K. ,and B. Gentner. 2011. Catch-and-release fishing: a comparison of intended and actual behaviour of marine anglers. North American Journal of Fisheries Management 28:1459–1471.
Ward, H. G. M., M. S. Quinn, and J. R. Post. 2013. Angler characteristics and management implications in a large, multistock, spatially structured recreational fishery. North American Journal of Fisheries Management 33:576–584.
Weston, C. 2016. Casting for recovery. Cancer Nursing Practice 15(10):14.
Westphal, L. M., M. Longoni, C. L. LeBlanc, and A. Wali. 2008. Anglers’ appraisals of the risks of eating sport-caught fish from industrial areas: lessons from Chicago’s Calumet region. Human Ecology Review 15:46.
World Bank. 2012. Hidden harvest: the global contribution of capture fisheries. Washington, D.C., World Bank. License: CC BY 3.0 IGO. Available at: https://openknowledge.worldbank.org/handle/10986/11873.
Young, M. A. L, S. Foale, and D. R. Bellwood. 2016. Why do fishers fish? A cross-cultural examination of the motivations for fishing. Marine Policy 66:114–123. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.10%3A_Recreational_Fishing_and_Keep_Fish_Wet.txt |
Learning Objectives
• Investigate the significance of Arapaima fishing in the Amazon.
• Examine the role of the Arapaima, one of largest freshwater fish of the world, as an example of a flagship species.
• Appreciate the cultural significance of the Arapaima.
• Explain how we detect overfishing.
• Explain the benefits and successful application of principles for sustainable governance of common property resources.
• Explore gender differences in Arapaima fisheries.
11.1 People and Fish of Amazonia
The settlement of the Amazon region is a story of many people and their relationship with the rain forest and its resources. Fish were a dominant part of the diets of indigenous people. The Amazon River basin, also known as Amazonia, is one of the world’s largest river systems, with approximately 12 times the volume of water carried by the Mississippi River. At its mouth, one cannot see across the Amazon from one bank to the other. The Amazonia region, which includes the Amazon, Orinoco, and rivers of Guyana, has the richest freshwater fish fauna in the world! Amazonia is a cradle of biodiversity, with over 3,000 fish species and likely many more yet to be discovered. For example, more than 100 new fish species were described between 2017 and 2019 (Jézéquel et al. 2020). The fish fauna in parts of the Amazon basin is still in a relatively good state of conservation (Reis et al. 2016), and fish provide for many ecosystem services, such as nutrient cycling, grazing, seed dispersal, and essential nutrition and livelihoods for many people of Amazonia. Sustainable fisheries are essential for the food security of people of this region, and unsustainable land and water use practices threaten this important hot spot for fish conservation (Pelicice et al. 2017).
The first humans to migrate across the land bridge from Siberia to Alaska during the Pleistocene (at least 16,500 years ago) settled in western North America. By the late Pleistocene and early Holocene (~12,000 years ago), humans had migrated from North and Central America to South America, likely via the Isthmus of Panama (Hester 1966). Early humans likely domesticated manioc, maize, squash, and beans in addition to hunting, fishing, and gathering (Lombardo et al. 2020). By the time that explorers from Portugal discovered present-day Brazil in 1500, there were hundreds of native tribes inhabiting the region. Some experts speculate that there may have been 15 million Amerindians in the basin before Europeans arrived (Smith 1999). Fish were important wild food, as revealed by bones of many fish species, including small characiforms, catfish, and Arapaima, at archeological sites from 11,200 to 8,000 years ago (Roosevelt 1999).
Portuguese colonists bartered with the native peoples and developed a profitable export trade for brazilwood and other commodities. However, tensions soon developed, and the Portuguese colonists turned to violent confrontations with indigenous tribes. The custom of native peoples of frequently moving villages to prevent damage to local flora and fauna conflicted with the European system of private ownership and permanent settlements. Indigenous people explored the many rivers and developed villages, passing on specialized local knowledge of fishing and other essential products from the rivers, lakes, and forests. The Native Amazonian people love and live successfully in rain forest communities. However, violence and exposure to novel diseases, such as smallpox, led to gradual replacement of indigenous people with colonists from Europe and Africa in the 17th century. Land surrounding large human settlements became highly modified due to logging, livestock grazing, and commercial agriculture.
Indigenous peoples of the Amazonian floodplains are themselves a diverse group, called ribeirinho, or river settlers. Ribeirinhos live alongside the Amazonian floodplains and have intimate knowledge about the river and forest resources upon which their livelihoods depend (Moran 1993). Indigenous people settled in the flooded forest ecosystem, where they continue to live today with little advanced technology and live largely on cassava manioc (to derive flour, tapioca, and bread), wild fish, bush meat, and pequi fruit (Dufour et al. 2016; Schor and Azenha 2017). All indigenous groups recognize many wild plants and animals, their relations to soil quality, and their useful properties. Increasingly via cash trading, they also purchase canned goods, frozen chicken, dairy, and other refrigerated foods.
Today, the people of Amazonia include indigenous peoples and colonists, each with differing cultures. Modern Brazilians descend from Portuguese colonists, African enslaved people, intermarriage of both races with indigenous peoples, and recent immigration by other Europeans and Asians (Hemming 2020). Colonists cleared the floodplains for farming and engaged in slash-and-burn tactics for profit-driven cattle grazing or soy plantations; hence it is difficult for each group to understand the other. Historically, the indigenous people have suffered genocide, violence, and exploitation of their lands for mining, cattle ranching, logging, hunting, and big agriculture.
Brazil was ruled by a Portuguese monarchy for more than three hundred years before becoming independent in 1822. Millions of enslaved people were imported to work on coffee plantations, until slavery was outlawed in 1888. When Brazil began democratic rule in 1985, groups fought to get rights for indigenous people. Brazil’s constitution (1988) (1) declared that indigenous people were descendants of original Brazilians and hence owned lands, and (2) guaranteed respect for their way of life and provided exclusive use of the goods and resources on indigenous lands. Today every forest tribe has its land protected (Hemming 2020).
Approximately 89% of the population of Brazil now resides in urban areas, and strong rural-to-urban migration continues. Children of rural migrants are exposed to different food options in urban areas, leading to reduced fish consumption. Fishing pressure is focused on few species (Bayley and Petrere 1989), and overfishing is driven by the demand for fish from urban settlements (Tregidgo et al. 2017). Agriculture production has grown dramatically in Brazil, resulting in clear-cutting of mature forest to plant grains and raise beef cattle (Nepstad et al. 2014). Deforestation is only one of many threats to the Amazon region. Other threats to fisheries include overfishing, nonnative species, aquaculture, pollution, water diversions, habitat loss, mining, and poor management.
Fisheries, river and lake ecosystems, and wetlands of Amazonia support many regional economies and livelihoods of traditional and indigenous communities (Goulding 1996). Most fishing in rural communities is for subsistence to feed families, and only the surplus is sold. Fish are still the cheapest and most important source of animal protein in the central Amazon. Per capita fish consumption is high in the Brazilian Amazon, at 5.8 times the world average for riverine dwellers and 2.5 times the world average for urban dwellers (Isaac and Almeida 2011).
Subsistence fisheries are a large economic activity and livelihood component of rural communities. Globally, small-scale fisheries contribute to food security and employ 32 million fishers (World Bank 2012). However, fisheries management agencies collect incomplete statistics because small-scale fisheries tend to be physically remote and agencies lack sufficient human and financial resources (Berkes et al. 2001). Arapaima fishing illustrates how innovative approaches to fisheries governance may lead to recovery of overfished populations and alleviate poverty without major government intervention.
11.2 Arapaima: An Example Freshwater Megafauna and Flagship Symbol
Arapaima (pronounced “air-ah-pie-ma”) is one of the most acclaimed fishery resources of the Amazon region and has considerable socioeconomic importance. In Brazil and Colombia, they are called Pirarucu, a Portuguese name meaning red fish. Arapaima are called Paiche in Peru, Ecuador, Venezuela, and Bolivia, and sometimes simply Giant Arapaima. Its large size (up to 3+ meters and >200 kg) and the high quality of its flesh make it one of the most historically important and overexploited fisheries in South America. The people of Guyana call Arapaima Oma, or the “mother of all fish,” which serves as a local taboo against harvest.
Arapaima is an important flagship genus for flooded forest ecosystem and human floodplain communities. Flagship taxa are used as a symbol to promote conservation awareness (Caro 2010). Their large size makes them a true freshwater megafauna like crocodiles, river dolphins, and other large fish. Freshwater megafauna face many threats, and 71% of these species are in decline (He et al. 2017, 2018). Arapaima continue to face intense fishing throughout their range (Watson et al. 2021). However, freshwater megafauna like the Arapaima have fewer conservation resources and efforts than marine or terrestrial megafaunas.
Fishing, in general, and fishing for Arapaima in particular, is a central element of the local economy and culture in Amazonia. Because these fish are obligate breathers, they are traditionally harvested by fishers using harpoons at the time when they surface to breathe. Men typically fish from canoes and search for signs of Arapaima near the surface. As they near the Arapaima, the harpooner throws the harpoon by hand. This is a specialized type of fishing, and the local fishers possess knowledge of the behavior that increases their likelihood of catching one. With appropriate training, fishers’ participation in management processes can contribute to the conservation and governance of these small-scale fisheries.
Many populations of Arapaima have been driven to local extinction due to overfishing (Castello et al. 2015a; Gurdak 2019a; Watson et al. 2021; Freitas and Sousa 2021). Much of the catch is illegal, with most specimens being caught below the minimum size limit or during the closed season (Cavole et al. 2015). The small-scale fishers are geographically dispersed, and governments in these regions have insufficient resources to devote to enforcing fishing rules. The riverine fishers who target Arapaima are marginalized and have limited formal education. Yet, compliance with regulations is essential to prevent overfishing and local extinction.
Arapaima represent only a small fraction of the fisheries harvest, but they are culturally important and symbolic as a flagship genus of tropical South American fisheries and floodplain management and conservation. Reducing the threats to Arapaima will also provide protections for many of the highly migratory fish of the Amazon basin. Collectively, the migratory fish contribute most of the fishery’s landings in the basin (Duponchelle et al. 2021). Migratory fish depend on multiple, distant, but interconnected habitats during their life cycle. Any threat to one of the habitats or the corridor that connects them can influence these important food fish (Goulding et al. 2019).
11.3 Habits, Habitat, and Life History of Arapaima
Arapaima live in floodplain lakes that experience seasonal variation in water levels, ranging from 4 to 15 meters. The floodplain along the sediment-rich waters of the Amazon basin consists of seasonally inundated rain forests, lakes, and winding channels. The seasonal flood pulse creates a new and expanding littoral zone that moves with the rising waters. Seasonal flood pulses provide new nutrient, detritus, and sediment inputs from the main river channel and drive the high productivity of numerous prey fish of the Arapaima (Watson et al. 2013; Castello et al. 2015b; Carvalho et al. 2018). Arapaima are more abundant in deeper and larger lakes with more space and food (Arantes et al., 2013; Campos-Silva and Peres, 2016). Juvenile Arapaima in particular benefit from lakes with large littoral zones that move with rising water (Castello et al. 2019).
Large Arapaima are the ultimate ambush predators. They belong to a group of primitive bony fish known as bonytongue fish, because their tongues are used to crush prey against the roofs of their mouths. Smaller Arapaima are generalist feeders, consuming a variety of invertebrates, such as the Amazon River prawns, mayflies, and crickets, while larger Arapaima can consume larger prey, often catfish, cichlids, hatchetfish, and pacu (Watson et al. 2013; Carvalho et al. 2018; Jacobi et al. 2020). During low water periods, many isolated lakes can become hypoxic (i.e., low in oxygen). The air-breathing habit permits Arapaima to survive in such environments and prey on fish stressed by low oxygen.
In addition to overfishing of Arapaima, many of its essential habitats are modified by deforestation, dams, pollution, and logging in nearby wetlands (Figure 11.3; Castello et al. 2013b; Castello and Macedo 2016; Pelicice et al 2017; Gurdak et al. 2019a). Because freshwater ecosystems are highly sensitive to human activities on water and on land, these growing impacts are currently a major constraint to conservation (Pelicice and Castello 2021). Human influences cause a complex chain of effects that alter the hydrology, water chemistry, and food webs of Amazon floodplain rivers. Current government policies, guided by short-term economic profits, ignore the scientific evidence of environmental degradation and threaten efforts to conserve and protect aquatic ecosystems and the many fishes that depend on them.
The life cycle of Arapaima is synchronized with the seasonal flooding cycle and consists of four main stages: (1) nest-bound embryo and sac fry, (2) adult-protected, schooling juveniles, (3) independent juveniles, and (4) reproductive adults (Figure 11.4). Although the Arapaima are among the largest freshwater fish in the world, their lifespan is only about 20 years. They attain reproductive maturity when they approach 150 cm in total length (TL) or age three or four. Size at reproductive maturity varies between 139 cm in the lower Amazon to 207 cm in the upper Amazon in Peru (Gurdak et al. 2019b). Arapaima migrate at the start of the rainy season in response to rising water levels and build nests in shallow, soft, sandy or muddy areas, usually under woody vegetation. Clearing a nest site likely serves to limit small predatory fish from eating eggs and larvae. Eggs are deposited in the nest by the female and fertilized by the male, and developing embryos are guarded by both parents. For such a large fish, fecundity is relatively low, with about 10,000 to 20,000 mature oocytes for an 80 kg female. However, the eggs are large (~2.5–3 mm) and hatch in about seven days to become sac fry.
The small fry are a dark color and stay near the parental male Arapaima’s head. The male’s head turns dark to help hide the fry. Males release a pheromone that attracts his offspring and keeps them close by as he guides his offspring into zooplankton-rich areas for feeding. The substance is referred to by local people as “Arapaima milk,” which may provide nutrition to young Arapaima as well as provide a means of chemical communications (Torati et al. 2017). Both parents continue to guard the juveniles as they school in search of food, but the female normally leaves after about one month, while the male stays with his offspring for up to three months. Juveniles are often preyed upon by other species of fish, particularly the abundant cichlid fish, such as the piranhas and Peacock Bass (Cichla or tucunaré).
Growth is fast, and juveniles disperse and live independent of parents at about 50 cm total length. In the central Amazon, Arapaima may grow to 30 cm TL in 3 months and 88 cm and 20kg in a year (Figure 11.5; Arantes et al. 2010), which may be the fastest juvenile growth of any fish (Schwenke and Buckel 2008; Sakaris et al. 2019). Growth is faster in the dry season, as more prey are concentrated. As adults, Arapaima have few natural predators because of their tough layer of scales. Only the rain forest caiman is known to prey on adults. Arapaima scales are among the toughest biological materials in nature, and they protect them from the abundant piranha (Sherman et al. 2017; Yang et al. 2019).
11.4 Biogeography and Conservation Status of Arapaima
Arapaima gigas is the most well researched species of Arapaima. Ichthyologist Albert Günther (1868) declared with no rationale that it was the only valid species, a view that persisted for over 100 years only because scientists never questioned his claim. However, as many as three other species of Arapaima have been recently named in Brazil, Peru, and Guyana (Stewart 2013a, 2013b). The most recent was Arapaima leptosoma, found in the Solimões River in Brazil. Arapaima mapae comes from the Lago do Amapá in Brazil, from which it takes its scientific name. Arapaima agassizii was named after famous biologist Louis Agassiz. Although these four Arapaima species were described in the 1800s, it was their different characteristics that have allowed Donald J. Stewart to classify them separately in his recent work. Although there is still no consensus on Arapaima taxonomy (Farias et al. 2019), ongoing studies indicate that there may be up to six valid species. Donald J. Stewart admonishes other scientists to “Beware of conventional wisdom—what we know might be completely wrong” (Stewart 2013a).
Available evidence indicates that Arapaima populations are likely decreasing in the entire Amazon basin (Castello and Stewart 2010). Where data do exist, there is a preponderance of juveniles, indicative of overfishing. Current distributions of the species cannot be accurately mapped due to uncertainty on the taxonomy and geographical distribution. However, the findings to date highlight the urgent need for caution in translocations of individuals. Conservation status is determined based on levels of reduction in population size, geographic range occupied, and number of populations. The Brazilian Environment Institute (IBAMA) classified Arapaima gigas as an overfished species or a species threatened with overfishing (Nogueira et al. 2020). Arapaima gigas was listed on the CITES Appendix II since 1975. Species listed in CITES Appendix II may be exported only after a nondetriment finding is affirmed. However, data are deficient for status assessment on most wild Arapaima populations. Populations from Guyana were classified as “near threatened” (Watson et al. (2021). Different species and different populations of Arapaima exhibit key life-history and ecological differences that may be relevant to their conservation (Watson et al. 2016; Watson and Stewart 2020). Two other species, Arapaima agassizii and Arapaima leptosoma, are recognized by the Brazilian Red List as “Data Deficient.” Given the taxonomic uncertainties, fisheries management in this region currently refers to Arapaima only at the genus level (Arantes et al. 2021).
11.5 Vulnerability to Overfishing
Several characteristics of Arapaima make them highly vulnerable to overfishing. First, they are obligate air breathers and typically must surface every 5–15 minutes to gulp air; this makes them easy to locate. Second, the high-quality, boneless flesh is highly sought, making Arapaima a popular commercial food fish. Third, their skin can be used in the manufacturing of shoes, bags and clothing, and its scales and tongue are used in the manufacturing of nail files and ornaments. One hundred years ago, Arapaima dominated fisheries in the Amazon. Unregulated fishing with gill nets led to overfishing and many local extinctions, leading to a ban on fishing for Arapaima in 1986. Yet, gill nets are still used in the Amazon to capture other small fish and inadvertently capture juvenile Arapaima.
Characteristics of Arapaima that make them vulnerable to overfishing:
• Obligate air breathers
• High-quality flesh
• Skin and bones used in products
To protect rich native biodiversity in the Amazon, biological reserves were established. The largest is the Mamirauá Ecological Reserve, one-third of which is in flooded forest. This reserve is approximately half the area of New Jersey. The thrust of this reserve is the integration of local people into reserve management. In biological reserves, agreements guarantee indigenous fishers the exclusive right to fish (or to hunt) Arapaima but only with harpoons. Harpoons provide an efficient catch method for targeting Arapaima. The harpooners, referred to as laguistas, are specialists in handling harpoons and are familiar with the habits of the Arapaima (Sautchuk 2012). Searching for Arapaima involves catching the fish unaware, to facilitate approach and, ultimately, harpooning. Experienced fishers have an extraordinary ability to detect very subtle visual and acoustic information from surfacing Arapaima (Castello 2004).
Where management is weak or nonexistent and multiple fishers compete to catch fish, the large individuals are rapidly removed from the population and catch rates are barely sufficient to cover the costs of fishing, and fishers seek other areas. Remoteness of the fishing communities means that government presence and enforcement of regulations are lacking. Monitoring landings is practically impossible because of the decentralized and illegal nature of the trade. One survey from 81 fishing communities indicated that the local Arapaima stocks are depleted in 76% of the communities and overfished in 17% (Castello et al. 2015a). Only 5% were well managed and only 2% were unfished. Illegal fishing is still the principal threat to Arapaima populations (Castello and Stewart 2010; Cavole et al. 2015; Faria et al. 2018).
In many areas, Arapaima are poached before they are able to mature and spawn; in some populations, 80–90% are killed long before they mature (Figure 11.6). A fishery that includes many small, immature fish in the catch is subject to growth overfishing, where the fish are removed well before they reach sexual maturity and their full growth potential. The result is size and age truncation, which is prevalent and often severe in exploited fish populations (Barnett et al. 2017).
Old fish have disproportionate effects on population growth, and scientists are beginning to recognize the benefits of big, old, fat, fertile, female fish in the population (BOFFFF; Hixon et al. 2014). Removal of too many immature fish reduces the number of BOFFFFs so that replenishment potential is restricted. Larger Arapaima are likely more effective at producing more offspring and protecting young from many predators.
Question to ponder
What characteristics of the Arapaima make them particularly vulnerable to overfishing? How might you develop a monitoring program to determine if overfishing is occurring for Arapaima?
The principle regulatory measures for Arapaima have been closed fishing season during the high-water spawning seasons (December 1 to May 31) and a 1.5-meter minimum length limit. Arapaima gigas is coveted in the leather fashion industry for their unique skin pattern, and the leather trade has increased in recent decades (Figure 11.7). CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments to ensure that international trade in specimens of wild animals and plants does not threaten their survival. In the United States, legal and illegal trade of Arapaima is monitored using Law Enforcement Management Information System (LEMIS) data from the U.S. Fish and Wildlife Service (USFWS). Legal harvest of Arapaima must be conducted with a specific management plan, and their international commercialization is also under control. In Brazil, Arapaima leather yields higher prices per unit on international markets than Arapaima meat, and the leather products are more likely to get exported. Arapaima leather trade has increased in recent decades as a substitute for decline in leather from pangolin, the most heavily trafficked wild mammal (Heinrich et al. 2019).
Exports of Arapaima are only allowed if they are either wild caught from management areas or captive bred (Sinovas et al. 2017). However, a recent study from Brazil revealed that almost 80% of Arapaima landings were illegal (Cavole et al. 2015), which was observed to be the highest level of illegal fishing activity reported in the literature. Trade in Arapaima is still new and changing, and future trends and effects on populations need further study.
11.6 Incorporating Fishers in the Management of Arapaima Fishing in the Amazon
Small-scale fisheries are often poorly managed, yet they employ most of the world’s 51 million fishers, produce about half of the global reported catch, and provide food, income, and livelihood to about 1 billion people. Hardin’s “Tragedy of the Commons” argued that without government regulations or private ownership, overharvest of common property resources was inevitable. Federal governments own the fishery resources of the Amazon and, therefore, are responsible for setting rules that govern fish harvest. In Brazil, resource management is done by the Brazilian Institute of the Environment. Policies of this agency are based on a scientific management model in which government technocrats and field agents design, implement, and enforce fisheries management regulations. Consequently, fishing agreements made by local communities were initially thought to have no legal validity because communities had no right to regulate local fisheries (McGrath et al. 2015).
“Common property” refers to the right to use something in common with others. However, after collapse of major fisheries, some planners began to lose faith in government regulation of fishing. As an alternative, Elinor Ostrom in Governing the Commons (1990) advocated for community-based management (or comanagement) approaches to manage the common property resources. Community-based management has the potential to overcome the tragedy of the commons. One flaw in the tragedy of the commons idea is that it ignores the social relations that characterize fishers throughout the world. Fishers are subject to social pressures that shape their behavior. Therefore, efforts to reduce illegal fishing should focus on establishing and enforcing sanctions for fishers who violate rules and regulations.
Top-down policies, often referred to as Decide-Announce-Defend (DAD), as noted earlier, too often lead to abandoned or ineffective policies. The DAD method is not suited for fisheries where a wide range of technical, social, cultural, and economic factors are influencing the fishing status and alternatives. Implementation of regulations involves a lot of people, and most are not in an obvious command structure (Prince 2003; Walker 2009). The alternative participatory approach is Engage-Deliberate-Decide (EDD). Here the fishers choose whether to cooperate in a process to deliberate among alternative management interventions. Traditional knowledge held by the fishers may play important roles in creating alternative approaches. The approach is sometimes referred to as “two-eyed seeing” (Reid et al. 2021). An early proponent of two-eyed seeing, Dr. Albert Marshall, describes two-eyed seeing as “learning to see from one eye with the strengths of Indigenous knowledges and ways of knowing, and from the other eye with the strengths of mainstream knowledges and ways of knowing, and to use both these eyes together, for the benefit of all.” Whether or not comanagement regimes will prevent the tragedy of the commons depends on strong commitment from leadership to work with local stakeholders to develop and enforce quotas (Gutiérrez et al. 2011; McGrath et al. 2015; Campos-Silva et al. 2017).
Two-Eyed Seeing
“Two-eyed seeing” means that we will be learning to see from one eye with the strengths from indigenous knowledge and indigenous ways of knowing, while the other eye is using mainstream knowledge or Western ways of knowing. We use both of these ways of knowing (i.e., eyes) simultaneously. Hopefully, we’re learning more in this way. With indigenous people, the knowledge is all about transforming the holder of that knowledge. And then that holder will bear a responsibility to act on knowledge. It’s not a Western approach to knowledge where the knowledge is just put in a book for others to find. However, knowledge is there to be acted upon. Indigenous ways of knowing are more interconnected because it’s the people who are learning and sharing. It’s more holistic learning and occurs in many different ways. Indigenous knowledge is not hierarchically structured. For example, in Western scientific organizations, we have high-level scientists and low-level workers. In indigenous ways of knowing, everyone is fully engaged in the traditions and experience by which most indigenous people learn new things, whereas the Western ways of knowing are individualistic. We compartmentalize knowledge, especially as we develop scientific disciplines. Sociology, biology, physics, chemistry, and other sciences are part of the work in different laboratories. The science and technology disciplines are often male dominated, objective, and scientific. Ways of knowing in Western science are not necessarily better or worse, just different from the ways of knowing in indigenous societies.
Comanagement is an efficient management scheme across fishery types to avoid the tragedy of the commons. In comanagement, fishers collaborate with managers and scientists. Fishers enact their own management by self-regulating under the advice of scientists. Scientists and fishers work together in enacting the management. For many small-scale fisheries, comanagement can be the only way to manage fisheries where other more institutional form of controls are absent or ineffective. This is true in most tropical coastal and developing nations. To be successful, comanagement should (1) develop practices embedded locally, historically, and culturally; (2) focus on fishers; and (3) empower fishers in decision making (Castello et al. 2009). When expected benefits of managing a fishery exceed the perceived costs of investing in better rules and norms, most users and their leaders are likely to organize around a comanagement scheme. The following eight principles were developed to guide effective comanagement of Arapaima fishing (Ostrom 1990; Castello et al. 2009):
1. Boundaries of resources and users are clearly defined.
2. Rules are established to permit the resource to be exploited sustainably.
3. Collective action is functional.
4. Resources and behavior of fishers are monitored.
5. Rule offenders are sanctioned.
6. Conflict resolution mechanisms exist.
7. Central governments authorize and recognize comanagement arrangements.
8. Management tasks are organized and distributed at different institution levels.
In the case of managing harvests of the Arapaima, the native fishers of the community provide much of the management and enforcement, as government attempts to restrict fishing have been unsuccessful due to a lack of enforcement. From 1993 to 1995, only 30% of the harvested Arapaima were longer than the legal length limit (Castello et al. 2011). Efforts to engage the Arapaima fishers in an experimental management process began in the newly created Mamirauá Sustainable Development Reserve in 1998. Part of the reserve was zoned for sustainable use and allowed local people to harvest resources if rules were in place to assure sustainable harvest. The first challenge was to replace the view that native peoples of Amazonia were “backward” with an attitude of respect for their role in stewardship of the ecosystem. The second was to overcome the lack of data on Arapaima populations so that harvest quotas could be developed.
Comanagement began in four fishing communities in one area of the reserve. Here a counting method was developed so that experienced harpooners could accurately count surfacing Arapaima soon after dawn based on subtle visual and aural cues. The counts proved to be highly correlated with abundance estimates conducted by scientists (Castello 2004). Arapaima are relatively sedentary during the first hours after dawn, reducing the chance of those individuals being double counted (Campos-Silva et al. 2018). This counting method was ~200 times faster and less expensive than the marking and repeated capture method used by scientists. By counting numbers of Arapaima before the harvest season, fishers learned to self-manage populations. Briefly, annual counts made in lakes during the dry season were used to determine the harvest quotas for the next year (Figure 11.8). Mathematical analysis of Arapaima populations demonstrated that catch rates of about 25% of adults were likely to maximize the sustainable harvest (Castello et al. 2011). Government officials visited the fishers and the experimental management areas and were convinced that the management scheme was sound.
The results of this first experiment with comanagement of Arapaima fishing were indisputable (Figure 11.9). The total population of Arapaima increased 9-fold, and the harvest quotas increased 10-fold within seven years. In addition, the number of fishers participating in management more than doubled, and the per capita income of fishers increased 8-fold (Viana et al. 2004; Castello et al. 2009). Arapaima fishers were more engaged in this new management scheme, and there were fewer violations of the newly formulated rules.
This type of comanagement scheme has proven successful in several different fishing communities that target Arapaima. For example, community-protected lakes in the western Brazilian Amazon had 33 times more Arapaima individuals than open-access lakes (Campos-Silva and Peres 2016). Similar responses to comanagement were observed elsewhere, leading to increases in the household income of Arapaima fishers (Oviedo et al. 2015, 2016; Petersen et al. 2016; Gurdak et al. 2019a; Watson et al. 2021; Gurdak et al. 2022). In addition, comanagement schemes resulted in time savings in fishing families, permitting more time for alternative pursuits, such as agriculture and cattle grazing (Schons et al. 2020). If the comanagement scheme could be implemented widely, the restored and well-managed Arapaima fisheries could yield as much as U.S. \$30 million per year (Castello et al. 2011).
Experiences with comanagement of Arapaima demonstrated the importance of bridging knowledge across stakeholders, such as inviting government officials to observe the monitoring practices. Also, the scheme would be ineffective if not for the melding of the unique skills fishers can offer in conducting fish counts with scientific knowledge to estimate allowable catch levels (Castello et al. 2011b). Comanagement of Arapaima fishing can promote a more just distribution of benefits while recognizing cultural and gender differences among fishers (Lopes et al. 2021). Incorporating Ostrom’s design principles did increase the density of Arapaima, and future refinements should emphasize defining boundaries and formulating graduated sanctions for violators (Arantes et al. 2021).
Among the indigenous people, fishing and hunting are always done by males, whereas domestic tasks, such as getting water, gathering firewood, and childcare are principally performed by females (Meggers 1996). Processing of fish captured by males is a task done mostly by females. Because the most valuable catches are sold, Arapaima fishing provides one of the very few sources of income for females. After comanagement for Arapaima began, both men and women showed increased interest in participating in the local fishing association, and female income increased eightfold (Freitas et al. 2020).
Question to ponder:
What elements of comanagement of Arapaima do you think are most important for conservation?
11.7 Culture of Arapaima
Arapaima meat is in great demand because it is boneless, odorless, mild, low in fat content, and high in protein. Therefore, it demands a high price in the “gourmet” restaurant market. International market price is U.S. \$20–25 per kilogram in Europe and the United States and \$12–15 per kilogram in South American cities (FAO 2022). Arapaima are also pet traded in Europe, North America, South America, and Asia. Demand for juvenile Arapaima as ornamental fish is also high, partly because as obligate air breathers they tolerate hypoxic (low levels of dissolved oxygen) water uninhabitable by other fish (Ohs et al. 2021). As Arapaima were supplied to ornamental fish breeders in other countries, some escaped and established populations in Java and Sumatra in Indonesia (Marková et al. 2020). While threatened in its native range, the Arapaima populations elsewhere have spread rapidly and become invasive. This phenomenon is called the “biodiversity conservation paradox”—species at risk in their native range are abundant in other settings.
Aquaculture of Arapaima for food has been nonintensive and generally conducted in ponds or in net cages in reservoirs (dos Santos et al. 2014). The production cycle begins when breeding size fish are allowed to breed in ponds and offspring are stocked in tanks, net cages, or ponds and fed pellets. A major barrier to successful aquaculture of Arapaima is the production of a sufficient number of juveniles for stocking. Fry survival is high only in the early months of the flooding season (Núñez et al. 2011). Closed recirculating aquaculture systems show promise for increasing survival of fry and juveniles (Burton et al. 2016). Within 14 months after egg hatching, Arapaima attain a marketable size of 10–15 kg (22–33 pounds) and 110–120 cm (43–47 inches) (Núñez 2012; Ohs et al. 2021).
Brazil has invested in rapid expansion of new aquaculture facilities in public waters (Lima-Junior et al. 2018). However, poor aquaculture management practices and aquaculture of nonnatives and water use conflicts are troubling in this megadiverse region. Government support for aquaculture has decreased in the past decade (Nobile et al. 2020). Revised laws that foster aquaculture have encouraged farmers to raise tilapia and other nonnative fish without containment systems to prevent escapes (Padial et al. 2017).
Arapaima culture operations are still in the early phase of development, and many challenges remain. Aquaculture production in Brazil is based largely on nonnative species (Lima et al. 2018). As many as 501 nonnative species have been imported for the ornamental trade. Native species, such as Arapaima, have great, unrealized potential to contribute to food security and poverty reduction, if integrated with national and local development plans for biodiversity protection (Schaefer et al. 2012). Aquaculture production of Arapaima is still relatively low compared to the potential and represents about 6% of total farmed fish production in Brazil (Nobile et al. 2020). Exports of farmed Arapaima are sold in high-end supermarkets, such as Whole Foods Market®, which uses a “Responsibly Farmed” logo to promote farmed Arapaima.
Question to ponder:
What concerns would you have about culture of nonnative fish species in Brazil’s aquaculture industry?
11.8 Fly-Fishing Tourism Targeting Arapaima
Sportfishing for Arapaima is not a part of local indigenous culture. Yet, Arapaima are already providing benefits from ecotourism, such as fish watching and catch-and-release sportfishing in the Rewa and Rupununi rivers of Guyana. Approximately 89% of Arapaima caught by fly-fishing survived release (Lennox et al. 2018). Obligatory air-breathing habits of Arapaima mean that fishing guides must always hold fish at the surface, enabling fish to access air for three or four breaths (typically) prior to release. Adopting similar comanagement principles, some indigenous peoples have developed ecotourism lodges, which cater to foreign visitors and provide employment and income to indigenous communities. This approach promotes support for local culture and local ecosystems while permitting sustainable tourism. Use of traditional ecological knowledge to develop tourism based on nature and recreational fishing represents an innovative approach to economic development in rural parts of Amazonia. Here the local people serve as fishing guides, and fly-fishing and catch-and-release practices assure that released Arapaima will survive. This type of nature tourism is likely to increase in popularity and participation in Guyana, where the Arapaima is protected by national legislation but recreational fishing is still permitted. The hope of conservationists is that recreational fishing will encourage anglers to support Arapaima conservation via protection of habitats, river-floodplain connections, and avoiding illegal trade.
Profile in Fish Conservation: Leandro Castello, PhD
Leandro Castello, is Associate Professor of Fish Conservation at Virginia Tech. He is from Brazil, and from an early age he loved to be in or near the water and wanted to work in a field that explored the roles of fish and fishing in aquatic ecosystems. His early exposure to fish showed him there were other worlds to explore. When diving, he loved the feeling of being underwater, where fish and other aquatic life often move slowly and make many sounds in this foreign world.
Castello began to study Arapaima after the Mamirauá Sustainable Development Reserve was established. Here he developed a keen eye for seeing the big picture and making connections among different elements in the social and ecological parts of the region. In fisheries and fish conservation, too often people focus exclusively on the fish and ignore the connections between fish and people and the ecosystems that sustain them both.
Dr. Castello worked directly with local fishers to observe their fishing techniques and assist in training to determine if fishers could accurately count Arapaima before harvest season to derive a harvest quota. His collaborations with local Arapaima fishers led to the first evaluation of community-based management of Arapaima fishing. The initial findings from his and other evaluations of Arapaima comanagement have achieved remarkable social and ecological outcomes. As a result, poverty has been alleviated in many rural communities of Amazonia, as fishing benefits can now be sustained.
He has also studied the migration habits of Arapaima, which required many hours searching for tagged Arapaima. In doing so, he noticed the curiosity of Arapaima, as they would approach the canoe and watch what he and his field partners were doing. He also witnessed the learning capabilities in Arapaima. These fish prove to be very difficult to capture with seine nets. When corralled in a net, they either bury their bodies in bottom muds or jump over the seine net. Efforts to culture Arapaima have provided other opportunities to observe their habituation and social learning.
Translating scientific knowledge into workable policies and practices will serve to facilitate conservation in the face of the major environmental challenges of our times. Castello’s developing body of research and outreach addresses the gap between science and policy. This “science-policy gap” is often considered in negative terms, thereby increasing anxiety among early career scientists seeking to influence policy. Through persistence in efforts to develop trusted relationships needed for participatory management, he has pioneered joint learning and reflection among stakeholders. Along with many collaborators, Castello has successfully influenced policy and practices in Amazonia, and the effects of comanagement of Arapaima fishing provide others with a sense of optimism. His influential studies of tropical, small-scale fisheries provide many lessons to apply to conservation and restoration of exploited fisheries. The small-scale fisheries he studies are extremely neglected by most scientists, society, and governments. Yet, these complex systems are filled with mysteries yet to be fully understood.
Leandro Castello teaches courses in fisheries techniques and systems ecology in conservation. He works diligently to instill a sense of service in his students. Consequently, his students and colleagues are making a difference in promoting better approaches to conservation. In addition to managing to prevent overharvest, his research has demonstrated the need for increased protection of floodplain forests to benefit food, income, and livelihood of local fishing. These advances made by Castello and his colleagues come at a time when environmental policies in Brazil are unfriendly to environmental protection and push for more mining, hydropower development, deforestation, and agribusiness. His research and writings provide a framework for reversing unprecedented degradation of freshwater ecosystems in the Amazon basin.
Leandro recognizes the many connections between existing and proposed hydropower dams and ongoing land cover changes and climatic shifts. For example, with other world-renowned scientists, he provided advice for balancing the need for hydropower with biodiversity conservation in some of the largest and most threatened rivers of the world. He and his scientific colleagues called for mitigation of environmental impacts from human developments in the Amazon, Congo, and Mekong rivers. These three river basins hold roughly one-third of the world’s freshwater fish species, most of which are not found anywhere else. Consequently, the siting of future hydropower dams will be critically important for conserving biodiversity. Many other fish that feed and sustain us, such as less charismatic forage fish (often smelly and slimy), need more attention by scientists and conservationists. The strong role of hatcheries in fish conservation and management is a North American legacy. However, in most other parts of the world, fish provide subsistence and a means for a livelihood and poverty reduction.
Key Takeaways
• Arapaima comprise a prime example of a threatened freshwater megafauna (i.e., animals ≥ 30 kg) for which conservation status evaluations are needed.
• Arapaima are highly vulnerable to overfishing due to obligate air breathing, large size, and high-quality meat.
• Arapaima prefer large floodplain lakes with abundant macrophytes for spawning and juveniles.
• Obligate air breathing means that Arapaima must surface every 5 to 15 minutes to gulp air, thereby exposing themselves to specialist harpoon fishers.
• With appropriate training, fishers’ participation in management processes can contribute to the conservation of small-scale fisheries.
• Arapaima represent a culturally important, symbolic flagship genus that serves to support floodplain management and conservation.
• Illegal harvest and overfishing greatly reduce the economic returns from Arapaima, often leading to their local extirpation.
• Including local stakeholders in conservation planning of Amazonian floodplains leads to restoration of Arapaima populations while alleviating poverty among fisherfolk.
• Involvement of indigenous communities in management is a significant step (two-eyed seeing) toward sustainable fisheries that should continue to be promoted.
This chapter was reviewed by Leandro Castello.
Long Descriptions
Figure 11.3: 1) Deforestation impacts uplands and wetlands, which impacts water chemistry and food chain; 2) dams impact dams and waterways, which impact hydrological alteration; 3) pollution impacts nutrients and toxins, mercury, and oil and gas, which impacts water chemistry and food chain; 4) overharvesting impacts wetland logging and exploitation of animals, which impacts food chain alteration. Jump back to Figure 11.3.
Figure 11.4: Life cycle of arapaima divided into four main stages: 1) nest-bound embryo and sac fry (~7 days); 2) adult-protected, schooling juveniles up to age 6 months); 3) independent juveniles (up to age 3-4 years); 4) reproductive adult (aged 3-4 years or more). Jump back to Figure 11.4.
Figure 11.5: Growth of juvenile arapaima rises substantially during the dry season with a growth of 1 kg/month and heightened growth continues into the wet season. Jump back to Figure 11.5.
Figure 11.6: Two length frequency distributions contrasting fished and unfished arapaima populations. Length of fished arapaima reach their maximum frequency before unfished arapaima. Jump back to Figure 11.6.
Figure 11.9: Top graph: x-axis shows year, y-axis shows arapaima (>1 m) per hectare. Jaraua (study area) increases consistently, with a decrease from 2003-2004. Bottom graph: x-axis shows year, y-axis shows income per fisher/fishing quota. Fishers, fishing quota, and income per fisher all increase. Income per fisher decreases from 2002-2003 and passes fishers in 2005. Jump back to Figure 11.9.
Figure References
Figure 11.1: Indigenous and ribeirinho people travel on rivers of Brazil in a voadeira, a motorized canoe. Fernando C. C. Castro, 2020. CC BY-SA 4.0. https://commons.wikimedia.org/wiki/File:Parque_Nacional_de_Anavilhanas_Fernando_Carvalheiro_Coelho_Castro_(01).jpg.
Figure 11.2: Arapaima gigas displayed in the Siam Centre, Bangkok. Bjoertvedt, 2009. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:Arapaima_gigas_01.JPG.
Figure 11.3: Schematic diagram of the main drivers influencing freshwater ecosystems in the Amazon. Kindred Grey, 2022. Adapted under fair use from The Vulnerability of Amazon Freshwater Ecosystems, by Castello et al., 2012. https://doi.org/10.1111/conl.12008.
Figure 11.4: The generalized life cycle of the Arapaima can be divided into four main stages: (1) nest-bound embryo and sac fry, (2) adult-protected, schooling juveniles, (3) independent juveniles, and (4) reproductive adults. Kindred Grey, 2022. CC BY 4.0. Adapted under fair use from Evidence of Recoveries from Tropical Floodplain Fisheries: Three Examples of Management Gains for South American Giant Arapaima, by Gurdak et. al., 2019. https://doi.org/10.47886/9781934874554.ch11. Includes Arapaima gigas, by Lankester Edwin Ray, 1908, public domain. https://commons.wikimedia.org/wiki/File:Arapaima_gigas1.jpg.
Figure 11.5: Juvenile Arapaima exhibit the fastest growth recorded in fish, reaching 15 kg or larger within the first year. Kindred Grey, 2022. CC BY 4.0. Data from Seasonality Influence on Biochemical and Hematological Indicators of Stress and Growth of Pirarucu (Arapaima gigas), an Amazonian Air-Breathing Fish, by Bezerra et. al., 2014. CC BY 3.0. https://doi.org/10.1155/2014/541278. Includes Arapaima gigas, by Lankester Edwin Ray, 1908, public domain. https://commons.wikimedia.org/wiki/File:Arapaima_gigas1.jpg.
Figure 11.6: Theoretical length frequency for unfished (top) and fished (bottom) populations of Arapaima. Kindred Grey, 2022. CC BY 4.0. Includes Arapaima gigas, by Lankester Edwin Ray, 1908, public domain. https://commons.wikimedia.org/wiki/File:Arapaima_gigas1.jpg.
Figure 11.7: Boots made from Arapaima leather, by Lucchese Boots, advertised on U.S. eBay website. Heinrich et. al., 2019. CC BY 4.0. https://doi.org/10.1111/csp2.75.
Figure 11.8: Integrating fishers who conduct counts of Arapaima prior to the fishing season in order to set harvest quotas. Kindred Grey, 2022. CC BY 4.0.
Figure 11.9: Responses of the Arapaima population, number of fishers, income per fisher, and fishing quota to the experimental comanagement process in the newly created Mamirauá Sustainable Development Reserve. Kindred Grey, 2022. CC BY 4.0. Data from Lessons from Integrating Fishers of Arapaima in Small-Scale Fisheries Management at the Mamiraua´ Reserve, Amazon, by Castello et. al., 2008. https://doi.org/10.1007/s00267-008-9220-5.
Figure 11.10: Leandro Castello, PhD. Used with permission from Leandro Castello. Photo by Jorge Pablo Castello. CC BY 4.0.
Text References
Arantes, C. C., L. Castello, X. Basurto, N. Angeli, A. Sene-Haper, and D. G. McGrath. 2021. Institutional effects on ecological outcomes of community-based management of fisheries in the Amazon. Ambio 51(3):678–690. DOI: 10.1007/s13280-021-01575-1.
Arantes, C. C., L. Castello, M. Cetra, and A. Schilling. 2013. Environmental influences on the distribution of Arapaima in Amazon floodplains. Environmental Biology of Fishes 96:1257–1267.
Arantes, C. C., L. Castello, D. J. Stewart, M. Cetra, and H. L. Queiroz. 2010. Population density, growth and reproduction of Arapaima in an Amazonian river-floodplain. Ecology of Freshwater Fish 19:455–465.
Araripe, J., P. S. do Rêgo, H. Queiroz, I. Sampaio, and H. Schneider. 2013. Dispersal capacity and genetic structure of Arapaima gigas on different geographic scales using microsatellite markers. PLoS ONE 8(1):e54470. https://doi.org/10.1371/journal.pone.0054470.
Barnett, L. A. K., T. A. Branch, R. A. Ranasinghe, and T. E. Essington. 2017. Old-growth fishes become scarce under fishing. Current Biology 27:2843–2848.
Bayley, P. B., and M. Petrere Jr. 1989. Amazon fisheries: assessment methods, current status and management options. Canadian Special Publication of Fisheries and Aquatic Sciences 1989: 385–398.
Berkes, F., R. Mahon, P. McConney, R. Pollnac, and R. Pomeroy, editors. 2001. Managing small-scale fisheries: alternative directions and methods. International Development Research Centre, Ottawa.
Burton, A. M., E. M. Calderero, R. E. B. Moran, R. L. A. Sánchez, U. T. A. Villamar, and N. G. O. Torres. 2016. A simple and low-cost recirculating aquaculture system for the production of Arapaima gigas juveniles. Revista Internacional de Investigación y Docencia 1(4):49–54.
Campos-Silva, J. V., J. E. Hawes, and C. A. Peres. 2018. Population recovery, seasonal site fidelity, and daily activity of piraucu (Arapaima spp.) in an Amazonian floodplain mosaic. Freshwater Biology 64:1255–1264.
Campos-Silva, J. V., and C. A. Peres. 2016. Community-based management induces rapid recovery of a high-value tropical freshwater fishery. Scientific Reports 6:34745. https://doi.org/10.1038/srep34745.
Campos-Silva, J. V., C. A. Peres, A. P. Antunes, J. Valsecchi, and J. Pezzuti. 2017. Community-based population recovery of overexploited Amazonian wildlife. Perspectives in Ecology and Conservation 15:266–270. https://doi.org/10.1016/j.pecon.2017.08.004.
Caro, T. 2010. Conservation by proxy: indicator, umbrella, keystone, flagship, and other surrogate species. Island Press, Washington, D.C.
Carvalho, F., M. Power, B. R. Forsberg, L. Castello, E. G. Martins, and C. E. C. Freitas. 2018. Trophic ecology of Arapaima sp. in a ria lake—river–floodplain transition zone of the Amazon. Ecology of Freshwater Fish 27:237–246. https://doi.org/10.1111/eff.12341.
Castello, L. 2008. Lateral migration of Arapaima gigas in floodplains of the Amazon. Ecology of Freshwater Fish 17:38–46. https://doi.org/10.1111/j.1600-0633.2007.00255.x.
Castello, L. 2004. A method to count pirarucu Arapaima gigas: Fishers, assessment, and management. North American Journal of Fisheries Management 24:379–389. https://doi.org/10.1577/m02-024.1.
Castello, L. 2021. Science for conserving Amazon freshwater ecosystems. Aquatic Conservation: Marine and Freshwater Ecosystems 31: 999–1004.
Castello, L., C. C. Arantes, D. G. McGrath, D. J. Stewart, and F. S. de Sousa. 2015. Understanding fishing-induced extinctions in the Amazon. Aquatic Conservation: Marine and Freshwater Ecosystems 25:587–598. https://doi.org/10.1002/aqc.2491.
Castello L., P. B. Bayley, N. N. Fabré, and V. S. Batista. 2019. Flooding effects on a long-lived, heavily exploited fish population of the central Amazon. Reviews in Fish Biology and Fisheries 29(6):1–14. https://doi.org/10.1007/s11160-019-09559-x.
Castello, L., V. J. Isaac, and R. Thapa. 2015. Flood pulse effects on multispecies fishery yields in the lower Amazon. Royal Society Open Science 2(11):150299. https://doi.org/10.1098/rsos.150299.
Castello, L., D. G. McGrath, C. C. Arantes, and O. T. Almeida. 2013a. Accounting for heterogeneity in small-scale fisheries management: the Amazon case. Marine Policy 38:557–565.
Castello, L., D. G. McGrath, L. L. Hess, M. T. Coe, P. A. Lefebvre, P. Petry, M. N. Macedo, V. F. Renó, and C. C. Arantes. 2013b. The vulnerability of Amazon freshwater ecosystems. Conservation Letters 6:217–229.
Castello, L., and D. J. Stewart. 2010. Assessing CITES non-detriment findings procedures for Arapaima in Brazil. Journal of Applied Ichthyology 26:49–56. https://doi.org/10.1111/j.1439-0426.2009.01355.x.
Castello, L., D. J. Stewart, and C. C. Arantes. 2011. Modeling population dynamics and conservation of Arapaima in the Amazon. Reviews in Fish Biology and Fisheries 21:623–640.
Castello, L., J. P. Viana, G. Watkins, M. Pinedo-Vasquez, and V. A. Luzadis. 2009. Lessons from integrating fishers of Arapaima in small-scale fisheries management at the Mamirauá Reserve, Amazon. Environmental Management 43:197–209.
Cavole, L. M., C. C. Arantes, and L. Castello. 2015. How illegal are tropical small-scale fisheries? An estimate for Arapaima in the Amazon. Fisheries Research 168:1–5. https://doi.org/10.1016/j.fishres.2015.03.012.
dos Santos, C. H. A., A. dos Santos, C. S. de Sá Leitão, M. N. Paula-Silva, and V. M. F. Almeida-Val 2014. Genetic relationships between captive and wild subpopulations of Arapaima gigas (Schinz, in Cuvier, 1822). International Journal of Fisheries and Aquaculture 6:108–123.
Dufour, D. L., B. A. Piperata, R. Murrieta, W. M. Wilson, and D. Williams. 2016. Amazonian foods and implications for human biology. Annals of Human Biology 43:330–348.
Duponchelle, F., V. J. Isaac, R. C. Doria, P. A. Van Damme, G. A. Herrera-R, E. P. Anderson, R. E. A. Cruz, M. Hauser, T. W. Hermann, E. Agudelo, C. Bonilla-Castillo, R. Barthem, C. E. C. Freitas, C. García-Dávila, A. García-Vasquez, J.-F. Renno, and L. Castello. 2021. Conservation of migratory fishes in the Amazon basin. Aquatic Conservation: Marine and Freshwater Ecosystems 31:1087–1105.
FAO. 2022. Arapaima gigas. Cultured Aquatic Species Information Programme. Text by J. Nuñez. Fisheries and Aquaculture Division, Rome. Available at: https://www.fao.org/fishery/en/culturedspecies/arapaima_gigas/en.
Farias, I. P., S. Willis, A. Leão, J. T. Verba, M. Crossa, F. Foresti, F. Porto-Foresti, I. Sampaio, and T. Hrbek. 2019. The largest fish in the world’s biggest river: genetic connectivity and conservation of Arapaima gigas in the Amazon and Araguaia-Tocantins drainages. PLoS ONE 14(8):e0220882. https://doi.org/10.1371/journal. pone.0220882.
Freitas, C. T., P. F. M. Lopes, J. V. Campos-Silva, M. M. Noble, R. Dyball, and C. A. Peres. 2020. Comanagement of culturally important species: a tool to promote biodiversity conservation and human well-being. People and Nature 2:61–81.
Freitas, H. C. P., and R. G. C. Sousa. 2021. Closed fishing season law a positive instrument to minimize illegal fishing of the remaining stock of Arapaima sp. in the Brazilian Amazon. Revista Ibero Americana de Ciências Ambientais 12:484–494. http://doi.org/10.6008/CBPC2179-6858.2021.001.0039.
Goulding, M., N. J. H. Smith, and D. J. Mahar. 1996. Floods of fortune: ecology and economy along the Amazon. Columbia University Press, New York.
Goulding, M., E. Venticinque, M. L. de B. Ribeiro, R. B. Barthem, R. G. Leite, B. Forsberg, P. Petry, U. L. da Silva-Júnior, P. S. Ferraz, and C. Cañas. 2019. Ecosystem-based management of Amazon fisheries and wetlands. Fish and Fisheries 20:138–158.
Gurdak, D. J., C. C. Arantes, L. Castello, D. J. Stewart, and L. C. Watson. 2019a. Evidence of recoveries from tropical floodplain fisheries: three examples of management gains for South American giant Arapaima. Pages 267–295 in C. C. Krueger, W. W. Taylor, and S-J. Youn, editors, From catastrophe to recovery: stories of fishery management success, American Fisheries Society, Bethesda, MD.
Gurdak, D. J., D. J. Stewart, L. Castello, and C. C. Arantes. 2019b. Diversity in reproductive traits of arapaima (Arapaima spp., Müller, 1843) in Amazonian várzea floodplains: conservation implications. Aquatic Conservation 29(2):245–257. https://doi.org/10.1002/aqc.3030.
Gurdak, D. J., D. J. Stewart, and M. Thomas. 2022. Local fisheries conservation and management works: implications of migrations and site fidelity of Arapaima in the lower Amazon. Environmental Biology of Fishes 105:2119–2132. https://doi.org/10.1007/s10641-021-01171-y.
Gutiérrez, N. L., R. Hilborn, and O. Defeo. 2011. Leadership, social capital and incentives promote successful fisheries. Nature 470:386–389.
He, F., C. Zarfl, V. Bremerich, A. Henshaw, W. Darwall, K. Tockner, and S. C. Jähnig. 2017. Disappearing giants: a review of threats to freshwater megafauna. Wires Water 4(3):e1208. https://doi.org/10.1002/wat2.1208.
He, F., V. Bremerich, C. Zarfl, J. Geldman, S. Langhans, J. N. W. David, W. Darwall, K. Tockner, and S. C. Jähnig. 2018. Freshwater megafauna diversity: patterns, status and threats. Diversity and Distributions 24:1395–1404.
Heinrich, S., J. V. Ross, and P. Cassey. 2019. Of cowboys, fish, and pangolins: US trade in exotic leather. Conservation Science and Practice 1:e75. https://doi.org/10.1111/csp2.75.
Hemming, J. 2020. People of the rainforest: The Villas Boas brothers, explorers and humanitarians of the Amazon. Oxford University Press.
Hester, J. T. 1966. Late Pleistocene environments and early man in South America. American Naturalist 100:377–388.
Hixon, M. A., D. W. Johnson, and S. M. Sogard. 2014. BOFFFFs: on the importance of conserving old-growth age structure in fishery populations. ICES Journal of Marine Science 71:171–2185.
Isaac, V. J., and M. C. Almeida. 2011. El consumo de pescado en la Amazonia brasileña. COPESCAALC Documento Ocasional No 13. FAO, Rome. Available at: https://www.fao.org/documents/card/en/c/f0b847ee-e6aa-5e4f-9d4b-6a0a3220e26f/.
Jacobi, C. M., F. Villamarin, J. V. Campos-Silva, T. Jardine, and W. E. Magnusson. 2020. Feeding of Arapaima sp.: integrating stomach contents and local ecological knowledge. Journal of Fish Biology 97:265–272.
Jézéquel, C., P. A. Tedesco, R. Bigorne, J. A. Maldonado-Ocampo, H. Ortega, M. Hidalgo, K. Martens, G. Torrente-Vilara,. Zuanon, A. Acosta, E. Agudelo, S B. Maure, D. A. Bastos, J. B. Gregory, F. G. Cabeceira, A. L. C. Canto, F. M. Carvajal-Vallejos, L. N. Carvalho, A. Cella-Ribeiro, R. Covain, C. Donascimiento, C. R. C. Dória, C. Duarte, E. J. G. Ferreira, A. V. Galuch, T. Giarrizzo, R. P. Leitão, J. G. Lundberg, M. Maldonado, J. I. Mojica, L. F. A. Montag, W. M. Ohara, T. H. S. Pires, M. Pouilly, S. Prada-Pedreros, L. J. de Queiroz, L. R. Py-Daniel, F. R. V. Ribeiro, R. R. Herrera, J. Sarmiento, L. M. Sousa, L. F. Stegmann, J. Valdiviezo-Rivera, F. Villa, T. Yunoki, and T. Oberdorff. 2020. A database of freshwater fish species of the Amazon basin. Scientific Data 7:96. https://doi.org/10.1038/s41597-020-0436-4.
Lennox, R. J, J. W. Brownscombe, S. J. Cooke, and A. J. Danylchuk. 2018. Post-release behaviour and survival of recreationally-angled arapaima (Arapaima cf. arapaima) assessed with accelerometer biologgers. Fisheries Research 207:197–203.
Lima-Junior, D. P., A. L. B. Magalhães, F. M. Pelicice, J. R. S. Vitule, V. M. Azevedo-Santos, M. L. Orsi, D. Simberloff, and A. A. Agostinho. 2018. Aquaculture expansion in Brazilian freshwaters against the Aichi Biodiversity Targets. Ambio 47:427–440.
Lombardo, U., J. Iriarte, L. Hilbert, J. Ruiz-Pérez, J. M. Capriles, and H. Veit. 2020. Early Holocene crop cultivation and landscape modification in Amazonia. Nature 581:190–193. DOI: 10.1038/s41586-020-2162-7.
Marková, J., R. Jerikho, Y. Wardiatno, M. M. Kamal, A. L. B. Magalhães, L. Bohatá, L. Kalous, and J. Patoka. 2020. Conservation paradox of giant arapaima Arapaima gigas (Schinz, 1822) (Pisces: Arapaimidae): endangered in its native range in Brazil and invasive in Indonesia. Knowledge & Management of Aquatic Ecosystems 421:47.
McGrath, D. G., L. Castello, O. T. Almeida, and G. M. Estupiñán. 2015. Market formalization, governance, and the integration of community fisheries in the Brazilian Amazon. Society and Natural Resources 28:513–529. https://doi.org/10.1080/08941920.2015.1014607.
Moran, E. 1993. Through Amazonian eyes: the human ecology of Amazonian populations. University of Iowa Press, Iowa City.
Nepstad, D., D. McGrath, C. Stickler, A. Alencar, A. Azevedo, B. Swette, T. Bezerra, M. DiGiano, J. Shimada, R. S. da Motta, E. Armijo, L. Castello, P. Brando, M. C. Hansen, M. McGrath-Horn, O. Carvalho, and L. Hess. 2014. Slowing Amazon deforestation through public policy and interventions in beef and soy supply chains. Science 344(6188):1118–1123. DOI: 10.1126/science.1248525.
Nobile, A. B., A. M. Cunico, J. R. S. Vitule, J. Queiroz, A. P. Vidotto-Magnoni, D. A. Z. Garcia, M. L. Orsi, F. P. Lima, A. A. Acosta, R. J. da Silva, F. D. do Prado, F. Porto-Foresti, H. Brandão, F. Foresti, C. Oliveira, and I. P. Ramos. 2020. Status and recommendations for sustainable freshwater aquaculture in Brazil. Reviews in Aquaculture 12:1495–1517.
Nogueira, F., M. Amaral, G. Malcher, N. Reis, M. A. D. Melo, I. Sampaio, P. S. Rêgo, and J. Araripe. 2020. The arapaima, an emblematic fishery resource: Genetic diversity and structure reveal the presence of an isolated population in Amapá. Hydrobiologia 847(15):3169–3183. https://doi.org/10.1007/s10750-020-04292-0.
Nuñez, J. 2012. Cultured aquatic species information programme: Arapaima gigas. Food and Agriculture Organization of the United Nations, Rome.
Núñez, J., F. Chu-Koo, M. Berland, L. Arévalo, O. Ribeyro, F. Duponchelle, and J. F. Renno. 2011. Reproductive success and fry production of the paiche or pirarucu, Arapaima gigas (Schinz), in the region of Iquitos, Perú. Aquaculture Research 42:815–822.
Ohs, C. L., J. E. Hill, S. E. Wright, H. M. Giddings, and A. L. Durland. 2021. Candidate species for Florida aquaculture: Arapaima Arapaima gigas. FA236. Institute of Food and Agricultural Sciences, University of Florida. https://doi.org/10.32473/edis-FA236-2021.
Ostrom, E. 1990. Governing the commons: the evolution of institutions for collective action. Cambridge University Press.
Oviedo, A. F. P., and M. Bursztyn. 2016. The fortune of the commons: participatory evaluation of small-scale fisheries in the Brazilian Amazon. Environmental Management 57:1009–d1023.
Oviedo, A. F. P., M. Bursztyn, and J. A. Drummond. 2015. Now under new administration: fishing agreements in the Brazilian Amazon floodplains. Ambiente & Sociedade 18(4):113–132.
Padial, A. A., A. A. Agostinho, V. M. Azevedo-Santos, F. A. Frehse, D. P. Lima-Junior, A. L. B. Magalhães, R. P. Mormul, F. M. Pelicice, L. A. V. Bezerra, M. L. Orsi, M. Petrere-Junior, and J. R. S. Vitule . 2017. The “Tilapia Law” encouraging nonnative fish threatens Amazonian River basins. Biodiversity and Conservation 26(1):243–246.
Pelicice, F. M., V. M. Azevedo-Santos, J. R. S. Vitule, M. L. Orsi, D. P. Lima-Junior, A. L. B. Magalhães, P. S. Pompeau, M. Petrere Jr., and A. A. Agostinho. 2017. Neotropical freshwater fishes imperiled by unsustainable policies. Fish and Fisheries 18:1119–1133.
Pelicice, F. M., and L. Castello. 2021. A political tsunami hits Amazon conservation. Aquatic Conservation: Marine and Freshwater Ecosystems 31:1221–1229. https://doi.org/10.1002/aqc.3565.
Petersen, T. A., S. M. Brum, F. Rossoni, G. F. V. Silveira, and L. Castello. 2016. Recovery of Arapaima sp. populations by community-based management in floodplains of the Purus River, Amazon. Journal of Fish Biology 89:241–248. https://doi.org/10.1111/jfb.12968.
Prince, J. D. 2003. The barefoot ecologist goes fishing. Fish and Fisheries 4:359–371.
Reid, A. J., L. E. Eckert, J-F. Lane, N. Young, S. G. Hinch, C. T. Darimont, S. J. Cooke, N. C. Ban, and A. Marshall. 2021. “Two-eyed seeing”: an indigenous framework to transform fisheries research and management. Fish and Fisheries 22:243–261.
Reis, R. E., J. S. Albert, F. Di Dario, M. M. Mincarone, P. Petry, and L. A. Rocha. 2016. Fish biodiversity and conservation in South America. Journal of Fish Biology 89:12–47.
Roosevelt, A. C. 1999. Twelve thousand years of human-environment interaction in the Amazon floodplain. Pages 371–392 in C. Padoch, J. M. Ayres, M. Pinedo-Vasquez, and A. Henderson, editors, Várzea: diversity, conservation, and development of Amazonia’s whitewater floodplains. New York Botanical Garden Press, New York.
Sakaris, P. C., D. L. Buckmeier, N. G. Smith, and D. J. Daugherty. 2019. Daily age estimation reveals rapid growth of age-0 Alligator Gar in the wild. Journal of Applied Ichthyology 35:1218–1224.
Sautchuk, C. E. 2012. Cine-weapon: the poiesis of filming and fishing. Vibrant Virtual Brazilian Anthropology 9:406–430. DOI: 10.1590/S1809-43412012000200015.
Schaefer, F., W. Kloas, and S. Würtz. 2012. Arapaima: Candidate for intensive freshwater culture. Global Aquaculture Advocate website. Available at: https://www.globalseafood.org/advocate/arapaima-candidate-for-intensive-freshwater-culture/.
Schons, S. Z., G. Amacher, K. Cobourn, and C. Arantes. 2020. Benefits of community fisheries management to individual households in the floodplains of the Amazon River in Brazil. Ecological Economics 169:106531. https://doi.org/10.1016/j.ecolecon.2019.106531.
Schor, T., and G. S. Azenha. 2017. Ribeirinho food regimes, socioeconomic inclusion and unsustainable development of the Amazonian floodplain. EchoGéo [online] 41:15052. DOI: https://doi.org/10.4000/echogeo.15052.
Schwenke, K. L., and J. A. Buckel. 2008. Age, growth, and reproduction of Dolphinfish (Coryphaena hippurus) caught off the coast of North Carolina. Fishery Bulletin 106:82–92.
Sherman, V. R., H. Quan, W. Yang, R. O. Ritchie, and M. A. Meyers. 2017. A comparative study of piscine defense: the scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula. Journal of the Mechanical Behavior of Biomedical Materials 73:1–16.
Sinovas, P., B. Price, E. King, A. Hinsley, and A. Pavitt. 2017. Wildlife trade in the Amazon countries: an analysis of trade in CITES listed species. Technical report prepared for the Amazon Regional Program (BMZ/DGIS/GIZ). UN Environment—World Conservation Monitoring Centre, Cambridge. Available at: https://www.cbd.int/doc/c/13f7/3a91/0b533d2c489c5e6ab06bc51f/sbstta-21-inf-08-en.pdf.
Smith, N. J. H. 1999. The Amazon River forest: a natural history of plants, animals, and people. Oxford University Press, New York.
Stewart, D. J. 2013a. A new species of Arapaima (Osteoglossomorpha: Osteoglossidae) from the Solimões River, Amazonas State, Brazil. Copeia 2013:470–476. doi: 10.1643/ci-12-017.
Stewart, D. J. 2013b. Re-description of Arapaima agassizii (Valenciennes), a rare fish from Brazil (Osteoglossomorpha: Osteoglossidae). Copeia 2013:38–51. doi: 10.1643/ci-12-013.
Torati, L. S., H. Migaud, M. K. Doherty, J. Siwy, W. Mullen, P. E. C. Mesquita, and A. Albalat. 2017. Comparative proteome and peptidome analysis of the cephalic fluid secreted by Arapaima gigas (Teleostei: Osteoglossidae) during and outside parental care. PloS One 12:e0186692.
Tregidgo, D. J., J. Barlowa, P. S. Pompeub, M.-D. A Rochac, and L. Parrya. 2017. Rainforest metropolis casts 1,000-km defaunation shadow. Proceedings of the National Academy of Sciences 114(32):8655–8865. https://doi.org/10.1073/pnas.1614499114.
Van der Sleen, P., and J. S. Albert. 2017. Field guide to the fishes of the Amazon, Orinoco, and Guianas. Princeton University Press, Princeton, NJ.
Viana, J. P., J. M. B. Damasceno, L. Castello, and W. G. R. Crampton. 2004. Community management of fishery resources in the Mamiraua Sustainable Development Reserve, Brazil. Pages 139–154 in K. M. Silvius, R. E. Bodmer, and J. M. V. Fragoso, editors, People in nature: wildlife conservation in South and Central America. Columbia University Press, New York.
Walker, P. 2009. Dinosaur DAD and enlightened EDD: engaging people earlier is better. Environmentalist 71:12–13.
Watson, L. C., and D.J . Stewart. 2020. Growth and mortality of the giant Arapaima in Guyana: implications for recovery of an over-exploited population. Fisheries Research 231:105692. https://doi.org/10.1016/j.fishres.2020.105692.
Watson, L. C., D. J. Stewart, K. Clifford, L. Castello, D. Jafferally, S. James, Z. Norman, and G. G. Watkins. 2021. Recovery, conservation status, and environmental effects on Arapaima populations in Guyana. Aquatic Conservation: Marine and Freshwater Ecosystems 31:2533–2546. https://doi.org/10.1002/aqc.3628.
Watson, L. C., D.J . Stewart, and A. M. Kretzer. 2016. Genetic diversity and population structure of the threatened giant Arapaima in southwestern Guyana: implications for their conservation. Copeia 104:864–872. https://doi.org/10.1643/cg-15-293.
Watson, L. C., D. J. Stewart, and M. A. Teece. 2013. Trophic ecology of Arapaima in Guyana: giant omnivores in neotropical floodplains. Neotropical Ichthyology 11:341–349. doi: 10.1590/s1679-62252013000200012.
World Bank. 2012. Hidden harvest: the global contribution of capture fisheries. World Bank, Washington, D.C. https://openknowledge.worldbank.org/handle/10986/11873. License: CC BY 3.0 IGO.
Yang, W., H. Quan, M. A. Myers, and R. O. Ritchie. 2019. Arapaima fish scale: one of the toughest flexible biological materials. Matter 1:1557–1566. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.11%3A_Integrating_Fishers_in_the_Management_of_Arapaima.txt |
Learning Objectives
• Describe the adaptive significance of biological characteristics of tuna.
• Describe how migratory patterns complicate tuna conservation.
• Summarize major historical changes in tuna fishing.
• Recognize and name the most common commercial tuna species of the world.
• Describe key elements of supply chains for industrial tuna fishing.
• Understand how national sovereignty influences international fisheries management.
• Relate current trends to future sustainability of tuna fisheries.
12.1 What’s Special about Tuna?
Tuna are highly adapted for life in the open ocean. Their streamlined bodies, built for speed and endurance, make long-distance migrations possible. In fact, the name “tuna” comes from the Greek thunnos, derived from the verb thuo, which means “to dart” or “to rush.” One cannot help but be mesmerized when watching tuna swimming—an experience hard to come by. Only a few public aquariums have exhibits large enough for the largest tuna. Divers swim with Bluefin Tuna in floating cages in Australia and Malta. Carl Safina, one writer who swims with tuna, described the Bluefin Tuna as “half a ton of laminated muscle rocketing through the sea as fast as you drive your automobile” (Ellis 2008).
Tuna regulate their core body temperature with specialized circulation near their swimming muscles, a condition known as heterothermy. Bluefin Tuna can elevate their core body temperature up to 20°C above surrounding ocean temperature to enhance swimming efficiency. The swimming mode of tuna involves high-frequency tail beats (1–2 Hz) with a stiff tail fin and extra-long tendons that connect the large muscles directly to the tail fin. Other metabolic adaptations lead to capacities exceeding those of other fish, such as an increased heart size, large gill surface area, high blood oxygen–carrying capacity, and elevated hematocrit. When speed is required, the tuna switches into high-speed mode: large dorsal and ventral fins retract into cavities, while the pectoral fins are pressed flat against the body. Consequently, tuna are among the fastest-swimming fish.
Heterothermy also allows tuna to migrate into cold waters to follow abundant prey fish. Bluefin Tuna swim in both subtropical oceans and cold seas. Tuna are also known for remarkable daytime vertical migrations to find abundant prey in deeper and colder waters. They migrate from spawning grounds to feeding grounds that may be separated by over 5,000 miles. Therefore, the tuna cross country borders, which makes drawing boundaries around populations nearly impossible. Arrival of tuna near coastal regions is predictable, and communities hold celebrations, festivals, and fishing tournaments when they arrive. Managing tuna is hard because they travel between many different jurisdictions.
The larger tuna species have long been targets of game fish enthusiasts, such as authors Ernest Hemingway and Zane Grey. Ernest Hemingway wrote, “It is a back-sickening, sinew-straining, man-sized job even with a rod that looks like a hoe handle.” Hemingway and Grey wrote extensively about big-game fishing, thereby bringing awareness of these awesome yet hidden creatures. Sportfishing for large tuna was a transformational experience. Hemingway wrote, “But if you land a big tuna . . . and finally bring him up alongside the boat, green-blue and silver in the lazy ocean, you will be purified and will be able to enter unabashed into the presence of the very elder gods and they will make you welcome” (Hemingway 1922).
Current controversies about tuna relate to our relationship with them. For centuries, these fish have been an important ocean commodity. Today, tuna are an emblem of globalization—they swim across the globe, crossing boundaries of many countries that claim an interest in their harvest. Trade in tuna products has transformed the world into a more connected and interdependent place. At the same time, tuna (Thunnus spp.) have become a charismatic flagship genus to raise awareness of global conservation issues. Managing tuna fisheries involves substantial coordination among regional and international commissions and organizations that represent at least 48 countries. In 2017, the United Nations set May 2nd as World Tuna Day to focus on conserving the world’s tuna. The story of fishing for tuna from prehistory to today’s globalized society should prompt us to reflect on how a sustainable global economy based on tuna fishing should proceed.
12.2 Tuna of the World
Tuna are part of a large, diverse family of epipelagic (i.e., near-surface) dwellers. The ancestral fish that gave rise to these specialized fish was a deep-ocean dweller that lived and survived the Cretaceous-Paleogene mass extinction event, which eliminated approximately 80 percent of all species of animals about 66 million years ago (Miya et al. 2013). This deep-ocean dweller did not resemble tuna. The unique tuna traits did not appear in fish until the first tuna-like fish emerged about 40–50 million years ago.
Tuna are most closely related to mackerels and billfish, such as swordfish and marlins. They are members of the family Scombridae, which includes mackerels, tuna, Wahoos, and bonito (Collett and Graves 2019). There are 51 species of Scombridae, many of which are important and familiar food fish. Mackerels and tuna support very important commercial and recreational fisheries, as well as substantial artisanal fisheries throughout the tropical and temperate oceans.
All species in the family are specialized fast-swimming predators, often called the high-performance sports cars of the fish world. Their bodies show off swimming adaptations. Drag is reduced by their fusiform body shape, smooth skin made up of tiny cycloid scales, a crescent-shaped caudal fin, body depressions for tucking in their pectoral fins, finlets behind the rear dorsal fin and anal fin, and lateral keel on each side of the tail fin (Figure 12.1). The caudal fin is stiff without flexible fin rays. The keel provides greater area for attachment of ligaments that connect the huge muscle mass to the tail fin. Tuna provided inspiration for engineers interested in designing of autonomous underwater vehicles. A robotic swimming tuna, RoboTuna, was created by a doctoral student at Massachusetts Institute of Technology in 1995 to mimic the tuna’s highly efficient propulsion. The earliest versions of the RoboTuna were not able to replicate the bursts of acceleration observed in real tuna.
All of the 7 species of bonito and 15 species of tuna are harvested. Fishery statistics do not identify them all to species. Seven species of tuna dominate the global landings and values as they enter international trade as fresh, frozen, and canned products:
• Albacore (Thunnus alalunga)
• Atlantic Bluefin Tuna (Thunnus thynnus)
• Pacific Bluefin Tuna (Thunnus orientalis)
• Southern Bluefin Tuna (Thunnus maccoyii)
• Bigeye Tuna (Thunnus obesus)
• Yellowfin Tuna (Thunnus albacares)
• Skipjack Tuna (Katsuwanus pelamis)
The largest species are Bluefin Tunas. Atlantic and Pacific Bluefin Tuna have a maximum recorded weight of 685 kilograms (1,510 pounds). The size of a species is related to the type of commodity the fish supports—namely sushi, loins, or canned (Figure 12.2.). At least three-quarters of all tuna landed is canned, and most of this is Skipjack, Yellowfin, and Albacore. Skipjack Tuna is the most caught species by number and weight, representing more than half of the global volume of tuna harvested (McKinney et al. 2020). Skipjack Tuna is marketed as “light” or “chunk light” tuna. Albacore is the most expensive canned tuna, marketed as “white” meat tuna. Large Bluefin Tuna and Bigeye Tuna are “red” meat tuna and are priced substantially higher because they are destined for sashimi and sushi markets, where they sell for \$45 to \$55 per pound. Bigeye Tuna and Yellowfin Tuna are known locally in Hawaii and in fish markets as ahi. Other tuna, such as the Little Tunny (Euthynnus alleteratus) and Blackfin Tuna (Thunnus atlanticus), are less important in global trade but are incredibly important to coastal artisanal and subsistence fisheries.
Water temperature preferences of tuna broadly predict their distribution on a global scale (Boyce et al. 2008). Bluefin Tuna, Bigeye Tuna, and Albacore have the widest temperature preferences and are found in waters as cold as 10°C. Skipjack and Yellowfin Tuna are tropical tuna and most abundant in waters with temperatures greater than 18°C. Consequently, the number of tuna species encountered by fisheries is highest in the largest and warmest ocean, the Pacific.
12.3 Historical Roots of Tuna Fishing
Tuna fishing is one of the oldest marine fishing traditions, often traced back 12,000 years. Other evidence confirms that indigenous people were tuna fishing off the northern Australian coast 42,000 years ago (O’Connor et al. 2011). Neanderthals knew that giant tuna moved through the Strait of Gibraltar every spring on their way to spawning grounds and in summer as they leave the Mediterranean. Tuna were followed by Orcas (Orcinus orca), whose breaching behavior revealed their locations. Orcas ambushed the migrating giant tuna as they swam the narrow channel at Gibraltar. Neanderthals caught Bluefin Tuna that beached themselves while trying to escape the Orcas (Adolf 2019). Extinction of the Neanderthals about 40,000 years ago corresponds to the arrival of Homo sapiens in Africa, who continued to exploit tuna as a food source.
As visual predators, tuna choose to migrate along the shallower waters along the coast where they find more abundant prey. Consequently, early fishers learned of the predictable journeys and built large traps fixed to the seabed. The term for tuna fishing is almadraba in Spain, tonnare in Italy, and madrague in France. This technique uses a maze of nets, anchored to the seabed, to catch tuna as they follow their migratory route (Figure 12.3). Once tuna are trapped in the central chamber, fishers would lift the net to the surface to harvest them. Some brave fishers even jump in the tuna-filled net to harpoon and attach ropes to the tail of each fish so that they can be lifted from the water. The trap fishing methods were described in ancient Greek and Roman literature from 1500 BC (Vargas and Corral 2007), and they are the oldest form of industrial fishing in the world. Catching a large shoal of tuna in such traps results in enormous profit.
Tuna was the first fish in human history to be captured, processed, and sold on a large industrial scale. The ancient civilization of Phoenicia (1550 BCE to 300 BCE) became prosperous because they were adept in maritime arts and shipbuilding, thereby permitting trade with ancient Greeks and other settlements in the Mediterranean. Phoenicians first began an industry based on catching, preserving, and trading tuna in the Mediterranean. The ancient Greeks, like the Japanese today, showed preference for the fatty belly cuts. The Phoenicians also invented a salting technique to conserve large quantities for trade to distant markets. Garum, a liquid fish extract derived from aging a mix of the entrails of tuna with salt water, became and remains an exclusive delicacy. Tuna trade grew from a small-scale consumption to massive trade by the sixth century BCE. Industrial fishing for tuna has expanded and persisted through the turmoil of wars, from the Punic Wars and the Fall of the Roman Empire in the Mediterranean to World War II, when the United States deployed tuna clipper ships as minesweepers.
The Roman legal concept of res communis meant that coastal fishing grounds were initially open to all. Phoenicians brought large-scale tuna fishing from the east to the west of the Mediterranean. Throughout the various shifts in ruling dynasties in Mediterranean countries, these fisheries persisted. During the Middle Ages (approximately from the 5th to the late 15th centuries), tuna fishing enriched the fortunes of Spanish dukes, who held a fishing monopoly along Spain’s southern coast.
After the Spanish Armada was defeated by the English navy in 1588, tuna catches dramatically decreased, and demand for the fish plummeted as continuing wars complicated trade. Many signs were emerging of local declines in Bluefin Tuna, which may represent the first documented fisheries collapse. In the 18th century, a monk, Brother Martín Sarmiento, referred to as the Tuna Saint, researched and wrote the first scientific study on sustainable tuna management. In the study, he warned of the decline in Bluefin Tuna and began to promote sustainable fishing, advocating for closed season and a ban on tuna fishing in the ocean. Spain had and still has the largest fishing fleet in Europe and the biggest industry for canning tuna. Tuna fisheries were on the verge of collapse as more and more almadrabas were discontinued. No one before Sarmiento had warned that overfishing was the cause of the tuna crisis. Warnings of the so-called Tuna Saint against fishing during the breeding season despite a ban were not effective at reducing fishing capacity.
The Tuna Saint’s recommendations to the duke to create catch quotas and enforce measures to protect the juvenile tuna were not accepted. Lack of regulation continued through the 19th century because of prevailing views that ocean fisheries were inexhaustible. In 1883, eminent scientist Thomas Henry Huxley declared that “Probably all the great sea fisheries are inexhaustible; that is to say, that nothing we do seriously affects the numbers of fish. Any attempt to regulate these fisheries seems consequently, from the nature of the case, to be useless.” The combined effects of fishing based on short-term profits and the increased availability of herring, cod, and salmon brought competition that doomed the giant tuna fisheries.
Despite their journeys back and forth the tuna . . . cannot avoid being eaten by larger fish, and especially by man.
—Brother Martín Sarmiento (1757)
Purse seines and longlines replaced beach seines and traps when tuna fishing effort expanded into the Atlantic Ocean. Japanese fisheries also expanded largely through pole and line fishing. Although canning methods were invented in the early 19th century, tuna were not canned until 1904, many decades after sardine, mackerel, herring, and salmon canneries became commonplace. Canning assured the consumer of a healthy protein that would keep a long time. The advent of canning and the wide distribution of tuna from tropical to subtropical oceans meant that people around the world and far from coastal areas became familiar with it. The rising demand for canned tuna at the start of the 20th century led to an expansion of the industrial fishing fleets, construction of many canneries, and control of prices by traders in the newly formed supply chain that exists to this day.
The labor-intensive almadrabas might have disappeared if not for the emerging demand in Japan for high quality Bluefin Tuna. During the 1960s, Bluefin Tuna were considered an undesirable food fish. Sport anglers caught them and sold them for cat food. Fishmongers would throw away the fatty belly meat. A restauranteur arranged to buy these for his sushi restaurant in Little Tokyo, Los Angeles. Japanese businessmen introduced American businessmen to sushi, and Hollywood, Chicago, and New York embraced sushi. Soon sushi restaurants were everywhere and sushi-quality tuna was in high demand. Improvements in freezing methods meant that tuna from around the world could be air shipped to Japan’s largest fish market, the Tsukiji Market. Japan Airlines would deliver electronics, cameras, and textiles to airports in eastern North America and return to Tokyo with crates of frozen Atlantic Bluefin Tuna.
Today, purse seines are the dominant gear used to target tuna, which form large, dense schools. The schools can be surrounded by a vertical net, after which the bottom of the net is drawn together to enclose the fish like tightening cords on a drawstring purse. Purse seines permit large catches of a single species, such as Yellowfin Tuna (Figure 1.3; Figure 12.4). Today, the demand for tuna has never been higher, and the largest super seining fishing vessel, the Albatun Tres, can net 3,000 tonnes in a single trip. As discussed in the following section, tuna fishing is highly industrialized and profit driven, depending on a complex, widespread supply chain.
12.4 Industrial Fishing, Supply Chains, and Status of the World’s Tuna
Tuna support the world’s largest global seafood companies. Commercial fisheries alone produced \$40.8 billion in sales in 2018, making tuna the most valuable commercial fish on the planet. Other values include subsistence fisheries, sport fisheries, unreported catch, and ecosystem benefits. Tuna is the second-most-consumed seafood in the United States behind shrimp, and the second-most-eaten fish in Britain, behind salmon. Projected increased seafood demand in China will further complicate its management (Crona et al. 2020). Keeping tuna as an affordable seafood product requires accurate information about the supply chain. The tuna supply chain encompasses all the activities required to get a business’s products to consumers, from catching, transfer to processors, transport to distributors, retailers and, finally, to consumers. It begins with the fishing boats and ends when the final product is sold to consumers far from the site of capture (Figure 12.5). An efficient supply chain saves money and helps processors and retailers produce and transport only what they can sell. Much of the tuna catch is exported from the country of origin, and the supply chain must be coordinated with regulations imposed by governments and regional fisheries management organizations (Kresna et al. 2017; Mullon et al. 2017).
Three main distribution channels for captured tuna include (1) fresh fish landings to processing facilities from fishing vessels or carrier boats; (2) frozen fish landings directly from fishing vessels; and (3) frozen fish transshipped from fishing vessels onto carrier vessels and then to canneries. Because the tuna purchased in your local restaurant or fish market could originate halfway across the globe, consumers may be unaware of how and where it was captured. The long and complex supply chain makes it challenging to guarantee that the tuna on your plate is really the one that it is supposed to be. Furthermore, financial interests of distributors all serve to deprive actual fishers of profits while enriching middlemen and distributors. Consumers have many questions that are often difficult to answer. How can we ensure that the tuna we buy is slavery free? Do fishers have safe working conditions and fair pay? Were the fish captured with minimal bycatch of threatened species? Is the fishery managed sustainably? One tool to ensure the standard safety and quality is the traceability database system along the supply chain. It is very crucial, because every actor in the chain has a responsibility to ensure food safety and quality through handling, manufacturing, packaging, and transporting the product. Additionally, major tuna-consuming countries are adopting import controls to permit traceability of illegal, unreported, unregulated fishing and to support sustainability certification.
Tuna are highly migratory; therefore, a global and interconnected framework of organizations and policies is in place for managing stocks around the world. Commercial tuna fishing occurs in all the world’s oceans and more than 70 countries. At least 580 industrial-scale tuna purse seine vessels are in operation globally (Hamilton et al. 2011). The largest companies, including Bumble Bee®, Chicken of the Sea®, and StarKist®, are pressured by consumers to adopt principles of responsible and sustainable fishing while keeping prices competitive. The global canned tuna market alone was valued at U.S. \$8.57 billion in 2020 and is expected to grow up to \$12.5 billion by 2028 (Grand View Research 2020).
The trend in per capita consumption of canned tuna in the United States (Figure 12.6) shows a steady rise before, during, and after World War II, when the tuna industry touted the fish’s health benefits and claimed that it tasted like chicken. By 1950, it had overtaken salmon as America’s most popular fish. Charlie the Tuna was a cartoon character created in 1961 to advertise StarKist® tuna. Charlie resembled the beatnik of the day, with a beret to show his hip, cultured tastes (Figure 12.7). The popular catch phrase was, “Sorry Charlie, StarKist doesn’t want tuna with good taste, but tuna that tastes good!” Consumption peaked at nearly 4 pounds per person in 1989, when Americans consumed between half to two-thirds of the global supply of canned tuna. Clearly, decades of advertising, such as Charlie the Tuna, worked on American consumers. However, since the peak, consumption has fallen by half. One reason for this recent and substantial decline is changing consumer preferences for convenience foods. Additionally, consumer concerns over the killing of dolphins may have played a role.
Dolphin-safe labeling began in the United States, in response to consumer reactions to dolphins killed in purse seines. Commercial tuna fisheries in the tropical oceans began to catch Yellowfin Tuna by spotting large aggregations of dolphins and seabirds associated with shoals of tuna and encircling them with purse-seine nets. These dolphin sets deployed very large nets (1,500–2,000 m long and 120–250 m deep) to encircle entire schools of tuna. Incidental take of dolphins was estimated at 550,000 in 1961 alone, and population estimates of spinner and spotted dolphins declined by more than half. Dolphin mortality was a problem for the purse-seine tuna industry, and many modifications in fishing methods and gears were tested. Principal innovations that were responsible for mortality reduction were “backing down” the net to allow dolphins to escape; and the Medina panel, which prevented dolphins from getting their snouts entangled in nets. The passage of the U.S. Marine Mammal Protection Act (1972), international agreements to limit dolphin mortality, and economic incentives, such as the dolphin-safe label, encouraged fishers to adopt improved fishing methods to minimize dolphin fatalities during fishing for tuna destined for canning. By 1988, a coalition of environmental groups called for a consumer boycott of the tuna caught by purse seines. Demonstrators carried signs saying, “Sorry Charlie—StarKist Kills Dolphins.”
In 1990, Bumble Bee, Chicken of the Sea and StarKist, the three largest tuna canners, voluntarily declared that they would no longer purchase tuna captured in association with dolphins. Soon the Marine Mammal Protection Act was amended to mandate that U.S. retailers exclude tuna caught using methods that set nets on schools of dolphins. Dolphin-safe tuna fishing must meet several standards: (1) no use of drift gill nets to catch tuna; (2) no accidental killing or serious injury to any dolphins during net sets; (3) no mixing of dolphin-safe and dolphin-deadly tuna; and (4) an independent observer must be on board attesting to the compliance. Recent observations show that entanglement mortality of dolphins has been reduced by 99% (Balance et al. 2021).
Today most tuna are captured in purse seines, and longlines are the second-most-common gear. Indonesia and Japan are consistently the top-two fishing nations (Figure 12.8). Five of the top tuna fishing nations—Japan, Taiwan (Republic of China), Spain, Korea, and the USA—have large fishing fleets that operate far from their home waters, whereas the others have large local or regional fleets. New technologies, such as sonar, have made tuna fishing much more effective. In response, the use of spotter planes is banned for fishing Atlantic Bluefin Tuna in the Mediterranean (Di Natale 2020). Many recreational tuna boats also use spotter planes in the eastern Atlantic Ocean, although the traditionalist harpoon fishers shun the technology (Whynott 1995; Decker 2016).
The Pacific Ocean has consistently had the highest landings, about 66% of the world’s tuna catch. The western and central Pacific Ocean is where many artisanal and industrial fisheries overlap. For the small island nations, fishing provides a major source of income, jobs, and food security (Bell et al. 2019). Yet, Pacific island nations have not fully realized the economic potential with the global tuna industry, despite the fact that 80% of it is caught within their exclusive economic zones (EEZs, i.e., within 200 miles). The 1982 United Nations Convention on the Law of the Sea awarded coastal states sovereign rights to (1) exploit and manage all living resources within their EEZ, (2) exclude distant water fleets in favor of developing their own fleets, and (3) charge distant water fleets rent for access. Eight island nations—the Federated States of Micronesia, Kiribati, Marshall Islands, Nauru, Palau, Papua New Guinea, Solomon Islands and Tuvalu, which support 80% of the purse-seine catch in their waters—formed an alliance and require collective bargaining to set rents for access by foreign vessels. The alliance also prioritized domestic over foreign vessels and set limits on the number of purse-seine vessels. The issue of sovereignty over tuna that migrate freely among EEZs remains a concern for small island nations (Bailey et al. 2012). Working to establish fair and equitable allocations of total allowable catches to the many parties will require more equitable sharing with the larger tuna-fishing nations.
Supply-chain management of tuna focuses mostly on the at-sea operations and marketing and processing standards. Throughout the world, tuna fishing is a male-dominated activity. Yet, women play essential roles in different nodes of the supply chain (Barclay et al. 2021). Management organizations typically exclude women for policy making, and existing policies fail to recognize women’s work in tuna supply chains and in supporting men who fish at sea. Weak gender-based policies make women more vulnerable or easily subjected to sexual harassment, exploitation, and abuse in the workplace.
The tuna fishing industry has long been plagued by overfishing, corruption, human rights abuses, fraud, and illegal, unreported, and unregulated fishing, all of which compromises the well-being of environments and communities. Pacific island fisheries are particularly imperiled by corruption and lack of strong governance (Hanich and Tsamleyi 2009). Additionally, illegal, unreported, and unregulated tuna fishing is a major problem, especially in the Pacific Ocean, where estimates show the value lost annually to coastal nations is approximately \$333.5 million (MRAG Asia Pacific 2021).
12.5 Recent Advancements in Tuna Fisheries
High-profile tuna brands have adopted corporate social responsibility guidelines to ensure that issues such as sustainability, IUU fishing, and social welfare are considered in business operations. French explorer Jacques Cousteau (1910–1997) had a way of making people passionate about marine life via his documentaries on underwater life and consequences of human negligence. After Cousteau visited an almadraba in action and dove in the innermost chamber surrounded by Bluefin Tuna and bonito, he wrote, in The Silent World (French: Le Monde du silence, 1956), that it was one of the “most horrible and grand” marine spectacles to be seen (Adolf 2019). Subsequently, nongovernmental organizations developed campaigns to reduce large-scale industrial fishing and promote sustainable fishing practices and the need for traceable tuna products (Bailey et al. 2016).
The supply-chain harvesters and retailers are playing a much larger role in shaping the international governance of tuna fishing. The number of fisheries that hold or are seeking sustainability certification have greatly increased over the past decade (Schiller and Bailey 2021). For example, the Marine Stewardship Council certifies pole-and-line–caught tuna (Figure 12.9), such as the Maldives Skipjack Tuna fishery of the Indian Ocean. Here the tuna are captured one by one and have low levels of bycatch and fish at levels that are sustainable. Tuna fishing is the second major source of income for the Maldives, after tourism. Fair Trade-certified fisheries meet a set of rigorous, audited criteria that work to protect the fundamental human rights of fishermen, as well as the ecosystems impacted by the trade. Consumers are willing to pay more for ecofriendly canned tuna, and sales at supermarkets have been trending upward (Sun et al. 2017).
Despite growing public concerns and efforts across the seafood sector to address corporate social responsibility, corruption and price fixing among the big-three tuna canning companies was recently exposed in a lawsuit brought by 25 major U.S. retailers. The big-three tuna brands control almost three-fourths of the shrinking American consumer market. Cans of tuna on grocery shelves were getting smaller and quality was dropping, yet prices increased. Guilty pleas were filed by all three tuna companies and several of their executives. The CEO of Bumble Bee Foods was sentenced to a 40-month prison sentence. Bumble Bee admitted to price fixing and agreed to pay a \$25 million fine as part of a plea agreement, and StarKist was sentenced and ordered to pay a \$100 million fine.
Globally, the abundance of tuna has declined by more than 50% over the past century, with steepest declines observed in the largest, longest-lived, highest-valued tuna (Juan-Jordá et al. 2011). Stocks are either overfished or fished at levels near the maximum sustainable yield levels, preventing further expansion of catches. Tuna fisheries that are overfished must be rebuilt with stricter measures to reduce overcapacity in the face of rising demand.
Two sources provide assessment of conservation status. The International Union for Conservation of Nature (IUCN) provides a global classification based on population decline and threats other than fishing pressure (Collette et al. 2011; Collette 2017). The status of world fisheries is periodically assessed for the seven species of major commercial tuna stocks. The assessment is challenging because of their migratory behavior and often differing spawning locations. Regional fisheries management organizations (RFMO) are responsible for stock assessment and management of 23 tuna stocks (6 Albacore, 4 Bigeye, 4 Bluefin, 5 Skipjack, and 4 Yellowfin stocks). Ideally, sustainable fishing means spawning-size fish abundance is at or above the level that produces maximum sustainable yield, fishing mortality is less than that which would produce the maximum sustainable yield, and there is minimal bycatch of nontarget species (ISSF 2022; Medley et al. 2022). There are five tuna RFMOs, which are responsible for assessing and managing the 23 stocks of the seven major commercial oceanic tuna species:
• IATTC: Inter-American Tropical Tuna Commission
• ICCAT: International Commission for the Conservation of Atlantic Tuna
• CCSBT: Commission for the Conservation of Southern Bluefin Tuna
• IOTC: Indian Ocean Tuna Commission
• WCPFC: Western and Central Pacific Fisheries Commission
Albacore are not overfished or experiencing overfishing. However, lack of reporting remains a concern, and the IUCN classifies them as Near Threatened. Atlantic Bluefin Tuna are rebuilding and classified as Near Threatened in eastern stock and Endangered in the smaller western stock. Both stocks are in a rebuilding phase. See section 12.6 for more details. Pacific Bluefin Tuna are overfished and down to 4.5% of their historic biomass (ISC 2022) and in need of a rebuilding plan. The Atlantic Bluefin Tuna (Thunnus thynnus) moved from Endangered to Least Concern, while the Southern Bluefin Tuna (Thunnus maccoyii) moved from Critically Endangered to Endangered. The Albacore Tuna (Thunnus alalonga) and Yellowfin Tuna (Thunnus albacares) both moved from Near Threatened to Least Concern. The Pacific Bluefin Tuna (Thunnus orientalis) moved from Vulnerable to Near Threatened in this update due to the availability of newer stock assessment data and models. Other tuna species reassessed for this Red List update include the Bigeye Tuna (Thunnus obesus), which remains Vulnerable, and the Skipjack Tuna (Katsuwonus pelamis), which remains Least Concern. Harvesting Bigeye Tuna with purse seines near FADs (fish aggregating devices) targets smaller Bigeye Tuna. Yellowfin Tuna are fully fished or overfished, and overfishing continues in the eastern Pacific and Indian oceans.
Currently, the traceability system in the tuna industry, even in the largest exporting country of Indonesia, is conducted through a paper-based system. However, a computer-based network, known as the blockchain, could revolutionize catch documentation and traceability through real-time data acquisition and integrated data access and transparency at every step along the supply chain. Under a blockchain-based system, fishing vessels are tracked with satellites (Taconet et al. 2019), and, from the time of capture, each tuna can be given a unique identification that is permanent and fully traceable across the blockchain database. At its core, blockchain technology is simply a digital, tamper-proof record of information that is accessible to businesses, restaurants, supermarkets, and, ultimately, even consumers. By tracking the fish from the moment it’s caught, blockchain would make it nearly impossible for any illegal or unreported tuna to enter the market over time. The traceability allowed by blockchain technology would allow consumers to be confident about what they are eating, where it came from, how it was produced, and how it got to them. Such new technology was piloted by the World Wildlife Fund (WWF) in 2017 and remains under development across several fisheries. Fisheries specialist Bubba Cook with WWF says, “If you have the opportunity as a consumer to know with confidence that you’re buying from a fishery that engages in sustainable and ethical practices, then of course you would want to do that” (Whiting 2020).
Thanks to demand for the highest-quality tuna for sushi and sashimi, the Japanese developed a new and more humane killing method that maintains the quality of the flesh. Any stress to a recently captured fish reduces the eating quality and shortens the storage life of the flesh (Poli et al. 2005). Some fish consumers have changed eating patterns as they learn that fish have consciousness, experience pain, are social, know how to use tools, and are able to communicate (see Chapter 5 in this book). Yet, even if the consumer is not concerned with the welfare of the tuna, preventing muscle spasms in dying tuna will improve the flesh quality. Spasms cause muscles to release lactic acid, which in turn leads to bacterial changes that acidify muscular tissue and give the meat a brownish tint and bitter taste.
The ikejime killing method is similar to pithing a frog. A spike is inserted quickly and directly into the hindbrain, thereby causing immediate brain death. Then, a thin needle or wire is inserted into the spinal column ceasing all muscle movement. The tuna is then bled and placed on ice. Tuna killed in this way have better flesh quality than those killed by suffocation or bleeding.
Question to ponder
What aspects of tuna fishing are most important to you as a consumer? What additional information would you prefer to be added to labels for all tuna products on the market?
12.6 Atlantic Bluefin Tuna
Atlantic Bluefin Tuna are one of three different species of Bluefin Tuna (Figure 12.10). The other very similar species are the Pacific Bluefin Tuna and the Southern Bluefin Tuna. Bluefin Tuna is one of the sea’s most valuable species, a highly migratory fish that has been harvested for many centuries. After a long history where fishing was primarily in the Mediterranean, new fisheries emerged throughout the Atlantic Ocean. The new fisheries adopted purse seines and longlines instead of beach seines and traps. The new gears were more effective, and increased fishing effort after World War II led to substantial declines in the harvest of Atlantic Bluefin Tuna and calls to develop an improved governance system to regulate fishing.
Bluefin Tuna were not always popular food fish. In the 1800s, the Japanese referred to tuna as neko-matagi, meaning “fish that even a cat would disdain.” Until recently, the red flesh and robust taste of Bluefin Tuna were not desirable for consumption. It was primarily a sport fish caught for fun along the Atlantic Coast from Nova Scotia to Massachusetts in the 1940s, 50s and 60s. The big tuna were weighed and photographed, then sent to landfills or sold for under \$1 per pound to be turned into pet food. Chasing giant Bluefin Tuna always attracted big-game anglers to tournaments, such as the International Tuna Cup Match, which began in 1937. Atlantic Bluefin Tuna recreational fishing increased as a specialized sport, some with hook-and-line fishing and others devoted to the use of harpoons (Decker 2016). The record Atlantic Bluefin Tuna landed in 1979 weighed 1,496 pounds—a record that continues to stand today. Television series, such as Wicked Tuna, brought broader attention to rod-and-reel fishing for Atlantic Bluefin Tuna.
Growth in market demand for Bluefin Tuna exploded in the 1970s, after Kobe beef, a fatty, well-marbled product, was first introduced and marketed in Japan (Longworth 1983). This resulted in appreciation of strong flavors and dark flesh, and Japanese developed a taste for toro, the fatty belly flesh of the Bluefin (toro means “to melt,” in reference to its buttery texture). Fish wholesalers wear masks and sanitize their hands as they examine the texture of tail meat from fresh and frozen tuna by touching, smelling, and sometimes tasting pieces of it. Sushi chefs handle and serve different cuts of Bluefin Tuna flesh. Every cut has a different name and purpose. The cuts from the cheeks and top of head are found only at a few high-end Japanese restaurants.
Japanese fishmongers were the first to store and age tuna to soften the rich flavor (Goulding 2000). When Bluefin Tuna was introduced to high-end restaurants, demand continued to skyrocket. Demand for high-quality sushi led to another expansion in Bluefin Tuna fishing well before tuna management was ready to adapt. Soon a heavily subsidized European Union fleet of giant, specialized purse-seining vessels vastly expanded the catch of Atlantic Bluefin Tuna. Bluefin Tuna caught from the Pacific, Atlantic, and Southern oceans were flash-frozen and shipped for auction at Japan’s Tsukiji Market, the biggest wholesale fish and seafood market in the world (Figure 12.11). At the first auction of the year, the first Bluefin Tuna auctioned receives special attention. The owner of a Japanese sushi restaurant chain set a record by paying more than \$3.1 million for a 278-kg (613-lb) Bluefin Tuna. These high bids receive a lot of press attention, which inspires customers to flock to sushi restaurants. However, the auction price is highly symbolic and not an accurate measure of the price of tuna.
Landing records for Atlantic Bluefin Tuna date back to 1525, from almadrabas in the western Mediterranean and the Strait of Gibraltar (Ganzedo et al. 2016). Landings have always shown short-term and long-term fluctuations associated with conditions that modify fishing conditions or spawning behavior and early survival of young Bluefin Tuna. One constraint to management of the Atlantic Bluefin Tuna has always been the lack of certainty over the spawning locations and migratory path. Atlantic Bluefin Tuna feed in the productive waters off the coasts of North America, Europe, and Africa (Block 2019). Each year mature fish make long migrations so they can reproduce in warm waters >24°C suitable for eggs and larvae. Tuna from each spawning ground mix during the rest of the year (Rooker et al. 2007). Therefore, an Atlantic Bluefin Tuna caught anywhere in the Atlantic cannot be identified to its spawning stock. The mid-Atlantic region has the highest mixing levels (Siskey et al. 2016).
Since 1950, landings of both stocks fluctuated, but landings demonstrated that the Eastern stock was larger (about 10-fold) (Figure 12.12). The Japanese fishing fleet started to actively fish Bluefin Tuna in the Atlantic in the 1950s. In 1966, tuna fishing nations formed the International Commission for the Conservation of Atlantic Tuna (ICCAT), and management decisions were made by representatives from 51 countries. Few regulations were in place in the early years of ICCAT. While ICCAT does not have regulatory or enforcing powers (Korman 2011), it is entrusted with collecting and compiling statistical data, generating scientific reports, proposing nonbinding management recommendations based on its findings, and creating an arena for contracting parties to meet and discuss recommendations. Scientific advice from ICCAT has often been watered down or manipulated for political purposes (Telesca 2020). Member states are responsible for the implementation of regulations, monitoring, sanctioning, and collection of data. It was 1975 before ICCAT recommended a minimum size of 6.4 kg (~age two and still immature), reflecting recommendations by the Tuna Saint in the 1800s (Mather et al. 1995). One of the most significant changes occurred in 1981, when ICCAT elected to divide governance into Eastern and Western management units using an effectively arbitrary boundary of 45°W longitude. In the 1990s, long-liners and purse seiners with spotting planes were prohibited in Mediterranean Sea at vulnerable times of year when ICCAT and others recognized that the Atlantic Bluefin Tuna were overfished (MacKenzie et al. 2009).
It was 1998 before ICCAT would establish the first country-based quotas for Bluefin Tuna. Quotas were set too high in response to economic and political pressures. The period from 1997 to 2007 (Figure 12.12) was time of fraud, blatant overfishing, and rule breaking, with catches over twice the annual quota. At this time of peak landings, a black market worth an estimated \$4 billion caught more than one out of every three Atlantic Bluefin Tuna (Guevara et al. 2012). Not surprisingly, by the turn of the century, the spawning stock hit a new low. Countries were forced to reveal their true catches; for example, France revealed its true catch was almost double the ICCAT quota. In 2010, some sushi consumers boycotted Bluefin Tuna over concerns about population declines.
Atlantic Bluefin Tuna are large as adults, have high fecundity, low early survival, and moderate longevity (>30 years). A 5-year-old female produces about 5 million small eggs (~1mm), while a 15-year-old female can carry up to 45 million (Rodriguez-Roda 1967). However, environmental conditions during early life greatly influence survival of the eggs and larvae. Therefore, Atlantic Bluefin Tuna depend on a broad representation of multiple age groups because not all spawning seasons provide favorable conditions for spawning and larval conditions to lead to large year classes. Spawning biomass of both stocks of Atlantic Bluefin Tuna dropped below the limits set by management organizations (Figure 12.13), triggering more regulations (Fromentin and Powers 2005; Fromentin 2009; Taylor et al. 2011; Fromentin et al. 2014; Cort and Abaunza 2015; Porch et al. 2019; Lauretta et al. 2020; Telesca 2020).
Illegal and unreported tuna fishing meant that catch statistics (Figure 12.13) were underreported, and stock assessments were biased toward estimating steep declines. Unreported catches from the Mediterranean (19,400 in 2006 and 28,600 in 2007) significantly contributed to the rapid decline in the stock (Agnew et al. 2009). Because of the mixing in the Atlantic, the successful rebuilding of the western population was tied to controlling the much larger fishing mortality rates that occur on the eastern stock (Taylor et al. 2011; Porch et al. 2019). For example, continued high fishing mortality rates in the Mediterranean Sea and eastern Atlantic compromise rebuilding efforts for the western Atlantic population.
Nongovernmental organizations also started campaigns to reduce fishing of Atlantic Bluefin Tuna. In 2007, ICCAT developed a plan to increase the minimum weight limit to 30 kg and implement surveillance and enforcement of quotas, with funding support from the European Unions. Nongovernmental organizations petitioned the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to restrict international trade in 2010. With 183 member states (including the EU countries), CITES is an unwieldy international group. Moreover, big tuna-fishing nations objected to the petition at the 2010 annual CITES conference, making deals with developing countries in return for their objecting to the proposal. The deciding incident was the screaming from the delegate from Libya over “imperialist nations” depriving Libya of its fair share of tuna. At the time, Libyan leader Muammar Gaddafi’s family was deeply involved in massive illegal tuna fisheries and smuggling and had expanded its EEZ to keep other countries out. The proposal to CITES was voted down by a clear majority, leaving ICCAT to enforce existing quotas to recover Mediterranean stock.
Also in 2010, the Center for Biological Diversity petitioned the National Marine Fisheries Service (NMFS) to list the Atlantic Bluefin Tuna (western stock) as endangered (Atlantic Bluefin Tuna Status Review Team 2011). The review by NMFS acknowledged the threats to coastal habitats but concluded that they do not represent a substantial risk to long-term persistence of the species. Furthermore, they judged that lowered quotas would allow for an increase in abundance. The ICCAT plan included an emergency clause that specified that if serious threat of stock collapse is detected in future stock assessments, ICCAT shall suspend all Atlantic Bluefin Tuna fisheries in the western Atlantic for the following year.
The path to eventual recovery of the Atlantic Bluefin Tuna is far from certain (Lauretta et al. 2020). Although overfishing is not occurring, the abundance measures are still below targets set by the ICCAT. If landings continue to stay below the total allowable catch, the population should grow. However, the giant specimens of tuna, as well as other newsworthy ginormous fish, are now rarer than in previous decades and centuries (Francis et al. 2019). There are signs that Atlantic Bluefin Tuna are expanding in the North Sea, Norwegian Sea, and northeast Atlantic as herring and mackerel have increased in abundance (MacKenzie et al. 2022). Hopeful signs for the Atlantic Bluefin Tuna may encourage adoption of similar strategies to recover the Southern Bluefin Tuna, the population of which was just 2.6% of the original unfished stocks (Nickson 2016).
The case of the Atlantic Bluefin Tuna highlights the challenge of managing fish populations in a complex global fishing supply chain. What has emerged may be viewed as a sociological and political problem or a “wicked problem,” difficult to solve because of the complex and interconnected nature and competing goals. Regional fisheries management organizations are reactive instead of proactive and respond to complaints from powerful constituencies with effective or ineffective policies, while marginalized peoples have little power to effect change (Webster 2015; Nakatsuka 2017). A large global and borderless economy easily leads to overcapacity of subsidized fishing fleets and competing interests and indifference. Marginalized groups have less political clout to mobilize efforts to address problems. Japan is the largest importer of Bluefin Tuna and considers sushi from them an acquired right. Consequently, when quotas are reduced, each country must adjust to meet the quota, creating incentives for fraud in reporting catches.
Consumption of Bluefin Tuna is an example of conspicuous consumption, which is the display of ostentatious wealth to gain status and reputation. Bluefin Tuna is a Veblen good, meaning the demand for it increases as one’s income rises (Veblen 1912). A Veblen good has an upward-sloping demand curve, which runs counter to the typical downward-sloping curve (Figure 12.14, top portion of curve). A rational consumer would consider alternative goods available in the market, and when the price for certain goods decreases, the demand should increase, and vice versa (Figure 12.14, bottom portion of curve). However, consumers have increasingly prized Bluefin Tuna as a status symbol as it becomes more and more uncommon and thus more expensive. The fewer Bluefin there are, the more sushi made, and so the more consumers want it, and thus the more it is overfished. Consumer behavior—that is, demand for a rare and expensive commodity—contributes to the decline in Bluefin Tuna abundance (Barclay 2015).
12.7 Tuna Ranching
Tuna ranches may have revolutionized the Bluefin Tuna industry, bringing fantastic profits. Increasingly, captured Bluefin Tuna are destined for aquaculture (Metian et al. 2014). However, they are controversial and have not reduced demands on wild stocks. Rather, tuna ranches became a point of conflict in the 1990s during the height of overfishing on all three species of Bluefin Tuna. An estimated 67 ranches spread across the Mediterranean, along with other ranches in Japan, Australia, and Mexico. Australia piloted tuna ranching in 1991 with funding from the Australian government, a Japanese fisheries foundation, and tuna boat owners in Australia. Tuna ranching is based on the capture of young Bluefin Tuna in purse seines. Because the entire process happens underwater, ranching made it impossible to verify the weight or number caught, leading to undersized tuna captured. These juveniles were transferred to large circular pens where they were fattened by feeding them sardine, herring, and mackerel. Tuna ranching has economic advantages: the fish are sold to ranches instead of being sold cheap to the Japanese; also, they have grown large enough (>25 kg) for the market to have improved fatty flesh quality.
Financing for many of the tuna ranches was traced largely to Japanese fish trading houses and Mitsubishi Corporation, a corporate giant that owns subsidiary companies that control much of the Bluefin Tuna market in Japan. Laundering tuna allowed the new industry to dodge quotas. Catches were underreported or traded with ranches in less-regulated countries and mixed with legal catches (Center for Public Integrity 2012). Some visionaries see a time when Bluefin Tuna aquaculture will not require harvesting young tuna to stock pens. Efforts to breed Bluefin Tuna in captivity have been successful in establishing a domestic population (Ortega and de la Gándara 2019). Selective breeding programs may reduce the feed requirements and grow-out times (Klinger and Mendoza 2019). Bluefin Tuna farming still presents many environmental concerns associated with other farmed carnivores, including the need to harvest forage fish for feed (Naylor et al. 2021). Time will tell if aquaculture can solve the problems of meeting the demands for the most expensive fish in the world today.
12.8 Outlook for Sustainability of Tuna Fisheries
Our relationship with tuna will continue to focus on these fish as a commodity and not a key part of the ocean ecosystems. Tuna fisheries continue to provide an important source of employment and foreign exchange for major fishing countries. Problems, such as overfishing, subsidies, human rights abuses, and fraud, as well as illegal, unreported, and unregulated fishing, are well recognized, and the experts have differing views of the future for sustainable tuna fisheries (Adolf 2019; Telesca 2020). The difference of opinions is due to a mix of positive signs and continuing challenges:
• Improved governance
• Traceability and ecocertification of tuna products
• Mercury contamination
• Oil spills
• Climate change and shifting baselines
• Ecosystem connections
Improved Governance
Countries that subsidize tuna fishing fleets can overfish stocks, while smaller subsistence fisheries are disadvantaged (Sumaila et al. 2014; Bush and Roheim 2018). Larger tuna fleets also target high-value species for export to the luxury market (Willis and Bailey 2020). Fishing fleets can target fishing in countries with little enforcement, and once the fish are landed at a port, it is very difficult to determine where, how, and by whom the fish were caught.
The FAO Code of Responsible Fisheries sets out international principles and standards of behavior to ensure effective conservation, management, and development of living aquatic resources (FAO 1995). These principles are intended to prevent overfishing, while meeting the needs of present and future generations in the context of food security, poverty alleviation, and sustainable development. Limiting access to tuna fishing via individual transferable quotas is controversial, as it focuses only on the aggregate economic performance through profit generation and not the well-being of tuna-fishing communities (Hallman et al. 2010). For example, led by powerful ranching investors, tuna fisheries in Malta transitioned from an open-access artisanal activity to an industrial one with an individual transferable quota system. The shift raised questions over who had legitimate fishing rights and decreased profitability for artisanal due to competition with industrial fishing (Said et al. 2016). The artisanal fishing of Bluefin Tuna in Malta has been ongoing since the 1700s, yet the future livelihood of artisanal fishers is now at risk. Furthermore, tuna ranching, owned by only five foreign companies, dominates much of the fishing for Bluefin Tuna in Malta. In Malta, the transition to industrialized tuna fishing resulted in very unequal benefits and was not aligned with FAO’s principles of responsible fishing.
Future decisions over tuna fishing can be improved by enhancing the function of the existing regional fisheries management organizations to counteract overcapacity of fishing fleets (Aranda et al. 2012). Some form of right-based management is being debated across multiple RFMOs, raising ethical questions in a world where food security, not profits, may become a top priority (DeBruyn et al. 2012; Dueri et al. 2016).
Question to ponder:
What factors should one consider when making a transition from artisanal and open-access fishing to a limited entry?
Policy changes that facilitate industrialization of tuna fishing and use of transferable quotas may be the beginning of the end for the artisanal tuna fishers. An alternative to individual transferable quotas was adopted by a coalition of eight island nations, dispersed over thousands of islands and atolls (Yeeting et al. 2018). The combined EEZs of the coalition support half of global catches of Skipjack Tuna and a quarter of all total global tuna catches. This agreement was designed to cap the number of purse-seine vessels by setting a benchmark price and allocating tradable fishing days. After this agreement was implemented, the price of fishing licenses rose, and tuna stocks increased (Adolf 2019). This partnership protects the food sovereignty of the island nations and may be the first step toward managing ownership of tuna resources.
There are signs from the most recent decade that more major stocks are being fished sustainably. Tuna stocks were more depleted for stocks with high commercial value, large size, and long lifespans. In addition, implementing and enforcing total allowable catches (TACs) had the strongest positive influence on rebuilding overfished tuna (Pons et al. 2017). RFMOs have made progress in implementing stock assessments for a wide range of taxa (Heidrich et al. 2022).
Traceability and Ecocertification of Tuna Products
The efforts to manage highly migratory tuna stocks have taught us that different governance arrangements, from state-based, public regulation to market-based, private initiatives, each have a role to play. Many consumers are concerned about illegal and unsustainable tuna fishing and will pay a premium price if they can verify the source of the product. Changes in management come from fishing companies that seek to differentiate their tuna products with a certification of sustainable fishing and global initiatives, such as the World Wildlife Fund’s Smart Fishing Initiative (Bailey et al. 2018). New tools, such as certification, recommendation lists, and traceability increasingly play important roles in modifying the purchasing behavior of consumers (Bush and Roheim 2018).
Improvements come from promoting the use of technology in fishing operations that permits both transparency and traceability of tuna products. Market incentives such as ecolabels can reduce illegal and unsustainable fishing by driving buyers toward more ethical and transparent producers while simultaneously excluding the rest. Electronic monitoring using cameras and other sensors on industrial tuna fishing boats supplements catch and effort information collected through logbooks, port sampling, and observer data. These procedural and technological advancements detect a vessel’s position and activity (Whiting 2020), while cameras record key aspects of fishing operations, such as observing bycatch of at-risk species. Local fishers and processors along the supply chain may then enter data into a database, such as a blockchain, via their mobile electronic devices (Figure 12.15). Consequently, the consumers at the end of the chain can see mobile-accessible information about location of the catch and suppliers along the entire supply chain. As of 2019, approximately 47% of the global tuna catch came from fisheries that either held or were seeking ecocertification from the Marine Stewardship Council (Schiller and Bailey 2021). An increase in certified tuna fisheries is expected as standards are established for electronic monitoring systems (Murua et al. 2022).
Mercury Contamination
Mercury is a persistent substance that can build up, or bioaccumulate, in living organisms. Bacteria and other living organisms convert mercury in the water to methylmercury, a highly toxic organic compound. Fish absorb methylmercury from their food as well as from water as it passes over their gills. As mercury-contaminated organisms are eaten and transformed at higher trophic levels, the concentration of methyl mercury increases through a process known as biomagnification (Figure 12.16). Because tuna are top predators as adults, they have high concentrations of mercury (Moura Reis Manhães et al. 2020). All three species of Bluefin Tuna have high concentrations of methylmercury that increase with age (Tseng et al. 2021). For example, the biggest Atlantic Bluefin Tuna ever caught off Delaware (873 pounds) had 2.5 parts per million, making it 2.5 times higher than the FDA action level for commercial fish (Absher 2005).
Mercury in fish is bound to proteins in fish tissues, including muscle. There is no method of cooking or cleaning fish that will reduce mercury levels. Both elemental and methylmercury can cross the blood-brain and placental barriers. The adult and fetal brains are targets for elemental mercury, and the brain and the kidneys are critical target organs for methylmercury. Methylmercury interferes with a cell’s ability to divide, and its effects on brain development can be permanent. Chronic exposures to children and developing fetuses show up later in the form of reduced performance on some tests of language, coordination, and intelligence. Chronic exposure to mercury in adults may be associated with an increased risk of cardiovascular diseases, reproductive harm, kidney disease, risk of dementia, and cancer (Ye et al. 2016).
Unfortunately, few consumers are aware of the mercury content in the tuna they eat. Some grocery chains now include FDA warnings to limit consumption of fresh or frozen tuna. California passed Proposition 65, which required warning about exposures to chemicals, including mercury, that cause cancer, birth defects, or other reproductive harm. However, tuna companies appealed the ruling requiring warning labels, and the court ruled that mercury in canned tuna is “naturally occurring” and therefore exempt from Proposition 65. However, whether the mercury is naturally occurring or added by human actions is irrelevant to the consumer. Jane Hightower, MD, found that many of her fish-loving patients had chronic methylmercury poisoning, which caused numerous symptoms that were not thought to be due to mercury until mercury levels were measured in the patient’s blood (Hightower 2008).
Concerns over mercury contamination will continue in the future, as the human health impact of chronic exposure to mercury is a topic of great controversy. Although aggressive regulation of mercury in North America and Europe since the 1970s reduced mercury emissions (Conniff 2016), the warming of the oceans will increase accumulation of mercury in tuna and other top predators (Shartup et al. 2019). Consumers should choose to substitute other lower-mercury fish for tuna. According to the FDA and the EPA, canned light tuna is the better, lower-mercury choice. Canned white and Yellowfin Tuna are higher in mercury, but still okay to eat one time per week. Bigeye Tuna and Bluefin Tuna, not typically used in canned tuna, should be avoided completely (Ballance et al. 2021).
Question to ponder
How much tuna can the average person eat? Apply the EPA/FDA advice of 0.7 ug/mercury/kg body weight per week to determine your safe weekly consumption of mercury. Use the calculator available at https://www.omnicalculator.com/ecology/fish-mercury#what-is-my-weekly-limit-for-mercury-intake.
Does your current consumption of tuna put you at risk for mercury poisoning?
Oil Spills
The Deepwater Horizon oil spill released ~4 million barrels of oil in the northern Gulf of Mexico in areas of known for spawning of Atlantic Bluefin Tuna. Oil can cause deformities and death in tuna eggs and larvae. Even short-term exposure of adults interferes with heart function in Atlantic Bluefin Tuna, which may lead to life-threatening arrhythmias (Brette et al. 2014). The Deepwater Horizon spill influenced less than 10% of the spawning area for Atlantic Bluefin Tuna and influenced only a single-year class (Hazen et al. 2016; Gracia et al. 2019).
Climate Change and Shifting Baselines
Long-term shifts in tuna are expected with climate change. Like other fish, the distribution of tuna has shifted northward in the Northern Hemisphere and southward in the Southern Hemisphere (Erauskin-Extramiana et al. 2019; Townhill et al 2021). These shifts will undoubtedly influence productivity of tuna and potential yields. Additionally, seafood rating systems (e.g., Monterey Bay Aquarium Seafood Watch) and seafood certifications (e.g., MSC) to inform purchasing decisions may consider the rising costs of fossil fuels in their rating systems (McKuin et al. 2021). Furthermore, setting appropriate baselines for recovery of tuna populations present a new challenge as old data sets are abandoned or forgotten. The average size of harvested tuna has been reducing over time. It is unlikely we will see a return of abundant giant tuna in our lifetimes. Shifting baselines affect our vision for the future.
Ecosystem Connections
Finally, the management of tuna seldom considers that they are also preyed upon in ocean ecosystems. Yet, predators such as large pelagic sharks and Orcas feed on tuna. Predators also depredate tuna caught in longline fisheries. Survival of killer whale calves was reduced and recruitment ceased when tuna stocks declined near the Strait of Gibraltar (Esteban et al 2016). Consequently, future stock assessments should consider the tuna predators when setting harvest quotas.
Profile in Fish Conservation: D. G. Webster, PhD
D. G. Webster is Associate Professor of Environmental Studies at Dartmouth University. Her major research interest is understanding feedbacks within global-scale social-ecological systems in order to improve environmental governance. Thus, she brings an important yet underutilized perspective from political science and organizational theory to bear on preventing collapse of international fisheries. She is author of two books, including Beyond the Tragedy in Global Fisheries, which explains the evolution of global fisheries governance through a responsive governance lens. Her research showed how fisheries all over the world may cycle through periods of effective and ineffective governance in what she calls the “management treadmill.” Her first book, Adaptive Governance: The Dynamics of Atlantic Fisheries Management, which won the International Studies Association’s Harold and Margaret Sprout Award, tested her vulnerability-response framework. Her contributions are relevant to the competition for fish associated with open access and declining fish stocks.
Webster’s concept of the governance treadmill helps to understand barriers to change and informs a wide range of crises. The concept was applied to the Maine lobster fishery, where governance shifted back and forth between effective and ineffective periods of management over a 200-year period. Recently, this concept helped scientists to demonstrate factors that help or hinder the alignment of government capacities toward prevention during public health crises, such as the COVID-19 pandemic. Stagnation in governance includes maladaptive responses by government, economy, and society that are ineffective. Often the very people with access to information and resources lack understanding to be effective. This was also evident in the response of ICCAT parties during the low ebb in Atlantic Bluefin Tuna populations.
Dr. Webster has explored new methods for exploring social-ecological systems as the lead investigator on a multi-institutional project called Fishscape: Modeling the Complex Dynamics of the Fishery for Tropical Tuna in the Eastern Pacific Ocean. This research focuses on international tuna fisheries, which are very difficult to manage. In the eastern Pacific alone, an area of about 10 million km2, over 200 purse-seine vessels from more than 10 countries fish for tuna. In this project, her research team uses a unique form of analysis, called “agent-based modeling,” to better model vessel search processes and better understand how different types of regulations will affect the fish and tuna fishers who rely of them. This project wrapped up in 2015.
Dr. Webster teaches courses related to global environmental governance, green business, marine policy, and environmental economics. She earned her PhD from the University of Southern California’s Political Economy and Public Policy program in 2005.
Key Takeaways
• Tuna are highly migratory species and, therefore, management of tuna fisheries involves substantial coordination among regional and international commissions and organizations.
• Oldest marine commercial fisheries targeted tuna in the eastern Mediterranean Sea.
• The principle of sovereignty over food demands that fisheries must be conceived as part of complex social and ecological systems where small-scale fishers play a central role in decision making.
• Popularity of tuna along with the far-distant fishing leads to increased demands, higher prices, illegal fishing, and incentives to invest in fishing fleets.
• Tuna stocks are more likely to be depleted for species with high commercial value and long lifespans.
• Subsidies for fishing fleets lead to overcapitalized and overfished tuna fisheries.
• Implementing, monitoring, and enforcing quotas have the strongest positive influence on rebuilding overfished tuna stocks, such as Atlantic Bluefin Tuna.
• Oversight and monitoring of tuna fisheries via vessel tracking and electronic monitoring are essential to prevent overfishing and illegal, unregulated, and unreported fishing.
• Future challenges to sustainable tuna fisheries include improved product tracing, concerns over mercury contamination, climate change, oil spills, and addressing ecosystem services provided by tuna.
This chapter was reviewed by Alfred “Bubba” Cook.
Long Descriptions
Figure 12.2: Illustration of seven common tunas; largest to smallest: 1) bluefin, 2) yellowfin, 3) bigeye, 4) albacore, 5) blackfin, 6) little, and 7) skipjack. Jump back to Figure 12.2.
Figure 12.5: Key: Green arrow – products and information flow; brown arrow – coordination and information flow; packaging material, vertical green arrow points to fish processing unit within a horizontal green arrow that includes, 1) tuna fish, 2) fishing vessel, 3) transit, 4) fish processing unit, 5) transporter, 6) distributor, 7) retailer; fish processing unit vertical brown arrow points both ways from fish processing unit to government. Jump back to Figure 12.5.
Figure 12.8: Top 10 tuna fishing nations (2018): 1) Indonesia (575,000 metric tons); 2) Japan (474,000 metric tons); 3) Papua New Guinea (325,000 metric tons); 4) Taiwan, China (320,000); 5) Spain (305,000); 6) Ecuador (300,000); 7) Republic of Korea (300,000); 8) USA (240,000); 9) Kiribati (195,000); 10) Philippines (150,000). Jump back to Figure 12.8.
Figure 12.12: Trends from 1950 to 2020, including 1) brown: new landings from eastern Atlantic and Mediterranean; 2) blue: eastern Atlantic and Mediterranean; 3) green Western Atlantic. Highest landing in 1995 with 55,000 metric tons of Eastern Atlantic and Mediterranean tuna. Jump back to Figure 12.12.
Figure 12.13: Two graphs show estimated spawning biomass; 1) Western: overfished 1970-2020; shaded line band is highest (105) in 1950 and declines through approx 2015; 2) Eastern: overfished 2000-2020; shaded line band is highest (900) in 1950 and 1980, then declines in 2010. Jump back to Figure 12.13.
Figure 12.16: Line graph shows increase in mercury with increasing trophic level with, 1) mercury in water, 2) mixed phytoplankton, 3) copepod, 4) menhaden, 5) tuna. Jump back to Figure 12.16.
Figure References
Figure 12.1: Body form of the Bigeye Tuna (Thunnus obesus) showing fins, finlets, and keels. Finlets are found between the last dorsal and/or anal fin and the caudal fin. Dr. Tony Ayling, 1982. CC BY-SA 1.0. https://commons.wikimedia.org/wiki/File:Thunnus_obesus_%28Bigeye_tuna%29_diagram.GIF.
Figure 12.2: Relative sizes of seven common tuna, with the Atlantic Bluefin Tuna (top) at about 8 ft (2.4 m) in this illustration. NOAA Central Library Historical Fisheries Collection, 1950–60s. Public domain. https://commons.wikimedia.org/wiki/File:Tuna_Relative_Sizes.jpg.
Figure 12.3: Tuna trap affixed to the sea bottom showing the long lead net to intercept migrating tuna and several chambers. NOAA, unknown date. Public domain. https://web.archive.org/web/20180413120529/http://www.photolib.noaa.gov/htmls/fish2059.htm.
Figure 12.4: Photo of Yellowfin Tuna caught in the Seychelles. Seychelles Nation, 2017. CC BY 4.0. https://commons.m.wikimedia.org/wiki/File:Yellow_fin_tuna_caught_in_Seychelles.jpg.
Figure 12.5: Representation of the flow of products, information, and coordination in the tuna supply chain. Kindred Grey. 2022. Adapted under fair use from “Developing a Traceability System for Tuna Supply Chains,” by Marimin Marimin (2017). https://www.researchgate.net/publication/320262859_Developing_a_Traceability_System_for_Tuna_Supply_Chains.
Figure 12.6: Trend in per capita consumption of canned tuna in the United States. Kindred Grey. 2022. CC BY 4.0. Data from USDA, 2018. https://www.ers.usda.gov/webdocs/DataFiles/50472/mtfish.xls?v=0.
Figure 12.7: Charlie the Tuna character appears on a can of StarKist® tuna. Kai Schreiber, 2006. CC BY-SA 2.0. https://flic.kr/p/c6uR9.
Figure 12.8: Top tuna fishing nations based on landings of seven tuna species in 2018. Kindred Grey. 2022. CC BY 4.0. Data from “Netting Billions: A Global Valuation of
Tuna,” by Macfadyen et.al., 2020. Page 9. https://www.pewtrusts.org/-/media/assets/2020/10/poseidon_tunavalue_technicaldocuments_merged_final.pdf.
Figure 12.9: Fishermen catching Skipjack Tuna using pole and line fishing in the Maldives. Paul Hilton, 2008. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:GP01PJT.jpg.
Figure 12.10: Atlantic Bluefin Tuna, Thunnus thynnus. It is also known as Bluefin Tuna, toro, Giant Bluefin, and Northern Bluefin Tuna. NOAA, unknown date. Public domain. https://commons.wikimedia.org/wiki/File:Bluefin-big.jpg.
Figure 12.11: A tuna seller at Japan’s Tsukiji Market, the biggest wholesale fish and seafood market in the world. User: Fisherman, 2006. CC BY-SA 3.0. https://commons.wikimedia.org/wiki/File:Tsukiji_Fish_market_and_Tuna.JPG.
Figure 12.12: Landings of Atlantic Bluefin Tuna from 1950 to 2020 (Sun et al. 2019). Kindred Grey. 2022. CC BY 4.0. Adapted from “More Landings for Higher Profit? Inverse Demand Analysis of the Bluefin Tuna Auction Price in Japan and Economic Incentives in Global Bluefin Tuna Fisheries Management,” by Sun et. al., 2019. CC BY 4.0. https://doi.org/10.1371/journal.pone.0221147.
Figure 12.13: Estimated spawning biomass of western and eastern stocks of Atlantic Bluefin Tuna since 1950. Kindred Grey. 2022. CC BY 4.0. Data from “Atlantic Bluefin Tuna: A Novel Multistock Spatial Model for Assessing Population Biomass,” by Taylor et. al., 2011. CC BY 4.0. https://doi.org/10.1371/journal.pone.0027693.
Figure 12.14: Demand curves for Veblen or luxury goods (top portion) and normal goods (bottom portion). Kindred Grey. 2022. CC BY 4.0.
Figure 12.15: A tuna fisherman entering data on local tuna catch with a digital device. USAID Digital Development, 2018. CC BY 2.0. https://flic.kr/p/2mAoAXW.
Figure 12.16: Bioaccumulation and biomagnification of mercury in water, primary producers, and three trophic levels. Kindred Grey. 2022. CC BY-SA 4.0. Includes “Drop of Water,” by Marco Livolsi, from Noun Project (Noun Project license); “Mixed Phytoplankton Community Coloured,” by Tracey Saxby, from https://ian.umces.edu/media-library/mixed-phytoplankton-community-coloured/ (CC BY-SA 4.0); “copepod2,” by Jane Hawkey, from https://ian.umces.edu/media-library/copepod2/ (CC BY-SA 4.0); “Brevoortia tyrannus (Atlantic Menhaden),” by Tracey Saxby, from https://ian.umces.edu/media-library/brevoortia-tyrannus-atlantic-menhaden/ (CC BY-SA 4.0); and “Thunnus albacares (Yellowfin Tuna),” by Tracey Saxby, from https://ian.umces.edu/media-library/thunnus-albacares-yellowfin-tuna/ (CC BY-SA 4.0).
Figure 12.17: D. G. Webster, PhD. Used with permission from D. G. Webster. CC BY-ND 4.0.
Text References
Absher, J. R. 2005. Crazy ’bout a mercury. Sportsman’s Guide, August 30. Available at: https://guide.sportsmansguide.com/crazy-bout-a-mercury/.
Adolf, S. 2019. Tuna wars: powers around the fish we love to conserve. Springer Nature, Amsterdam.
Agnew, D., J. Pearce, G. Pramod, T. Peatman, R. Watson, J. R. Beddington, and T. J. Pitcher. 2009. Estimating the worldwide extent of illegal fishing. PLoS One 4:e4570. https://doi.org/10.1371/journal.pone.0004570.
Aranda, M., H. Murua, and P. DeBruyn. 2012. Managing fishing capacity in tuna regional fisheries management organisations (RFMOs): development and state of the art. Marine Policy 36:985–992.
Atlantic Bluefin Tuna Status Review Team. 2011. Status review report of Atlantic Bluefin Tuna (Thunnus thynnus). Report to National Marine Fisheries Service, Northeast Regional Office. March 22.
Bailey, M., J. Flores, S. Pokajam, an U. R. Sumaila. 2012. Towards better management of Coral Triangle tuna. Ocean and Coastal Management 63(2012):30–42. https://doi.org/10.1016/j.ocecoaman.2012.03.010.
Bailey, M., A. M. M. Miller, S. R. Bush, P. A. A. M. van Zwieten, and B. Wiryawan. 2016. Closing the incentive gap: the role of public and private actors in governing Indonesia’s tuna fisheries. Journal of Environmental Policy and Planning 18(2):141–160. https://doi.org/10.1080/1523908X.2015.1063042.
Bailey, M., H. Packer, L. Schiller, M. Tlusty, and W. Swartz. 2018. The role of corporate social responsibility in creating a Seussian world of seafood sustainability. Fish and Fisheries 19(5):782–790. https://doi.org/10.1111/faf.12289.
Ballance, L. T., T. Gerrodette, C. E. Lennert-Cody, R. L. Pitman, and D. Squires. 2021. A history of the tuna-dolphin problem: successes, failures, and lessons learned. Frontiers in Marine Science 23:1310–1314.
Barclay, E. 2015. Why some chefs just can’t quit serving Bluefin Tuna. The Salt (blog), January 7. https://www.npr.org/sections/thesalt/2015/01/07/375366742/why-somechefs-just-cant-quit-serving-bluefin-tuna.
Barclay, K. M., A. N. Satapornvanit, V. M. Sydally, and M. J. Williams. 2021. Tuna is women’s business too: applying a gender lens to four cases in the western and central Pacific. Fish and Fisheries 23:584–600.
Bell, J. D. 2019. Realising the food security benefits of canned fish for Pacific island countries. Marine Policy 100:183–191.
Block, B. A., editor. 2019. The future of Bluefin Tuna: ecology, fisheries management, and conservation. Johns Hopkins University Press. Baltimore.
Boyce, D. G., D. P. Tittensor, and B. Worm. 2008. Effects of temperature on global patterns of tuna and billfish richness. Marine Ecology Progress Series 355:267–276.
Brette, F., B. Machado, C. Cros, J. P. Incardona, N. L. Scholz, and B. A. Block. 2014. Crude oil impairs cardiac excitation-contraction coupling in fish. Science 343(6172):772–776.
Bush, S. R., and C. A. Roheim. 2018. The shifting politics of sustainable seafood consumerism. Pages 331–348 in M. Boström, M. Micheletti, P. Oosterveer, The Oxford handbook of political consumerism, Oxford University Press. https://doi.org/10.1093/oxfordhb/9780190629038.013.16.
Center for Public Integrity. 2012. Looting the seas. Digital Newsbook Edition. Available at: https://cloudfront-files-1.publicintegrity.org/documents/pdfs/Looting%20the%20Seas%201-3.pdf.
Collette, B. B. 2017. Bluefin Tuna science remains vague. Science 358:879–882.
Collette, B. B., K. E. Carpenter, B. A. Polidoro, M. J. Juan-Jordá, A. Boustany, D. J. Die, C. Elfes, W. Fox, J. Graves, L. R. Harrison, R. McManus, C. V. Minte-Vera, R. Nelson, V. Restrepo, J. Schratwieser, C-L Sun, A. Amorim, M. Brick Peres, C. Canales, G .Cardenas, S-K. Chang, W-C. Chiang, N. de Oliveira Leite Jr, H. Harwell, R. Lessa, F. L. Fredou, H. A. Oxenford, R. Serra, K-T. Shao, R. Sumaila, S-P. Wang, R. Watson, and E. Yáñez. 2011. Conservation: high value and long life—double jeopardy for tuna and billfishes. Science 333:291–292.
Collette, B. B., and J. Graves. 2019. Tuna and billfishes of the world. Johns Hopkins University Press, Baltimore.
Conniff, R. 2016. Tuna’s declining mercury contamination linked to U.S. shift away from coal. Scientific American, November 23. https://www.scientificamerican.com/article/tunas-declining-mercury-contamination-linked-to-u-s-shift-away-from-coal/.
Cort, J. L., and P. Abaunza. 2015. The fall of the tuna traps and the collapse of the Atlantic Bluefin Tuna, Thunnus thynnus (L.): fisheries of northern Europe from the 1960s. Reviews in Fisheries Science & Aquaculture 23:346–373.
Crona, B., E. Wassénius, M. Troell, K. Barclay, T. Mallory, M. Fabinyi, W. Zhang, V. W. Lam, L. Cao, P. J. Henriksson, and H. Eriksson. 2020. China at a crossroads: an analysis of China’s changing seafood production and consumption. One Earth 3(1):32–44.
DeBruyn, P., H. Murua, and M. Aranda. 2012. The precautionary approach to fisheries management: how this is taken into account by tuna regional fisheries management organisations (RFMOs). Marine Policy 38:397–406.
Decker, C. 2016. Harpoon: the passion of hunting the magnificent Bluefin Tuna. Self-published by Mark Decker.
Di Natale, A. 2020. Why the Bluefin Tuna aerial spotting ban is still there? Collected Volumes Scientific Papers ICCAT 76(2):389–394. Available at: https://www.iccat.int/Documents/CVSP/CV076_2019/n_2/CV076020389.pdf.
Dueri, S., P. Guillotreaub, R. Jiménez-Toribioc, R. Oliveros-Ramosa,d, L. Boppe, and O. Maury. 2016. Food security or economic profitability? Projecting the effects of climate and socioeconomic changes on global Skipjack Tuna fisheries under three management strategies. Global Environmental Change 41:1–12.
Ellis, R. 2008. Tuna: a love story. Alfred A. Knopf, New York.
Esteban, R., P. Verborgh, P. Gauffier, J. Giménez, C. Guinet, and R. de Stephanis. 2016. Dynamics of killer whale, Bluefin Tuna and human fisheries in the Strait of Gibraltar. Biological Conservation 194:31–38.
Erauskin-Extramiana, M., H. Arrizabalaga, A. J. Hobday, A. Cabré, L. Ibaibarriaga, I. Arregui, I., H. Murua, and G. Chust. 2019. Large-scale distribution of tuna species in a warming ocean. Global Change Biology 25:2043–2060. doi:10.1111/gcb.14630.
Francis, F. T., B. R. Howard, A. E. Berchtold, T. A. Branch, L. C. T. Chaves, J. C. Dunic, B. Favaro, K. M. Jeffrey, L. Malpica-Cruz, N. Maslowski, J. A. Schultz, N. S. Smith, and I. M. Côté. 2019. Shifting headlines? Size trends of newsworthy fishes. PeerJ 7:e6395. https://doi.org/10.7717/peerj.6395.
Fromentin, J.-M. 2009. Lessons from the past: investigating historical data from Bluefin Tuna fisheries. Fish and Fisheries 10:197–216.
Fromentin, J.-M., S. Bonhommeau, H. Arrizabalago, and L. T. Kell. 2014. The spectre of uncertainty in management of exploited fish stocks: the illustrative case of Atlantic Bluefin Tuna. Marine Policy 47:–-14.
Fromentin J-M., and J. E. Powers. 2005. Atlantic Bluefin Tuna: population dynamics, ecology, fisheries and management. Fish and Fisheries 6: 281–306.
Ganzedo, U., J. M. Polanco-Martínez, Á. M. Caballero-Alfonso, S. H. Faria, J. Li, and J. J. Castro-Hernández. 2016. Climate effects on historic Bluefin Tuna captures in the Gibraltar Strait and western Mediterranean. Journal of Marine Systems 158:84–92.
Goulding, I. 2000. Refrigerated transport of frozen tuna. INFOFISH International 6:48–53.
Gracia, A., S. A. Murawski, and A. R. Vázquez-Bader. 2019. Impacts of deep oil spills on fish and fisheries. Pages 414–430 in S. A. Murawski, C. H. Ainsworth, S. Gilbert, D. J. Hollander, C. B. Paris, M. Schlüter, and D. L. Wetzel, editors, Deep oil spills, Springer, Cham, NY.
Grand View Research. 2020. Canned tuna market shares worth \$11.89 billion by 2030. Available at: https://www.grandviewresearch.com/press-release/global-canned-tuna-market.
Guevara, M. W., K. Wilson, M. G. Rey, M. Patrucić, B. Alfter, D. Donald, M. Foster, L. Sisti, F. Laurin, T. Riggins, S. Alecci, and G. Tuysuz. 2012. The black market in Bluefin. International Consortium of Investigative Journalists. https://www.icij.org/investigations/looting-the-seas/overview-black-market-bluefin/.
Hallman, B., S. Barrett, R. P. Clarke, J. Joseph, and D. Squires. 2010 Limited access in transnational tuna fisheries. Pages 195–214 in R. L. Allen, J. Joseph, and D. Squires, editors, Conservation and management of transnational tuna fisheries, Wiley-Blackwell, New York.
Hamilton, A., A. Lewis, M. A. McCoy, E. Havice, and L. Campling. 2011. Market and industry dynamics in the global tuna supply chain. Major Tuna Industry Status Report, Pacific Islands Forum Fisheries Agency. https://www.ffa.int/node/567.
Hanich, Q., and M. Tsamenyi. 2009. Managing fisheries and corruption in the Pacific Islands region. Marine Policy 33:386–392.
Hazen, E., Carlisle, A., Wilson, S., J. E. Ganong, M. R. Castleton, R. J. Schallert, M. J. W. Stokesbury, S. J. Bograd, and B. A. Block. 2016. Quantifying overlap between the Deepwater Horizon oil spill and predicted Bluefin Tuna spawning habitat in the Gulf of Mexico. Science Reports 6:33824. https://doi.org/10.1038/srep33824.
Heidrich, K. N., M. J. Juan-Jordá, H. Murua, C. D. H. Thompson, J. J. Meeuwig, and D. Zeller. 2022. Assessing progress in data reporting by tuna regional fisheries management organizations. Fish and Fisheries 23(6):1264–1281. https://doi.org/10.1111/faf.12687.
Hemingway, Ernest. 1922. At Vigo, in Spain, is where you catch the silver and blue tuna, the king of all fish. Toronto Star Weekly, February 18.
Hightower, J. 2008. Diagnosis: mercury, money, politics, & poison. Island Press, Washington, D.C.
ISC. 2022. Stock status and conservation information (from ISC22 Plenary Report). International Scientific Committee. Available at: https://isc.fra.go.jp/recommendation/index.html.
ISSF. 2022. Status of the world fisheries for tuna: March 2022. ISSF Technical Report 2022-04. International Seafood Sustainability Foundation, Washington, D.C. Available at: https://fisheryprogress.org/sites/default/files/documents_actions/ISSF-2022-04-Status-of-the-World-Fisheries-for-Tuna-March-2022.pdf.
Juan-Jordá, M. J., I. Mosqueira, A. B. Cooper, J. Freire, and N. K. Dulvy. 2011. Global population trajectories of tuna and their relatives. Proceedings of the National Academy of Sciences 108(51):206500–20655.
Klinger, D. H., and N. Mendoza. 2019. The resource and environmental intensity of Bluefin Tuna aquaculture. Pages 312–334 in BA. Block, editor, The future of Bluefin Tuna: ecology, fisheries management, and conservation. Johns Hopkins University Press, Baltimore.
Korman, S. 2011. International management of a high sea fishery: political and property-rights solutions and the Atlantic Bluefin. Virginia Journal of International Law 51:697–748.
Kresna, B. A., K. B. Seminar, and M. Marimin. 2017. Developing a traceability system for tuna supply chains. International Journal of Supply Chain Management 6:52–62.
Lauretta, M., A. Kimoto, A. Hanke, T. Rouyer, M. Ortiz, and J. Walter. 2020. Western Atlantic Bluefin Tuna virtual population analysis stock projections. Collected Volumes Scientific Papers ICCAT 77(2):606–615.
Longworth, J. W. 1983. Beef in Japan. University of Queensland Press, Brisbane, Australia.
MacKenzie, B. R., K. Aarestrup, K. Birnie-Gauvin, M. Cardinale, M. Christoffersen, H. S. Lund, Iñigo Onandia, G. Quilez-Badia, M. R. Payne, A. Sundelöf, C. Sørensen, and M. Casini. 2022. Improved management facilitates return of an iconic fish species. bioRχiv, January 5. https://www.biorxiv.org/content/10.1101/197780v2.
MacKenzie, B. R, H. Mosegaard, A. Rosenberg. 2009. Impending collapse of Bluefin Tuna in the northeast Atlantic and Mediterranean. Conservation Letters 2:26–35. DOI: 10.1111/j.1755-263X.2008.00039.x.
Mather, F. J., M .M. Mason, and A. C. Jones. 1995. Historical document: life history and fisheries of Atlantic Bluefin Tuna. NOAA Technical Memorandum NMFS-SEFSC 370:1–165. https://doi.org/10.5962/bhl.title.4783.
McKinney, R., J. Gibbon, E. Wozniak, and G. Garland. 2020. Netting billions: a global valuation of tuna. Report, Pew Charitable Trusts. Available at: https://www.pewtrusts.org/-/media/assets/2020/10/nettingbillions2020.pdf.
McKuin, B., J. T. Watson, S. Stohs, and J. E. Campbell. 2021. Rethinking sustainability in seafood: synergies and trade-offs between fisheries and climate change. Elementa: Science of the Anthropocene 9(1):00081. https://doi.org/10.1525/elementa.2019.00081.
Medley, P. A. H., J. Gascoigne, and G. Scarcella. 2022. An evaluation of the sustainability of global tuna stocks relative to marine stewardship council criteria (version 9). ISSF Technical Report 2022-03. International Seafood Sustainability Foundation, Washington, D.C.
Metian, M., S. Pouil, A. Boustany, and M. Troell. 2014. Farming of Bluefin Tuna: reconsidering global estimates and sustainability concerns. Reviews in Fisheries Science & Aquaculture 22:184–192.
Miya M., M. Friedman, T..P. Satoh, H. Takeshima, and T. Sado, W. Iwasaki, Y. Yamanoue, M. Nakatani, K. Mabuchi, J. G. Inoue, J. Y. Poulsen, T. Fukunaga, Y. Sato, and M. Nishida. 2013. Evolutionary origin of the Scombridae (tunas and mackerels): members of a Paleogene adaptive radiation with 14 other pelagic fish families. PLoS ONE 8(9):e73535. https://doi.org/10.1371/journal.pone.0073535.
Morua, H., J. Ruiz, A. Justel-Rubio, and V. Restrepo. 2022. Minimum standards for electronic monitoring systems in tropical tuna purse seine and longline fisheries. ISSF Technical Report 2022-09. International Seafood Sustainability Foundation, Washington, D.C.
MRAG Asia Pacific. 2021. Towards the quantification of illegal, unreported and unregulated (IUU) fishing in the Pacific Islands region. Available at: https://www.ffa.int/files/FFA%20Quantifying%20IUU%20Report%20-%20Final.pdf.
Moura Reis Manhães, B., A. de Souza Picaluga, T. L. Bisi, A. de Freitas Azevedo, J. P. M. Torres, O. Malm, and J. Lailson-Brito. 2020.Tracking mercury in the southwestern Atlantic Ocean: the use of tuna and tuna-like species as indicators of bioavailability. Environmental Science and Pollution Research 27:6813–6823.
Mullon, C., P. Guillotrrau, E. D. Galbraith, J. Fortilus, C. Chaboud, L. Bopp, O. Aumont, and D. Kaplan. 2017. Exploring future scenarios for the global supply chain of tuna. Deep-Sea Research II 140:251–267.
Nakatsuka, S. 2017. Best practices for providing scientific recommendations in regional fisheries management organizations: lessons from Bluefin Tuna. Fisheries Research 195:194–201.
Naylor, R. L., R. W. Hardy, A. H. Buschmann, S. R. Bush, L. Cao, D. H. Klinger, D. C. Little, J. Lubchenco, S. E. Shumway, and M. Troell. 2021. A 20-year retrospective review of global aquaculture. Nature 591:551–563.
Nickson, A. 2016. New science puts decline of Pacific Bluefin at 97.4 percent. Pew website. Available at: at https://www.pewtrusts.org/en/research-and-analysis/articles/2016/04/25/new-science-puts-decline-of-pacific-bluefin-at-974-percent.
O’Connor, S., R. Ono, and C. J. Clarkson. 2011. Pelagic fishing at 42,000 years before the present and the maritime skills of modern humans. Science 334(6059):1117–1121.
Ortega A., and F. de la Gándara 2019. Spain’s Atlantic Bluefin tuna aquaculture. Pages 299–311 in B. A. Block, editor, The future of Bluefin Tuna: ecology, fisheries management, and conservation. Johns Hopkins University Press, Baltimore.
Poli, B. M., G. Parisi, F. Scappini, and G. Zampacavallo. 2005. Fish welfare and quality as affected by preslaughter and slaughter management. Aquaculture International 13:29–49.
Pons, M., T. A. Branch, M. C. Melnychuk, O. P. Jensen, J. Brodziak, J. M. Fromentin, S. J. Harley, A. C. Haynie, L. T. Kell, M. N. Maunder, A. M. Parma, V. R. Restrepo, R. Sharma, R. Ahrens, and R. Hilborn. 2017. Effects of biological, economic and management factors on tuna and billfish stock status. Fish and Fisheries 18:1–21.
Porch, C. E., S. Bonhommeau, G. A. Diaz, H. Arrizabalaga, and G. Melvin. 2019. The journey from overfishing to sustainability for Atlantic Bluefin Tuna, Thunnus thynnus. Pages 3–44 in B. A. Block, editor, The future of Bluefin Tuna. ecology, fisheries management, and conservation. Johns Hopkins University Press, Baltimore.
Rooker, J. R., R. Jaime, A. Bremer, B. A. Block, H. Dewar, G. de Metrio , A. Corriero, R. T. Kraus, E. D. Prince, E. Rodríguez-Marín, and D. H. Secor. 2007. Life history and stock structure of Atlantic Bluefin Tuna (Thunnus thynnus). Reviews in Fisheries Science 15:265–310.
Said, A., J. Tzanopoulos, and D. MacMillan. 2016. Bluefin Tuna fishery policy in Malta: the plight of artisanal fishermen caught in the capitalist net. Marine Policy 73:27–34.
Sarmiento M., and G. B. Pérez. 1757. De los Atunes y sus transmigraciones. Caixa de Pontevedra, Madrid.
Schartup, A. T., C. P. Thackray, A. Qureshi, C. Dassuncao, K. Gillespie, A. Hanke, and E. M. Sunderland. 2019. Climate change and overfishing increase neurotoxicant in marine predators. Nature 572:648–650.
Schiller, L., and M. Bailey. 2021. Rapidly increasing eco‐certification coverage transforming management of world’s tuna fisheries. Fish and Fisheries 22:592–604.
Siskey, M. R., M. J. Wilberg, R .J. Allman, B. K. Barnett, and D. H. Secor. 2016. Forty years of fishing: changes in age structure and stock mixing in northwestern Atlantic Bluefin Tuna (Thunnus thynnus) associated with size-selective and long-term exploitation. ICES Journal of Marine Science 73:2518–2528.
Sumaila, U. R., A. Dyck, and A. Baske. 2014. Subsidies to tuna fisheries in the western central Pacific Ocean. Marine Policy 43:288–294.
Sun, C-H. J., F-S. Chiang, M. Owens, and D. Squires. 2017. Will American consumers pay more for eco-friendly labeled canned tuna? Estimating US consumer demand for canned tuna varieties using scanner data. Marine Policy 79:62–69.
Sun, C-H., F-S. Chiang, D. Squires, A. Rogers, and M-S. Jan. 2019. More landings for higher profit? Inverse demand analysis of the Bluefin Tuna auction price in Japan and economic incentives in global Bluefin Tuna fisheries management. PLoS ONE 14 (8):e0221147. https://doi.org/10.1371/journal.pone.0221147.
Taconet, M., D. Kroodsma, and J. A. Fernandes. 2019. Global atlas of AIS-based fishing activity: challenges and opportunities. FAO, Rome. Available at: www.fao.org/3/ca7012en/ca7012en.pdf.
Taylor, N. G., M. K. McAllister, G. L. Lawson, T. Carruthers, and B. A. Block. 2011. Atlantic Bluefin Tuna: a novel multistock spatial model for assessing population biomass. PLoS ONE 6(12):e27693. https://doi.org/10.1371/journal.pone.0027693.
Telesca, J. E. 2020. Red gold: the managed extinction of the Giant Bluefin Tuna. University of Minnesota Press, Minneapolis.
Townhill, B. L., E. Couce, J. Bell, S. Reeves, and O. Yates. 2021. Climate change impacts on Atlantic oceanic island tuna fisheries. Frontiers in Marine Science 8. https://doi.org/10.3389/fmars.2021.634280.
Tseng, C-M., S-J. Ang, Y-S. Chen, J-C. Shiao, C. H. Lamborg, X. He, and J. R. Reinfelder. 2021. Bluefin Tuna reveal global patterns of mercury pollution and bioavailability in the world’s oceans. Proceedings of the National Academy of Sciences 118(38):e2111205118.
Vargas, E. R., and D. F. del Corral. 2007. The origin and development of tuna fishing nets (almadrabas). Pages 187–204 in T. Bekker-Nielsen and D. B. Casola, editors, Ancient nets and fishing gear. Proceedings of the International Workshop on Nets and Fishing Gear in Classical Antiquity: A First Approach. Aarhus University Press, Aarhus, Denmark.
Veblen, T. 1912. The theory of the leisure class. Macmillan, London.
Webster, D. G. 2015. Beyond the tragedy in global fisheries. MIT Press, Cambridge, MA.
Whiting, K. 2020. Blockchain could police the fishing industry—here’s how. World Economic Forum, February 12. https://medium.com/ktrade/blockchain-could-police-the-fishing-industry-heres-how-9d6953acf44.
Whynott. D. 1995. Giant Bluefin. North Point Press, New York.
Willis, C., and M. Bailey. 2020. Tuna trade-offs: balancing profit and social benefits in one of the world’s largest fisheries. Fish and Fisheries 21:740–759.
Ye, B-J., B-G. Kim, M-J. Jeon, S-Y. Kim, H-C. Kim, T-W. Jang, H-J. Chae, W-J. Choi, M-N. Ha, and Y-S. Hong. 2016. Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication. Annals of Occupational and Environmental Medicine 28:5.
Yeeting, A. D., H. P. Weikard, M. Bailey, V. Ram-Bidesi, and S. R. Bush. 2018. Stabilising cooperation through pragmatic tolerance: the case of the Parties to the Nauru Agreement (PNA) tuna fishery. Regional Environmental Change 18(3):885–897. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.12%3A_Conserving_Tuna_-_The_Most_Commercially_Valuable_Fish_on_Earth.txt |
Learning Objectives
• Describe the life history, characteristics, habitats, and behaviors of grouper that influence their vulnerability to overharvest.
• Define the many roles of grouper in the ecosystem.
• Recognize how conspicuous consumption patterns contribute to overfishing in grouper.
• Describe movements of different stages in the grouper life cycle.
• Suggest appropriate management strategies to restore overfished grouper populations.
13.1 The Grouper: Their Remarkable Life History and Behavior
Grouper are a diverse group of marine fish, which are characterized by their large size and relatively low reproductive rates. The common name, grouper, applies to 175 fish species in the family Epinephelidae, formerly tribe Epinephelini under subfamily Epinephelinae and family Serranidae (Sadovy de Mitcheson and Liu 2022). In other parts of the world, grouper are variously called cabrillas, garropas, gropers, lapu-lapu, pugapo, hapuku, or hammour. The name “grouper” is believed to derive from the Portuguese garoupa. There are sixteen genera of grouper, the most diverse being Epinephelus with 87 species and Mycteroperca with 15 species. Some smaller species of grouper are classified in several other genera, such as Alphestes, Cephalopholis, Cromileptes, Dermatolepis, and Variola.
One allure of the grouper is the massive size reached by some species. The taxon includes the largest of all reef fish (among teleosts), the Giant (Epinephelus lanceolatus), the Pacific Goliath (E. quinquefasciatus), and the Atlantic Goliath (E. itajara) Grouper that can exceed 2 m in total length, although few exceed 1 m (Craig et al. 2011). The Giant Grouper grows up to 2.7 m (8.9 ft) in length and 400 kg (880 lbs) in weight.
The morphologies of grouper are similar in that they typically have a stout body, large head, and large mouth with impressive suction volume. The body form allows them to act as rover predators or ambush predators, usually swallowing a single large prey whole.
Many, but not all, grouper are protogynous hermaphrodites, which means that they first mature and reproduce as females and then transition to males later. Consequently, the sex ratio is typically skewed in favor of females, especially in exploited populations. Large males maintain territories on the coral reefs, rocky outcroppings, or artificial reefs, while females may remain at shallower depths before migrating to these sites during the spawning season. Juvenile grouper typically have a different color pattern and occupy different habitats than adults. They have an episodic life history strategy, with many small offspring, slow growth, late reproduction, large size, and long life spans (Kindsvater et al. 2017; Figure 13.1).
One of the common behaviors of grouper is the formation of large spawning aggregations that occur at consistent locations at specific times of year, times of day, and phases of the moon. Spawning aggregations serve to synchronize spawning time and maximize fertilization success. Elaborate courtship behaviors have been observed during spawning (Erisman et al. 2007), which often occurs near sunset, presumably to minimize mortality of the pelagic eggs from visual predators. Grouper spawning aggregations are also a strong draw for SCUBA divers in many popular tourist destinations, including Palau, Belize, and French Polynesia. Despite the many ecological, social, and economic benefits provided by the grouper, there is often little government interest in management and documenting landings and values in the many small island states. Furthermore, there have been too few studies on effects of pollutants, habitat degradation, and climate change on grouper populations.
13.2 Grouper Habitats
Grouper typically occupy coral and rocky reefs found predominantly in tropical and subtropical areas of the Atlantic and Indo-Pacific regions (Craig et al. 2011; Sadovy de Mitcheson and Liu 2022). Most occur in relatively shallow coastal waters where they are easily fished by locals familiar with the reef structure, but some species extend farther offshore on deeper reefs down to about 300 meters. Like many coral reef fish, adult and juvenile grouper often use very different habitats that are threatened from human modification (Sambrook et al. 2019). Managers must protect the connected, interacting collections of juxtaposed habitat patches to preserve the life cycle of grouper (Mumby 2006). It’s a truism in fish conservation that to conserve fish species, we must conserve their habitat. However, the reality of habitat conservation is for more complex because habitats are dynamic and vary in space and time.
The Atlantic Goliath Grouper is a case in point (Figure 13.2). Their eggs are pelagic, and developing embryos are transported via currents to shallow-water habitats, such as mangroves and seagrass meadows, where they first settle in mangrove leaf litter (Lara et al. 2009). The juvenile habitats are essential for growth and survival to maintain steady recruitment of new adults to the coral reefs. However, these shallow-water habitats are often degraded or transformed to less-productive habitats (Valiela et al. 2001; Aronson et al. 2003; Coté et al. 2005; Waycott et al. 2009; McKenzie et al. 2020). Some grouper make long migrations between nursery habitats and reefs (McMahon et al. 2012). Coral reefs throughout the world are changing due to overfishing, climate change, water quality, ocean acidification, and coral diseases and bleaching (Arundsen et al. 2003). Any declines in coral reef fish or invertebrates directly limit the food base for adult grouper (Russ et al. 2021). Consequently, the recovery of overfished populations, such as the Goliath Grouper populations in Florida, depends on availability of high-quality mangrove habitat in southwest Florida as well as controls on harvest (Koenig et al. 2007; Shideler et al. 2015b).
13.3 Spawning Aggregations and Implications for Fishing
If slow life history and high value create a double jeopardy for grouper, one additional trait adds a triple jeopardy condition. Grouper display spawning aggregations, temporary gatherings of large numbers of grouper for spawning at specific times and places. Location and timing are known by local fishers. In some species, aggregations may be transient—that is, made up of fish that travel long distances and persist for only days or weeks. Others are resident spawning aggregations that involve fish that travel short distances and persist for minutes or hours. These resident aggregations are often timed during the winter full moon (Colin 1992). Male grouper typically arrive at the site first and spend longer than females. Strong spawning-site fidelity is displayed by grouper. One individual returned to the very same spawning site for eight consecutive years (Washckewithz and Wirtz 1990).
These spawning aggregations make grouper extremely vulnerable at the same time that reproductive values are highest (Erisman et al. 2017). As grouper move around, local fishers learn their patterns and can use GPS (global positioning systems) to relocate these spots and target the spawning aggregations. Fisher knowledge influences the extent to which aggregations are perceived as predictable (Robinson et al. 2015). In some cases, fishers have known for centuries where and when aggregations form (Erisman et al. 2017). More of the grouper population can be harvested when fish aggregate to spawn. It’s a phenomenon that fisheries professionals have named hyperstability (Erisman et al. 2011). Because fishermen can’t catch them fast enough, the catch per unit effort remains high even as populations plummet. This results in faulty information on the abundance of grouper stocks (Robinson et al. 2015). Heavy selective fishing pressure on grouper aggregations removes mature older individuals (Coleman et al. 1996). In the case of the Nassau Grouper (Epinephelus striatus), declines were first noticed when spawners failed to show at historical spawning aggregation sites (Coleman et al. 1996; Aguilar-Perera 2006; Aguilar-Perera et al. 2014).
Therefore, effective management requires understanding and consideration of life history and ecological and socioeconomic drivers, as well as strong enforcement of fishing regulations. Active spawning aggregations, due to their discrete nature and high productivity, are clearly important source areas for grouper populations. Hence, these isolated sites support abundance of grouper and represent focal points for establishing no-kill marine reserves (Sadovy and Domeier 2005; Sadovy de Mitcheson 2016; Paxton et al. 2021).
13.4 Grouper and Ecosystem Services
Grouper provide many direct and indirect services in coral reef ecosystems. Spawning aggregations have indirect effects on marine ecosystems. Egg boons are the large, though temporary, egg concentrations that provide highly nutritious fatty acids and support multiple trophic levels (Figure 13.3; Fuiman et al. 2015). Whale sharks also aggregate seasonally to feed on eggs from fish spawning aggregations, attracting tourism that depends on conservation and provides economic returns far more valuable than the capture fisheries (Colman 1997; Sala et al. 2001; Heyman et al. 2001, 2010). Loss of grouper translates to a loss of trophic redistribution via egg boons.
Grouper are among the largest apex predators on coral reefs and are critical for balancing the abundance of many other fish (Hensel et al. 2019), typically damselfish (Pomacentridae) and wrasses (Labridae). Grouper predation may provide some level of biocontrol for invasive lionfish (Maljkovic et al. 2008; Mumby et al. 2011). Spawning aggregations also support high local abundance of sharks (Mourier et al. 2016). Some grouper species, such as the Red Grouper (Epinephelus morio), create habitat structure by clearing away sediment, thereby creating refuges for other fish and invertebrates from predation in these complex habitats (Coleman et al. 2011).
As large predators, grouper contribute to overall high fish abundance, especially on complex reefs (Hensel et al. 2019). Removal of predators from coral reefs releases many invertebrates from predation control. For example, the Crown-of-Thorns Starfish (Acanthaster planci) increased threefold after a 61% decline in reef fish predators, resulting in a reef dominated by turf algae instead of reef-building corals (Dulvy et al. 2004).
Grouper also display unique collaborative hunting behavior with moray eels. When hungry, the grouper will approach the moral eel with a head-shaking gesture, signaling “Let’s hunt together.” The grouper and moray eel then hunt together to facilitate more frequent prey capture. The large-bodied, slow-moving predators use burst speed and vacuum action of the large buccal cavity to capture fish chased out of crevices of coral reefs (Bshary et al. 2006).
13.5 Fisheries, Management, and Conservation Status of Grouper
Grouper are among the most heavily exploited high-priced reef fish. They have excellent white meat flesh with a light, sweet taste and large chunky flakes that work well with any cooking method. As one of the best ocean fish to eat fresh, grouper are highly sought after by commercial, recreational, and subsistence fishers. They are typically sold fresh in local seafood markets, where they are often the highest-priced fish. They are also part of the live reef fish trade in Southeast Asia, where plate-sized fish may sell for \$180 per kilogram.
The annual market value of grouper worldwide has been estimated between U.S. \$350 million (Pauly and Zeller 2015) and \$1 billion (Sadovy de Mitcheson et al. 2020). However, the economic value of live Nassau Grouper for tourism was 20 times higher than the landed value (Sala et al. 2001). Recreational fishing for grouper is worth hundreds of millions of U.S. dollars in the Gulf of Mexico, where they are often one of the top targets of recreational fishers (Southwick et al. 2016).
Factors such as distance to fish markets and local human population density are often associated with overfishing. Early investigators revealed that many grouper populations displayed signs of both growth overfishing and recruitment overfishing and called for management interventions (Sadovy 1994). Local fishers may assist in instituting restrictions to conserve these most vulnerable populations because they know the time and location of spawning aggregations. Effective management of grouper requires understanding and consideration of their life history and ecological and socioeconomic drivers.
Grouper are caught by gill nets, hook and line, spears, trawls, and traps. There are only a few species that are well studied, and remarkably few official landing records exist for many small-scale grouper fisheries in some tropical and subtropical nations. Lack of detailed catch and effort data makes the assessment of risks of overfishing these valuable fish quite challenging. Larger more economically valuable grouper are often overfished, and fishers switch to harvesting other fish, including smaller grouper species. Partnerships of local fishers and scientists are essential to restore local populations, such as the Nassau Grouper and Atlantic Goliath Grouper. Often the only available information is from recollections of fishers who report that grouper catches were abundant many years ago (Aguilar-Perera et al. 2009; Bender et al. 2014; Amorim et al 2018). Without detailed monitoring, managers must struggle to manage without a fair determination of historical baseline conditions (Bunce et al. 2008; Knowlton and Jackson 2008; Pinnegar and Engelhard 2008).
At least 35 different species are harvested to support small-scale, localized commercial and recreational fisheries. Since 1950, the global catches of grouper have increased about 30 times (Figure 13.4). Since the 1980s, most of the catch and the increase was from Asian countries, which accounted for more than 80% of recent landings. Indonesia and China have the largest grouper landings. Many countries that harvest them vastly underreport landings to the FAO. Landings from Cuba, which once had a productive grouper fishery, declined since the 1990s (Claro et al. 2009). Landings in North, Central, and South America are an order of magnitude lower than Asia’s. Therefore, the USA is a net importer of grouper (Sadovy de Mitcheson and Yin 2015). Consequently, as demand increased, many local fishing communities have seen rapid depletion and overfishing (Coleman et al 2000; Sadovy de Mitcheson et al. 2013).
Vulnerability to overfishing is related to ease of capture and a slow life history. For many of the larger grouper species, the combination of slow growth, long life (exceeding four decades), late sexual maturity (up to eight years), and strong site fidelity contribute to this vulnerability. They can easily be approached by divers and captured by spear, hook and line, and even cyanide (Wilcox 2016). Fisheries target adults that are marketed directly for food, as well as juveniles for mariculture grow-out operations (Sadovy and Pet 1998). Catches of many species have declined, and there is “no sign of any slowing down” of declines (Sadovy de Mitcheson et al. 2013). In response to reduced grouper supplies, restaurants often substitute other, less-expensive fish, prompting development of quick assays to identify mislabeled species (Ulrich et al. 2015).
If slow life history and high value create a double jeopardy for grouper, one additional trait creates a triple jeopardy condition. Grouper spawning aggregations, as noted, make them extremely vulnerable at the same time that reproductive values are highest. Furthermore, fishing can cause rapid depletion of sex-changing species due to selection for large adults. Males are usually larger, older, and less numerous than females. Recruitment in grouper is highly variable, and loss of reproductive potential has long-term consequences (Chong-Montenegro and Kindsvater 2022).
There is no question that fishing is the major factor driving grouper stocks on the downward spiral, but those that have large spawning aggregations are most vulnerable to declines (Coleman et al. 1996; Asch and Erisman 2018; Sadovy de Mitcheson et al. 2020). Because it takes a long time for scientists to obtain needed life history information, fisheries-independent survey data, and catch history, grouper populations may be overfished long before data are even available for a stock assessment. Without formal stock assessments, general indicators of population status are based on catch trends. Very few grouper stocks that have spawning aggregations are managed sustainably. In a recent global analysis of the status of populations that form spawning aggregations, 45% were unknown, 33% were decreasing, and 5% were already gone (Figure 13.5). Only 12% had stable populations, and 5% were increasing.
Of the 167 species of grouper, 9.6% are vulnerable, 4.8% are near threatened, 1.2% are endangered, and 0.6% are critically endangered (Figure 13.6). The majority of species (68.9%) are classified as least concern and 15% are data deficient, with insufficient data for classification. The larger (>50 cm total length) and long-lived (>20 years) species of grouper that also had smaller geographic ranges were most likely to be endangered or critically endangered (Luiz et al. 2016). Market prices for grouper are escalating, and other lower-valued fish are often mislabeled or substituted.
To protect grouper from overfishing, many measures are being implemented, such as minimum and slot-size limits, recreational bag limits, commercial fishing quotas, gear and seasonal controls, marine protected areas, and limited entry (Rocklin et al. 2022). The effectiveness will depend on traits of the species and the local context. Regulations to prevent marketing of undersize fish will mitigate growth overfishing. Allowing smaller fish to reach maturity at least once before harvest will mitigate recruitment overfishing. Size-limit regulations focused on protecting spawning-size fish may be ineffective for deepwater recreational fishing. Grouper have a physoclistous (i.e., closed) swim bladder, making them particularly susceptible to ruptured swim bladders, bloating, stomach distention, and protruding eyes caused by rapid decompression when hauled to the surface (Brulé et al. 2015). The proportion of grouper with distended stomachs was 70% in one study of commercial hook-and-line fishing and as high as 95% for Red Grouper in water deeper than 41 m (Bacheler and Buckel 2004). Consequently, minimum size limits may be ineffective regulations (Rudershausen et al. 2007).
Lack of data collection for many species of grouper leaves important knowledge gaps that prevent effective management. Identifying and protecting sites of known spawning aggregations with closed seasons are recommended to prevent the rapid declines or allow for population recovery (Coleman et al. 2000). Since experienced local fisheries can detect the declines in grouper abundance, the locations of aggregations are often known. No-take marine fishery reserves represent a viable means to protect resources while simplifying enforcement. Grouper show significant increases in size and biomass within no-take marine protected areas (MPAs), especially for smaller and medium-sized species and those that do not migrate (Chiappone et al. 2000; Nemeth et al. 2005; Howlett et al. 2016; Erisman et al. 2017; Belharet et al. 2020; Chollette et al. 2020; Rojo et al. 2021). It takes a long time for them to recover to preharvested levels after full protection, often 20 or more years (Russell et al. 2012).
Because some grouper populations have been exploited for millennia, it is a challenge to establish realistic conservation targets (Guidetti and Micheli 2011). Large individuals are often rapidly extirpated from shallow reefs and restricted to deep waters. Coastal fishers usually have detailed knowledge on diet and trophic relationships of exploited fish (Ribeiro et al. 2021). Often the local ecological knowledge of coastal fishers is the only source of information on sites of historical spawning aggregations.
Question to ponder:
Compare and contrast the life history traits of Pacific Salmon with those of grouper. Which traits make each group particularly vulnerable to overfishing?
13.6 Live Reef Fish Trade
A specialty at many top restaurants in some Asian countries is live fish for the consumer to select for their menu item. The live reef food fish trade has a long history, but it has grown substantially since the 1990s as the number of superaffluent people in Asia grows. Improved airline connections also spurred the expansion, allowing for the more rapid transport necessary for live animals. The destination for the live reef fish trade is centered in Hong Kong, which has more billionaires than any other city (Philips et al. 2008). In 2017, the financial center of Hong Kong posted rapid growth in its ultrawealthy population to overtake the New York metropolitan area as the world’s largest ultrawealthy city (Wealth-X 2018). The Asian affluent are outgrowing the conventional definitions of luxury. It’s not just about owning luxury materials but often more importantly experiencing it—often before others do. Plate-sized live grouper held for sale at restaurants are examples of what economists call Veblen goods (Veblen 1912). Unlike normal supply-demand relationships, even as the price of Veblen goods increases, the demand increases. High prices associated with certain size classes and species may make it worthwhile for fishermen to focus their fishing effort on that size class.
Harvest of live grouper to meet the demands of the live reef fish trade is primarily in the Coral Triangle region (Sadovy de Mitcheson 2019). This is one of the most important reef systems in the world, encompassing Indonesia, Malaysia, the Philippines, Papua New Guinea, the Solomon Islands, and Timor-Leste. Indonesia and the Philippines are the largest exporters of grouper (Khasanah et al. 2020). The coral reef fishers learn to “free the size that does not pay” and are able to be very selective by choice of hook, location, and depth. The supply chain for the live reef fish trade is not well monitored from the fisher to first buyers, exporters, importers, wholesalers, retailers, and consumers. Up to 80% of the live fish on sale may be juveniles, and many larger species are rare (To and Sadovy de Mitcheson 2009).
The growing demand for live grouper has increased the interest in capture-based culture of the fish. Here, large numbers of juveniles are harvested and raised in cages to the most profitable size (Pierre et al. 2008). This type of fish culture depends on unchecked harvest of juvenile grouper, and the resulting fisheries are likely to be unsustainable (Sadovy de Mitcheson and Liu 2008; To and Sadovy de Mitcheson 2009). The unfortunate reality is that the demand for live grouper for international trade far outstrips the sustainable supply (Sadovy et al. 2003). Strong enforcement of fishing regulations is lacking, and underreporting of harvest is common.
Whether this unique market demand affects profits or fish populations depends on biology, particularly the sex and maturity of the target size. Many grouper populations near Hong Kong were virtually extirpated, forcing suppliers to seek fish from distant locations. Market-driven, size-selective fishing can result in decreases in the catch of large, disproportionately fecund fish—the big old fat fertile female fish (BOFFFFs)(Reddy et al. 2013). A fishery that targets large grouper would influence male abundance, leading to concerns of sperm limitation on productivity (Koenig et al. 1996; Heppell et al. 2006). However, a fishery that targets the plate-size grouper (20–40 cm) is taking subadult fish, which can quickly extirpate local populations (Reddy et al. 2013; Kindsvater et al. 2017). Therefore, these fisheries need strong enforcement of regulations limiting catch of juveniles and adults. While lucrative fisheries target live reef fish markets (Sadovy de Mitcheson et al. 2017), overfishing by harvesting juveniles threatens the livelihoods of many who rely on fish as their primary protein source.
Question to ponder
In what ways are the marine tropical fish trade similar to the live reef fish trade? Are there similarities in approaches to regulate these two industries?
13.7 Culture of Grouper
High prices paid for plate-sized grouper and a short culture time have driven many Asian countries to invest in culture facilities (Pierre et al. 2008; Tupper and Sheriff 2008). At least 47 species of grouper are raised in culture grow-out pens and fed until they reach a marketable size (Rimmer and Glamuzina 2019). Full life-cycle aquaculture is not yet possible for most species. Rather, juveniles are harvested from the wild at sizes ranging from 2 to 112 cm (Sadovy and Pet 1998).
Mass production of fry from Giant Grouper was first achieved in Taiwan in 1996 and was soon followed by other Asia-Pacific countries. In Taiwan, grouper production depends on hatcheries for approximately two-thirds of its output. Milt from Giant Grouper has been used to fertilize eggs of Tiger Grouper to produce a hybrid (Tiger Grouper ♀ × Giant Grouper ♂). The hybrid has improved growth rate. In Vietnam, hybrid grouper is the second-most-important crop for nursery farms due to strong market demand and sales prices, fast growth rate, and higher survival compared to other grouper crops (Dennis et al. 2020).
Grouper farms employ numerous workers for spawning, larval rearing, and grow-out phases of their operations. The largest production comes from China, Taiwan, and Indonesia (Rimmer and Glamuzina 2019). Although some farms use formulated feed, many still rely on harvesting other marine fish to feed grouper. Disease outbreaks are common and result in reduced survival to market size. Culture of grouper does not reduce fishing pressure on them, and millions of fishers globally will continue to depend on wild capture. The process is a relatively new venture, and prospects are still uncertain (Sadovy and Lau 2002). Yet, recent data shows that about 50% of live grouper imported to Hong Kong are from fish farms (Rimmer and Glamuzina 2019). Future advances in selection of improved strains, first foods, feed formulation, full-life-cycle hatcheries, and water quality enhancements are expected.
13.8 Case Study: Nassau Grouper
The Nassau Grouper (Epinephelus striatus) is the most important finfish in The Bahamas and valued culturally, economically, and ecologically. It occurs in rocky bottoms and coral reefs in over 30 countries and territories from the Gulf of Mexico and along the tropical western Atlantic and Caribbean south to Brazil. The name striatus refers to the pattern of light background and irregular dark brown bars, which helps it blend into its habitat (Figure 13.7). People in The Bahamas rely on Nassau Grouper as an important food as well as a target for a thriving dive and tourism industry. Grouper supported many Bahamians for centuries, providing over \$1 million in landings per year. Nassau Grouper is the essential ingredient in the local comfort food, Bahamian boiled fish, or simply “boil,” which is eaten for breakfast, lunch, or dinner.
Nassau Grouper were once plentiful across shallow coastal zones of Bermuda, Florida, The Bahamas, the Yucatán Peninsula, and throughout the Caribbean. The first-ever eye-witness account described a spectacular gathering of 30,000 to 100,000 large adult Nassau Grouper (Lavett-Smith 1972). Despite an increase in observers, this observation remains the largest grouper aggregation ever recorded. In a six-day survey of this same site 40 years later, only five Nassau Grouper were observed (Erisman et al. 2013). As early as the 1990s, available evidence showed that Nassau Grouper were overfished and many spawning aggregations had disappeared (Sadovy 1994; Aguilar-Perera and Aguilar-Dávila 1996; Chiappone et al. 2000; Claro and Lindeman 2003; Claro et al. 2009; Aguilar-Perera 2014). The collapse of the Nassau Grouper throughout its range was due to overfishing on spawning aggregations (Sadovy and Eklund 1999; Sala et al. 2001; Aguilar-Perera 2006). Historical landing records in The Bahamas and elsewhere show that much of the annual harvests of Nassau Grouper was taken from spawning aggregations during the winter months. The population decline resulted in a drop in commercial landings of 86% over the past 20 years (Sherman et al. 2016). Over 60 Nassau Grouper spawning aggregation sites were identified globally, but many of these have been lost due to overfishing (Sadovy and Eklund 1999; Sadovy de Mitcheson et al. 2008). Nassau Grouper is classified as endangered by the International Union for the Conservation of Nature (Bertoncini et al. 2018) and is listed as threatened under the U.S. Endangered Species Act (81 FR 42268, June 29, 2016).
Nassau Grouper are solitary reef dwellers. However, mature individuals migrate during the full moon to spawning aggregation sites. Movements of Nassau Grouper are highly synchronized to specific spawning sites at predictable times (Bolden 2000; Starr et al. 2007; Stump et al. 2017). First, they leave territories in shallow water near winter full moon, then migrate to their spawning site in water ~100 m deep (Washckewithz and Wirtz 1990). Synchronization is helped by sounds produced by migrating Nassau Grouper (Hazlett and Winn 1962; Rowell et al. 2015). One explanation for the consistency of migration routes and spawning locations is that younger fish learn migration routes from more experienced migrators and their unique sounds. Different color patterns develop when Nassau Grouper are ready to spawn. A bicolor pattern indicates a nonaggressive submissive state acquired by both males and females near the time of spawning. The dark phase is acquired by females who are followed by numerous bicolor fish during courtship (Colin 1992). The courtship occurs in late afternoon, followed by a spawning rush near sunset, where the bicolor female swims upward and releases eggs while the males follow behind releasing sperm (Sadovy and Eklund 1999).
A mix of habitats is important for the life cycle of the Nassau Grouper. After spawning in deep water, their fertilized eggs float and reach the surface within three to five hours of spawning, and newly hatched embryos are also positively buoyant within two to three days after hatching (Colin 1992). Wind-driven currents likely influence the transport of small larvae during the first days after spawning. Larval Nassau Grouper are adapted for life in near-surface waters and have elongated dorsal spines that resemble small underwater kites. Larvae feed on plankton for 35 to 40 days before settling in seagrass meadows, macroalgal beds, or mangrove nursery habitats. Juvenile Nassau Grouper may be supported by feeding on crabs from adjacent seagrass beds (Eggleson et al. 1998). As the young grow, they move to offshore reefs.
Belize was one of the first countries to protect the Nassau Grouper via closed fishing seasons at sites of spawning aggregations. The effect of seasonal closures is evident in comparison of size distributions of exploited sites with unexploited sites (Figure 13.8). Nassau Grouper begin to mature at approximately 48 cm in length, and by the time they reach 56 cm, 75% are mature (Carter et al. 1994; Sadovy and Colin 1995, Sadovy and Eklund 1999). Fishing has eliminated many of the largest and most fertile individuals (Figure 13.8).
In The Bahamas, the fishing industry contributes approximately \$85 to 90 million annually, with Nassau Grouper sales of approximately \$1.5 million. Nassau Grouper populations are much more abundant in the Exuma Cays Land and Sea Park, where all fishing has been prohibited
since 1986. Protection of their spawning aggregations began in 1998 with seasonal closures of two sites during the winter months. During the closed season, the capture or sale of Nassau Grouper is prohibited. Beginning in 2004, the closed season was extended countrywide. By 2010, a majority of the fishers (82%) still had concerns about the future of The Bahamas’ Nassau Grouper fishery, as the catch per day remained low (Cheung et al. 2013). Problems with enforcing the seasonal closure and poaching, as well as the introduction of air compressors by spear fishers, meant that they remained overfished in The Bahamas. Existing management measures, such as the small 3-pound (1.4-kg) size limit and noncompliance with fishing regulations in The Bahamas, likely prevent recovery of these fish (Sherman et al. 2016). Tourist visitation effectively stopped during the COVID-19 pandemic from spring through the autumn of 2020, resulting in an increase in large Nassau Grouper in one marine protected area (Kough et al. 2022).
In 1985, the Cayman Island government, responding to fishermen’s concerns over declining numbers and size of Nassau Grouper, restricted fishing on five known spawning aggregations to only residents using hook-and-line gear. In 2003, the government passed legislation to establish no-take during spawning months and bag and slot limits away from aggregation sites in the rest of the year to allow recreational and artisanal catch outside the spawning season.
The protections initiated by the Cayman Islands government resulted in sustained recovery of a population of Nassau Grouper previously on the brink of extirpation (Figure 13.9). More individuals are larger than 65 cm, and spawning biomass and recruitment have increased (Stock et al. 2021). Little Cayman now has the largest-known spawning aggregation for Nassau Grouper, and Cayman Brac is markedly improved (Sadovy de Mitcheson 2020; Waterhouse et al. 2020). Management interventions to safeguard the Little Cayman spawning aggregation provide other countries a ray of hope for grouper recovery.
Strict regulations on fishing can diminish livelihoods of subsistence fishers. Dive tourism may provide alternative livelihoods and mitigate the negative effects of closures for displaced fishers (Sala et al. 2001; Heyman et al. 2010; Usseglio et al. 2016). To learn more about the incredible long-term work underway in the Cayman Islands to protect the Nassau Grouper as part of the Grouper Moon Project, watch the video https://youtu.be/TfsUsCgCH0A.
13.9 Case Study: Goliath Grouper
The Goliath Grouper is the largest grouper in the Atlantic Ocean and one of the two largest species of grouper in the world, reaching ~2.5 m (7–8 ft) in total length. In the western Atlantic Ocean, it ranges from North Carolina to southern Brazil, including the Gulf of Mexico and the Caribbean Sea. Advertisers tout Florida as the only place in the world where Goliath Grouper can be found on a regular basis throughout the year and in their spawning aggregation sites in late summer. Goliath Grouper were intensively overfished long before landing records were kept so that old photographs from fishing marinas provide hints to the past (Figure 13.10). They have several traits that make them vulnerable to overfishing, including high longevity, late maturation, site fidelity, aggregative spawning, and a lack of fear of humans (Sadovy and Eklund 1999).
The largest grouper ever caught and certified by the International Game Fishing Association was a 680-pound (309-kg) Atlantic Goliath Grouper. This record fish was taken off the coast of southern Florida in 1961 after decades of overfishing (McClenachan 2009). One analysis revealed that increasing fishing effort and widespread use of fish finders reduced the abundance of adults to only 5 to 10% of virgin levels (Porch et al. 2006). The Goliath Grouper has been severely overfished throughout its range, and a fishing moratorium was initiated in U.S. and state waters in 1990 and throughout the Caribbean in 1993 (Aguilar-Perera et al. 2009). In the Caribbean Sea in Mexico and Belize, few people even remember the presence of this giant fish (Graham et al. 2009; Bravo-Caldero et al. 2021). Similarly, in Brazil even low levels of spearfishing led to depletion of Goliath Grouper, which are considered functionally extinct despite a ban imposed in 2002 (Giglio et al. 2017).
Goliath Grouper live at least 37 years or more and reach sexual maturity after four years (males) and six years (females) (Bullock et al. 1992). Each year, they migrate to gather in reproductive aggregations of up to 100 individuals. They spawn during the summer (January to March) in the Southern Hemisphere, similar to summer spawning (July to September) in the Northern Hemisphere. Sounds produced serve to synchronize timing of migration (Mann et al. 2009). Juveniles and adults often return to the same site to spawn year after year, making them particularly susceptible to overfishing (Colin 1994). Spawning occurs at night, presumably to avoid egg predation by opportunistic egg predators, such as scad and herring. In many regions, the spawning aggregations are known only from anecdotal recollections by veteran fishers, and others have disappeared without having been documented (Aguilar-Perera et al. 2009; Bueno et al. 2016).
The Origins of the Atlantic Goliath Grouper Common Name
Scientists who describe new species are responsible for giving it a valid Latinized binomial name. According to the International Code of Zoological Nomenclature (ICZN), the first part identifies the genus to which the species belongs, and the second part identifies the species within the genus. Only scientific names are covered by the ICZN. Common, or vernacular, names often vary among regions. In North America, common names are standardized by a committee of the American Society of Ichthyologists and Herpetologists (ASIH) and the American Fisheries Society (AFS). The common name for Epinephelus itajara was formerly the jewfish. I observed my first jewfish in the John G. Shedd Aquarium when I was a young boy. I thought it was a strange and nondescriptive name for such a ginormous fish. The historical origins and meaning of “jewfish” are unclear because scientists did not have to explain common names when describing fish species. A story that jewfish were so named because they were an inferior fish, fit only for Jews, persisted since the 1800s (Grossman 2015). The Common and Scientific Names Committee of AFS received complaints about the offensive jewfish name, as well as the squawfish name, derogatory toward women. The Names Committee changed the accepted common name of the squawfish to the pikeminnow in 1998. Soon complaints about the jewfish name led to a formal petition signed by senior fisheries scientists sent to the committee. Clearly names and their meaning have tremendous power, and associating Jews with a large-jawed grouper extended to members of the Jewish faith. After committee deliberations in 2001, they declared that the new accepted common name would be Atlantic Goliath Grouper.
Although most fishing for Goliath Grouper is offshore near reefs and structures, the species is mangrove dependent and shows a distinct size-related habitat shift. Juveniles are found exclusively in spatially complex, fringing Red Mangrove (Rhizophora mangle) shorelines (Frías-Torres 2006; Koenig et al. 2007). The mangrove forests support a high diversity of fish and invertebrates and are threatened worldwide. Mangroves create a narrow fringe habitat between land and sea at tropical latitudes (25ºN to 30ºS). Since 1980, at least 35% of mangrove forests were lost to coastal development (Valiela et al. 2001). High-quality mangrove habitat in southwest Florida is the key to recovery (Frías-Torres 2006; Koenig et al. 2007; Koenig and Coleman 2009). Juveniles spend their first five to six years of life in mangroves, and it was here in the juvenile population that the first signs of recovery appeared (Cass-Calay and Schmidt 2009).
The functional extinction of the critically endangered Atlantic Goliath Grouper in many parts of the range has attracted much attention, and fishing moratoria are common. Recovery of populations depends on conditions in nursery areas (Koenig et al. 2007; Shideler et al. 2015b; Lobato et al. 2016) and far-distant spawning aggregations. Research that combines local ecological knowledge and takes advantage of technologies, such as bioacoustics, biotelemetry, sonar, and remote and autonomous underwater vehicles, may lead to more accurate information on grouper spawning aggregations (Erisman et al. 2017). Photo-identification is widely used for noninvasive mark-recapture analysis and appears to be well suited for the sedentary, large Goliath Grouper in marine parks frequented by divers (Hostim-Silva et al. 2017).
Recovery of the critically endangered Atlantic Goliath Grouper will require actions to (1) protect coastal lagoons with fringing mangrove nursery areas; (2) locate spawning aggregations and learn from traditional ecological knowledge; (3) adopt large no-take protected areas and evaluate diving tourism alternatives (Heyman et al. 2010; Shideler and Pierce 2016); and (4) halt poaching (Giglio et al. 2014). However, given the strict nature of regulations needed, leadership, social networks, and comanagement at the local level are often the glue that will make these conservation plans successful (Gutiérrez et al. 2011).
There are signs of recovery in Florida waters after thirty years of a fishing moratorium on Atlantic Goliath Grouper (Figure 13.11; Koenig and Coleman 2011). Grouper represent only one of many valuable residents of threatened coral reef ecosystems. Restoring coral reef ecosystems will require reducing and reversing carbon emissions that are driving global climate change (Knowlton and Jackson 2008).
While full recovery is still uncertain, sport fishers are aware of the increase in large Goliath Grouper. Return of a spawning aggregation near Jupiter, Florida, is one encouraging sign of recovery (Frías-Torres 2013). Many people unfamiliar with the history of changes in Florida reefs now consider Goliath Grouper to be novel and intolerable because of the moratorium on fishing for them. Some recreational anglers called for the lifting of the fishing moratorium. However, the reasons given to support this petition (below) are not supported by scientific evidence (Koenig et al. 2020).
False claims in support of lifting the moratorium:
• Goliath Grouper compete directly with recreational reef fish fishermen for and substantially reduce the populations of grouper and snappers on reefs in south Florida.
• Goliath Grouper are dangerous to divers.
• Goliath Grouper interfere with fishing by taking baited hooks, or hooked or speared fish.
• Goliath Grouper compete directly with lobster fishermen by eating many lobsters in south Florida.
• Goliath Grouper, because of their large size, require huge amounts of food to survive and eat indiscriminately, reducing biodiversity on reefs.
• Our reefs are “out of balance”; Goliath Grouper have to be “thinned out” to regain that balance.
• There must be a periodic kill of hundreds of adult Goliath Grouper to obtain data on size, age, and reproductive condition necessary for stock assessment.
Furthermore, Goliath Grouper hold the unfortunate distinction of having the highest levels of liver and muscle mercury of any commercially important shallow-water grouper species. Mercury levels in the muscle tissues of most adults and many juveniles from Florida samples exceeded safe levels for human consumption (Malinowski 2019). The large size of Goliath Grouper adds to the interest and pressure by sport anglers to lift the current harvest moratorium on them. Divers and scientists, however, oppose lifting the moratorium. Despite opposition by scientists and divers, Florida officials lifted the Goliath Grouper ban in 2022 (Collins 2022). The new rules prohibit spear fishing and limit annual harvest to 300 fish between 24 and 36 inches. Time will tell if the fishery is sustainable.
Grouper spawning aggregations are also a strong draw for SCUBA divers in many popular tourist destinations, including Palau, Belize, and French Polynesia. Consequently, future developments may focus on creating tourist adventures based on diving with grouper. Divers are willing to pay more for Goliath Grouper encounters (Shideler and Pierce, 2016), making them more valuable as diving attractions than for harvest (Shideler et al. 2015a).
Question to ponder:
What do you suspect are the principal reasons for opposing the creation of no-take marine reserves to protect grouper populations?
Profile in Fish Conservation: Yvonne Sadovy de Mitcheson, PhD
Yvonne Sadovy de Mitcheson has been Professor at the University of Hong Kong for 30 years and is well known as the foremost expert on grouper conservation and ecology. She teaches many courses that deal with the biology, fisheries management, and conservation of fish. Her research and scholarly writings leave an important global legacy, providing a roadmap for conservation and fisheries management of grouper and other marine fish.
Dr. Sadovy’s early studies were based in the Caribbean and represent many of the first investigations into the exploitation of sex-changing coral reef fish, especially grouper that form spawning aggregations. Her first investigations in this region revealed that many grouper populations were overfished and that the monitoring and assessment activities were inadequate. For five years, she served as the Director of the Fisheries Research Laboratory of the government of Puerto Rico and then as biologist with the Caribbean Fishery Management Council of the National Marine Fisheries Service (NOAA, USA).
She is the author or coauthor of more than 160 publications that investigate the biology and conservation of marine fish, with particular emphasis on the grouper and other reef fish vulnerable to fishery exploitation. Studies that focus on the trade in live tropical food and ornamental fish, locally, regionally, and globally, revealed several global threats from fishing. Additionally, she and her collaborators added significantly to our knowledge of reproduction, including sex differentiation, maturation and gonadal development, and age and growth of many reef fish. She spearheaded investigations of the live reef fish markets and trade in Hong Kong and their role in supporting imports of many highly valued species, several of which are threatened. Her efforts led to adoption of scientific protocols for documenting and monitoring fished and unfished grouper spawning aggregations throughout the world.
Yvonne’s keen interest in public education on marine conservation issues has expanded the impact of her studies to effect awareness and facilitate policy changes. Professor Sadovy de Mitcheson founded and is currently co-Chair of the IUCN World Conservation Union Specialist Group on Grouper and Wrasses. She shares her expertise with conservation groups such as the World Wide Fund for Nature Hong Kong, Wildlife Conservation Society, TRAFFIC–East Asia, and the Food and Agriculture Organization of the United Nations. She is Director of the Science and Conservation of Reef Fish Aggregations, a nonprofit organization that seeks to raise awareness about the vulnerabilities of fish spawning aggregations and improve their protection and management. This collaborative effort resulted in books including Reef Fish Spawning Aggregations: Biology, Research and Management, Manual for the Study and Conservation of Reef Fish Spawning Aggregations, and training modules. She coauthored Groupers of the World: A Field and Market Guide, which is a comprehensive and colorful description of over 150 species of grouper.
Recent research efforts focused on the development of a scientific model for sustainable exports of the endangered Napoleon Wrasse (Cheilinus undulatus), the largest coral reef species and a part of the live reef food fish trade. Her early work on the Nassau Grouper in the tropical western Atlantic was a major impetus for sustainable management planning, and she recently completed a major management plan on this species for FAO. Recently, she has investigated the threats and opportunities for the growing international demand for dried swim bladders and is leading a team to develop a facial recognition app to aid enforcement in the trade for the Napoleon Wrasse.
Key Takeaways
• Large body size, slow growth, high longevity, late reproductive maturity, and the reproductive behavior of forming spawning aggregations all contribute to the vulnerability of grouper stocks.
• Length or creel limits are often ineffective for grouper in deep waters, where they develop barotrauma after deepwater capture.
• Long time periods are required to recover larger grouper species, such as the Goliath Grouper and Nassau Grouper.
• Local management interventions may include bans on fishing during reproductive seasons, marine protected areas, shift to grouper tourism via SCUBA diving, and adopting international standards for the trade in international live reef food fish.
• Poor fisheries governance structures are in place in less-developed countries, and many grouper stocks are data deficient.
• Protective management actions will take decades to evaluate because of the long time to maturity and long recovery times for grouper.
• Goliath Grouper were protected in Florida waters by a fishing moratorium since 1990, and signs of recovery are emerging.
This chapter was reviewed by Felicia Coleman.
Long Descriptions
Figure 13.1: Red Grouper with robust body and small scales. Their head and body are dark reddish brown, shading pink or reddish below with occasional white spots on the sides and black spots on the cheeks. Jump back to Figure 13.1.
Figure 13.2: Diagram of habitats used at different life stages for Goliath Grouper; 1) post larvae settle in mangrove litter and roots; 2) juveniles hide in mangrove microhabitats; 3) older juveniles migrate to coral reefs; 4) adults live on reefs for 40+ years; 5) adults migrate and spawn into water column; 6) fertilized eggs drift in currents; 7) larvae hatch from eggs and drift in currents for 30-80 days. Jump back to Figure 13.2.
Figure 13.3: Length (cm) on x-axis and trophic level on y-axis. From smallest length (0.01 cm) and lowest trophic level to longest length (1000 cm) and highest trophic level: Decomposers, Microplankton, crustacean zooplankton, gelatinous zooplankton, planktivores, intermediate predators, top predators. Eggboons point to all groups except for predators. Jump back to Figure 13.3.
Figure 13.4: X-axis shows years from 1950-2020. Y-axis shows grouper capture production (t) in thousands from 0 to 500. Increases consistently with a higher rate of increase from 2010-2020. Jump back to Figure 13.4.
Figure 13.5: Pie chart shows that status of exploited grouper aggregations is often unknown or declining; gone (5%), unknown (45%), decreasing (33%), same (12%), increasing 5%. Jump back to Figure 13.5.
Figure 13.6: Pie chart shows conservation status of groupers; data deficient (15%), critically endangered (1%), endangered (1%), vulnerable (9%), near threatened (5%), least concern (69%). Jump back to Figure 13.6.
Figure 13.7: Nassau grouper with large eyes and a robust body. Light beige with five dark brown vertical bars, a large black saddle blotch on top of the base of the tail, and a row of black spots below and behind each eye. Jump back to Figure 13.7.
Figure 13.8: Two bar graphs. Standard length (cm) on x-axis from 0-85. Number of fish on y-axis from 0-200. Top graph: Unexploited. There are more females than males for almost every length. 48cm have the most fish (170). Bottom graph: Exploited. There are more females than males for almost every length. 32cm have the most fish (120). Jump back to Figure 13.8.
Figure 13.9: Line graph shows population estimate for Nassau Grouper at Little Cayman from 2005 to 2018. Population grows from 2,000 in 2005 to 7,000 in 2018. Population decreased from 2006-2009. Jump back to Figure 13.9.
Figure 13.11: Diagram of goliath grouper population from 1930-2000. Population is highest in 1930, declines until 1970, then starts to increase again until 2000. Jump back to Figure 13.11.
Figure References
Figure 13.1: Red Grouper (Epinephelus morio) is commonly caught by recreational and commercial fishers from southern Brazil to North Carolina, including the Gulf of Mexico and Bermuda. Simões et. al., 2014. CC BY 4.0. https://commons.wikimedia.org/wiki/File:Epinephelus_morio_in_Madagascar_Reef.jpg;
Figure 13.2: Conceptual diagram illustrating the Goliath Grouper life cycle and movement of various life stages throughout the nearshore and reef environments. Kindred Grey. 2022. CC BY-SA 4.0. Adapted from Goliath Grouper Life Cycle, by Jane Hawkey, Integration and Application Network, https://ian.umces.edu/media-library/goliath-grouper-life-cycle/. CC BY-SA 4.0.
Figure 13.3: Flow energy from grouper eggs to components of the coral reef ecosystem (solid arrows) and trophic transfers through the food web (dashed arrows). Kindred Grey. 2022. CC BY-SA 4.0. Adapted from Egg Boons: Central Components of Marine Fatty Acid Food Webs, by Fuiman et. al., 2015. https://doi.org/10.1890/14-0571.1. Includes Mixed Phytoplankton Community Coloured by Tracey Saxby, Integration and Application Network from https://ian.umces.edu/media-library/mixed-phytoplankton-community-coloured/ (CC BY-SA 4.0), Feather duster worm by Diana Kleine, Marine Botany UQ from https://ian.umces.edu/media-library/feather-duster-worm/ (CC BY-SA 4.0), Paraclanus spp by Kim Kraeer, Lucy Van Essen-Fishman, Integration and Application Network from https://ian.umces.edu/media-library/paraclanus-spp/ (CC BY-SA 4.0), Panulirus argus (spiny lobster): side view by Caroline Donovan, Integration and Application Network from https://ian.umces.edu/media-library/panulirus-argus-spiny-lobster-side-view/ (CC BY-SA 4.0), Moerisia spp. (Jellyfish) by Tracey Saxby, Integration and Application Network from https://ian.umces.edu/media-library/moerisia-spp-jellyfish/ (CC BY-SA 4.0), Chromis chromis (Mediterranean Chromis) by Tracey Saxby, Integration and Application Network from https://ian.umces.edu/media-library/chromis-chromis-mediterranean-chromis/ (CC BY-SA 4.0), Carcharhinus plumbeus (Sandbar Shark) by Tracey Saxby, Integration and Application Network from https://ian.umces.edu/media-library/carcharhinus-plumbeus-sandbar-shark/ (CC BY-SA 4.0), Oncorhynchus tshawytscha (Chinook Salmon): adult by Emily Nastase, Integration and Application Network from https://ian.umces.edu/media-library/oncorhynchus-tshawytscha-chinook-salmon-adult/ (CC BY-SA 4.0), Eubalaena glacialis (Right Whale) by Jamie Testa, Integration and Application Network from https://ian.umces.edu/media-library/eubalaena-glacialis-right-whale/ (CC BY-SA 4.0), and Turtle eggs by Kim Kraeer, Lucy Van Essen-Fishman, Integration and Application Network from https://ian.umces.edu/media-library/turtle-eggs/ (CC BY-SA 4.0).
Figure 13.4: Grouper capture fisheries catches reported to FAO from 1950 to 2018. Kindred Grey. 2022. CC BY 4.0. Data from The Importance of Grouper and Threats to Their Future, by Yvonne Sadovy de Mitcheson and Min Liu Biology, in Ecology of Grouper, 2022. https://doi.org/10.1201/b20814.
Figure 13.5: Current known status reflecting changes of exploited grouper aggregations globally, as noted by fisher interviews, monitoring, or underwater surveys (N = 509). Kindred Grey. 2022. CC BY 4.0. Data from The Importance of Grouper and Threats to Their Future, by Yvonne Sadovy de Mitcheson and Min Liu Biology, in Ecology of Grouper. 2022. https://doi.org/10.1201/b20814.
Figure 13.6: Categories of all grouper species (N=167) according to the IUCN Red List (IUCN Red List Assessments, updated November 2018). Kindred Grey. 2022. CC BY 4.0. Data from The Importance of Grouper and Threats to Their Future, by Yvonne Sadovy de Mitcheson and Min Liu Biology, in Ecology of Grouper, 2022. https://doi.org/10.1201/b20814.
Figure 13.7: Large Nassau Grouper at The Pinnacle, Saba, Netherlands Antilles. Aquaimages, 2006. CC BY-SA 2.5. https://commons.wikimedia.org/wiki/File:3846_aquaimages.jpg.
Figure 13.8: Length-frequency distributions by sex for exploited and unexploited sites in Belize. Kindred Grey. 2022. CC BY 4.0. Data from NOAA, 2013. Public domain. https://www.fisheries.noaa.gov/resource/document/nassau-grouper-epinephelus-striatus-bloch-1792-biological-report.
Figure 13.9: Population estimates of Nassau Grouper at the spawning aggregation on Little Cayman Island from 2005 to 2018. Kindred Grey. 2022. CC BY 4.0. Data from Recovery of Critically Endangered Nassau Grouper (Epinephelus striatus) in the Cayman Islands Following Targeted Conservation Actions, by Waterhouse et. al., 2020. https://doi.org/10.1073/pnas.1917132117.
Figure 13.10: A postcard with six large Atlantic Goliath Grouper hanging in front of a sign for the Office Meteor Boat Company, ca. 1940. Haffenreffer Collection. Florida Keys History Center, Monroe County Public Library, 2016. CC BY 2.0. https://flic.kr/p/PKAodm.
Figure 13.11: Conceptual diagram illustrating the biomass and population numbers of Goliath Grouper in south Florida. Kindred Grey. 2022. CC BY-SA 4.0. Adapted from Goliath Grouper Population (Florida), by Kris Beckert, Integration and Application Network (2008, CC BY-SA 4.0, https://ian.umces.edu/media-library/goliath-grouper-population-florida/). Includes Epinephelus itajara (Atlantic Goliath Grouper) 2 by Kim Kraeer, Lucy Van Essen-Fishman, Integration and Application Network, from https://ian.umces.edu/media-library/epinephelus-itajara-atlantic-goliath-grouper-2/ (CC BY-SA 4.0).
Figure 13.12: Yvonne Sadovy de Mitcheson, PhD. Used with permission from Yvonne Sadovy de Mitcheson. Photo by Alan Lai Kin Lun / Good Show Photography. CC BY-ND 4.0.
Text References
Aguilar-Perera, A. 2006. Disappearance of a Nassau Grouper spawning aggregation off the southern Mexico Caribbean coast. Marine Ecology Progress Series 327:289–296.
Aguilar-Perera, A. 2014. An obituary for a traditional aggregation site of Nassau Grouper in the Mexican Caribbean. Proceedings of the Gulf and Caribbean Fisheries Institute 66:384–388.
Aguilar-Perera, A., and W. Aguilar-Dávila. 1996. A spawning aggregation of Nassau Grouper Epinephelus striatus (Pisces: Serranidae) in the Mexican Caribbean. Environmental Biology of Fishes 45:351–361.
Aguilar-Perera, A., C. González-Salas, A. Tuz-Sulub, and H. Villegas-Hernández. 2009. Fishery of the Goliath Grouper, Epinephelus itajara (Teleostei: Epinephelidae) based on local ecological knowledge and fishery records in Yucatan, Mexico. International Journal of Tropical Biology 57:557–566.
Amorim, P., P. Sousa, M. Westmeyer, and G. M. Menezes. 2018. Generic Knowledge Indicator (GKI): a tool to evaluate the state of knowledge of fisheries applied to snapper and grouper. Marine Policy 89:40–49.
Aronson, R. B., J. F. Bruno, W. F. Precht, P. W. Glynn, C. D. Harvell, L. Kaufman, C. S. Rogers, E. A. Shinn, and J. F. Valentine. 2003. Causes of coral reef degradation. Science 302(5650):1502–1504.
Asch, R. G., and B. Erisman. 2018. Spawning aggregations act as a bottleneck influencing climate change impacts on a critically endangered reef fish. Diversity and Distributions 24: 1712−1728.
Belharet, M., A. Di Franco, A. Calò, L. Mari, J. Claudet, R. Casagrandi, M. Gatto, J. Lloret, C. Sève, P. Guidetti and P. Melià. 2020. Extending full protection inside existing marine protected areas, or reducing fishing effort outside, can reconcile conservation and fisheries goals. Journal of Applied Ecology 57:1948–1957.
Bender, M. G., G. R. Machado, P. J. A. Silva, S. R. Floeter, C. Monteiro-Netto, O. J. Luiz, and C. E. L. Ferreira. 2014. Local ecological knowledge and scientific data reveal overexploitation by multigear artisanal fisheries in the southwestern Atlantic. PLoS ONE 9(10):e110332. doi: 10.1371/journal.pone.0110332.
Bertoncini, Á., A. Aguilar-Perera, J. Barreiros, M. Craig, B. Ferreira, and C. Koenig. 2018. Epinephelus itajara. The IUCN Red List of Threatened Species 2018: e.T195409A46957794.
Bolden, S. K. 2000. Long-distance movement of a Nassau Grouper (Epinephelus striatus) to a spawning aggregation in the central Bahamas. Fishery Bulletin 98:642–645.
Bravo-Calderon, A., A. Saenz-Arroyo, S. Fulton, A. Espinoza-Tenorio, and E. Sosa-Cordero. 2021. Goliath Grouper Epinephelus itajara oral history, use, and conservation status in the Mexican Caribbean and Campeche Bank. Endangered Species Research 45:283–300.
Brulé, T., J. Montero-Muñoz, N. Morales-López, and A. Mena-Loria. 2015. Influence of circle hook size on catch rate and size of Red Grouper in shallow waters of the southern Gulf of Mexico. North American Journal of Fisheries Management 35:1196–1208.
Bshary, R., A. Hohner, K. Ait-el-Duoudi, and H. Fricke. 2006. Interspecific communicative and coordinated hunting between grouper and Giant Moray Eels in the Red Sea. PLoS Biology 4(12):e431.
Bueno, L. S., A. A. Bertoncini, C. C. Koenig, F. C. Coleman, M. O. Freitas, J. R. Leite, T. F. de Souza, and M. Hostim-Silva. 2016. Evidence for spawning aggregations of the endangered Atlantic Goliath Grouper Epinephelus itajara in southern Brazil. Journal of Fish Biology 89:876–889.
Bullock, L. H., M. D. Murphy, M. F. Godcharles, and M. E. Mitchell. 1992. Age, growth, and reproduction of jewfish Epinephelus itajara in the eastern Gulf of Mexico. Fishery Bulletin 90:243–249.
Bunce, M., L. D. Rodwell, R. Gibb, and L. Mee. 2008. Shifting baselines in fishers’ perceptions of island reef fishery degradation. Ocean and Coastal Management 51:285–302.
Carter, J., G. J. Marrow, and V. Pryor. 1994. Aspects of the ecology and reproduction of Nassau Grouper, Epinephelus striatus, off the coast of Belize, Central America. Proceedings of the 43rd Gulf and Caribbean Institute 43:65–111.
Cass-Calay, S. L. and T. W. Schmidt. 2009. Monitoring changes in the catch rates and abundance of juvenile Goliath Grouper using the ENP creel survey, 1973–2006. Endangered Species Research 7:183–193.
Cheung, W. W. L., Y. Sadovy de Mitcheson, M. T. Braynen, and L. G. Gittens. 2013. Are the last remaining Nassau Grouper Epinephelus striatus fisheries sustainable? Status quo in The Bahamas. Endangered Species Research 20:27–39.
Chiappone, M., R. Sluka and K. S. Sealey. 2000. Grouper (Pisces: Serranidae) in fished and protected areas of the Florida Keys, Bahamas and northern Caribbean. Marine Ecology Progress Series 198: 261–272.
Chollett, I., M. Priest, S. Fulton, and W. D. Heyman. 2020. Should we protect extirpated fish spawning aggregation sites? Biological Conservation 241:108395. https://doi.org/10.1016/j.biocon.2019.108395.
Chong-Montenegro, C., and H. K. Kindsvater. 2022. Demographic consequences of small-scale fisheries for two sex-changing groupers of the tropical Eastern Pacific. Frontiers in Ecology and Evolution 10:850006. https://doi.org/10.3389/fevo.2022.850006.
Claro, R., and K. C. Lindeman. 2003. Spawning aggregation sites of snapper and grouper species (Lutjanidae and Serranidae) on the insular shelf of Cuba. Gulf and Caribbean Research 14 (2):91–106.
Claro, R., Y. Sadovy de Mitcheson, K. C. Lindeman, and A. R. Garcia-Cagide. 2009. Historical analysis of Cuban commercial fishing effort and the effects of management interventions on important reef fishes from 1960–2005. Fisheries Research 99:7–16.
Coleman, F. C., C. C. Koenig, and L. A. Collins. 1996. Reproductive styles of shallow-water grouper (Pisces: Serranidae) in the eastern Gulf of Mexico and the consequences of fishing spawning aggregations. Environmental Biology of Fishes 47:129–141.
Coleman, F. C., C. C. Koenig, G. R. Huntsman, J. A. Musick, A. M. Eklund, J. C. McGovern, R.W. Chapman, G. R. Sedberry, and C. B. Grimes. 2000. American Fisheries Society position statement: long-lived reef fishes: the grouper-snapper complex. Fisheries 25(3):14–21.
Coleman, F. C,. K. C. Scanlon, and C. C. Koenig. 2011. Grouper on the edge: shelf edge spawning habitat in and around marine reserves of the northeastern Gulf of Mexico. Professional Geographer 63(4):1–19.
Colin, P. L. 1994. Preliminary investigations of reproductive activity of the jewfish, Epinephelus itajara (Pisces: Serranidae). Proceedings of the Gulf and Caribbean Fisheries Institute 43:138–147.
Colin, P. L. 1992. Reproduction of the Nassau grouper, Epinephelus striatus (Pisces: Serranidae), and its relationship to environmental conditions. Environmental Biology of Fishes 34:357–377.
Collins, D. 2022. Florida moves to officially lift 32-year ban on Goliath Grouper fishery. Outdoor Life, March 4. Available at: https://www.outdoorlife.com/fishing/florida-votes-to-officially-lift-32-year-ban-on-goliath-grouper/.
Colman, J. G. 1997. A review of the biology and ecology of the Whale Shark. Journal of Fish Biology 51:1219–1234.
Côté, I. M., J. A. Gill, T. A. Gardner, and A. R. Watkinson. 2005. Measuring coral reef decline through meta-analysis. Philosophical Transactions of the Royal Society B 360:385–395.
Craig, M. T., Y. J. Sadovy de Mitcheson, and P. C. Heemstra. 2011. Groupers of the world: a field and market guide. National Inquiry Services Center, Grahamstown, South Africa.
Dennis, L. P., G. Ashford, T. Q. Thai, V. V. In, N. H. Ninh, and A. Elizur. 2020. Hybrid grouper in Vietnamese aquaculture: production approaches and profitability of a promising new crop. Aquaculture 522:735108. https://doi.org/10.1016/j.aquaculture.2020.735108.
Domeier, M. L. 2012. Revisiting spawning aggregations: definitions and challenges. Pages 1–20 in Y. Sadovy de Mitcheson and P. L. Colin, editors, Reef fish spawning aggregations: biology, research and management, Springer, New York.
Dulvy, N. K., R. P. Freckleton, and N. V. C. Polunin. 2004. Coral reef cascades and the indirect effects of predator removal by exploitation. Ecology Letters 7:410–416.
Eggleston, D. B., J. J. Grover, and R. N. Lipcius. 1998. Ontogenetic diet shifts in Nassau Grouper: trophic linkages and predatory impact. Bulletin of Marine Science 63:111–126.
Erisman, B. E., L. G. Allen, J. T. Claisse, D. J. Pondella II, E. F. Miller, and J. H. Murray. 2011. The illusion of plenty: hyperstability masks collapses in two recreational fisheries that target fish spawning aggregations. Canadian Journal of Aquatic Sciences 68:1705–1716.
Erisman, B. E., W. D. Heyman, S. Fulton, and T. Rowell 2018. Fish spawning aggregations: a focal point of fisheries management and marine conservation in Mexico. Gulf of California Marine Program, La Jolla.
Erisman, B. E., W. Heyman, S. Kobara, T. Ezer, S. Pittman, O. Aburto-Oropeza, and R. S. Nemeth. 2017. Fish spawning aggregations: where well-placed management actions can yield big benefits for fisheries and conservation. Fish and Fisheries 18:128–144.
Erisman, B. E., C. McKinney-Lambert, and Y. Sadovy de Mitcheson. 2013. Sad farewell to C. Lavett-Smith’s iconic Nassau spawning aggregation site. Proceedings of the Gulf and Caribbean Fisheries Institute 66:421–422.
FAO. 2009. The state of world fisheries and aquaculture 2008. Food and Agricultural Organization, Fisheries Department, Rome.
Frías-Torres, S. 2006. Habitat use of juvenile Goliath Grouper Epinephelus itajara in the Florida Keys, USA. Endangered Species Research 2:1–6.
Frías-Torres, S. 2013. Should the critically endangered Goliath Grouper Epinephelus itajara be culled in Florida? Oryx 47(1): 88–95. doi:10.1017/S0030605312000361.
Fuiman, L. A., T. L. Connelly, S. K. Lowerre-Barbieri, and J. W. McClelland. 2015. Egg boons: central components of marine fatty acid food webs. Ecology 96:362–372.
Giglio, V. J., M. G. Bender, C. Zapelini, and C. E. L. Ferreira. 2017. The end of the line? Rapid depletion of a large-sized grouper through spearfishing in a subtropical marginal reef. Perspectives in Ecology and Conservation 15:115–118.
Giglio, V. J., A. A. Bertoncini, B. P. Ferreira, M. Hostim-Silva, and M. O. Freitas. 2014. Landings of Goliath Grouper, Epinephelus itajara, in Brazil: despite prohibited over ten years, fishing continues. Brazilian Journal of Nature Conservation 12:118–123.
Graham, R. T., K. L. Rhodes, and D. Castellanos. 2009. Characterization of the Goliath Grouper Epinephelus itajara fishery of southern Belize for conservation planning. Endangered Species Research 7:195−204.
Grossman, G. D. 2015. The jewfish and me. Medium, November 22. Available at: https://garydavidgrossman.medium.com/the-jewfish-and-me-99e34b6a6693#.5wl45gitf.
Gutiérrez, N. L. R. Hilborn, and O. Defeo. 2011. Leadership, social capital and incentives promote successful fisheries. Nature 470:386–389.
Harrington, J., B. Awad, K. Kingon, and A. Haskins. 2009. Goliath Grouper study: a survey analysis of dive shop and charter boat operators in Florida. Final Report. Florida Fish and Wildlife Conservation Commission. Available at: https://cefa.fsu.edu/sites/g/files/imported/storage/original/application/a379d337b1af201412c51763eb86b5f0.pdf.
Hazlett, B., and H. E. Winn. 1962. Sound producing mechanism of the Nassau Grouper, Epinephelus striatus. Copeia 2:447–449.
Hensel, E., J. E. Allgeier, and C. A. Layman. 2019. Effects of predator presence and habitat complexity on reef fish communities in The Bahamas. Marine Biology 166, 136. https://doi.org/10.1007/s00227-019-3568-3.
Heppell, S. S., S. A. Heppell, F. C. Coleman, and C. C. Koenig. 2006. Models to compare management options for a protogynous fish. Ecological Applications 16:238–249.
Heyman, W. D., L. M. Carr, and P. S. Lobel. 2010. Diver ecotourism and disturbance to reef fish spawning aggregations: it is better to be disturbed than to be dead. Marine Ecology Progress Series 419:201–210.
Heyman, W. D., R. T. Graham, B. Kjerfve, and R. E. Johannes. 2001. Whale Sharks Rhincodon typus aggregate to feed on fish spawn in Belize. Marine Ecology Progress Series 215:275–282.
Hostim-Silva, M., A. A. Bertoncini, M. Borgonha, J. R. Leite, M. O. Freitas, F. A. Daros, L. S. Bueno, A. P. C. Farro, and C. C. Koenig. 2017. The Atlantic Goliath Grouper: conservation strategies for a critically endangered species in Brazil. Pages 367–405 in M. R. Rossi-Santos, and C. W. Finkl, editors, Advances in marine vertebrate research in Latin America, Springer, New York.
Howlett, S. J., R. Stafford, M. Waller, S. Antha, and C. Mason-Parker. 2016. Linking protection with the distribution of grouper and habitat quality in Seychelles. Journal of Marine Biology 2016:7851425. DOI:10.1155/2016/7851425.
Khasanah, M., N. Nurdin, Y. Sadovy de Mitcheson, and J. Jompa. 2020 Management of the grouper export trade in Indonesia. Reviews in Fisheries Science & Aquaculture 28:1–15.
Kindsvater, H., J. Reynolds, Y. Sadovy de Mitcheson, and M. Mange. 2017. Selectivity matters: rules of thumb for management of plate-sized, sex-changing fish in the live reef food fish trade. Fish and Fisheries 18:821–836.
Knowlton, N, and J. B. Jackson. 2008. Shifting baselines, local impacts, and global change on coral reefs. PLoS Biology 6:e54.
Koenig, C. C., F. C. Coleman, A. M. Eklund, J. Schull, and J. Ueland. 2007. Mangrove as essential nursery habitat for Goliath Grouper (Epinephelus itajara). Bulletin of Marine Science 80:567–586.
Koenig, C. C., F. C. Coleman, and K. Kingon. 2011. Pattern of recovery of the Goliath Grouper Epinephelus itajara population in the southeastern US. Bulletin of Marine Science 87:891–911.
Koenig, C. C., F. C. Coleman, and C. R. Malinowski. 2020. Atlantic Goliath Grouper of Florida: to fish or not to fish. Fisheries 45(1):20–32.
Kough, A. S. B. C. Gutzler, J. G. Tuttle, N. Palma, L. C. Knowles, and L. Waterhouse. 2022. Anthropause shows differential influence of tourism and a no-take reserve on the abundance and size of two fished species. Aquatic Conservation: Marine and Freshwater Ecosytems 32:1693–1709.
Lara, M. R., J. Schull, D. L. Jones, and R. Allman. 2009. Early life history stages of Goliath Grouper Epinephelus itajara (Pisces: Epinephelidae) from Ten Thousand Islands, Florida. Endangered Species Research 7(3):221–228.
Lavett-Smith, C. 1972. A spawning aggregation of Nassau Grouper, Epinephelus striatus (Bloch). Transactions of the American Fisheries Society 101:257–261.
Luiz, O. J., R. M. Woods, E. M. P. Madin, and J. S. Madin. 2016. Predicting IUCN extinction risk categories for the world’s data deficient groupers (Teleostei: Epinephelidae). Conservation Letters 9(5):342–350.
Malinowski, C. R. 2019. High mercury concentrations in Atlantic Goliath Grouper: spatial analysis of a vulnerable species. Marine Pollution Bulletin 143:81–91.
Maljkovic, A., T. E. van Leeuwen, and S. N. Cove. 2008. Predation on the invasive Red Lionfish, Pterois volitans (Pisces: Scorpaenidae), by native groupers in The Bahamas. Coral Reefs 27(3):501. DOI:10.1007/s00338-008-0372-9.
Mann, D. A., J. V. Locascio, F. C. Coleman, and C. C. Koenig. 2009. Goliath Grouper (Epinephelus itajara) sound production and movement patterns on aggregation sites. Endangered Species Research 7:229–236.
McClenachan, L. 2009. Historical declines of Goliath Grouper populations in south Florida, USA. Endangered Species Research 7:175–181.
McKenzie, L. J., L. M. Nordland, B. L. Jones, L. C. Cullen-Unsworth, C. Roelfsema, and R. K. F. Unsworth. 2020. The global distribution of seagrass meadows. Environmental Research Letters 15(7):074041. DOI: 10.1088/1748-9326/ab7d06.
Mourier, J., J. Maynard, V. Parravicini, L. Ballesta, E. Clua, M. L. Domeier and S. Planes. 2016. Extreme inverted trophic pyramid of reef sharks supported by spawning groupers. Current Biology 26:2011–2016.
Mumby, P. J. 2006. Connectivity of reef fish between mangroves and coral reefs: algorithms for the design of marine reserves at seascape scales. Biological Conservation 128:215–222. https://doi.org/10.1016/j.biocon.2005.09.042.
Mumby, P. J., A. R. Harborne, and D. R. Brumbaugh. 2011. Grouper as a natural biocontrol of invasive lionfish. PLoS ONE 6:e21510.
Pauly, D., and D. Zeller. 2015. Sea around us concepts, design and data. Sea Around Us, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada.
Pavlowich, T., and A. R. Kapuscinski. 2017. Understanding spearfishing in a coral reef fishery: fishers’ opportunities, constraints, and decision-making. PLoS ONE 12(7):e0181617.
Paxton, A. B., S. L. Harter, S. W. Ross, C. M. Schobernd, B. J. Runde, P. J. Rudershausen, K. H. Johnson, K. W. Shertzer, N. M. Bacheler, J. A. Buckel, G. T. Kellison, and J. C. Taylor. 2021. Four decades of reef observations illuminate deep-water grouper hotspots. Fish and Fisheries 22:749–761.
Philips, S., S. Sitaraman, C. M. Hong, and G. Yan. 2008. Inside the affluent space: a view from the top to anticipate the needs of the emerging affluent. World Association of Research Professionals, April. Available at: https://www.warc.com/fulltext/ESOMAR/88139.htm.
Pierre, S., S. Gaillard, and N. Prevot. 2008. Grouper aquaculture: Asian success and Mediterranean trials. Aquatic Conservation Marine and Freshwater Ecosystems 18(3):297–308.
Pinnegar, J. K., and G. H. Engelhard. 2008. The “shifting baseline” phenomenon: a global perspective. Reviews in Fish Biology and Fisheries 18:1–16.
Porch, C. E., A.-M. Eklund, and G. P. Scott. 2006. A catch-free stock assessment model with application to Goliath Grouper (Epinephelus itajara) off southern Florida. Fishery Bulletin 104:89–101.
Reddy, S. M. W., A. Wentz, O. Aburto-Oropeza, M. Maxey, S. Nagavarapu, S., and H. M. Leslie. 2013. Evidence of market-driven size-selective fishing and the mediating effects of biological and institutional factors. Ecological Applications 23:726–741.
Ribeiro, A. R., L. M. A. Damasio, and R. A. M. Silvano. 2021. Fishers’ ecological knowledge to support conservation of reef fish (groupers) in the tropical Atlantic. Ocean and Coastal Management 204:105543. https://doi.org/10.1016/j.ocecoaman.2021.105543.
Rimmer, M. A., and B. Glamuzina. 2019. A review of grouper (Family Serranidae: Subfamily Epinephelinae) aquaculture from a sustainability science perspective. Reviews in Aquaculture 11(1):58–87.
Robinson, J., N. A .J. Graham, J. E. Cinner, G. R. Almany, and P. Waldie. 2015. Fish and fisher behaviour influence the vulnerability of groupers (Epinephelidae) to fishing at a multispecies spawning aggregation site. Coral Reefs 34:371–382.
Rocklin, D., I. Rojo, M. Muntoni, D. Mateos-Molina, I. Bejarano, A. Caló, M. Russell, J. Garcia, F. C. Félix-Hackradt, C. W. Hackradt, and J. A. García-Charton. 2022. Fisheries regulation groupers’ management and conservation. Pages 118–165 in F. C. Félix-Hackradt, C. W. Hackradt, and J. A. García-Charton, editors, Biology and ecology of groupers, CRC Press, Boca Raton, FL.
Rojo, I., J. D. Anadón and J. A. García-Charton. 2021. Exceptionally high but still growing predatory reef fish biomass after 23 years of protection in a Marine Protected Area. PLoS ONE 16(2):e0246335.
Rowell, T. J., R. S. Nemeth, M. T. Schärer and R. S. Appeldoorn. 2015. Fish sound production and acoustic telemetry reveal behaviors and spatial patterns associated with spawning aggregations of two Caribbean groupers. Marine Ecology Progress Series 518:239–254.
Rudershausen, P. J., J. A. Buckel, and E. H. Williams. 2007. Discard composition and release fate in the snapper and grouper commercial hook-and-line fishery in North Carolina, USA. Fisheries Management and Ecology 14:103–113.
Russ, G. R., J. R. Rizzari, R. A. Abesamis, and A. C. Alcala. 2021. Coral cover a stronger driver of reef fish trophic biomass than fishing. Ecological Applications 31(1):e02224. https://doi.org/10.1002/eap.2224.
Russell, M. W., B. E. Luckhurst, and K. C. Lindeman. 2012. Management of spawning aggregations. Pages 371–404 in Y. Sadovy de Mitcheson and P. L. Colin, editors, Reef fish spawning aggregations: biology, research and management, Springer, Dordrecht.
Sadovy, Y. 1994. Grouper stocks of the western central Atlantic: the need for management and management needs. Proceedings of the 60th Gulf and Caribbean Institute 60:577–584.
Sadovy, Y., and W. L. Cheung. 2003. Near extinction of a highly fecund fish: the one that nearly got away. Fish and Fisheries 4:86–99.
Sadovy, Y., and M. Domeier. 2005. Are aggregation fisheries sustainable? Reef fish fisheries as a case study. Coral Reefs 24: 254–262.
Sadovy, Y., T. J. Donaldson, T. R. Graham, F. McGilvray, G. Muldoon, M. Phillips, and M. Rimmer. 2003. While stocks last: the live reef food fish trade. Asian Development Bank, Manila.
Sadovy, Y., and P. P. F. Lau. 2002. Prospects and problems for mariculture in Hong Kong associated with wild-caught seed and feed. Aquaculture Economics and Management 6:177– 190.
Sadovy, Y., and J. Pet. 1998. Wild collection of juveniles for grouper mariculture: just another capture fishery? Live Reef Fish Information Bulletin 4:36–39.
Sadovy de Mitcheson, Y. 2020. Island of hope for the threatened Nassau Grouper. Proceedings of the National Academy of Sciences 117:2243–2244.
Sadovy de Mitcheson, Y. 2019. The live reef food fish trade; undervalued, overfished and opportunities for change. International Coral Reef Initiative.
Sadovy de Mitcheson, Y. 2016. Mainstreaming fish spawning aggregations into fisheries management calls for precautionary approach. BioScience 66(4):295–306.
Sadovy de Mitcheson, Y., M. T. Craig, A. A . Bertoncini, K. E. Carpenter, W. W. L. Cheung, J. H. Choat, A. S. Cornish, S. T. Fennessy, B. P. Ferreira, P. C. Heemstra, M. Liu, R. F. Myers, D. A. Pollard, K. L. Rhodes, L. A. Rocha, B. C. Russell, M. A. Samoilys, and J. Sanciangco. 2013. Fishing groupers towards extinction: a global assessment of threats and extinction risks in a billion dollar fishery. Fish and Fisheries 14:119–136.
Sadovy de Mitcheson, Y., C. Linardich, J. P. Barreiros, G. M. Ralph, A. Aguilar-Perera, P. Afonso, B. E. Erisman, D. A. Pollard, S. T. Fennessy, A. A. Bertoncini, R. J. Nair, K. L. Rhodes, P. Francour, T. Brulé, M. A. Samoilys, B. P. Ferreira, and M. T.Craig. 2020. Valuable but vulnerable: over-fishing and under-management continue to threaten grouper so what now? Marine Policy 116:103909. https://doi.org/10.1016/j.marpol.2020.103909.
Sadovy de Mitcheson, Y., and M. Liu. 2022. The importance of grouper and threats to their future. Pages 191–230 in F. C. Félix-Hackradt, C. W. Hackradt, and J. A. García-Charton, editors, Biology and ecology of groupers, CRC Press, Boca Raton, FL.
Sadovy de Mitcheson, Y., and X. Yin. 2015. Cashing in on coral reefs: the implications of exporting reef fishes. Pages 166–179 in C. Mora, editor, Ecology of fishes on coral reefs, Cambridge University Press.
Sala, E. Ballesteros, and R. M. Starr. 2001. Rapid decline of Nassau Grouper spawning aggregations in Belize: fishery management and conservation needs. Fisheries 26(10):23–30.
Sambrook, K., A. S. Hoey, S. Andréfouët, G. S. Cumming, S. Duce, and M. C. Bonin. 2019. Beyond the reef: the widespread use of non-reef habitats by coral reef fishes. Fish and Fisheries 20:903–920.
Sherman, K. D., C. P. Dahlgren, J. R. Stevens, and C. R. Tyler. 2016. Integrating population biology into conservation management for endangered Nassau Grouper Epinephelus striatus. Marine Ecology Progress Series 554:263–280.
Shideler, G. S., D. W. Carter, C. Liese, and J. E. Serafy. 2015a. Lifting the Goliath Grouper ban: angler perspectives and willingness to pay. Fisheries Research 161:156–165.
Shideler, G. S., and B. Pierce. 2016. Recreational diver willingness to pay for Goliath Grouper encounters during the months of their spawning aggregation off eastern Florida, USA. Ocean and Coastal Management 129:36–43.
Shideler, G. S., S. R. Sagarese, W. J. Harford, J. Schull, and J. E. Serafy. 2015b. Assessing the suitability of mangrove habitats for juvenile Atlantic Goliath Grouper. Environmental Biology of Fishes 98:2067–2082.
Southwick, R., D. Maycock and M. Bouaziz. 2016. Recreational fisheries economic impact assessment manual and its application in two study cases in the Caribbean: Martinique and The Bahamas. FAO Fisheries and Aquaculture Circular No. 1128. Bridgetown, Barbados.
Starr, R. M., E. Sala, E. Ballesteros, and M. Zabala. 2007. Spatial dynamics of the Nassau Grouper, Epinephelus striatus, in a Caribbean atoll. Marine Ecology Progress Series 343:239–249.
Stock, B. C., S. A. Heppell, L. Waterhouse, I. C. Dove, C. V. Pattengill-Semmens, C. M. McCoy, P. G. Bush, G. Ebanks-Petrie, and B. X. Semmens. 2021. Pulse recruitment and recovery of Cayman Islands Nassau Grouper (Epinephelus striatus) spawning aggregations revealed by in situ length-frequency data. ICES Journal of Marine Science 78:277–292.
Stump, K., C. P. Dahlgren, K. D. Sherman, and C. R. Knapp. 2017. Nassau Grouper migration patterns during full moon suggest collapsed historic fish spawning aggregation and evidence of an undocumented aggregation. Bulletin of Marine Science 93:375–389.
To, A. W. L., and Y. J. Sadovy de Mitcheson. 2009. Shrinking baseline: the growth in juvenile fisheries, with the Hong Kong grouper fishery as a case study. Fish and Fisheries 10:396–407.
Tupper, M., and N. Sheriff. 2008. Capture-based aquaculture of groupers. Pages 217–253 in A. Lovatelli and P. F. Holthus, editors, Capture-based aquaculture: global overview, FAO Fisheries Technical Paper No. 508, Rome.
Ulrich, R. M., D. E. John, G. W. Barton, G. S. Hendrick, D. P. Fries, and J. H. Paul. 2015. A handheld sensor assay for the identification of grouper as a safeguard against seafood mislabeling fraud. Food Control 53:81–90.
Usseglio, P., A. M. Friedlander, H. Koike, J. Zimmerhackel, A. Schuhbauer, T. Eddy, and P. Salinas-de-León. 2016. So long and thanks for all the fish: overexploitation of the regionally endemic Galapagos Grouper Mycteroperca olfax (Jenyns 1840). PLoS ONE 11(10):e0165167.
Valiela, I., J. L. Bowen, and J. K. York. 2001. Mangrove forests: one of the world’s threatened major tropical environments. BioScience 51(10):807–815.
Veblen, T. 1912. The theory of the leisure class. Macmillan, London.
Waschkewitz, R., and P. Wirtz. 1990. Annual migration and return to the same site by an individual grouper, Epinephelus alexandrinus (Pisces, Serranidae). Journal of Fish Biology 36:781–782.
Waterhouse, L., S. A. Heppell, C. V. Pattengill-Semmens, C. McCoy, P. Bush, B. C. Johnson, and B. X. Semmens. 2020. Recovery of critically endangered Nassau Grouper (Epinephelus striatus) in the Cayman Islands following targeted conservation actions. Proceedings of the National Academy of Sciences 117(3):1587–1595.
Waycott, M., C. M. Duarte, T. J. Carruthers, R. J. Orth, W. C. Dennison, S. Olyarnik, A. Calladine, J. W. Fourqurean, K. L. Heck Jr., A. R. Hughes, G. A. Kendrick, W. J. Kenworthy, F. T. Short, and S. L. Williams. 2009. Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Academy of Sciences of the United States of America 106:12377–12381.
Wealth-X. 2018. World ultra wealth report. Available at: https://www.wealthx.com/report/world-ultra-wealth-report-2018/.
Wilcox, C. 2016. Fishing with cyanide. Hakai Magazine, June 30. Available at: https://hakaimagazine.com/news/fishing-cyanide/. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.13%3A_Grouper_and_Spawning_Aggregations.txt |
Learning Objectives
• Describe the historical development of Atlantic Menhaden fishing.
• Summarize key characteristics of life history and ecological role of Atlantic Menhaden.
• Articulate the special challenges of managing fisheries on small, pelagic forage fish that are low on the food chain and make them vulnerable to both environmental change and overfishing.
• Highlight the false assumptions of single-species management for maximum sustainable yield.
• Explain the benefits of adopting a fishery policy that uses ecological reference points.
• Describe value preferences of key stakeholders in the Atlantic Menhaden fisheries.
14.1 Early Lessons Learned from Menhaden Fishing
Indigenous people along the Atlantic Coast and early European colonists relied heavily on abundant Atlantic Menhaden (Brevoortia tyrannus) (Figure 14.1). At least 30 popular names are used to describe the menhaden. In Maine and Massachusetts, the names “pogy” and “hardhead” are used. In New York and New Jersey, the name “mossbunker” (with a variety of spellings) is common, whereas in Delaware and Chesapeake Bay, the names “old-wife,” “alewife,” “greentail,” and “bug-fish” are also used. In the Carolinas, they may be referred to as “fat-back,” “yellow-tail,” or “yellow-tailed shad.” “Pogy” and “menhaden” were likely derived from Native American dialects of New England. Somehow, the name “Munnawhatteaûg,” which means “fertilizer” or “manure,” was corrupted to menhaden. As early as 1661, the name “mossbanker” was in use based on Jacob Steendam’s poem “Praise of New Netherland”:
The black and rock-fish, herring, mackerel,
The haddock, mossbanker, and roach, which fill
The nets to loathing; and so many, all
Cannot be eaten.
The history of menhaden management reveals challenges of breaking from long-standing traditions in fisheries management. The Atlantic Menhaden was labeled as the “most important fish in the sea” by author and historian Bruce Franklin because of its utility to Native Americans and European colonists in the Atlantic coastal regions (Figure 14.2). Native Americans instructed early colonists how to plant their crops with abundant menhaden as manure. Later, colonists often plowed excess harvest of menhaden in the soil of farms along the shore, until new products utilizing them were discovered, initiating a large industrial fishery.
Soon colonists realized the value of the menhaden as a baitfish, as well as an important source of oil, manure (guano), and fish meal. From 1850 to 1870, numerous factories from Maine to North Carolina began to manufacture oil from menhaden. Soon the yield of oil from menhaden would exceed yield of oil from whaling. Fish scrap, or waste after oil was pressed out of the fish, was sold as manure for fertilizer.
A large industry based on menhaden developed along the Atlantic Coast in the late 19th century. Although there were no fishing regulations at the time, the U.S. Oil and Guano Association monitored companies and total catch. By 1876, menhaden yields were 462 million pounds and valued at \$1,657,790 (Goode 1880). At the time, Marshall McDonald, Commissioner of Fisheries for Virginia, wrote that “this industry is yet in its infancy.” The early landings exceeded the volume of recent menhaden landings from both the Gulf of Mexico and Atlantic Coast of 1,581,578 pounds, valued at \$161 million (National Marine Fisheries Service 2020). Currently, the landings of menhaden are second in volume behind Alaska Pollock, and they are higher than landings of salmon and cod combined. Value of menhaden landings ranks 10th after high-valued seafoods. Estimates from 1878 indicated that 279 sail vessels caught nearly 900 million menhaden, which were processed by 56 factories and yielded 4 million barrels of fish oil and 30,000 tons of guano (Goode 1880).
The reduction factories that were once widespread along the Atlantic Coast were smelly operations. In the 20th century, many states banned them in the interest of coastal development and odor abatement. The only states on the Atlantic Coast that still permit reduction fishing are North Carolina and Virginia. Since 2005, all harvested menhaden are processed at one facility at Reedville, Virginia, owned by Omega Protein, a subsidiary of Canadian-based Cooke Aquaculture. While there are four species of menhaden, the most abundant are the Atlantic Menhaden, distributed from Maine to Florida, and the Gulf Menhaden (Brevoortia patronus), distributed in the Gulf of Mexico. Two other species are distributed in the Gulf of Mexico and the Atlantic Coast of Florida.
Early commercial vessels learned that the purse seine is more effective than any other fishing apparatus for catching menhaden (Figure 14.3). A school of almost any size may be surrounded by the net, resulting in a catch composed entirely of menhaden. Factory fleets exclusively rely on the purse seine. Early versions extended 90 to 180 feet below the surface and from 800 to 1,500 feet in length (Goode 1880); some boats carried both long and short purse seines to adapt to the size of menhaden schools.
14.2 Life History of Menhaden
Menhaden have an opportunistic life history strategy, characterized by many small offspring, small body size, rapid growth, early maturity, and short life span relative to other fish. Menhaden spawn offshore from fall through spring, with peak spawning in fall and winter. Atlantic Menhaden exhibit indeterminate batch spawning, which means that the eggs in the female continue to mature during the spawning season for release in later spawns. Mature menhaden may spawn up to 10 times per season. The fertilized eggs are small (~1.6 mm), and mature females may produce about 240 eggs per gram of body weight, and sometimes as many as 700. Total fecundity is difficult to know because eggs continue to mature during a long spawning season, fish spawn multiple times, and the number of eggs is strongly influenced by menhaden size (Figure 14.4). Because of variability in spawning time and growth, some Atlantic Menhaden may become sexually mature by age 1 (~20–24 cm), while most become fully mature at age 4. In the absence of fishing, Atlantic Menhaden can live 10 to 12 years and attain a length of 38 cm (i.e., 15 inches). The larger menhaden are big enough to become the preferred prey of large Striped Bass and Ospreys.
Eggs are buoyant in sea water and drift with currents. After hatching, the larval (~1–2 cm) and juvenile (~3.0–3.5 cm) Atlantic Menhaden drift with currents, grow rapidly, and return to bays and estuaries, which are important nursery areas. After less than one year in bays and estuaries, most of the juveniles return to sea. Atlantic Menhaden grow rapidly in the first year, and the smallest menhaden caught in the fishery will include some age-0 fish. Growth rates are also strongly influenced by densities and water temperature, and high landings in one year may permit faster growth the following year. In addition, wind and climate conditions have a large influence on growth (Midway et al. 2020). Consequently, environmental conditions that lead to large year classes or year-class failure may occur at a variety of times and locations.
The life history characteristics result in highly variable recruitment where there may be no discernible relationship between abundance of spawners and the resulting recruitment of offspring (Schaaf and Huntsman 1972). Further, the biological reference points used to adjust fishing quotas are also highly uncertain (Schueller and Williams 2017). This means that a harvest quota that was at one time sustainable may lead to the collapse of a fishery after climatic conditions become less favorable for reproduction and growth.
Many other small, pelagic fish, such as sardine and anchovy, also support large coastal fisheries that are known to show dramatic fluctuations in abundance. High levels of commercial fishing on these small pelagic fish increase the chance for collapse (MacCall et al. 2016). Well-documented and widespread collapses of Pacific Sardine (Sardinops sagax) occurred in the 1940s and again from 2008 to the present. Recruitment in other clupeiform (herring-life) fish is driven largely by environmental variation or climatic regime shifts (Essington et al. 2015). For example, Atlantic Menhaden recruitment is strongly influenced by sea surface temperature (Deyle et al. 2018), which leads to high catch variability in the youngest adult age classes and variability in the commercial harvest. Consequently, aspects of the life history of Atlantic Menhaden may translate to poor prediction of trends with classical fisheries models (Szuwalski and Thorson 2017).
14.3 Ecological Role of Menhaden
Atlantic Menhaden swim through the water column with their mouths wide open, thereby trapping food particles on the gill rakers. Gill structures of the Atlantic Menhaden (Figure 14.5) create an effective sieve for efficient filter feeding. Both plant and animal plankton are consumed by Atlantic Menhaden. When smaller, they feed primarily on phytoplankton; however, they shift their diet to primarily consume zooplankton as they grow. By one oft-cited estimate, Atlantic Menhaden are capable of filtering 23–27 liters of water per minute (Peck 1894). Consequently, they manage the large algal bloom occurrences in the bay because they eat vast quantities of phytoplankton, thereby reducing concentrations of nutrients. Watch this video to observe feeding behavior (Filter-Feeding Menhaden Caught on Camera, https://www.youtube.com/watch?v=WhprcLcGGBs).
All carnivorous sea mammals, fish, and seabirds are potential predators of menhaden. Consequently, whales, dolphins, sharks, tuna, swordfish, bonito, Striped Bass, Weakfish, Tarpon, and bluefish likely consume large numbers of menhaden. Atlantic Menhaden are an important link between the plankton and numerous carnivorous predators (Figure 14.6).
The feeding behavior of predators on large schools of menhaden provides an impressive display, which is easily seen from a distance. Consider the sharks entering a large school of menhaden captured with this drone-mounted video camera off the coast of New York Hampton in 2017.
Fish predators force the menhaden to move near the surface, where they are more easily eaten by piscivorous birds. Ospreys, along with Bald Eagles, feed on menhaden, which are easily captured from the water surface (Figure 14.7). Chesapeake Bay once supported the largest concentration of breeding Ospreys in the world, and breeding populations of both Bald Eagles and Ospreys have been recovering since DDT was banned. The high lipid content of Atlantic Menhaden nourishes Ospreys, which breed throughout the coastal waters of the mid-Atlantic and northeastern United States (Spitzer and Poole 1980). One study indicated that Atlantic Menhaden comprised 24% of fish brought to Osprey nestlings in lower estuarine sites (Glass and Watts 2009).
Until recently, few investigations have quantitatively linked abundance of menhaden predators to their abundance. However, after regulation of the Atlantic Menhaden fishery, the fish rebounded and expanded back into their historic range while Humpback Whales were recovering after the ban on whaling in 1955 (Stevick et al. 2003; Brown et al. 2018; Lucca and Warren 2019). Observations by Gotham Whale (GothamWhale.org), a New York City–based whale research organization, have shown an increase in whale sightings in the New York–New Jersey Bight in the last 10 years (Brown et al. 2022). Watch this video of pilot whales and Humpback Whales feeding on pods of menhaden: Menhaden Conservation Works, New York, by Timothy Del Grosso, https://vimeo.com/239293026.
Black Skimmer, a widely distributed tern-like bird, is uniquely adapted to feeding on surface-dwelling fish. As the bird flies low, its long lower mandible plows the water, snapping the bill shut when it contacts a fish. Black Skimmers consume many species of small fish, and Atlantic Menhaden makes up one-fourth of its diet (Gordon et al. 2000). Watch this video: Black Skimmers–003, 2007, https://www.youtube.com/watch?v=7USpTc6MUoc. Populations of Black Skimmers have declined 86% between 1944 and 2015, leading to its listing as a Species of High Concern for conservation.
Strong overlap often occurs with size of forage fish eaten by birds, such as cormorants, boobies, pelicans, and those caught by commercial fishing (Pikitch et al. 2012, 2014, 2018). However, the impact that fishing on forage fish has on their predators will depend on number and types of alternative prey and the size overlap between fish taken by fishing and predators (Hilborn et al. 2017). For example, there is strong overlap with size of menhaden harvested and size eaten by Atlantic Bluefin Tuna. Striped Bass eat a wider range of menhaden sizes, and the larger Striped Bass can eat larger menhaden, which are targeted by commercial fishing (Walter et al. 2003; Overton et al. 2008; Figure 14.8). Watch this video to see Bluefin Tuna feeding on menhaden: Bluefin Tuna Near Shore Attacking Menhaden 2020, https://www.youtube.com/watch?v=e-0JAodI2A0.
Question to ponder:
What considerations are most important when setting Atlantic Menhaden harvest regulations?
14.4 Industrial Fishing, Marine Pelagic Fish, and Menhaden
The industrial menhaden fishery is an example of what is happening in many parts of the world in fisheries that target small pelagic forage fish. Many products are produced from small pelagic forage fish, including canned anchovy and sardine, fish sauce, moisturizers, human health supplements, bait, fish oil, and fish meal. Globally, these marine fisheries are significant sources of livelihood, with over three-fourths of the production coming from developing countries. Fisheries for marine pelagic fish often have low levels of bycatch and greenhouse gas emissions because of the schooling behavior of fish and the use of purse seines that target them. However, some of these pelagic fisheries also take squid, seabirds, mammals, and carnivorous fish, raising concerns from conservationists. Of further concern, demand for small pelagic fish is likely to increase in the future for use in aquaculture feeds (Merino et al. 2010).
Anchovy and sardine, which make up 52% of landings of marine pelagic fish, share a similar life history pattern with Atlantic Menhaden. They produce numerous small offspring, reach a small body size, grow rapidly, mature early, and live a short life. Like menhaden, anchovy and sardine eat phytoplankton and zooplankton at or near the base of the food web by filtering particles or biting individual particles. Sardine and anchovy also have extensive coastwide migrations. These traits mean that marine pelagic forage fish show speedy and sometimes dramatic reactions to environmental change. Furthermore, overfishing and climate change in combination may drive collapse of anchovy and sardine fisheries (Checkley et al. 2017; Izquierdo-Peña et al. 2020).
Because Atlantic Menhaden undergo extensive migrations and are mostly harvested from inshore (state) waters, their management is coordinated through the Atlantic States Marine Fisheries Commission (ASMFC), a deliberative body of fisheries management agencies from the Atlantic Coast states. After Maryland banned the use of purse seines to harvest Atlantic Menhaden in 1931, Virginia and North Carolina were the only states to permit reduction purse-seine fishing. This fishery is concentrated in Virginia waters of Chesapeake Bay and offshore to stay close to the only surviving menhaden reduction plant in Reedville. Large purse seines are used to harvest menhaden for reduction to fish meal to oil (Figure 14.9). Smaller purse-seine rigs, called “snapper rigs,” are used for capture of menhaden for bait. In 1999, the lower Chesapeake Bay was the center of the Atlantic Menhaden fishery, with the bay, Virginia’s eastern shore, and Virginia Beach accounting for 67% of the total harvest of Virginia and North Carolina fleets (Smith 1999).
To assist ship captains in locating schools of menhaden, an airplane pilot in a spotter plane directs the ship’s two smaller purse boats, whose mission it is to trap the fish in an ever-tightening net. A hydraulic rig lifts the net to bring the catch closer to the surface, where a large vacuum hose sucks the fish into the ship’s hold. The crew’s pay is determined by the catch, so fishing crews work from Sunday night to Friday night. The oily catch is unloaded in Reedville each night, after which the crew returns to fishing grounds to catch more menhaden.
14.5 Demand for Products From Small Marine Pelagic Fish
Small marine pelagic fish, often herring or sardine, consume and process marine algae and incorporate omega-3 fatty acids in their bodies. Foods that are high in omega-3 fatty acids are essential for humans because these fatty acids cannot be synthesized in the body. Therefore, they must be consumed in the diet. Omega -3 fatty acids have many effects on the heart and blood vessels of humans, including reduction in triglycerides, irregular heartbeat, arterial plaque, and blood pressure. Therefore, their health benefits of omega-3 fatty acids have been promoted for heart health in patients with coronary heart disease to reduce the risk of heart attacks (Manson et al. 2020). More recent studies focus on the potential influence of omega-3 fatty acid consumption on cancer, depression, inflammation, cognitive decline, and ADHD (Arellanes et al. 2020).
Demand for small pelagic fish is likely to increase to meet growing demands for bait, aquaculture, and fish oil supplements. Forage fish are captured and sold as bait for sportfishing and crab and lobster traps. Global demand for use of fish meal in aquaculture feeds is rising dramatically, and fish oil is a growing global industry (Merino et al. 2010; World Bank 2013). In 1997, the Food and Drug Administration approved the use of refined menhaden oil for use in foods and supplements. Omega Protein, Inc., which operates the only marine oil refinery in the United States, produces several grades of refined menhaden oil.
Future demands for menhaden soluble fats, oil, and meal, while expected to be higher, are uncertain for several reasons. First, because of rising fish meal costs, feed industries are replacing fish meal with fermented soy and soybean protein concentrates. Globally, a surplus of soy depresses the demand for and price of fish meal. Second, similar products can be naturally derived from other sources. For example, marine algae chorella and spirulina, which can be cultured, are also high in omega-3 fatty acids, minerals, and antioxidants. Similarly, krill, flax, soybeans, nuts, and other plants also contain high levels. Some food companies are working to create a plant-based oil, LatitudeTM, that is high in omega-3. Finally, since the use of menhaden to produce omega-3 supplements is classified by the FDA as food, there is less regulatory oversight, there are no clinical trials, and supplements may contain harmful levels of mercury, PCBs, and dioxins (Hong et al. 2015; Sherratt et al. 2020).
14.6 Menhaden Population Dynamics
By 1876, menhaden yields already exceeded 200,000 metric tons (Figure 14.10). After World War II, menhaden fisheries went through a boom, bust, and recovery, which forced coastwide coordination of harvest quotas in the 1980s and 1990s.
Early studies of population dynamics of Atlantic Menhaden applied single species population analysis tools, such as equilibrium yield and stock recruitment. With these mathematical tools, scientists can predict, theoretically, the largest catch that can be taken from a species’ stock over an indefinite period (Finley 2011). These models predict a dome-shaped relationship between long-term average yield, or equilibrium yield (Y), and population biomass (Figure 14.11). This result is because the rate of increase (r) declines in a linear manner as population approaches carrying capacity. Fisheries managers monitor catch per unit effort as a primary index of abundance because abundance is difficult to quantify. From the 1950s and through the 1960s, catch per unit effort decreased as fishing effort increased, as was expected (Figure 14.12 A; Schaff and Huntsman 1972). During the 1950s and 1960s, a dome-shaped relationship was evident from the scatterplot of the data (Figure 14.12 B). Since 1966, the data points diverged from the expected dome-shaped relationship between catch and effort to a linear relationship between catch per unit effort and fishing effort (Figure 14.12).
This linear decline in catch per unit effort was not reversed with reductions in fishing. Examine the data scatter, which shows how the reduction in effort after 1965 results in similar measures of catch per unit effort and total catch (Figure 14.12). There is a time lag in the response of menhaden populations to fishing reductions, related to their life history as well as changes in environmental conditions and/or predator abundance, which may also influence dynamics of the fish.
Without fishing, the mortality of Atlantic Menhaden is about 25% per year. However, with typical levels of fishing observed, mortality was between 65 to 85% per year (Figure 14.13). Predicting the population dynamics and estimating mortality of Atlantic Menhaden are also complicated by movements along the coast. One tagging study indicated that during May and June, an estimated 91% of Atlantic Menhaden from North and South Carolina moved northward. In the winter, an estimated 55% of the sample tagged north of Chesapeake Bay moved southward to the bay and North and South Carolina (Liljestrand et al. 2019). Therefore, it is difficult to measure abundance of a mobile population.
If fishing mortality gets too high, few fish in the largest size classes will survive to reproduce, and biomass of spawning fish will decrease. The first management plan was developed in response to major changes in the fishery efficiency at capturing menhaden, enhanced processing capacity, as well as the development of new markets for products. Recognizing that seasons and mesh size restrictions had not prevented decline in menhaden, the first plan focused on determining the appropriate age to first harvest them (ASMFC 1981). Only later did plans estimate target and threshold levels used to determine if quotas should be adjusted (ASMFC 1999).
Monitoring records of juvenile Atlantic Menhaden in Chesapeake Bay indicate that reproductive success has been low for many decades (Figure 14.14 top). Fishing mortality for Atlantic Menhaden has been below the single-species management threshold in recent decades (Figure 14.14 bottom). Consequently, the Atlantic Menhaden stock status was not overfished, and overfishing is not occurring (SEDAR 2020a).
Question to ponder
What risks are of most concern to you if fishery management continues to make harvest decisions based on single-species analysis? Who is most likely to be harmed by menhaden overharvest?
14.7 Shift from Maximum Sustainable Yield to Ecosystem-Based Management
Fish resources cannot be stored in the sea, they die.
—Chapman 1955, cited in Finley 2011
Early studies of population dynamics of Atlantic Menhaden determined biological reference points, such as maximum sustainable yield, based on a false assumption that they were unaffected by predator abundance and that their natural mortality was a constant. For example, analysts assumed that 36% of Atlantic Menhaden would die each year in the absence of fishing, based on extensive tagging studies during a period when stocks of Striped Bass and other piscivores were at moderate-to-low levels (Ahrenholz et al. 1987). It is hard to imagine or justify that the death rate from predators, diseases, and parasites would be constant over a longer time frame and fixed for all ages. The menhaden story illustrates the scientific principle that Everything Is Connected to Everything Else (the First Law of Ecology) and, therefore, single-species management is ill advised (Pikitch et al. 2012).
By 2000, modern forage fish management recognized that menhaden, herring, and sardine indirectly influenced multiple organisms dependent on forage fish. Management of menhaden had become complicated by many stakeholders concerned with the status of large fish, such as cod, salmon, Striped Bass, sharks, and tuna, as well as seabirds, sea lions, whales, and dolphins that feed on forage fish. Industrial fishing and predators both rely on menhaden, which are more vulnerable to collapse from fishing when predators become more abundant. While early ASMFC management documents acknowledged menhaden’s role as a forage fish, ecological objectives were not added until 2001 (ASMFC 2001). For the next two decades, managers and scientists worked on collecting data and developing models that would assess the species with consideration for the role it plays in the ecosystem. In 2020, the ASMFC (SEDAR 2020) provided ecological reference points to permit the management to protect and maintain the important ecological role Atlantic Menhaden play along the coast (Chagaris et al. 2020; Drew et al. 2021). This was the beginning of a precedent-setting shift from single-species maximum sustainable yield management to ecosystem-based management.
Similar forage fishery management controversies exist worldwide, where forage species such as anchovy, sardine, and other forage species support large industrial fisheries, and needs for supporting fish, mammal, and bird predators is poorly quantified (Pikitch et al. 2012, 2018; Grémillet et al. 2016, 2018; Hilborn et al. 2017). Chesapeake Bay supports a large biomass of age 1 and 2 menhaden as well as age-0 juveniles that recruit to the bay as larvae from ocean spawning. Although Atlantic Menhaden are highly productive, their short life spans mean that sudden changes in population sizes can occur, and the risk of collapse is enhanced by overfishing.
The current demand for Atlantic Menhaden for fish oil and meal is filled largely by one company, Omega Protein, a subsidiary of Cooke Aquaculture. Consequently, the benefits of the fishery are concentrated in the local economy. Reductions in menhaden quotas influence local jobs, county economic outputs, and profits to the company (Kirkley et al. 2011). Quota reductions would reduce local benefits but lead to potential increases in recreational angling, charter boat income, and other jobs. Yet, this menhaden monopoly has not proven to be protection from competition. Just as other products replaced fertilizers and industrial oils produced from menhaden, we can expect the fish oil and fish meal products from menhaden to be replaced by cheaper alternatives. When the need for products produced by menhaden can be met by other products, demand will decrease.
The Atlantic Menhaden at one time ranged from Nova Scotia to Florida. However, immense schools of the fish became less commonplace to many observers. The contraction in the range of Atlantic Menhaden led many environmental groups to become vocal advocates for reducing quotas. In other forage fish, size of fish harvested by the fishery is very similar to the size eaten by seabirds (Pikitch 2012, 2014). In Chesapeake Bay and on the Atlantic Coast, many fish consume Atlantic Menhaden, including Striped Bass (Morone saxatilis), Atlantic Weakfish (Cynoscion regalis), Bluefish (Pomatomus saltatrix), and Bluefin Tuna (Thunnus thynnus). These fish vary in size, so that any fishing on Atlantic Menhaden will likely influence some predators. Models used in previous analysis were frequently inadequate for estimating the impact of fishing forage species on their predators (Pikitch et al. 2017; Hilborn et al. 2017).
Those working to rebuild populations of whales, Bluefin Tuna, Bluefish, Striped Bass, and. Atlantic Weakfish have long challenged the goals of Atlantic Menhaden management. In the 21st century, managers are in the process of transitioning to a new management goal that recognizes that Atlantic Menhaden provide important ecosystem services, including (1) supporting predators as a food resource, (2) supporting a large, directed fishery, and (3) filtering phytoplankton from the water column, mostly as age-0 juveniles.
Incorporating such ecosystem-based goals in management means that quotas will need to be set to provide more forage fish for Striped Bass, Bald Eagles, and other predators. In August 2017, the ASMFC Atlantic Menhaden Management Board approved Draft Amendment 3 to the Fisheries Management Plan. The decision was influenced by a study of the northwest Atlantic ecosystem model, which showed that “birds, highly migratory species, sharks, and marine mammals were . . . negatively affected by increased fishing on menhaden,” though none so much as the Striped Bass (Buchheister et al. 2017a, 2017b). This important scientific finding emphasized that menhaden abundance significantly impacts predator population abundance. Higher fishing mortality on menhaden would mean fewer large menhaden to feed an enhanced population of Striped Bass, as well as reduced abundance of large menhaden during spawning. If Striped Bass were capable of depleting prey populations (Uphoff and Sharov 2018), then they are competing with the menhaden fishery for the very same fish. The draft amendment was the first proposal that considers the use of ecological reference points (ERPs) to manage the resource and changes to the allocation method. In addition, it presents a suite of management options for quota transfers, quota rollovers, incidental catch, the episodic events set aside program, and the Chesapeake Bay reduction fishery cap.
The timeline for key elements in Atlantic Menhaden management are summarized below.
Timeline of Important Management Actions Affecting Atlantic Menhaden
August 2005: First harvest limit on menhaden in Chesapeake Bay imposed by Atlantic States Marine Fisheries Commission (ASMFC)
October 2012: Chesapeake Bay Foundation (CBF) calls for reductions in catch
December 2012: ASMFC adopts a new management plan aimed at reducing harvest
February 2013: Virginia General Assembly passes bill reducing menhaden harvest
March 2014: Virginia Marine Resources Commission creates harvest allocation for bait fishery and reporting requirements for menhaden harvested in Virginia
May 2015: Chesapeake Bay Foundation urges ASMFC to consider ecological reference points in management plan
August 2016: ASMFC delays decision on menhaden harvest cap
October 2016: ASMFC increases the menhaden harvest quota despite lack of data to support an increase
October 2017: A group of more than 100 top ecologists urged the ASMFC to move forward with ecosystem-based management for Atlantic Menhaden
November 2017: ASMFC decreases the cap menhaden harvest and continues to evaluate ecological reference points
February 2018: Coalition of conservation and recreational fishing interests supports new legislation that would ensure Virginia avoids the consequences of falling out of compliance with the menhaden fishery management plan
March 2018: Menhaden legislation is stalled in Virginia General Assembly
August 2018: ASMFC postpones a motion to declare Virginia out of compliance with menhaden plan
December 2018: CBF opposes the certification of Omega Protein’s sustainable menhaden fishery
February 2019: ASMFC commits to further study of ecological effects of menhaden harvest
March 2019: CBF objects to seafood sustainability certification for Omega Protein’s Atlantic menhaden fishery
August 2019: Omega Protein application for sustainability certification challenged
September 2019: Omega Protein knowingly violates the menhaden harvest cap
October 2019: ASMFC finds Virginia out of compliance with harvest cap
November 2019: Virginia governor asks U.S. Secretary of Commerce to impose moratorium on Virginia’s menhaden harvest
December 2019: U.S. Secretary of Commerce supports ASMC, announces deadline for compliance
February 2020: Virginia General Assembly passes legislation to transfer management authority from General Assembly to the Virginia Marine Resources Commission
April 2020: VMRC imposes new menhaden harvest cap to bring Virginia into compliance
August 2020: ASMFC adopts new ecological reference points to guide menhaden management
Source: Chesapeake Bay Foundation. https://www.cbf.org/about-the-bay/more-than-just-the-bay/chesapeake-wildlife/menhaden/timeline-of-menhaden-conservation.html.
The argument that was developed during the period of menhaden controversy can be summarized as follows:
An Argument for Reduced Menhaden Quota
Premises:
• Menhaden are a keystone species; their filter feeding clarifies the water, allowing sunlight to reach eelgrass beds, thereby promoting scallop and juvenile fish habitat.
• Menhaden provide one source of food for Striped Bass, Bluefish, Weakfish, and fluke, as well as whales, all of which are valuable to the recreational economy of the region.
• Products from menhaden can be naturally derived from other sources:
• Chorella and spirulina are high in Omega-3 fatty acids, minerals, and antioxidants.
• Manufacturers are working on canola, which is high in omega-3 fatty acids.
• Marine recreational fishing on sportfish is dependent on menhaden for food and produces high economic benefits and more jobs than commercial fishing.
Claim:
• Quota on menhaden should be reduced to benefit other parts of the ecosystem and the local economy.
The argument for reduced menhaden quotas implies that fisheries management targets for predator and prey cannot be developed in isolation (Drew et al. 2021). Rather, there are tradeoffs in fisheries management due to the simple law that a fish can only die once. A fish harvested by the menhaden reduction fishery cannot also feed Striped Bass. If commercial fleets harvest menhaden at higher rates, there will be lower abundance of predators, such as Striped Bass. Alternatively, reduced fishing mortality for Striped Bass will result in higher predation mortality on menhaden.
When the reduction industry asks, “Can we harvest more menhaden?” the answer appears to be “Yes.” However, higher fishing on Atlantic Menhaden will likely reduce the biomass of Striped Bass (Figure 14.15) and other high-profile fish that people eat and love to catch, such as Bluefish and Weakfish.
On August 5, 2020, at their meeting in Arlington, the Atlantic States Marine Fisheries Commission voted to implement ecological reference points (ERP) to manage Atlantic Menhaden. ERPs are numeric benchmarks used by managers to promote not only the sustainable harvest of menhaden but also broader ecosystem needs, such as supporting key predators (SEDAR 2020b). Three ecological reference points were adopted in the management of Atlantic Menhaden:
1. ERP target: the maximum fishing mortality rate (F) on Atlantic Menhaden that sustains Atlantic Striped Bass at their biomass target when Striped Bass are fished at their F target
2. ERP threshold: the maximum F on Atlantic Menhaden that keeps Atlantic Striped Bass at their biomass threshold when Striped Bass are fished at their F target
3. ERP fecundity target and threshold: the long-term equilibrium fecundity that results when the population is fished at the ERP F target and threshold, respectively
The adoption of menhaden ecological reference points resulted from a transparent and balanced approach that was informed by science and consistent investments in objective, peer-reviewed research. The menhaden may provide a prime example of ecosystem-based management for other fisheries to strategically plan and implement (Chagaris et al. 2020).
14.8 Stakeholders and Conflicting Values
At a time of precedent-setting change in management, in 2019, the Atlantic Menhaden fishery achieved approval for meeting the Marine Stewardship Council (MSC) certification standards. Fisheries that carry the council’s blue checkmark are required to follow internationally recognized best practices for operating healthy, sustainable fisheries. The MSC standards are considered perhaps the strictest and most reliable, with 28 indicators of seafood sustainability. Atlantic Menhaden fishing with purse seines collects minimal amounts of bycatch, and harvests have been monitored effectively for many decades, thereby permitting estimation of reference points and adjustment of quotas. The MSC fishery standards are based on three core principles that every fishery must meet:
1. Sustainable fish stocks: Fishing activity must be at a level that ensures it can continue indefinitely.
2. Minimizing environmental impact: Fishing operations must be managed to maintain the structure, productivity, function, and diversity of the ecosystem.
3. Effective management: The fishery must comply with relevant laws and have a management system that is responsive to changing circumstances.
However, special interest groups objected to the certification on the grounds that it recognized only the health of the Atlantic Menhaden fishery and not the species’ role in the ecosystem. The Theodore Roosevelt Conservation Partnership paid \$6,500 to the MSC to formally contest the certification. In particular, the certification process does not consider the role that Atlantic Menhaden play in supporting Striped Bass, and declines in Striped Bass are a major concern of recreational fishing interests. The fight against MSC certification is a conflict that is best understood in terms of the stories told by stakeholders.
The Atlantic Menhaden conflict is similar to others in which forage fish are harvested in places where valuable sport and commercial fisheries depend on forage fish. The conflict has persisted for decades. As it played out with Atlantic Menhaden, stories told by managers, stakeholders, and scientists each conveyed differing reasons why we needed to account for menhaden’s role as a forage species. However, until recently fisheries management of predators and prey was not well coordinated. Commercial landings of Striped Bass peaked in 1973, and then recreational fishing increased (Richards and Rago 1999). Quotas were changed for Atlantic Menhaden and Striped Bass, but scientists were not able to predict the effects of predator-prey links. The demand for fish oil and fish meal products increased, and menhaden harvesters lobbied for higher quotas. After decades of careful management of harvest for Striped Bass, recovery of their populations influenced predation pressure on Atlantic Menhaden (Uphoff and Sharoff 2018). The recreational Striped Bass anglers had fished before and after the fishing moratorium witnessed changes and told the story of the expected link with menhaden. Vocal activists played a significant role in criticizing Omega Protein’s operations and mobilizing support for reduced quotas, especially in federal waters off New York and New Jersey (e.g., Menhaden Defenders and Theodore Roosevelt Conservation Partnerships). Listening to the many stories that were brought to the Atlantic States Marine Fisheries Commission meetings emphasizes the importance of dealing with conservation conflicts over forage fish as stories to understand and not problems to solve (Harrison and Loring 2020).
The dynamics of the menhaden story will be important to follow in the future, as it is one of the first pelagic, forage fisheries to adopt ecological reference points and at the same time receive sustainability certification. Globally, small pelagics contribute over 15% of the marine fisheries yields, and over three-fourths of that contribution is from developing countries. The future of sustainability certification for menhaden and others will require that management systems are in place to safeguard forage fish in order to protect the stability of top predators from widely fluctuating food levels (Essington et al. 2015; Izquierdo-Peña et al. 2020). The menhaden management story is ongoing, and the future responses will inform managers of the validity of the approach that was adopted in 2020.
Question to ponder
What stakeholders in menhaden management are represented? Which stakeholders were not included? What are the stories told by different stakeholders? How do these stories help understand conflict and select appropriate intervention? Can you associate each stakeholder with a preferred management action?
Profile in Fish Conservation: Kristen Anstead, PhD
Kristen Anstead, PhD, is Stock Assessment Scientist with the Atlantic States Marine Fisheries Commission. In this role, she is responsible for periodically analyzing the status of fished populations, including the horseshoe crabs, American Eel, Atlantic Sturgeon, Atlantic Menhaden, and others. In addition to her work for the ASMFC, since 2013 she has been Science Editor and, since 2019, Co-Chief Editor for Fisheries, a leading fisheries science publication.
Dr. Anstead grew up in Maine and attended Bates College, a small, liberal arts college in Lewiston, where she earned a B.S. degree in biology. After graduating from Bates, she worked as a field biologist in several jobs. In the Mpala Research Center, Nanyuki, Kenya, she assisted in an ecology program to improve understanding of the effects of cattle grazing on the diversity and abundance of plants and wild animals. As a field biologist with the University of Georgia Marine Institute, located on Sapelo Island, Georgia, she was able to contribute to the Georgia Coastal Ecosystems Long-Term Ecological Research.
As a Fisheries Observer in Alaska, she worked onboard commercial fishing boats operating in the Bering Sea and Gulf of Alaska. Fisheries observers are the eyes and ears on the water and witness new findings in commercial fisheries. Many fisheries specialists report that their experiences as a fishery observer was a great stepping-stone to a successful fisheries career.
After 10 years of experience as a field biologist, Kristen enrolled in graduate studies at Old Dominion University. She led a novel study to investigate the contribution of multiple nursery areas to the population of Atlantic Menhaden before joining the ASMFC as a Stock Assessment Scientist. Since 2015, her work has contributed to numerous stock assessments conducted by the Atlantic States Marine Fisheries Commission. Her knowledge, skills, and abilities from her years as a field biologist, along with her specialties, mean that she brings a unique balance to her work in stock assessment. As a Stock Assessment Scientist for Atlantic Menhaden, she is frequently reminded how much people care about menhaden, a noncharismatic fish that people will never see on a restaurant menu.
Dr. Anstead encourages students to pursue fieldwork positions to get some hands-on experience and an understanding of how science interacts with communities. For students interested in the management process, everything produced by the ASMFC is in the public domain to ensure that decisions are made in the public interest. See more about the Atlantic States Marine Fisheries Commission here.
Key Takeaways
• Menhaden sustained a large and important fishery for Native Americans and later early European colonists.
• Landings of menhaden fisheries are the largest by volume on the Atlantic Coast.
• Menhaden fishery supports jobs, and menhaden are transformed to useful products, most importantly fish oils and meals.
• Life history of Atlantic Menhaden represents an opportunistic strategy characterized by many small offspring, fast growth, early maturity, and small adult body size.
• Menhaden are grouped with other fish that eat plankton and are eaten by predatory fish, squid, birds, and mammals.
• Menhaden and other small, pelagic forage fish are highly responsive to climate variation.
• High levels of fishing effort increase the risk of collapse of menhaden.
• Management of Atlantic Menhaden recently adopted ecological reference points in order to adjust quotas in response to abundance of predators, such as Striped Bass.
This chapter was reviewed by Kristen Anstead.
URLs
Sharks entering a large school of menhaden: https://www.nationalgeographic.com/news/2017/08/shark-feeding-frenzy-menhaden-school-hamptons-drone-video-spd
Atlantic States Marine Fisheries Commission: http://www.asmfc.org/
Long Descriptions
Figure 14.3: Illustration of purse seine: large wall of netting deployed around an entire area or school of fish. The seine has floats along the top line with a lead line threaded through rings along the bottom. Jump back to Figure 14.3.
Figure 14.4: Line graph with x-axis as fork length (cm) from 0-40 and y-axis as fecundity (thousands) from 0-500. Line show exponential curve with lowest point at 15 cm/0 fecundity, increasing to 35cm/500 fecundity. Jump back to Figure 14.4.
Figure 14.10: Landings of Atlantic Menhaden over time; 1) 1955-1980, boom, bust, and recovery; 2) 1980-2000, beginning of coastwide management; 3) 2000-2010, first steps toward ecosystem modeling; 4) 2010-2015, first coastwide quota and lenfest report; 5) 2015- ;amendment 3 and the ERP assessment. Jump back to Figure 14.10.
Figure 14.11: Population biomass increases as yield decreases. MSY shows parabolic relationship between equilibrium yield, population biomass, and intrinsic rate of population increase. Jump back to Figure 14.11.
Figure 14.12: Two scatter plots with fitted lines. A: As effort increases, catch per unit of effort decreases. B: Parabolic shape opening downward shows highest point at effort=1000, catch=600. Jump back to Figure 14.12.
Figure 14.14: Top graph shows Atlantic Menhaden biomass and recruitment from 1955 to 2016. Biomass and recruitment peak in 1955. Bottom graph shows atlantic menhaden fishing mortality from 1955 to 2016. Single species F thresholh remains at 0.6 mortality; single species F target remains at 0.2 mortality. Fishing mortality peaks at 1971. Jump back to Figure 14.14.
Figure 14.15: Biomass has continually increased from 1980-2020. If overfishing continues for menhaden, the graph will begin to trend downwards. If there is no menhaden fishing, graph will level out. Jump back to Figure 14.15.
Figure References
Figure 14.1: Illustration of the Atlantic Menhaden adult. Artemas Ward, 1923. Public domain. https://commons.wikimedia.org/wiki/File:Menhaden,_photo_from_The_Encyclopedia_of_Food_by_Artemas_Ward.jpg.
Figure 14.2: Map of the range of Atlantic Menhaden from Nova Scotia, Canada, along the nearshore and coastal waters of the United States Atlantic Coast to Florida. NOAA via The Path to an Ecosystem Approach for Forage Fish Management: A Case Study of Atlantic Menhaden, by Anstead et. al., 2021. CC BY 4.0. http://dx.doi.org/10.3389/fmars.2021.607657.
Figure 14.3: Purse seines were adopted early on as a preferred method for harvesting menhaden. Benjamin Franklin Conklin, 1887. Public domain. https://commons.wikimedia.org/wiki/File:FMIB_45912_Menhaden_Fishery.jpeg.
Figure 14.4: Relationship between fork length (cm) and predicted number of ova (fecundity) for Atlantic Menhaden. Kindred Grey. 2022. CC BY 4.0. Data from Fecundity of Atlantic Menhaden, Brevoortia tyrannus, by Lewis et. al., 1987. https://doi.org/10.2307/1351894.
Figure 14.5: Illustration of the (A) first gill arch showing gill rakers (a) and gill lamellae (m); and (B) enlarged section of six gill rakers showing fine rows of hooks for filter feeding. Hugh McCormick Smith, 1907. Public domain. https://commons.wikimedia.org/wiki/File:FMIB_51375_Gill_of_Mehnaden.jpeg.
Figure 14.6: Simplified food web showing the links that Atlantic Menhaden provide between plankton and carnivorous animals. Kindred Grey. 2022. CC BY 4.0. Includes Brevoortia Patronus, by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC, 2008 (CC BY 2.0, https://commons.wikimedia.org/wiki/File:BrevoortiaPatronus.jpg), Bluefin-big, by NOAA, 2004 (public domain, https://commons.wikimedia.org/wiki/File:Bluefin-big.jpg), fishing ship, by Gan Khoon Lay, 2019 (Noun Project license, https://thenounproject.com/icon/fishing-ship-2760125/), seagull, by Daniela Baptista, 2016 (Noun Project license, https://thenounproject.com/icon/seagull-781412/), Humpback Whale, by Philipp Lehmann, 2017 (Noun Project license, https://thenounproject.com/icon/humpback-whale-957308/), and bass fish, by Phạm Thanh Lộc, 2019 (Noun Project license, https://thenounproject.com/icon/bass-fish-3385868/).
Figure 14.7: Osprey in flight with a menhaden held in its talons. Russ, 2016. CC BY 2.0. https://flic.kr/p/KV7Yym.
Figure 14.8: Relationship between the size of Striped Bass (total length, mm) and the size of prey fish (total length, mm) consumed. Kindred Grey. 2022. CC BY 4.0. Data from Interactions between Adult Migratory Striped Bass (Morone saxatilis) and Their Prey during Winter off the Virginia and North Carolina Atlantic Coast from 1994 through 2007, by Overton et. al. 2008. http://hdl.handle.net/1834/19906.
Figure 14.9: Purse-seine boats encircling a school of menhaden. Robert K. Brigham, 1968. Public domain. https://commons.wikimedia.org/wiki/File:Menhaden_fishing_-_purse_seine_boats.jpg.
Figure 14.10: Atlantic Menhaden landings (thousands of metric tons, mt) from the reduction and bait fisheries during each of the five periods of assessment and management history. Coastwide harvest quotas began in 2013 and are indicated on the graph in red. Kindred Grey. 2022. CC BY 4.0. Data from The Path to an Ecosystem Approach for Forage Fish Management: A Case Study of Atlantic Menhaden, by Anstead et. al. 2021. https://doi.org/10.3389/fmars.2021.607657.
Figure 14.11: Relationship between equilibrium yield (Y, green curve) and intrinsic rate of population increase (r, tan line) and population biomass with the maximum sustainable yield (dashed line). Kindred Grey. 2022. CC BY 4.0. Data from Maximum Sustainable Yield, by Tsikliras and Froese, 2018. https://doi.org/10.1016/B978-0-12-409548-9.10601-3.
Figure 14.12: (A) Straight line fitted to fisheries data on catch per unit effort and effort (vessel-weeks) for Atlantic Menhaden from 1955 to 1969. (B) Total catch plotted against effort. Kindred Grey. 2022. CC BY 4.0. Data from Effects of Fishing on the Atlantic Menhaden Stock: 1955–1969, by W. E. Schaaf and G. R. Huntsman, 1972. https://doi.org/10.1577/1548-8659(1972)101<290:EOFOTA>2.0.CO;2.
Figure 14.13: Annual mortality against effort for 1955–1966. Kindred Grey. 2022. CC BY 4.0. Data from Effects of Fishing on the Atlantic Menhaden Stock: 1955–1969, by W. E. Schaaf and G. R. Huntsman, 1972. https://doi.org/10.1577/1548-8659(1972)101<290:EOFOTA>2.0.CO;2.
Figure 14.14: (A) Estimated Atlantic Menhaden biomass and recruitment from 1955 to 2016. (B) Atlantic Menhaden fishing mortality (ages 2–4) from 1955 to 2016 with lines depicting management target (solid) and threshold (dashed). Kindred Grey. 2022. CC BY 4.0. Data from Maximum Sustainable Yield, by Tsikliras and Froese, 2018. https://doi.org/10.1016/B978-0-12-409548-9.10601-3.
Figure 14.15: Projected biomass of Striped Bass in future under different fishing mortality rates for Atlantic Menhaden. Kindred Grey. 2022. CC BY 4.0. Adapted from Evaluating Ecosystem-Based Reference Points for Atlantic Menhaden (Brevoortia tyrannus), by Buchheister et. al., 2017. CC BY 4.0. http://dx.doi.org/10.1080/19425120.2017.1360420.
Figure 14.16: Kristen Anstead, PhD. Used with permission from Kristen Anstead. CC BY 4.0.
Text References
Ahrenholz, D. W., W. R. Nelson, and S. P. Epperly. 1987. Population and fishery characteristics of Atlantic Menhaden, Brevoortia tyrannus. United States Fishery Bulletin 85(3):569–600.
Anstead, K., K. Drew, D. Chagaris, M. Cieri, A. M. Schueller, J. E. McNamee, A. Buchheister, G. Nesslage, J. H. Uphoff Jr., M. J. Wilberg, A. Sharov, M. J. Dean, J. Brust, M. Celestino, S. Madsen, S. Murray, M. Appelman, J. C. Ballenger, J. Brito, E. Cosby, C. Craig, C. Flora, K. Gottschall, R. J. Latour, E. Leonard, R. Mroch, J. Newhard, D. Orner, C. Swanson, J. Tinsman, E. D. Houde, T. J. Miller, and H. Townsend. 2021. The path to an ecosystem approach for forage fish management: a case study of Atlantic Menhaden. Frontiers in Marine Science 8. https://doi.org/10.3389/fmars.2021.607657.
Arellanes, I. C., N. Choe, V. Solomon, X. He, B. Kavin, A. E. Martinez, N., Kono, D. P. Buennagel, N., Hazra, G., Kim, and L. M. D’Orazio. 2020. Brain delivery of supplemental docosahexaenoic acid (DHA): a randomized placebo-controlled clinical trial. EBioMedicine 59(2):102883. DOI: https://doi.org/10.1016/j.ebiom.2020.102883.
ASMFC. 2001. Amendment 1 to the Interstate Fishery Management Plan for Atlantic Menhaden. Fishery Management Report No. 37, Atlantic States Marine Fisheries Commission. Available at: https://www.asmfc.org/uploads/file/menhadenAm_1.PDF.
ASMFC. 2020. ASMFC Atlantic Menhaden Board prepares to move forward with Menhaden ecological reference points. News Release, Atlantic States Marine Fisheries Commission. February 7.
ASMFC. 1999. Atlantic Menhaden stock assessment report for peer review. Stock Assessment Report No. 99-01, Atlantic States Marine Fisheries Commission. Available at: http://www.asmfc.org/uploads/file/feb99menhadenPeerReviewrpt.pdf.
ASMFC. 1981. Fishery Management Plan for Atlantic Menhaden. Fishery Management Report No. 2, Atlantic States Marine Fisheries Commission. Available at: http://www.asmfc.org/uploads/file/1981MenhadenFMP.pdf.
Brown, D. M., J. Robbins, P. L. Sieswerda, C. Ackerman, J. M. Aschettino, S. Barco, T. Boye, T., R. A. DiGiovanni, K. Durham, A. Engelhaupt, and A. Hill. 2022. Site fidelity, population identity and demographic characteristics of Humpback Whales in the New York Bight apex. Journal of the Marine Biological Association of the United Kingdom 102(1-2):157–165.
Brown, D. M., J. Robbins, P. L. Sieswerda, R. Schoelkopf, and E. C. M. Parsons. 2018. Humpback Whale (Megaptera novaeangliae) sightings in the New York–New Jersey Harbor estuary. Marine Mammal Science 34:250–257.
Buchheister, A., T. J. Miller, and E. D. Houde. 2017a. Evaluating ecosystem-based reference points for Atlantic Menhaden. Marine and Coastal Fisheries 9:457–478.
Buchheister, A., T. J. Miller, E. D. Houde, and D. A. Loewensteiner. 2017b. Technical documentation of the northwest Atlantic continental shelf (NWACS) ecosystem model. Report to the Lenfest Ocean Program, Washington, D.C. University of Maryland Center for Environmental Sciences Report TS-694-17. Available at: http://hjort.cbl.umces.edu/NWACS/TS_694_17_NWACS_Model_Documentation.pdf.
Butler, C. M., P. J. Rudershausen, and J. A. Buckel. 2010. Feeding ecology of Atlantic Bluefin Tuna (Thunnus thynnus) in North Carolina: diet, daily ration, and consumption of Atlantic Menhaden (Brevoortia tyrannus). U.S. National Marine Fisheries Service Fishery Bulletin 108:56–69.
Chagaris, D., K. Drew, A. Schueller, M. Cieri, J. Brito, and A. Buchheister. 2020. Ecological reference points for Atlantic Menhaden established using an ecosystem model of intermediate complexity. Frontiers in Marine Science 7:606417. https://doi.org/10.3389/fmars.2020.606417.
Checkley, D. M., R. G. Asch, and R. R. Rykaczewski. 2017. Climate, anchovy, and sardine. Annual Review of Marine Science 9:469–493.
Deyle, E., A. M. Schueller, H. Ye, G. M. Pao, and G. Sugihara. 2018. Ecosystems-based forecasts of recruitment in two menhaden species. Fish and Fisheries 19:769–781.
Drew, K., M. Cleri, A. M. Schueller, A. Buchheister, D. Chagaris, G. Nesslage, J. E. McNamee, and J. H. Uphoff Jr. 2021. Balancing model complexity, data requirements, and management objectives in developing ecological reference points for Atlantic Menhaden. Frontiers in Marine Science 8:608059. https://doi.org/10.3389/fmars.2021.608059.
Essington, T. E., P. E. Moriarty, H. E. Froehlich, E. E. Hodgson, L. E. Koehn, K. L. Oken, M. C. Siple, and C. C. Stawitz. 2015. Fishing amplifies forage fish population collapses. Proceedings of the National Academy of Sciences of the United States of America 112(21):6648–6652.
Finley, C. 2011. All the fish in the sea: maximum sustainable yield and the failure of fisheries management. University of Chicago Press. DOI: 10.7208/chicago/9780226249681.001.0001.
Franklin, H. B. 2008. The most important fish in the sea: menhaden and America. Shearwater Press, Washington, D.C.
Glass, K. A., and B. D. Watts. 2009. Osprey diet composition and quality in the high- and low-salinity areas of lower Chesapeake Bay. Journal of Raptor Research 43:27–36.
Goode, G. B. 1887. Fisheries and fishery industries of the United States. Government Printing Office, Washington, D.C.
Goode, G. B. 1880. A history of the menhaden. Orange Judd, New York. Available at: https://www.biodiversitylibrary.org/item/40759.
Gordon, C. A., D. A. Cristol, and R. A. Beck. 2000. Low reproductive success of Black Skimmers associated with low food availability. Waterbirds: The International Journal of Waterbird Biology 23:468–474.
Harrison, H. L., and P. A. Loring. 2020. Seeing beneath disputes: a transdisciplinary framework for complex conservation conflicts. Biological Conservation 248:108670. https://doi.org/10.1016/j.biocon.2020.108670.
Hilborn, R., R. O. Amorosa, E. Bogazzi, O. P. Jensen, A. M. Parma, C. Szuwalski, and C. J. Walters. 2017. When does fishing forage species affect their predators? Fisheries Research 191:211–221.
Hong, M. Y., J. Lumibao, P. Mistry, R. Saleh, and E. Hoh. 2015. Fish oil contaminated with persistent organic pollutants reduces antioxidant capacity and induces oxidative stress without affecting its capacity to lower lipid concentrations and systemic inflammation in rats. Journal of Nutrition 145:939–944. doi: 10.3945/jn.114.206607.
Izquierdo-Peña, V., S. E. Lluch-Cota, F. P. Chavez, D. B. Lluch-Cota, E. Morales-Bojórquez, and G. Ponce-Díaz. 2020. Is there a future in the sustainability certification of sardine and anchovy fisheries? Fisheries 45(10):554–560.
Jensen, A. L. 1975. Computer simulation of effects on Atlantic Menhaden yield of changes in growth, mortality, and reproduction. Chesapeake Science 16:139–142.
Jensen, A. L. 1976. Time series analysis and forecasting of Atlantic Menhaden catch. Chesapeake Science 17:305–307.
Kirkley, J. E., T. Hartman, T. McDaniel, K. McConnell, and J. Whitehead. 2011. An assessment of the social and economic importance of Menhaden (Brevoortia tyrannus) (Latrobe, 1802) in Chesapeake Bay region. VIMS Marine Resource Report No. 2011-14, Gloucester Point, VA. Available at: https://mrc.virginia.gov/vsrfdf/pdf/RF09-11_Aug11.pdf. Accessed 18 April 2021.
Lewis, R. M, D. W. Arenholtz, and S. P. Epperly. 1987. Fecundity of Atlantic Menhaden, Brevoortia tyrannus. Estuaries 10:347–350. Available at: https://link.springer.com/content/pdf/10.2307/1351894.pdf.
Liljestrand, E. M., M. J. Wilberg, and A. M. Schueller. 2019. Estimation of movement and mortality of Atlantic Menhaden during 1966–1969 using a Bayesian multi-state mark-recovery model. Fisheries Research 210:204–213.
Lucca, B. M., and J. D. Warren. 2019. Fishery-independent observations of Atlantic Menhaden abundance in the coastal waters south of New York. Fisheries Research 218:229–236.
MacCall, A. D., W.J . Sydeman, P. C. Davison, and J. A. Thayer. 2016. Recent collapse of northern anchovy biomass off California. Fisheries Research 175:87–94.
Merino, G., M. Barange, and C. Mullon. 2010. Climate variability and change scenarios for a marine commodity: modelling small pelagic fish, fisheries and fishmeal in a globalized market. Journal of Marine Systems 81:196–205. https://doi.org/10.1016/j.jmarsys.2009.12.010.
Midway, S. R., A. M. Schueller, R. T. Leaf, G. M. Nesslage, and R. M. Mroch III. 2020. Macroscale drivers of Atlantic and Gulf Menhaden growth. Fisheries Oceanography 29(3):252–264.
National Marine Fisheries Service. 2020. Fisheries of the United States, 2018. U.S. Department of Commerce, NOAA Current Fishery Statistics No. 2018 Available at: https://media.fisheries.noaa.gov/dam-migration/fus_2018_factsheet.pdf
Overton, A. S., J. C. Griffin, F. J. Margraf, E. B. May, and K. J. Hartman. 2015. Chronicling long-term predator responses to a shifting forage base in Chesapeake Bay: an energetics approach. Transactions of the American Fisheries Society 144:956–966.
Overton, A. S., C. S. Manooch III, J. W. Smith, and K. Brennan. 2008. Interactions between adult migratory Striped Bass (Morone saxatilis) and their prey during winter off the Virginia and North Carolina Atlantic Coast from 1994 through 2007. U.S. National Marine Fisheries Service Fishery Bulletin 106(2):174–182.
Peck, J. I. 1894. On the food of the menhaden. Bulletin of the U.S. Fisheries Commission 13:113–126.
Pikitch, E. K., P. D. Boersma, I. L. Boyd, D. O. Conover, P. M. Cury, T. E. Essington, and S. S. Heppell. 2012. Little fish, big impact: managing a crucial link in ocean food webs. Lenfest Ocean Program, Washington, D.C. Available at: https://www.lenfestocean.org/~/media/legacy/lenfest/pdfs/littlefishbigimpact_revised_12june12.pdf?la=en.
Pikitch, E. K., P. D. Boersma, I. L. Boyd, D. O. Conover, P. M. Cury, T. E. Essington, S. S. Heppell, E. D. Houde, M. Mangel, D. Pauly, É. Plagányi, K. Sainsbury, and R. S. Steneck. 2018. The strong connection between forage fish and their predators: a response to Hilborn et al. (2017). Fisheries Research 198. DOI: 10.1016/j.fishres.2017.07.022.
Pikitch, E. K., K. J. Rountos, T. E. Essington, C. Santora, D. Pauly, R. Watson, U. R. Sumaila, P. D. Boersma, I. L. Boyd, D. O. Conover, P. Cury, S. S. Heppell, E. D. Houde, M. Mangel, É. Plagányi, K. Sainsbury, R. S. Steneck, T. M. Geers, N. Gownaris, and S. B. Munch. 2014. The global contribution of forage fish to marine fisheries and ecosystems. Fish and Fisheries 15(1):43–64. doi:10.1111/faf.12004.
Richards, R. A., and P. J. Rago. 1999. A case history of effective fishery management: Chesapeake Bay Striped Bass. North American Journal of Fisheries Management 19:356–375.
Schaff, W. E., and G. R. Huntsman. 1972. Effects of fishing on the Atlantic Menhaden stock: 1955–1969. Transactions of the American Fisheries Society 101:290–297.
Schueller, A. M., and E. H. Williams. 2017. Density-dependent growth of Atlantic Menhaden: impacts on current management. North American Journal of Fisheries Management 37:294–301.
SEDAR. 2020a. SEDAR 69: Atlantic Menhaden benchmark stock assessment report. SouthEast Data Assessment and Review, North Charleston, SC. Available at: http://sedarweb.org/sedar-69.
SEDAR. 2020b. SEDAR 69: Atlantic Menhaden ecological reference points stock assessment report. SouthEast Data Assessment and Review, North Charleston, SC. Available at: http://sedarweb.org/sedar-69.
Sherratt, S. C. R., M. Lero, and R. P. Mason. 2020. Are dietary fish oil supplements appropriate for dyslipidemia management? A review of the evidence. Current Opinion in Lipidology 31(2):94–100. doi: 10.1097/MOL.0000000000000665.
Smith, H. M. 1907. Fishes of North Carolina. North Carolina Geological and Economic Survey, vol. 2. E. M. Uzzell, Raleigh, NC.
Smith, J. W. 1999. Distribution of Atlantic Menhaden, Brevoortia tryrannus, purse-seine sets and catches from southern New England to North Carolina, 1985–96. U.S. Department of Commerce, NOAA Technical Report NMFS 144.
Spitzer, P. R., and A. F. Poole. 1980. Coastal Ospreys between New York City and Boston: a decade of reproductive recovery 1969–1979. American Birds 34:233–242.
Stevick, P. T., J. Allen, P. J. Clapham, N. Friday, S. K. Katona, F. Larsen, J. Lien, D. K. Mattila, P. J. Palsbøll, J. Sigurjónsson, T. D. Smith, N. Øien, and P. S. Hammond. 2003. North Atlantic Humpback Whale abundance and rate of increase four decades after protection from whaling. Marine Ecology Progress Series 258:263–273.
Szuwalski, C. S., and J. T. Thorson. 2017. Global fishery dynamics are poorly predicted by classical models. Fish and Fisheries 18:1085–1095.
Uphoff, J. H. Jr. 2003. Predator-prey analysis of Striped Bass and Atlantic Menhaden in upper Chesapeake Bay. Fisheries Management and Ecology 10:313–322.
Walter, J. F. III, A. S. Overton, K. H. Ferry, and M. E. Mather. 2003. Atlantic Coast feeding habits of Striped Bass: a synthesis supporting a coast-wide understanding of trophic biology. Fisheries Management and Ecology 10:349–360.
World Bank. 2013. Fish to 2030: prospects for fisheries and aquaculture. World Bank Report Number 83177-GLB. Available at: http://www.fao.org/3/i3640e/i3640e.pdf. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.14%3A_Menhaden_and_Forage_Fish_Management.txt |
15.1 In Search of Principles
The arc of the moral universe is long, but it bends toward justice.
—Dr. Martin Luther King Jr.
There are few inviolate laws of fisheries conservation and management. One such law is “Fish Die!” Its witty corollary is, “If your parents had no children, odds are good that you will not either.” The first Great Law of Fishing — “Fisheries that are unlimited become unprofitable”—has persisted since formulated by Michael Graham (1943). Scientists search for guiding principles to help organize our knowledge. A principle, when it is understood and accepted, serves to guide our thinking and assist in guiding actions. In the first chapter, I proposed the working principle, “Passionate and persistent people who understand the fish and the place will find a way to create partnerships to conserve valued fish in perpetuity.” This principle highlights the importance of groups of people because groups are collectively smarter than individual experts in problem solving, decision making, innovating, and predicting (Arminpour et al. 2020). Recovery stories of collapsed fisheries highlight the importance of people and partnerships (Krueger et al. 2019). In fact, the common traits of important leaders in nature conservation are passion, persistence, and engagement in partnerships (Nielsen 2017).
Here I summarize key takeaways for implementing successful fish conservation organized as Fisheries Systems, Ecological Systems, and Management System principles.
Decisions are made in context that includes ecological systems, social systems, and institutions or management systems.
Fisheries are continually changing as the many actors, institutions, and fish resources are influenced by the social-ecological setting (Figure 15.1). Each of these interacting systems may contribute to success or failure. In some cases, the habitat may be degraded. In others, the management system fails to respond to declines in catches in a timely manner. In others, the social system fails to support efforts to protect fish. Furthermore, understanding social systems, including cultural norms and institutions, local knowledge, and social learning, provides more options for enhancing well-being of fishing communities (Carlson et al. 2020).
15.2 Fisheries Systems Principles
Fisheries that are unlimited become unprofitable.
Russell (1931) derived a simple equation for overfishing by expressing sustainable yield as the sum of recruitment and individual growth minus mortality (Figure 15.2). This simple equation means that what comes in must go out if you ever intend to get the population stabilized. Russell’s equation has had a profound influence on early thinking to classify fish stocks as overfished when their population is below the level that would maximize harvest. Consequently, much of fisheries science in the mid-20th century focused on estimating parameters and maximum sustainable yields for stocks (Schaefer 1954). Yet this simplistic single-species model underestimates the risks of harvesting on populations and ecosystems (Lichatowich and Gayeski 2020).
Fishing remains the last major hunting and gathering industry. As such fishing supports human livelihoods, food security, human health, and recreation., the tremendous diversity of fishing activities and styles complicates management. Because fisheries are often public resources where access cannot be easily controlled, overfishing and fisheries collapse are common. Famous collapses of the Northwest Atlantic Cod and California abalone and sardine fisheries highlight the failures of weak regulations on fishing (Radovich 1982; Tegner 1993; Mason 2002; Bavington 2010; Kurlansky 2010) and subsequent ecological, economic, and social disruptions. Widespread and well-publicized fisheries collapses generated substantial public awareness (Clover 2008; Hilborn and Hilborn 2012), leading to the passage of new amendments to the Magnuson-Stevens Fishery Conservation and Management Act in 1996 and 2007. The recent amendments made overfishing illegal, while mandating the rebuilding of all depleted fish stocks.
Overfishing is common across the full spectrum of fish life histories, not just top predators (Pinsky et al. 2011). Furthermore, overfishing is often exacerbated by illegal, unreported, and unregulated (IUU) fishing, leading to food and nutritional insecurity, loss of jobs, and loss of income to local fishers and economies (Agnew et al. 2009; Sumaila et al. 2020). Progress toward sustainable fisheries requires a global commitment to environmental, economic, and social goals over time (Duarte et al. 2020). Use of commonsense reforms could result in recovery of overfished stocks and increases in fish abundance, profits, and food security from marine fisheries (Costello et al. 2016; Cabral et al. 2018).
Anthropocene era will be a time of uncertainty.
Concern for the decline of biodiversity in the world’s oceans has never been higher as the combined failures of science, governance, subsidies, overcapitalization, and international cooperation have revealed (Costello et al. 2010; Sala et al. 2021). Nowhere is the biodiversity crisis more acute than in freshwater ecosystems, which cover less than 1% of Earth’s surface yet host approximately one-third of vertebrate species and approximately half of all fishes (Fricke et al. 2022). Twenty-eight percent of freshwater fishes are at risk globally (Dudgeon 2019; Tickner et al. 2020). Given recent dramatic declines in freshwater biodiversity, which far exceed declines observed in terrestrial or marine ecosystems, priority actions must be taken to reverse this trend (Ahmed et al. 2022). Yet many forms of freshwater life are valued more for their utilitarian value than their ecological and intrinsic value. Many fish are given unpopular or misleading labels, such as “trash fish,” “rough fish,” or “bait,” and receive little conservation attention (Monroe et al. 2009; Rypel et al. 2021).
The future will bring uncertainty associated with rapid change in climate regimes worldwide (Davies 2016). As ocean temperatures warm, fish move poleward or upstream to find suitable temperatures. For example, fewer Atlantic Cod are caught in U.S. waters compared with historical levels, and sustainable yields for many exploited populations are declining (Free et al. 2019). Climate warming will result in a shift in some tropical tuna beyond traditional prime fishing grounds. Warming of inland waters will challenge current fisheries management priorities, as cold-water specialists are relegated to new habitats (Lynch et al. 2010; Dauwalter et al. 2020; Gallagher et al. 2022). Inland fisheries are important sources for food and sport, and collapses induced by recreational fishing and climate change will be challenging to predict (Cooke and Cowx 2004). While uncertainty can contribute to inaction, we should accept uncertainty as an inevitable reality that calls for continual learning and adaptive management. Given the growing uncertainty, alternative approaches to creating and applying new knowledge in collaboration with many partners will be needed to fill the gap that exists in applying evidence-based conservation in fish conservation (Toomey et al. 2016; Kidd et al. 2019; Nguyen et al. 2019).
Learning from past successes, we can get off the pathological management treadmill that impedes recovery.
Successful examples of fish conservation often share similar elements of governance structures that include successful and trusted partnerships. Partnerships are key to effective responses to management problems. Without engagement, governing bodies respond to problems with interventions that fail to solve the problem. Instead, the signals of problems increase, leading to further political concern (Figure 15.3; Webster 2015). For example, once overfishing is recognized as a problem, it is difficult to stop. Typically, when fish populations are severely overexploited, fishing effort increases with diminishing returns. While demand increases, fishing fleets have few alternatives and oppose new fishing restrictions. As conditions worsen, more and more intense signals are received by scientists, decision makers, firms, the public, and other actors. Political concerns grow until the political will supports new governance measures that permit a shift to the effective management cycle (right-hand side of Figure 15.3). A more effective vision of fishing often means catching fewer fish with greater value, less effort, and less habitat alteration. Over the long term, fisheries governance cycles between periods of effective and ineffective management. Strong and effective governance structures can prolong periods of effective governance.
It’s time to stop pretending that fish don’t feel pain and formulate animal welfare guidance for fishing and aquaculture.
Currently, many are engaged in lively debates regarding the welfare of fish in recreational and commercial fisheries, as well as fish farms. Fish are capable of certain higher cognitive processes, which raises questions regarding ethics and welfare. The fundamental question whether and why fish matter in our moral deliberations is an applied ethics question (Bovenkerk and Meijboom 2012). New research is devoted to the difficult goal of establishing whether fish have awareness and can suffer (Browman et al. 2019; Hubená et al. 2022; Mason and Lavery 2022). The debate will continue, as some remain unconvinced that fish are sentient and call for higher standards for evidence, while others advocate for welfare protections for fish. An argument presented by Arlinghaus et al. (2020) bypasses the debate by promoting welfare based on the functions of natural populations of fish. This argument is summarized as follows:
Premise: Well-being is important to the conservation of populations and fisheries, regardless of whether the animal is able to think and feel.
Premise: Animal welfare can be considered without invoking or relying on concepts such as consciousness, sentience, or pain.
Claim: Therefore, recreational angling welfare and ethics relies on measurable endpoints of fish well-being other than pain.
Oversight and sanctions are needed to encourage compliance with regulations.
Noncompliance with fishing regulations is a pervasive problem in recreational, commercial, and subsistence fisheries (Boonstra and Österblom 2014; Cepic and Nunan 2017; Bergseth and Roscher 2018). Without oversight, knowledge of fishing regulations may be lacking. Without oversight, illegal, unreported, and unregulated fishing will lead to overfishing. Subsidies for fishing fleets lead to overcapitalized and overfished fisheries. Advances in vessel tracking and electronic monitoring continue to improve our abilities to monitor for compliance.
Comanagement holds great promise for successful and sustainable fisheries.
Comanagement respects the rights of stakeholders to organize and establish institutions (including regulations) for long-term sustainability that are recognized by higher authorities (Ostrom 2009). Moving from top-down decision making based on Decide-Announce-Defend (DAD) to Engage-Deliberate-Decide (EDD) may lead to better decisions for complex fish conservation issues. DAD approaches may lead to quicker decisions but often results in ineffective policies. The DAD method is not suited for fisheries where a wide range of technical, social, cultural, and economic factors are influencing the current situation. Also, successful implementation involves a lot of people, and these people are not in an obvious command structure, but they can choose whether to cooperate (Walker 2009; Prince 2010). Comanagement of fisheries leads to enhanced interaction, deliberation, learning, and participation of stakeholders from the fishing community and government (Gutiérrez et al. 2011; Wamukota et al. 2012; McCay et al. 2014; Berkes 2015; Botto-Barrios and Saavedra-Díaz 2020; Arantes et al. 2021; Gurdak et al. 2022; Silver et al. 2022).
Ecocertification of products from capture fisheries and aquaculture contributes to more sustainable, socially responsible seafood.
The United States is the world’s largest fish importer, with 90% of seafood consumed by Americans coming from foreign fisheries (NOAA 2017). Yet, 25–30% of wild-caught seafood imported into the country is illegally caught (Pramod et al. 2014). Therefore the U.S. demand contributes to illegal, unreported, and unregulated (IUU) fishing worldwide. The power of this market demand can be used to encourage socially responsible fishing and seafood guides that affect retailers’ choice of what they will sell (Kittinger et al. 2017). To leverage the power of the market, fisheries must develop reliable systems for tracing seafood products so that labeling is possible (Willette and Cheng 2018).
The Marine Stewardship Council’s theory of change describes how certification influences responsible fishing and marketing practices in ways that combat illegal fishing and provides greater benefits to fishers (Figure 15.4; Adolf et al. 2016; Arton et al. 2018; Willett and Cheng 2018).
15.3 Social Systems Principles
Fisheries management in poorer nations should have a much stronger emphasis on human health and well-being.
People in the developing world heavily rely on fish for nutrition and fishing to support their livelihoods. Unfortunately, many of these developing countries have weak governance and are often net exporters of seafood to well-nourished countries with strong governance (Golden et al. 2016). Fish and other seafood will be essential to feed the estimated 10 billion people expected to be living on Earth by 2050. Industrialization of fishing, poor governance, and the expansion of foreign fishing threaten fisheries of small nations. Sensitivities to food insecurity in tropical ecosystems will be exacerbated by climate change and other human-induced habitat alterations (Free et al. 2019). Consequently, the historical rights of small-scale fishing communities to marine and inland resources, as traditional users for thousands of years, should be recognized to allow equitable allocation of fishery benefits (Schreiber et al. 2022). Currently, fishing incomes are below national poverty lines in 34% of the countries with data (Teh et al. 2020). In many artisanal fisheries (Figure 15.5), most of the catch is consumed domestically. Coral reefs and mangroves, which are essential ecosystems for many tropical coastal subsistence and artisanal fisheries, will be heavily degraded by coastal development, warming, and ocean acidification.
Rights, equity, and justice are mainstream principles of good fisheries governance.
New norms of practice in the form of governmental laws and regulations, voluntary codes of conduct, trade agreements, and market-based tools have emerged in response to global concerns about overfishing and unjust distribution of fishery benefits (Lam 2016). Consequently, we apply ethical reasoning in fisheries management. Rights, equity, and justice are mainstream principles of good fisheries governance. The ethical matrix (table 15.1) combines consequentialist and rights-based ethics along with Rawls’ theory of justice as fairness, while considering all interest groups. Better compliance with the FAO code of conduct for responsible fishing will lead to enhanced fisheries sustainability.
Interest group Ethical principle
Well-being (consequentialist or utilitarian theory: welfare and health) Autonomy (rights-based or deontology theory: freedom and choice) Justice (social contract theory and Rawlsian "justice as fairness")
Producers Satisfactory income and working conditions Managerial freedom Fair trade laws and practices
Consumers Food safety and quality of life Democratic and informed choice Availability of affordable food
Organisms Animal welfare Behavioral freedom Intrinsic value
Environment Conservation Biodiversity Sustainability
Table 15.1: Ethical matrix from Lam (2016) showing outcomes for interest groups by following three ethical principles. Deontology refers to the study of the nature of duty and obligation. Rawlsian refers to a theory of justice, developed by John Rawls, that aims to constitute a system to ensure the fair distribution of primary social goods.
Effective governance of fisheries depends on effective community leaders.
Leaders who can build legitimacy and find ways to balance the concerns of competing interest groups help make the shift to effective governance responses. For example, the fisheries commissioner in Maine, who is credited with establishing more effective lobster management, built social networks and won the trust of lobster fishers while keeping abreast of scientific studies of the lobster fishery. Consequently, when difficult times emerged, the political will was sufficient to support governance responses instituting a conservation ethic to prevent overfishing (Acheson 1997).
Transform arguments into partnerships because facts don’t win arguments.
The popular press often unwittingly spreads misinformation and misunderstanding about fish conservation issues (Orth et al. 2020; Shiffman et al. 2020). Increasingly, citizens are ready to deny findings from science that contradict their opinions (Schmid and Betsch 2019). Many of us do nothing to correct false or unsubstantiated beliefs, based on the presumed “backfire effect” myth, in which attempts to correct false beliefs increase misperceptions among the group in question (Nyhan 2021). However, it is preferable to form partnerships and develop trust among all stakeholders. The guidance to “build trust and listen” leads to group efforts focused on seeking the right answer together rather than defending one view. Formation of viable, long-term partnerships is more likely to lead to lasting policy changes.
A nudge may be more effective in changing behavior than forced compliance.
A nudge, unlike forced compliance, uses subtle changes and indirect suggestions to make certain decisions more salient, thereby improving voluntary compliance (Thaler and Sundstein 2008). For example, scientists know that keeping fish in or over the water and holding them with clean, wet hands or a soft rubber net will help keep their slime layer and scales intact and the fish disease free. The nonprofit organization Keep Fish Wet works to change social norms about the practice of catch-and-release angling. Prominent anglers and guides demonstrate how to land fish with minimal air exposure and handling, thereby nudging others to adopt the new behavior. Social norms are important drivers of human behavior and are known to influence how fishers interact with animals and their environment. The role of social norms within the context of recreational angling is of particular interest, given that angling behavior is seldom formally or easily monitored and enforced (Mackay et al. 2018). Increasingly, findings from psychological science may serve to promote behaviors that support conservation (Clayton and Myers 2015).
Conflicting value orientations are common in many fisheries.
Throughout this book, we have seen many ways in which fish and fishing matter to people. Relational values comprise a broader framework for including all values, not simply economic values, that can arise from a person’s or society’s relationship with nature (Chan et al. 2018). The ecological, spiritual, cultural, financial, academic, and recreational significance of a fish in human experience reflects pluralistic values to consider when formulating conservation strategies. We may think about the values-beliefs-norms-action causal chain when evaluating potential conservation interventions. For example, consider how biocentric values support beliefs, norms, and actions regarding shark conservation (Figure 15.6). Those with strong biocentric, altruistic, and egoistic values are likely to believe in an ecological worldview that sharks are at risk and they have the ability to effect change. From these beliefs, a sense of obligation to take actions becomes a norm, which leads to certain specific actions to protect sharks. Similarly, biocentric values lead to beliefs about harms to individual fish and implementing welfare actions in aquaculture and in fisheries. Successful conservation requires that we acknowledge and consider pluralistic values from biocentric to anthropocentric.
Values drive selection of management objectives, policies, and practices.
A wide variety of conservation and management approaches naturally emerge as a result of differing values (Figure 15.7). Heterogeneous values among stakeholders translate to differing priority for objectives, policies, and practices. Laissez-faire approaches arise from strong values of autonomy and belief in the workings of the free market. Utilitarian values lead to selecting an objective of maximum sustained yield, precautionary policies, and practices such as closed seasons or quotas. Conservation and wise use of fishery resources may in some cases greatly alleviate poverty and improve the well-being in fishing communities. In other cases, recreational fishing and diving provide largely unexamined psychological benefits to participants whose values focus on spending time in unspoiled natural systems. Laissez-faire approaches arise from strong values of autonomy and belief in the workings of the free market. Utilitarian values lead to selecting an objective of maximum sustained yield, precautionary policies, and practices such as closed seasons or quotas. Conservationists have put considerable hope into the idea that we may be able to defend ecosystem services by translating them into monetary terms. A fundamental criticism of this approach is that it may lead to marginalizing certain social groups (Sorlin 2012). In other cases, ecological reference points are emerging when stakeholders hold ecocentric values, such as we saw with new policies and practices implemented for Atlantic Menhaden management. Over long time horizons, we should anticipate shifts in how people value fish. For example, the change in anglers’ values from utilitarian self-interest toward biocentric, ecosystem-based conservation is evident among fly fishers and rough fish anglers. Biocentric value orientations contribute to greater support for stewardship objectives, policies, and practices, while at the same time contributing to less support for the use of technological angling aids (Bruskotter and Fulton 2007).
The tragedy of the commons is not inevitable if we embrace pluralism and pragmatism.
When fishers act solely in their own interests when accessing a public fishery, they ultimately overfish. The primary roles of government at the local, state, national, and international levels is to define and manage shared fisheries resources. However, notable failures have led many to adopt some type of participatory approach to involve fishers in management. Adopting pragmatism means that we emphasize actionable knowledge and practical experiences of all stakeholders. For these participatory programs to be effective, it must be clear how stakeholder input is used in decision making (Crandall et al. 2019). Pluralism emphasizes respect for multiple ways of knowing and thinking about fish conservation issues. Plurality means we examine perspectives and understandings from traditional Western and Indigenous knowledge systems to support decisions (Bingham et al. 2021; Reid et al. 2021).
Building trust among various stakeholders is critical to effective governance and conservation.
Conservation programs require substantial interagency coordination, collaboration, and knowledge sharing. Yet, many fisheries institutions have a history of conflict and discrimination against women, Black, Indigenous, and people of color. Although historical injustices cannot be undone, changes in treatment may reduce discrimination in the future. Differing value orientations often lead to distrust. Distrust is often recognized as a major obstacle to effective natural resource management, leading to fear or opposition (Stern and Coleman 2015). Procedural fairness and technical competency are keys to developing stakeholder trust. Procedural fairness exists when stakeholders believe they have a voice in the decision process regardless of outcome (Riley et al. 2018). Direct, frequent, and timely communication is essential to demonstrate that stakeholder input is valued. Also, dialogue with stakeholders should focus on conversations that allow stakeholders to share their concerns and fears. New norms are emerging for stakeholder engagement with a greater attention to diversity, equity, inclusion, justice, and accessibility (Arismendi and Penaluna 2016; Worm et al. 2021).
15.4 Ecological Principles
Big, old, fat, fecund female fish, or “BOFFFFs,” contribute substantially to population productivity and stability.
The examples presented in fishing for living dinosaurs, Arapaima, and grouper highlight the importance of BOFFFFs for conservation. Larger females are far more productive than the same weight’s worth of smaller females (Barneche et al. 2018). Management practices that ignore the value of large females contribute to declines seen in some fish stocks, such as the Atlantic Cod Gadus morhua (Figure 15.8). In a broad range of fishes, older females spawn earlier and may have more protracted spawning seasons than younger females (Francis et al. 2007).
Increasingly, modern methods for aging fish reveal longevity estimates far exceeding those from earlier studies. Fish having long life spans with repeated spawning is a bet-hedging response to life in variable environments where larval survival and successful recruitment may be uncommon. More large fish are living life in the slow lane. Recent studies revealed that Bowfins live ~2–3 times longer than previously estimated for wild populations. With Bowfin, over the past two decades, there has been increased demand for roe for caviar, increased participation in recreational angling, and increased harvest through modern bowfishing (Lackman et al. 2019, 2022; Scarnecchia et al. 2019). Ecological functions of Bowfin and other rough fish must be considered (Rypel et al. 2021).
Sometimes it’s the habitat.
Initiatives to “protect the habitat” are common among supporters of bonefish, tarpon, trout, char, grouper, salmon, sharks, sturgeon, and many others. In fish that use multiple habitats to meet different resource needs throughout their lives, a loss of an essential habitat may limit the ability of an overfished population to recover. For example, many studies demonstrate the key function of mangroves and seagrass beds as reef fish nurseries and freshwater streams as salmon nurseries. Increasingly, marine protected areas (MPA) are used to protect essential habitats (Giakoumi et al. 2018; Sala and Giakoumi 2018; Gilchrist et al 2020). More than 17,000 MPAs protect almost 11.2 million square miles (29 million square kilometers) of ocean. In other words, nearly 8.2% of the ocean, an area the size of North America, is under some kind of protection (UNEP–WCMC 2020).
Although there are few freshwater protected areas, the enforcement of the U.S. Clean Water Act and water quality standards led to improvements in diversity and abundance of riverine fish and other biota in many large rivers (Yoder et al. 2019). Scientific management of the Chesapeake Bay crab population that has called for cleaner water and improved habitat also will help crabs. Reducing the levels of nutrients reaching the bay from farms and lawns and better managing of polluted runoff before it gets into rivers and streams will help improve water quality and contribute to the recovery of both Blue Crabs and bay grasses. Habitat restoration is the most effective tool for conservation of nongame fish, which are often hardly visible, small bodied, co-occurring with a large number of species over their distributional range, and sharing essential habitat requirements. Because of these characteristics, freshwater (especially stream) habitat protection should achieve conservation for multiple species.
Recovery of fish populations is possible but takes long-term effort and partnerships.
Well-documented case studies demonstrate this principle for Eastern Brook Trout, Goliath Grouper, Lake Erie Walleye, and Snail Darter, as well as others (Kraft 2019; Vandergoot et al. 2019; Koenig et al. 2020). In all successful recoveries, there is substantial effort in developing coordinated, multiagency approaches with stakeholder input. In 2022, the U.S. Fish and Wildlife Service announced an important milestone in fish conservation. The most famous darter in the world, the Snail Darter, was considered recovered (Loller 2022), demonstrating that the Endangered Species Act is working to recover endangered species.
15.5 Final Takeaway
It is easy to become disillusioned with the magnitude of the global challenges for recovering at-risk fish populations or maintaining valuable fisheries. However, if we focus on the principle that passionate and persistent people who understand the fish and the place will find a way to create partnerships to conserve valued fish in perpetuity, we can work to implement actions at local levels. Many inspiring stories exist about the recovery of overfished or collapsed highly degraded ecosystems (Krueger et al. 2019). Collectively, these stories revealed that no single silver bullet worked. Rather, strategies that engaged and nurtured partnerships with stakeholders led to increased trust and effective collaboration.
Profile in Fish Conservation: Emmanuel A. Frimpong, PhD
Emmanuel A. Frimpong is currently Professor in the Department of Fish Conservation at Virginia Tech. He grew up in Ghana, a country where fish were, first and foremost, food. He began fishing with his dad at the age or nine and recalls that every fish caught came home to be eaten by the family. This reminds us of the priority of food for human survival before humans can consider the role of fish, fishing, and conservation in a broader context. He recalls that for centuries, the indigenous people of Ghana have loyally guarded patches of forest and accompanying streams where freshwater fish are protected from harvest.
Dr. Frimpong received his BS from the University of Science & Technology in Ghana, MS from the University of Arkansas at Pine Bluff, and PhD from Purdue University. Later he earned a second MS in statistics from Virginia Tech. He joined the faculty at Virginia Tech in 2007. He collaborates with the U.S. Agency for International Development’s AquaFish Innovation Lab on research and development projects in Ghana, Kenya, and Tanzania. He is a significant contributor to research and development in Ghana and sub-Saharan Africa and was named to the prestigious Carnegie African Diaspora Fellow program. As a fellow, he is actively engaged in educational projects proposed and hosted by faculty of higher education institutions in Ghana, Kenya, Nigeria, South Africa, Tanzania, and Uganda. His research in the United States is funded by the National Science Foundation’s Division of Environmental Biology and the U.S. Geological Survey’s Aquatic Gap Analysis Program.
Dr. Frimpong and his students study the ecology and conservation of freshwater fish, with emphasis on how anthropogenic alterations to habitats and landscapes differentially affect species as a result of differences in their life history traits and the nature of biotic, especially mutualistic, interactions. Findings of his research team demonstrated how specific landscape and habitat changes, such as agriculture and aquaculture, urban development, introduction of nonnative species, and climate change, drive current conditions for stream fish. Frimpong developed a comprehensive database describing more than 100 biological traits of 809 freshwater fish, which is available to scientists everywhere. This improved understanding of determinants of fish distributions helps us predict how the distribution of species will respond to anthropogenic changes to their environment, while suggesting solutions to declining populations. In addition to studies of stream fish ecology, he has examined approaches to encouraging sustainable production aquaculture (especially in sub-Saharan Africa) as an alternative to overexploitation of natural fisheries.
Dr. Frimpong has demonstrated that unremarkable streams and common fish can reveal many ecological principles, such as the existence of important mutualistic interactions among stream fishes. These small, common fish are also important to fish conservation initiatives. Lack of information about common fish perpetuates ineffectual conservation practices. Frimpong recommends that we put ourselves in the fins of a fish to better appreciate their special underwater capabilities and threats to their continued existence. Particularly, aquatic biodiversity in West and Central Africa is grossly undersampled and unstudied. In Ghana and elsewhere, many undocumented, undescribed, and cryptic clusters of species are lumped into one species due to lack of detailed study. These taxonomic oversights influence our understanding of rarity, a key to conservation status. Yet, he explains to his students and colleagues that people are unaware of fish in local waters, and fish appreciation remains an untapped need for fish conservation.
This chapter was reviewed by Francesco Ferretti and Emmanual A. Frimpong.
Long Descriptions
Figure 15.2: Flow chart depicts key factors in fish stock biomass; 1) recruitment; 2) growth; 3) stock biomass (leads back to recruitment and growth). Stock biomass points to either harvest or natural death. Jump back to Figure 15.2.
Figure 15.4: 1) fisheries which meet the MSC standard are independently certified as sustainable; 2) consumers preferentially purchase seafood with the MSC ecolabel; 3) retailers and restaurants choose MSC certified sustainable seafood; 4) a traceable supply chain assures consumers that only seafood from an MSC certified fishery is sold with the MSC ecolabel; 5) market demand for MSC certified seafood increases; 6) more fisheries choose to improve their practices and volunteer to be assessed against the MSC standard. Jump back to Figure 15.4.
Figure 15.6: 1) Values: biocentric, altruistic, and egotistic. 2) Beliefs: ecological worldview, perception of risk to sharks, realization of personal agency to reduce threats of sharks. 3) Norms: sense of obligation to take action to reduce threats. 4) Actions: adoption of shark conservation-centric fishing guidelines, membership in shark/marine conservation groups, participation in shark conservation policy processes, personal advocacy for fishery compliance, policy adoption. Jump back to Figure 15.6.
Figure 15.8: Atlantic cod that is gray green with reddish brown spots. Their lateral line is pale, almost white. Cod are streamline in shape, have a broad square tail fin, three rounded dorsal fins, two anal fins and no fin spines. Jump back to Figure 15.8.
Figure References
Figure 15.1: An improved understanding of coupled social-ecological system dynamics will yield more effective fisheries and marine conservation decisions. Kindred Grey. 2022. Adapted under fair use from Bridging the Divide between Fisheries and Marine Conservation Science, by Salomon et. al., 2011. http://dx.doi.org/10.5343/bms.2010.1089.
Figure 15.2: Conceptual model depicting key factors that decrease or increase fish stock biomass according to Russell’s 1931 equation. Kindred Grey. 2022. CC BY 4.0.
Figure 15.3: The management or governance treadmill. Kindred Grey. 2022. CC BY 4.0. Adapted from Scapegoats, Silver Bullets, and Other Pitfalls in the Path to Sustainability, by D. G. Webster, 2017. CC BY 4.0. http://dx.doi.org/10.1525/elementa.212.
Figure 15.4: The Marine Stewardship Council’s theory of change describes how the organization envisages itself contributing to more sustainable seafood practices. From What Do We Know About the Impacts of the Marine Stewardship Council Seafood Ecolabelling Program? A Systematic map, by Arton et. al., 2020. CC BY 4.0. https://doi.org/10.1186/s13750-020-0188-9.
Figure 15.5: Small-scale artisanal fisheries target many species using handlines, and most fish landed are sold and eaten domestically. Photography by Dino Sassi – Marcel Fayon, Photo Eden LTD, 1977. Public domain. https://commons.wikimedia.org/wiki/File:Fisherman_and_his_catch_Seychelles.jpg.
Figure 15.6: Values-belief-norms-actions framework for depicting the chain of causality linking relational values to beliefs, norms, and actions in the context of shark conservation. Kindred Grey. 2022. CC BY 4.0. Adapted from Introducing Relational Values as a Tool for Shark Conservation, Science, and Management, by Skubel et. al., 2019. CC BY 4.0. http://dx.doi.org/10.3389/fmars.2019.00053,
Figure 15.7: Values drive selection of management objectives, policies, and practices. Kindred Grey. 2022. CC BY 4.0.
Figure 15.8: Atlantic Cod is one of many fish where large females play a disproportionate role in producing future offspring. Peter. 2011. CC BY 2.0. https://commons.wikimedia.org/wiki/File:Atlantic_cod_%281%29.jpg.
Figure 15.9: Emmanuel A. Frimpong, PhD. Used with permission from Emmanuel A. Frimpong. CC BY-ND 4.0.
Text References
Acheson, J. M. 1997. The politics of managing the Maine lobster industry: 1860 to the present. Human Ecology 25(1):3–27.
Adolf, S., S. R. Bush, and S. Vellema. 2016. Reinserting state agency in global value chains: the case of MSC certified Skipjack Tuna. Fisheries Research 182:79–87.
Agnew, D. J., J. Pearce, G. Pramod, T. Peatman, R. Watson, J. R. Beddington, and T. J. Pitcher. 2009. Estimating the worldwide extent of illegal fishing. PLoS ONE 4:e4570.
Ahmed, S. F., P. S. Kumar, M. Kabir, F. T. Zuhara, A. Mehjabin, N. Tasannum, A. T. Hoang, Z. Kabir, and M. Mofijur. 2022. Threats, challenges and sustainable conservation strategies for freshwater biodiversity. Environmental Research 214(Part 1):113808. doi: 10.1016/j.envres.2022.113808.
Aminpour, P., S. A. Gray, A. J. Jetter, J. E. Introne, A. Singer, and R. Arlinghaus. 2020. Wisdom of stakeholder crowds in complex social-ecological systems. Nature Sustainability 3:191–199. DOI: 10.1038/s41893-019-0467-z.
Arantes, C. C., L. Castello, X. Basurto, N. Angeli, A. Sene-Haper, and D. G. McGrath. 2021. Institutional effects on ecological outcomes of community-based management of fisheries in the Amazon. Ambio 51(3):678–690.
Arismendi, I., and B. E. Penaluna. 2016. Examining diversity inequities in fisheries science: a call to action. BioScience 66(7):584–591.
Arlinghaus, R., I. G. Cowx, B. Key, B. K. Diggles, A. Schwab, S. J. Cooke, A. B. Skiftesvik, and H. I. Browman. 2020. Pragmatic animal welfare is independent of feelings. Science 370(6513):180.
Arton, A., A. Leiman, G. Petrokofsky, H. Toonen, and C. Longo. 2018. What do we know about the impacts of the Marine Stewardship Council seafood ecolabelling program? A systematic map. Environmental Evidence 9(1). DOI:10.1186/s13750-020-0188-9.
Barneche, D. R., D. R. Robertson, C. R. White, and D. J. Marshall. 2018. Fish reproductive-energy output increases disproportionately with body size. Science 360(6389):642–645.
Bavington, D. 2010. Managed annihilation: an unnatural history of the Newfoundland cod collapse. University of British Columbia Press, Vancouver.
Bergseth, B. J., and M. Roscher. 2018. Discerning the culture of compliance through recreational fisher’s perceptions of poaching. Marine Policy 89:132–141.
Berkes, F. 2015. Coasts for people: interdisciplinary approaches to coastal and marine resource management. Routledge, New York.
Beverton, R. J. H., and E. D. Anderson. 2002. Reflections on 100 years of fisheries research. ICES Marine Science Symposia 215:453–463.
Bingham, J. A., S. Milne, G. Murray, and T. Dorward. 2021. Knowledge pluralism in First Nations’ salmon management. Frontiers in Marine Science 8:671112. https://doi.org/10.3389/fmars.2021.671112.
Boonstra, W. J., and H. Österblom. 2014. A chain of fools: or, why it is so hard to stop overfishing. Maritime Studies 13:1–20.
Botto-Barrios, D., and L. M. Saavedra-Díaz. 2020. Assessment of Ostrom’s social-ecological system framework for the comanagement of small-scale marine fisheries in Colombia: from local fishers’ perspectives. Ecology and Society 25(1):12.
Bovenkerk, B., and F. L. B. Meijboom. 2012. The moral status of fish: the importance and limitations of a fundamental discussion for practical ethical questions in fish farming. Journal of Agricultural and Environmental Ethics 25:843–860.
Browman, H. I., S. J. Cooke, I. G. Cowx, S. W. G. Derbyshire, A. Kasumyan, B. Key, J. D. Rose, A. Schwab, A. B. Skiftesvik, E. D. Stevens, C. A. Watson, and R. Arlinghaus. 2019. Welfare of aquatic animals: where things are, where they are going, and what it means for research, aquaculture, recreational angling, and commercial fishing. ICES Journal of Marine Science 76(1):82–92.
Bruskotter, J. T., and D. C. Fulton. 2007. The influence of angler value orientations on fisheries stewardship norms. American Fisheries Society Symposium 55:157–167.
Cabral, R. B., J. Mayorga, M. Clemence, J. Lynham, S. Koesendrajana, U. Muawanah, D. Nugroho, Z. Anna, A. Ghofar, N. Zulbainarni, S. D. Gaines, and C. Costello. 2018. Rapid and lasting gains from solving illegal fishing. Nature Ecology & Evolution 2:650–658.
Carlson, A. K., W. W. Taylor, M. R. Cronin, M. J. Eaton, L. E. Eckert, M. A. Kaemingk, A. J. Reid, and A. Trudeau. 2020. The social-ecological odyssey in fisheries and wildlife management. Fisheries 45(5):238–243.
Cepić, D., and F. Nunan. 2017. Justifying non-compliance: the morality of illegalities in small scale fisheries of Lake Victoria, East Africa. Marine Policy 86:104–110.
Chan, K. M. A., R. K. Gould, and U. Pascual. 2018. Editorial overview: relational values: what are they, and what’s the fuss about? Current Opinion in Environmental Sustainability 35:A1–A7.
Clayton, S., and G. Meyers. 2015. Conservation psychology: understanding and promoting human care for nature. 2nd ed. John Wiley, New York.
Clover, C. 2008. The end of the line: how overfishing is changing the world and what we eat. University of California Press, Berkeley.
Cooke, S. J., and I. G. Cowx. 2004. The role of recreational fishing in global fish crises. BioScience 54:857–859.
Cooke, S. J., V. M. Nguyen, J. M. Chapman, A. J. Reid, S. J. Landsman, N. Young, S. G. Hinch, S. Schott, N. E. Mandrak, and C. A. D. Semeniuk. 2021. Knowledge co-production: a pathway to effective management, conservation, and governance. Fisheries 46(2):89–97.
Costello, C., D. Ovando, T. Clavell, C. K. Strauss, R. Hilborn, M. C. Melnychuk, T. A. Branch, S. D. Gaines, C. S. Szuwalski, R. B. Cabral, D. N. Rader, and A. Leland. 2016. Global fishery prospects under contrasting management regimes. Proceedings of the National Academy of Sciences 113(18):51235–5129.
Costello, M. J., M. Coll, R. Danovaro, P. Halpin, H. Ojaveer, and P. Miloslavich. 2010. A census of marine biodiversity knowledge, resources and future challenges. PLoS ONE 5:e12110.
Crandall, C. A., M. Monroe, J. Dutka-Gianelli, and K. Lorenzen. 2019. Meaningful action gives satisfaction: stakeholder perspectives on participation in the management of marine recreational fisheries. Ocean & Coastal Management 179:104872. DOI:10.1016/j.ocecoaman.2019.104872.
Dauwalter, D. C., A. Duchi, J. Epifanio, A. Gandolfi, R. Gresswell, F. Juanes, J. Kershner, J. Lobón-Cerviá, P. McGinnity, A. Meraner, P. Mikheev, K. Morita, C. C. Muhlfeld, K. Pinter, J. R. Post, G. Unfer, L. A. Vøllestad, and J. E. Williams. 2020. A call for global action to conserve native trout in the 21st century and beyond. Ecology of Freshwater Fishes 29(3):429–432.
Davies, J. 2016. The birth of the Anthropocene. University of California Press, Berkeley.
Duarte, C. M., S. Agusti, E. Barbier, G. L. Britten, J. C. Castilla, J-P. Gattuso, R. W. Fulweiler, T. P. Hughes, N. Knowlton, C. E. Lovelock, H. K. Lotze, M. Predragovic, E. Poloczanska, C. Roberts, and B. Worm. 2020. Rebuilding marine life. Nature 580:39–51.
Dudgeon, D. 2019. Multiple threats imperil freshwater biodiversity in the Anthropocene. Current Biology 29(19):R960–R967.
Essig, R. J., R. W. Laney, M. H. Appelman, F. A. Harris, R. A. Rulifson, and K. L. Nelson. 2019. Pages 533–566 in C. C. Krueger, W. W. Taylor, and S. Youn, editors, From catastrophe to recovery: stories of fisheries management success, American Fisheries Society, Bethesda, MD.
Francis, R. C., M. A. Hixon, M. E. Clarke, S. A. Murawski, and S. Ralston. 2007. Fisheries management—ten commandments for ecosystem-based fisheries scientists. Fisheries 32(5):217–233.
Free, C. M., J. T. Thorson, M. L. Pinsky, K. L. Oken, J. Wiedenmann, and O. P. Jensen. 2019. Impacts of historical warming on marine fisheries production. Science 363(6430):979–983.
Fricke, R., W. N. Eschmeyer, and R. Van der Laan, editors. 2022. Eschmeyer’s catalog of fishes: genera, species, references. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp.
Gallagher, B. K., S. Geargeoura, and D. J. Fraser. 2022. Effects of climate on salmonid productivity: a global meta-analysis across freshwater ecosystems. Global Change Biology 28:7250–7269. doi:10.1111/gcb.16446.
Giakoumi, S., J. McGowan, M. Mills, M. Beger, R. H. Bustamante, A. Charles, P. Christie, M. Fox, P. Garcia-Borboroglu, S. Gelcich, P. Guidetti, P. Mackelworth, J. M. Maina, L. McCook, F. Micheli, L. E. Morgan, P. J. Mumby, L. M. Reyes, A. White, K. Grorud-Colvert, and H. P. Possingham. 2018. Revisiting “success” and “failure” of marine protected areas: a conservation scientist perspective. Frontiers in Marine Science 5:223. https://doi.org/10.3389/fmars.2018.00223.
Gilchrist, H., S. Rocliffe, L. G. Anderson, and C. L. A. Gough. 2020. Reef fish biomass recovery within community-managed no take zones. Ocean and Coastal Management 192:105210. https://doi.org/10.1016/j.ocecoaman.2020.105210.
Golden, C. D., E. H. Allison, W. W. L. Cheung, M. M. Dey, B. S. Halpern, D. J. McCauley, M. Smith, B. Vaitla, D. Zeller, and S. S. Myers. 2016. Nutrition: fall in fish catch threatens human health. Nature 534:317–320.
Graham, M. 1943. The fish gate. Faber & Faber, London.
Gurdak, D. J., D. J. Stewart, and M. Thomas. 2022. Local fisheries conservation and management works: implications of migrations and site fidelity of Arapaima in the lower Amazon. Environmental Biology of Fishes 105:2119–2132. https://doi.org/10.1007/s10641-021-01171-y.
Gutiérrez, N. L., R. Hilborn, and O. Defeo. 2011. Leadership, social capital and incentives promote successful fisheries. Nature 470:386–389.
Hilborn, R., with U. Hilborn. 2012. Overfishing: what everyone needs to know. Oxford University Press.
Hubená, P., P. Horký, and O. Slavík. 2022. Fish self-awareness: limits of current knowledge and theoretical expectations. Animal Cognition 25:447–461.
Kittinger, J. N., L. C. L. Teh, E. H. Allison, N. J. Bennett, L. B. Crowder, E. M. Finkbeiner, C. Hicks, C. G. Scarton, K. Nakamura , Y. Ota, J. Young, A. Alifano, A. Apel, A. Arbib, L. Bishop, M. Boyle, A. M. Cisneros-Montemayor, P. Hunter, E. Le Cornu, M. Levine, R. S. Jones, J. Z. Koehn, M. Marschke, J. G. Mason, F. Micheli, L. McClenachan, C. Opal, J. Peacey, S. H. Peckham, E. Schemmel, V. Solis-Rivera, W. Swartz, and T. ‘A. Wilhelm. 2017. Committing to socially responsible seafood. Science 356:912–913.
Koenig, C. C., F. C. Coleman, and C. R. Malinowski. 2020. Atlantic Goliath Grouper of Florida: to fish or not to fish. Fisheries 45(1):20–32.
Kraft, C. 2019. Adirondack Brook Trout and acid rain. Pages 299–322 in C. C. Krueger, W. W. Taylor, and S. Youn, editors, From catastrophe to recovery: stories of fishery management success, American Fisheries Society, Bethesda, MD.
Krueger, C. C., W. W. Taylor, and S. Youn, editors. 2019. From catastrophe to recovery: stories of fisheries management success. American Fisheries Society, Bethesda, MD.
Kurlansky, M. 2010. Cod: a biography of the fish that changed the world. Penguin, New York.
Lackmann, A. R., A. H. Andrews, M. G. Butler, E. S. Bielak-Lackmann, and M. E. Clark. 2019. Bigmouth Buffalo Ictiobus cyprinellus sets freshwater teleost record as improved age analysis reveals centenarian longevity. Communications Biology 2:1–14.
Lackmann, A. R., E. S. Bielak-Lackmann, M. G. Butler, and M. E. Clark. 2022. Otoliths suggest lifespans more than 30 years for free-living Bowfin Amia calva: implications for fisheries management in the bowfishing era. Journal of Fish Biology 101:1301–1311. https://doi.org/10.1111/jfb.15201.
Lam, M. 2016. The ethics and sustainability of capture fisheries and aquaculture. Journal of Agricultural and Environmental Ethics 29:35–65.
Lichatowich, J., and N. Gayeski. 2020. Wild Pacific Salmon: myths, false assumptions, and a failed management paradigm. Pages 397–427 in M. Kurlansky, Salmon: A fish, the Earth, and the history of their common fate. Patagonia, Ventura, CA.
Loller, T. 2022. Snail Darter, focus of epic conservation fight, is recovered. Washington Post, October 4.
Lynch, A. J., W. W. Taylor, and K. D. Smith. 2010. The influence of changing climate on the ecology and management of selected Laurentian Great Lakes fisheries. Journal of Fish Biology 77:1764–1782.
Mackay, M., S. Jennings, E. van Putten, H. Sibly, and S. Yamazaki. 2018. When push comes to shove in recreational fisheries compliance, think ‘nudge.’ Marine Policy 95:256–266.
Mason, F. 2002. The Newfoundland cod stock collapse: a review and analysis of social factors. Electronic Green Journal UCLA Library 17. doi:10.5070/G311710480.
Mason, G. J., and J. M. Lavery. 2022. What is it like to be a bass? Red herrings, fish pain and the study of animal sentience. Frontiers in Veterinary Science 9:788289. https://doi.org/10.3389/fvets.2022.788289.
McCay, B. J., F. Micheli, G. Ponce-Díaz, G. Murray, G. Shester, S. Ramirez-Sanchez, and W. Weisman. 2014. Cooperatives, concessions, and comanagement on the Pacific Coast of Mexico. Marine Policy 44:49–59.
Monroe, J. B., C. V. Baxter, J. D. Olden, and P. A. Angermeier. 2009. Freshwaters in the public eye: understanding the role of images and media in aquatic conservation. Fisheries 34(12):581–585.
Nguyen, V. M., N. Young, M. Corriveau, S. G. Hinch, and S. J. Cooke. 2019. What is “usable” knowledge? Perceived barriers for integrating new knowledge into management of an iconic Canadian fishery. Canadian Journal of Fisheries and Aquatic Sciences 76:463–474.
Nielsen, L. A. 2017. Nature’s allies: eight conservationists who changed our world. Island Press, Washington, D.C.
NOAA. 2017. FishWatch: sustainable seafood. Available at: https://www.fishwatch.gov.
Nyhan, B. 2021. Why the backfire effect does not explain the durability of political misperceptions. Proceedings of the National Academy of Sciences 118(15):e1912440117. https://doi.org/10.1073/pnas.1912440117.
Orth, D. J., J. D. Schmitt, and C. D. Hilling. 2020. Hyperbole, simile, metaphor, and invasivore: messaging around the science of a Blue Catfish invasion. Fisheries 45(12):638–646.
Ostrom, E. 2009. A general framework for analyzing sustainability of social-ecological systems. Science 325:419–422.
Pinsky, M. L., O. P. Jensen, D. Ricard, and S. R. Palumbi. 2011. Unexpected patterns of fisheries collapse in the world’s oceans. Proceedings of the National Academies of Sciences 108(20):8317–8322.
Pramod, G., K. Nakuma, T. J. Pitcher, and L. Delagran. 2014. Estimates of illegal and unreported fish in seafood imports to the USA. Marine Policy 48:102–113.
Prince, J. 2010. Rescaling fisheries assessment and management: a generic approach, access rights, change agents, and toolboxes. Bulletin of Marine Science 86(2):197–219.
Radovich, J. 1982. The collapse of the California sardine fishery: What have we learned? California Cooperative Oceanic Fisheries 23:56–78.
Reid, A. J., L. E. Eckert, J. F. Lane, N. Young, S. G. Hinch, C. T. Darimont, S. J. Cooke, N. C. Ban, and A. Marshall. 2021. “Two-eyed seeing”: an Indigenous framework to transform fisheries research and management. Fish and Fisheries 22:243–261.
Riley, S. J., J. K. Ford, H. A. Triezenberg, and P. E. Lederle. 2018. Stakeholder trust in a state wildlife agency. Journal of Wildlife Management 82:1528–1535.
Russell, E. S. 1931. Some theoretical considerations on the “overfishing” problem. Journal du Conseil International pour l’Exploration de la Mer 6:3–20.
Rypel, A. L., P. Saffarinia, C. C. Vaughn, L. Nesper, K. O’Reilly, C. A. Parisek, M. L. Miller, P. B. Moyle, N. A. Fangue, M. Bell-Tilcock, D. Ayers, and S. R. David. 2021. Goodbye to “rough fish”: paradigm shift in the conservation of native fishes. Fisheries 46(12):605–616.
Sala, E., and S. Giakoumi. 2018. No-take marine reserves are the most effective protected areas in the ocean. ICES Journal of Marine Science 75:1166–1168. doi: 10.1093/icesjms/fsx059.
Sala, E., J. Mayorga, D. Bradley, R. B. Cabral, T. B. Atwood, A. Auber, W. Cheung, C. Costello, F. Ferretti, A. M. Friedlander, S. D. Gaines, C. Garilao, W. Goodell, B. S. Halpern, A. Hinson, K. Kaschner, K. Kesner-Reyes, F. Leprieur, J. McGowan, L. E. Morgan, D. Mouillot, J. Palacios-Abrantes, H. P. Possingham, K. D. Rechberger, B. Worm, and J. Lubchenco. 2021. Protecting the global ocean for biodiversity, food and climate. Nature 592:397–402.
Scarnecchia, D. L., and J. D. Schooley. 2020. Bowfishing in the United States: history, status, ecological impacts, and the need for management. Transactions of the Kansas Academy of Science 123:285–338.
Schaefer, M. B. 1954. Some aspects of the dynamics of populations important to the management of the commercial marine fisheries. Inter-American Tropical Tuna Commission Bulletin 1(2):26–56.
Schmid, P., and C. Betsch. 2019. Effective strategies for rebutting science denialism in public discussions. Nature and Human Behavior 3:931–939.
Schreiber, M. A., R. Chuenpagdee, and S. Jentoft. 2022. Blue Justice and the co-production of hermeneutical resources for small-scale fisheries. Marine Policy 137:104959. https://doi.org/10.1016/j.marpol.2022.104959.
Shiffman, D. S., S. J. Bittick, M. S. Cashion, S. R. Colla, L. E. Coristine, D. H. Derrick, E. A. Gow, C. C. Macdonald, M. M. O’Ferrall, M. Orobko, R. A. Pollom, J. Provencher, and N. K. Dulvy. 2020. Inaccurate and biased global media coverage underlies public misunderstanding of shark conservation threats and solutions. iScience 23(6):101205. https://doi.org/10.1016/j.isci.2020.101205.
Silver, J. J., D. K. Okamoto, D. Armitage, S. M. Alexander, C. Atleo, J. M. Burt, R. Jones, L. C. Lee, E-K. Muhl, A. K. Salomon, and J. S. Stoll. 2022. Fish, people, and systems of power: understanding and disrupting feedback between colonialism and fisheries science. American Naturalist 200:168–180.
Stern, M. J., and K. J. Coleman. 2015. The multidimensionality of trust: application in collaborative natural resource management. Society and Natural Resources 28:117–132.
Sumaila, U.R., D. Zeller, L. Hood, M.L.D. Palomares, Y. Li, and D. Pauly. 2020. Illicit trade in marine fish catch and its effects on ecosystems and people worldwide. Science Advances 6(9). DOI: 10.1126/sciadv.aaz3801.
Tegner, M. J. 1993. Southern California abalones: Can stocks be rebuilt using marine harvest refugia? Canadian Journal of Fisheries and Aquatic Sciences 50:2010–2018.
Thaler, R., and C. Sunstein. 2008. Nudge: improving decisions about health, wealth, and happiness. Penguin Books, New York.
Tickner, D., J. J. Opperman, R. Abell, M. Acreman, A. H. Arthington, S. E. Bunn, S. J. Cooke, J. Dalton, W. Darwall, G. Edwards, I. Harrison, K. Hughes, T. Jones, D. Leclère, A. J. Lynch, P. Leonard, M. E. McClain, D. Muruven, J. D. Olden, S. J. Ormerod, J. Robinson, R. E. Tharme, M. Thieme, K. Tockner, M. Wright, and L. Young. 2020. Bending the curve of global freshwater biodiversity loss: an emergency recovery plan. BioScience 70(4):330–342.
UNEP-WCWM. 2020. Protected planet report. Available at: https://livereport.protectedplanet.net.
Vandergoot, C. S., M. D. Faust, J. T. Francis, D. W. Einhouse, R. Douin, C. Murray, and R. L. Knight. 2019. Back from the brink: sustainable management of the Lake Erie Walleye fishery. Pages 431–466 in C. C. Krueger, W. W. Taylor, and S. Youn, editors, From catastrophe to recovery: stories of fishery management success, American Fisheries Society, Bethesda, MD.
Walker, P. 2009. Dinosaur DAD and enlightened EDD—engaging people earlier is better. Environmentalist 71:12–13.
Wamukota, A. W., J. E. Cinner, and T. E. McClanahan. 2012. Comanagement of coral reef fisheries: a critical evaluation of the literature. Marine Policy 36:481–488.
Webster, D. G. 2015. Beyond the tragedy in global fisheries. MIT Press, Cambridge, MA.
Willette, D. A., and S. H. Cheng. 2018. Delivering on seafood traceability under the new U.S. import monitoring program. Ambio 47:25–30. https://doi.org/10.1007/s13280-017-0936-4.
Worm, B., C. Elliff, J. G. Fonseca, F. R. Gell, C. Serra-Gonçalves, N. K. Helder, K. Murray, H. Peckham, L. Prelovec, and K. Sink 2021. Making ocean literacy inclusive and accessible. Ethics in Science and Environmental Politics 21:1–9.
Yoder, C. O., E. T. Rankin, V. L. Gordon, L. E. Hersha, and C. E. Boucher. Pages 233–265 in C. C. Krueger, W. W. Taylor, and S. Youn, editors, From catastrophe to recovery: stories of fisheries management success, American Fisheries Society, Bethesda, MD. | textbooks/bio/Ecology/Fish_Fishing_and_Conservation/1.15%3A_Takeaways_for_Successful_Fish_Conservation.txt |
Introduction
There are many reasons to enter into a monitoring program, but the reasons must be well-considered before doing so. Long-term monitoring takes time, money and effort that could be spent in other endeavors such as management, research, and outreach. Monitoring is conducted most often when the resources of concern are of high economic or social value, part of a legally-mandated planning process, the result of a judicial decision, or the result of a crisis. Many times it is a combination of these factors that gives rise to a monitoring program. In addition, monitoring may be conducted as part of a formal research program where long-term trends in an ecologically or socially important response variable are the most important outcome. Also if a population or natural community seems rare or there is the perception by scientists or stakeholders that a decline is evident, then monitoring may be called for to clarify the perception. Most often monitoring programs are designed to help managers and policy makers make more informed decisions. Monitoring allows decisions to be based less on beliefs and more on facts. We may believe that grasshopper sparrows in New England are decreasing in abundance because grasslands are being converted to housing (Figure 1.1). Only after a rigorous, unbiased monitoring program has been in place can we say that yes, indeed, the population seems to be declining (Figure 1.2) and that the decline is associated with the loss of grasslands. However, we cannot ascribe the cause of the decline to grassland loss unless a more rigorous research program is put into place. Monitoring provides the hypothesis for the decline; research is often implemented in a structured before-after control-impact design assesses cause-and-effect relationships.
Monitoring Resources of High Value
Typically we think of monitoring as something that is done because we value a resource and we do not want to lose it, or we wish to maximize it. For economic goods and services, we often will monitor so that we can maximize profit margins while minimizing adverse effects. But economics are not the only values placed on resources. Monitoring the haze present over the Grand Canyon is in response to aesthetic values as well as human health concerns. Ottke et al. (2000) described the importance of considering cultural values in natural resources monitoring and provided examples from 13 case studies around the world. As an example, rarity, in of itself, is often used to initiate a monitoring program. Rare species, populations, or gene pools may be valued sufficiently to initiate and maintain a monitoring program to ensure that these rare organisms persist. Regardless of the motivation for initiating a monitoring program, all require a monitoring approach that allows unbiased sampling, assessment of trends over time, the potential for extrapolation to unsampled areas, and (in some cases) comparisons between areas managed in different ways.
Economic Value
Monitoring the antler size of white-tailed deer killed on a property leased for hunting, crop loss from Canada goose foraging, or monitoring tree growth on a timber industry landholding all represent examples of specific resources that the owner or manager may wish to manage for economic gain. Economic value commonly drives monitoring programs at a variety of scales. The U.S. Forest Service Forest Inventory and Analysis program is a good example of a well-structured national monitoring program that was initiated to assess the timber value, primarily economic, on non-federal lands in the US (Sheffield et al. 1985). Over time, however, the program evolved into a multi-resource monitoring program and has since been used to assess other natural resource values on non-federal forest lands (McComb et al. 1986). Similarly, but on a local scale, farmers may monitor the effects of birds on corn seed depredation, or deer on soybean production. Communities in Africa are directly involved in monitoring programs to assess the potential for crop damage and then work with authorities to find ways of minimizing the adverse effects of having African elephants in their fields (Songorwa 1999).
Social, Cultural, and Educational Value
Monitoring systems that provide the basis for resource management decisions are often initiated and maintained to support resources held in the public trust. Yet not all resources held in the public trust are monitored. While the selection of resources that are monitored is partially driven by economics, the perceptions, concerns, and cultural values of society also play a role. Programs such as the Breeding Bird Survey Program (Sauer et al. 2007), the North American Amphibian Monitoring Program run by the USGS, the Monitoring Avian Productivity and Survivorship (MAPS) Program created by The Institute for Bird Populations in 1989, and the EPA’s program of monitoring and assessing water quality all represent organized, large-scale efforts to acquire data to make more informed resource management decisions. Each has indicators chosen due to a variety of social, cultural, and economic values.
Programs such as these that are supported by federal agencies also have a long-standing reputation for monitoring various biophysical components of ecosystems. The Long Term Ecological Research (LTER) program maintains sites throughout the US that provide long-term information on ecosystem structure and function. More recently the National Ecological Observatory Network (NEON) was initiated as a continental-wide program to help understand the impacts of climate change, land-use change, and invasive species on ecosystems and ecosystem services. The importance of these data may not be apparent for years or decades, but the educational benefit that accrues over time may be invaluable. Consider the impact of having monitored carbon dioxide in the atmosphere, ice cover, and plant phenology (the timing of flowering and fruiting) that collectively provided evidence for climate change and insights into likely changes in biota.
Economic Accountability
When push comes to shove, however, economics is almost always the horse that pulls the cart in natural resource programs. When an instructor wants to monitor the progress of a student in learning material she gives a test, or asks for a paper or report. When members of Congress on an Appropriations Committees allocate millions of dollars to the US Fish and Wildlife Service to ensure protection of endangered species, they want to know that the money is being spent wisely and that the actions being taken are effective. Indeed, the General Accounting Office (GAO) has as its primary responsibility monitoring of appropriations to ensure that the taxpayers’ dollars are being spent wisely by our federal agencies (GAO 2007). In both these cases, whether a teacher or an appropriations committee, the supervisory power is asking for a sense of accountability that can only be ascertained through careful monitoring.
In a 2007 report developed jointly by the GAO and the National Academy of Sciences, they state, “One of the greatest challenges facing the United States in the 21st century is sustaining our natural resources and safeguarding our environmental assets for future generations while promoting economic growth and maintaining our quality of life”, if that is even possible (Czech 2006). “To manage natural resources effectively and efficiently, policymakers need information and methods to analyze the dynamic interplay between the economy and the environment. Enhancing the information used to make sound decisions can be facilitated by developing national environmental assessments. These assessments provide a framework for organizing information on the status, use, and value of natural resources and environmental assets, as well as on expenditures on environmental protection and resource management.” (GAO 2007). Forums such as this one (GAO 2007) provide a strategic and economic framework for the integration of monitoring efforts that span agencies and resources. Whether it is a student taking a quiz or a researcher managing a multi-million dollar monitoring program, the goal is to find the answer to a simple question: “How are we doing?”
So who cares about monitoring and the millions spent on it? You should. This is because public funds often drive monitoring programs and resources held in the public trust are frequently the targets being monitored! Those who represent you in Congress and in State legislatures, local planning boards, and NGO Boards of Directors should also care about monitoring. Government agencies and NGOs have issued “State of the Environment” reports for countries such as the U.S., Australia, and Canada (Beeton 2006, Environment Canada 1996, Heinz Center 2002). A compilation of over 50 such reports has been assembled by the National Council on Science, Policy and the Environment. These reports are based on whatever monitoring data are available to directly report changes over time in important resources or indicators of those resources. Similar reports, although less common, are also beginning to emerge from scientists working in developing nations (Guarderas et al. 2008).
In addition to these broad ‘State of the Environment’ reports, policy-makers and elected officials often demand that agencies provide periodic updates on the effectiveness of their work. Is the US taxpayer getting the “Biggest bang for the buck?” “Is our management effective?” “Why should we continue to pay for collecting data year after year?” According to managers and regulators employed by state and federal agencies, NGOs, and industries, accountability has become a key component of their work. Industry often is most concerned about the economic efficiency of certain management actions. If management actions are not as effective as planned and the monitoring influences the bottom line (it will), then industry will demand a change to more efficient and effective management and monitoring. A timber company may wish to ensure that the goals of leaving a riparian buffer strip are met to the extent that it was worth foregoing the profits, or an NGO may wish to ensure that their limited funds are being effective in restoring a prairie ecosystem. Hence, from purely a practical standpoint, monitoring questions are often of utmost importance to a manager because they are designed to assess how far her expenses go toward meeting her goals. At the end of the day, the results of such assessments will determine whether or not a management action is viable.
But monitoring is not free. It costs money to do it correctly. Hence, monitoring efforts are also driven by the money available to spend on monitoring. Indeed, whether we like it or not, budgets determine our options in resource management, and funds for monitoring are always among the first parts of the budget to be critically reviewed. The system tends to encourage short sightedness: in many budget planning processes it is easier to acquire funding for new innovative projects than to continue ongoing efforts. Getting funding to build a new visitor center at a refuge may be easier than maintaining it. Getting a monitoring program initiated may be easier than finding the funding to continue it for a long enough period of time to ensure that the results are used. The implications associated with continuing a commitment to a monitoring program must be accounted for in the design of monitoring programs.
Monitoring as a Part of Resource Planning
Monitoring is also a key part of the planning process used by federal agencies, many NGOs, and some industries. People make plans. You have plans for the weekend, for your next vacation, or for your retirement. Plans are based on assumptions, some of which may turn out to not be correct, and despite the best plans, there are often uncertainties that arise to disrupt plans. If you get a flat tire on your car then your plans change for the weekend. Monitoring the function of your car by regularly checking the tire pressure may have prevented that flat. A US Fish and Wildlife Service Refuge may have a refuge management plan, but if an invasive species should establish itself unexpectedly, then the plan may have to change. Monitoring the changes in the primary structures and functions of the Refuge (plant communities, distributions of species, erosion, sedimentation, rates of change in species dominance) may allow quick response and rapid removal of the invasive that may not be possible if one must wait for the next planning cycle. Hence monitoring is almost always included as a key component of natural resource (and other) plans.
Certainly there are specific guidelines regarding monitoring resources on federal landholdings such as USFWS National Wildlife Refuges (Schroeder 2006). Yet the specifics of the monitoring goals, strategies and interpretation are often left somewhat vague in Comprehensive Conservation Plans (CCPs), National Forest Management Plans, and many others. Clearly there are exceptions to this (see the Northwest Forest Plan example below), but quite often the development of a detailed monitoring plan comes after the management plan has been developed and approved and not developed as an integral component of the management plan. If we truly do care if we are being effective in our management and if we are spending money wisely to achieve goals then the monitoring plan should be an integral component of a management plan (Figure 1.3).
From the standpoint of achieving planning goals that relate to wildlife species and their habitats, a properly designed monitoring effort allows managers and biologists to understand the long-term dependency of selected species on various habitat elements. Habitat is defined as the set of resources that support a viable population over space and through time (McComb 2007). Identifying those key resources, or reliable indicators of them, can provide information on how a species may respond to changes. The challenge when developing a monitoring plan is to assess the impacts of the dynamic nature of resource availability on a species. In other words, we must assess if changes in occurrence, abundance, or fitness in a population are independent from or related to changes in the availability of resources assumed to contribute to the species’ habitat (Cody 1985).
Even with timely planning, implementation of any natural resources plan is done with some uncertainty that the actions will achieve the desired results. Nothing in life is certain (except death!). But by incorporating uncertainty into a project we can reduce many of the risks associated with not knowing. Managers should expect to change plans following implementation based on measurements taken to see if the implemented plan is meeting their needs. If not, then mid-course corrections will be necessary. Many natural resource management organizations in North America use some form of adaptive management as a way of anticipating changes to plans and continually improving plans (Walters 1986) (Figure 1.4).
Monitoring in Response to a Crisis
Monitoring to address a perceived crisis has been repeated with many species: northern spotted owls, red-cockaded woodpeckers, and nearly every other species that have been listed as threatened or endangered in the US under the Endangered Species Act or similar state legislation. Although many of these monitoring programs were developed during a period of social and ecological turmoil, many are also remarkably well structured because the stakes are so high. For instance in the case of the northern spotted owl, the butting heads of high economic stakes and the palpable risk of loss of a species culminated in a crisis that spawned one of the most comprehensive and costly wildlife monitoring programs in US history: the monitoring outcome from the Northwest Forest Plan (NWFP). The NWFP was designed to fulfill the mandate of the Endangered Species Act by enabling recovery of the federally endangered northern spotted owls and also addressed other species associated with late successional forests over 10 million ha of federal forest land in the Pacific Northwest of the US. In his Record of Decision regarding the plan, Judge Dwyer emphasized the importance of effectiveness monitoring to the NFWP, and monitoring has been an integral part of it since its implementation; “Monitoring is central to the [Plan’s] validity. If it is not funded, or done for any reason, the plan will have to be reconsidered.” (USDA, USDI 1994; Dwyer 1994).
One component of NWFP effectiveness monitoring was a plan for the northern spotted owl. The northern spotted owl monitoring program is one of the most intensive avian population monitoring efforts in North America. The purpose of the plan is to record data that reveals trends in spotted owl populations and habitat to assess the success of the NWFP at reversing the population decline for this species (Lint 2005). To this end, the specific objectives of the monitoring program are to (1) assess changes in population trend and demographic performance of spotted owls on federally administered forest land within the range of the owl, and (2) assess changes in the amount and distribution of nesting, roosting, and foraging habitat (owl habitat) and dispersal habitat for spotted owls on federally administered forest land (Lint 2005).
Population monitoring for northern spotted owls encompasses 11 demographic study areas from northern Washington to northern California. Three parameters are estimated from the data to assess trends: Survival, fecundity and lambda (population rate of change). As you can see from Figure 1.5 the trends in population change varied quite widely among the demographic study areas, lending support for use of these study areas as strata within the monitoring framework.
Populations seem to be declining on the Wenatchee (WEN) site in the eastern Washington Cascades, but remaining somewhat stable on the Tyee site in the Oregon Coastal Ranges (Figure 1.6). In a case such as this, with such wide differences in trends, where does that leave managers regarding use of these data? The magnitude of population declines on the Wenatchee study site raises significant concerns and the first reaction is that the plan has failed.
But the Tyee data indicate that the plan is succeeding. So which is it? Lint (2005) concluded that it is too early to say if the plan has failed or succeeded because restoration of habitat for the species takes longer than the 10 years that monitoring had occurred. But monitoring also revealed other stressors on the population such as competition with barred owls and the potential for increased mortality from West Nile virus, further complicating the interpretation of the monitoring data. Indeed, even with the most rigorous design, uncertainty is inevitable.
Given the importance of economic considerations, the question begs to be asked: Was the monitoring worth over \$2 million spent per year (Lint 2001)? Consider the price that taxpayers would pay for not monitoring. First, we could easily lose a species due to plan failure or from other more contemporary stressors. Second, the NWFP would likely be challenged in court again, costing the taxpayers a considerable amount in legal fees. Third, we learned much more about the species and drivers of populations by having collected these data so that the results can (and do) influence how managers make decisions. We also have research-quality data to address future issues with this species and others like it. But the answer to the question, “Was the monitoring worth it…” is, clearly, “It depends”. It depends on who is doing the evaluating. Some segments of society will answer “Of course it was worth it”. Others will say that “It had to be done legally”. Still others would say that, “The money would have been better spent on addressing the needs of the displaced forest workers.” All are valid points. And the data collected provide each segment of society information with which to base their arguments. Thus, although the cost is the deciding factor, societal values can never be ignored; it is after all society who grants us a social license to manage animals and their habitats.
Monitoring in Response to Legal Challenges
Effectiveness monitoring was strongly suggested by Judge Dwyer in his Record of Decision on the implementation of the NWFP over 10 million ha of federal lands in the Pacific Northwest. His decision emphasized the importance of monitoring as a component of this multi-agency plan and influenced plan design. But legal decisions can influence not only the structure of a plan, but also influence how and sometimes determine if the plan and all of its principal components, including monitoring, are implemented.
If a resource is valued highly enough, litigation may be enacted that results in judicial decisions that influence the likelihood that monitoring will be conducted. For instance, there are times when monitoring is an integral part of a written plan, but agencies and managers do not have the funding to initiate or maintain a monitoring program. Concerned citizens may file a lawsuit that results in the re-appropriation of public funds to provide for monitoring. A slightly different example of this involves the McLean Game Refuge, a 1700-ha private tract located in north-central Connecticut in the Towns of Granby and Simsbury. The Refuge was established in 1932 by bequest of former Governor and Senator of Connecticut, George McLean. Decisions about Refuge use, maintenance, and management are made by a manager under the oversight of a Board of Trustees. A proposal to use partial cutting approaches (thinning, group selection, and shelterwood methods) in the McLean Game Refuge in 2001 met with significant opposition by local residents. The decision to manage the forest was based on suggestions from natural resources professionals that active management could diversify forest structure and composition and hence could lead to more diverse animal communities. Following a public meeting and a series of hearings in civil court, this opposition culminated in a judicial ruling that allowed the Refuge Manager to proceed with the harvest. However, the judge also encouraged the manager to monitor the changes in animal species composition and habitat so that any future harvests could be informed by the information gained from the monitoring effort. The judicial decision not only stipulated that monitoring ought to be carried out but also influenced how managers monitor animals and habitat. Monitoring of bird communities and habitat structure and composition was initiated prior to the timber harvest and again after the harvests. Monitoring indicated that following one growing season after harvests, detections of seven species were higher in the thinned stands while detections of wood thrushes were higher in uncut controls. Was the cutting the correct thing to do? That depends on who is asking the question, but now the debate can be more informed than it was in 2001.
Adaptive Management
Although adaptive management has already been introduced above, it deserves to be addressed at greater length because it is central to successful monitoring and management practices. Adaptive management is a process to find better ways of meeting natural resource management goals by treating management as a hypothesis (Figure 1.4). The results of the process also identify gaps in our understanding of ecosystem responses to management activities. The adaptive management process incorporates learning into the management planning process, and the data collected from the monitoring conducted within this framework provide feedback about the effectiveness of preferred or alternative management practices. The information gained can help to reduce the uncertainty associated with ecosystem and human system responses to management. Adaptive management has been classified as both active and passive (Walters and Holling 1990).
Passive adaptive management is a process where the ‘best’ management option and associated actions are identified, implemented and monitored. The monitoring may or may not include unmanaged reference areas as points of comparison to the managed areas. The changes observed over time in the managed and reference areas are documented and the information is used to alter future plans. Hence the manager learns by managing and monitoring, but the information that is gained from the process is limited, especially if reference areas are not used. Without reference areas we do not know if changes over time are due to management or some other exogenous factors.
Active adaptive management treats the process of management much more like a scientific experiment than passive adaptive management. Under active adaptive management, management approaches are treated as hypotheses to be tested. The hypotheses are developed specifically to identify knowledge gaps and management actions are designed to fill those gaps. Typically, hypotheses are developed based on modeling the responses of the system to management (e.g. using forest growth models, or landscape dynamics models). Management is then conducted and key states and processes are monitored to see if the system responded as it was predicted. Reference areas are also monitored and the data from these areas are used as controls to compare responses of ecosystems and human systems to management. By collecting monitoring data in a more structured hypothesis-testing framework, system responses can be quantified and used to identify probabilities associated with achieving desired outcomes in the future. Whereas passive adaptive management is somewhat reactive in approach (reacting to monitoring data), active adaptive management is proactive and follows a formal experimental design.
Adaptive management generally consists of six major steps (Figure 1.4):
• Set goals (define the desired future condition)
• Develop a plan to meet the goals based on best current information
• Implement the plan
• Monitor the responses of key states and processes to the plan
• Analyze the monitoring data
• Adjust the plan based on results from analysis the monitoring data.
Before anything is implemented or monitored, the problem must be assessed both inside and outside the organization. Public involvement in the process from the very beginning is key to identification of points of concern and uncertainty. With information in hand from a series of listening sessions, the cycle can more formally begin. Important components include designing a plan considered to be the preferred or best plan among several alternative plans, identifying reference areas to use as points of comparison, and implementing and monitoring the plan to learn from the management actions.
An Example of Monitoring and Use of Adaptive Management
When we discussed the 1993 NWFP above, the economic and social impacts of regulating logging to conserve or foster late-successional habitat were not adequately addressed. The efforts of the NWFP’s authors to end the stalemate between segments of the population who supported continued timber management on federal lands, and those who saw federal lands as refuges for late-successional and old-growth species, particularly the northern spotted owl, are a key component of the story.
Indeed, the objectives of the NWFP as a whole are threefold:
1. Protecting and enhancing habitat for mature and old-growth forests and related species.
2. Restoring and maintaining the ecological integrity of watersheds and aquatic ecosystems.
3. Producing a predictable level of timber sales, special forest products, livestock grazing, minerals and recreational opportunities, as well as maintaining the stability of rural communities and economies.
Using an adaptive management approach, a monitoring program was established to better understand the extent to which management attains these objectives and to more fully grasp the interplay among them. The monitoring program relies on both internal and external sources of data. For instance, internal data were collected directly by the Regional Monitoring Team or by cooperators funded through the monitoring program. External data were collected by programs such as the U.S. Forest Service’s Forest Inventory and Analysis Program. Data include information on populations and (occasionally) fitness of key species as well as information on the changes in area of old forests, socioeconomic conditions in the region, and watershed condition (Haynes et al. 2006). Recently 10-year results were released and researchers can now make the first of these assessments (Haynes et al. 2006). This wealth of information is readily available to managers and the public and it helps adapt past and inform new decisions made on both public and adjacent private lands in the Pacific Northwest (Spies et al. 2007)
Summary
Monitoring is done for a variety of reasons, but at its core, monitoring is done to provide information and make more informed decisions. In many instances, monitoring is done either as a legal requirement or in response to a crisis. As species become listed as threatened or endangered, as economically important species (e.g., deer) decline in number, or pest species that jeopardize human health increase in number, then immediate action and monitoring are often called for by managers and the public. If challenged in court then a judge can have considerable influence over the establishment and continuation of a monitoring program.
In other cases a manager, landowner or stakeholder may simply realize that knowing how a resource is changing over time can mean that management may be more effective in the future. Foresters certainly take this approach by using continuous forest inventory, but wildlife managers also have recognized the importance of long-term monitoring data. Programs addressing trends in breeding birds, amphibians, carbon dioxide, EPA’s program of monitoring and assessing water quality, and the NEON program all represent organized large scale efforts to acquire data to more fully understand system responses to stressors and hence make more informed resource management decisions. With all monitoring programs, however, funding is important to consider. Funding can be tenuous, especially when monitoring is long-term, and the individuals, agencies, or organizations responsible for the monitoring efforts often must spend considerable effort explaining the value of their monitoring programs to ensure that funding continues.
Whatever the impetus is for establishing a monitoring program, the objectives must be clear and specific, the questions treated as hypotheses and the data collected in a rigorous and unbiased manner to ensure that they are able to inform future decisions. The true importance of these steps will become clear after a plan is implemented and difficult questions arise, including when or if to make changes in the monitoring protocol, when monitoring should end, and at what point the data initiate a change in management actions. All of these decisions are best made by managers and stakeholders working together. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.01%3A_Introduction.txt |
Ecological monitoring addresses a diversity of questions, interests and organizational objectives, but all monitoring programs face similar challenges and obstacles. These can include, but are not limited to, biases in sampling design, logistical constraints, funding limitations, and the inevitable complexities associated with data analysis. There is much to learn from how past monitoring programs have successfully overcome these common challenges, and this chapter details the development and challenges of several large-scale monitoring programs. The following programs are not meant as an exhaustive review, but rather an example of current monitoring strategies and initiatives focused on animal or plant populations.
Millions of dollars are spent every year on monitoring various species and communities at scales ranging from local projects to global initiatives. The 2003 United Nations Environmental Program list includes 65 major monitoring and research programs throughout the world involved in efforts related to climate change, pollutants, wetlands, air quality, and water quality (to name a few) (Spellerberg 2005). Likewise, across the United States, there is a diversity of monitoring programs with varying goals, objectives and institutional mandates. Some federal programs, such as the Biomonitoring of Environmental Status and Trends (BEST) program are involved in monitoring the effects of environmental pollutants on wildlife populations occupying National Wildlife Refuges. Others, such as the USGS Breeding Bird Survey (BBS), have decades worth of data that can be used to identify long-term trends in bird species at both regional and national scales, but does not relate these data to habitat elements per se, although numerous investigators have taken this step (e.g., Flather and Sauer 1996, Boulinier et al. 1998a, Cam et al. 2000, Boulinier et al. 2001, Donovan and Flather 2002). In addition to these federal efforts, non-government organizations, such as the Wildlife Conservation Society, have relied heavily on national and international monitoring efforts to provide a basis for understanding changes in the resources they are most interested in protecting. Finally, citizen-based monitoring programs that result in numerous checklist monitoring programs and biological atlases have been conducted throughout the world. Given the legal mandates associated with environmental compliance and accountability, monitoring efforts will continue to be the basis for making decisions about how and where to invest resources to achieve societal goals and agency mandates.
Federal Monitoring Programs
The Biomonitoring of Environmental Status and Trends (BEST)
The importance of monitoring animal populations to detect the effects of environmental contaminants has been a major environmental concern since the 1960’s (Johnson et al. 1967). One such example occurred at the Kesterson National Wildlife Refuge during the 1980’s, where large population declines and deformities in fish were linked to high selenium levels in agricultural drainwater used to irrigate wetlands on and off the Refuge (Marshal 1986, Harris 1991). Selenium levels also were associated with alarming deformities in waterfowl hatchlings including twisted wings, swollen heads and missing eyes. Environmental catastrophes like this increased the pressure on the US Fish and Wildlife Service (FWS) to expand monitoring programs to assess existing and anticipate future effects of environmental contaminants on fish and wildlife populations and their habitats within National Wildlife Refuges (Figure 2.1). In response to this need, the Biomonitoring of Environmental Status and Trends (BEST) Program was initiated to develop a comprehensive approach for monitoring the Nation’s protected areas at multiple levels of biological complexity ranging from organisms to populations to communities. The overall goal of the program is to provide scientific information on the impacts of environmental contaminants for natural resource management and conservation planning. The consequences of environmental pollutants and contaminants are complex and may take years, if not decades, to manifest themselves in animal and plant populations. Therefore, clearly defined goals and objectives are a necessary first step for monitoring the ecological effects of environmental pollution.
What is the goal of the monitoring program?
BEST has three major goals: (1) measure and assess the effects of contaminants on selected species and habitats, (2) conduct research and activities directed at providing innovative biomonitoring methods and tools, and (3) deliver effective and efficient tools for assessing contaminant threats to species and habitats. The first goal of the BEST Project focuses on the occurrence, severity, and changes in environmental contaminants on wildlife populations. The primary audience for this information is resource managers attempting to identify regions of the country where contaminant threats to biological resources warrant further investigation. Unfortunately, the tools necessary for identifying biocontaminants and tracking their effects in wildlife populations is an inexact science, and so the second goal focuses on evaluating and testing monitoring methods within an adaptive framework. There is a general emphasis on monitoring methods that can be linked to demographic parameters (such as reproductive rates and survival). These types of methods are the most difficult and laborious of population parameters to estimate, and so BEST is continually investing in developing new methods of collecting the necessary data. The third goal focuses on exploiting information technologies, such as internet-based data gathering methods, as distributing tools that facilitate the communication of monitoring principles, techniques, and results to others.
Where and how to monitor?
Given that the goals of BEST are so wide-ranging, the early stages of the program encountered many obstacles common to incipient monitoring efforts. Challenges included selecting unbiased areas for monitoring, studying contaminant levels at different levels of biological organization, and choosing what exactly to measure. Ironically, one of the program’s initial objectives of identifying existing or potential contaminant-related problems led to a biased selection of areas aimed at maximizing the potential for identifying contaminants and their ecological effects. That is, they were looking for sites with pre-existing problems of contamination and so had no way of comparing changes in wildlife populations that could be effected by environmental contamination with areas that were not contaminated (i.e., control sites). Because of the inferential limitations of selecting only highly affected sites, a second network of lands was required to produce unbiased estimates. The first network of sites is used to describe the exposure and response of selected species to contaminants and measure the changes in exposure and response over time. A second set of networks describes contaminants and their effects in important habitats used by species of concern. This second habitat-based network would not only describe the distribution of contaminants and their effects, but also describe indirect effects (e.g. reduction of prey items) and changes in habitat quality over time. Therefore, BEST adopted a monitoring approach that relies on multiple lines of evidence from different regions for identifying contaminant exposure at multiple ecosystem levels.
What to monitor?
After the identification of a site suffering environmental contamination, the larger and more difficult questions of what to measure and the techniques to use still remained. Researchers working on BEST decided to employ a 2-tiered monitoring approach that includes a variety of methods for assessing environmental contamination including biomarkers, toxicity tests and bioassays, community health indices, and residue analyses. The first tier includes methods that are applicable to a wide variety of habitats and are readily available and inexpensive. The second tier includes more specialized (and also more expensive) methods than traditional Tier 1 methods. These methods provide greater insight for specific situations and would be more useful in determining cause-and-effect relationships for a selected species or habitat.
As an example of this general approach, and one of BEST’s most successful programs, is the Large River Monitoring Network (LRMN) which measures and assesses the effects of contaminants on resident fish in rivers throughout United States. The LRMN serves as a searchable online database (http://www.cerc.usgs.gov/data/best/search/ ) where one can access data on fish health in multiple river basins by using a suite of organismal and suborganismal “endpoints”. These endpoints are meant to monitor and assess the effects of environmental contaminants in fish populations and include variables such as age, length, weight, lesions, and a number of other biological markers. As a national monitoring program, BEST-LRMN is unique in that it utilizes these biomarkers to evaluate persistent chemicals in the environment and to detect changes before population effects may be evident. The online relational database allows anyone to access information organized by basin (e.g., Colorado Basin), species (e.g., brown trout), and gender. Since the initial application of the program in 1995, a considerable knowledge-base has been developed regarding the characteristics and advantages for assessing the impacts of environmental contaminants on fish populations throughout the country.
The North American Breeding Bird Survey (BBS)
Similar to the BEST Program, environmental contaminants spurred the need to monitor bird populations throughout the United States. Rachel Carson’s book Silent Spring brought national attention to the potential effects of Dichloro-Diphenyl-Trichloroethane (DDT) on bird populations. Responding to the potential of pesticide effects on avian populations, Chandler Robbins and colleagues at the Patuxent Wildlife Research Center developed the North American Breeding Bird Survey (BBS) with the goal of monitoring bird populations over large geographic areas. Beginning in 1966, this pioneering work has resulted in the creation of one of the world’s most successful long-term, large-scale, international avian monitoring programs (Sauer et al. 2005, Thogmartin et al. 2006, U.S. Geological Survey 2007).
What is the goal of the monitoring program?
The mission of the BBS is to provide scientifically credible measures of the status and trends of North American bird populations at continental and regional scales to inform biologically sound conservation and management actions (U.S. Geological Survey 2007). Although this was an ambitious goal, clearly stating the objective early on has helped many to successfully use these data for many purposes. For example, BBS data have been instrumental in the development of methods to estimate population trends from survey data (Link and Sauer 1997b, a, 1998; Sauer et al. 2003; Alpizar-Jara et al. 2004; Sauer et al. 2004), quantifying the effects of habitat loss and fragmentation (Boulinier et al. 1998a, 2001), and studying community ecology at large geographic scales (Flather and Sauer 1996, Cam et al. 2000, La Sorte and McKinney 2007). A literature review in 2002 found that more than 270 scientific publications have relied heavily, if not entirely, on BBS data, making this one of most widely used and applied monitoring programs in the world.
Where and how to monitor?
The founders of this program had a monumental task in addressing some of the key questions in monitoring program design. How can a single program effectively describe and monitor over 420 bird species throughout the continental U.S. and Canada? Every square meter of a national landscape cannot be monitored, so which spots should be surveyed? How can it be done in a way that allows the data to be scaled up (or down)? The protocol they developed stipulates that each year during June, the height of the avian breeding season in the region, BBS participants skilled in avian identification collect bird population data along roadside survey routes. Each survey route is 40 km (24.5 miles) long with stops at 1-km (0.5-mile) intervals. At each stop, a 3-minute point count is conducted. During the count, every bird heard or seen within a 0.5-km (0.25-mile) radius is recorded. Surveys start one-half hour before local sunrise and take about 5 hours to complete. Over 4,100 survey routes are located across the continental U.S. and Canada. Predictably, this amount of work results in a vast and complicated database of information on bird populations.
What to monitor?
Although the decision of what exactly to monitor was largely determined by the stated objectives of the plan, researchers still faced a number of obstacles to collecting these data and providing one of the most important products of the BBS: annual estimates of population trends and relative bird abundances at various geographic scales for more than 420 bird species. For example, not all bird species are effectively sampled using road-side surveys. Birds vary in their detectability and some species avoid roads all together; this had to be accounted for. Much thought and analysis, however, has been devoted to assuring data quality and dealing with the associated biases of road-side sampling and this is an ongoing area of research (Barker et al. 1993; Sauer et al. 1994; Kendall et al. 1996; Link and Sauer 1997b, a; Boulinier et al. 1998b; Link and Sauer 1998; Hines et al. 1999; Pollock et al. 2002; Alpizar-Jara et al. 2004; Sauer et al. 2004; Thogmartin et al. 2006; Link and Sauer 2007). In addition, the program attempts to randomly distribute routes in order to sample habitat types that are representative of the entire region. Other requirements such as consistent methodology and observer expertise, visiting the same stops each year, and conducting surveys under suitable weather conditions are necessary to produce comparable data over time and between geographic regions. A large sample size (number of routes) is needed to average local variations and reduce the effects of sampling error. Variation in counts can be associated with sampling techniques as well as the true (i.e., natural) variation in population trends. Indeed, the survey produces an index of relative abundance rather than a complete count of breeding bird populations, and assumes that fluctuations in these indices of abundance are representative of the population as a whole. Another issue, quite separate from variation, is that the precision of abundance estimates will change with sample size. The density of BBS routes varies considerably across the continent, reflecting regional densities of skilled birders who tend to be associated with urbanization patterns. Consequently, abundance estimates in regions with fewer routes are less precise than estimates in regions with a large number of routes. The greatest densities of surveys are in the New England and Mid-Atlantic states, whereas densities are lower elsewhere in the US.
Despite these complicated issues of sampling design and analysis (indeed, selecting what to monitoring often entails much more than simply choosing a species!), the efforts of BBS researchers has resulted in a valuable source of information on bird population trends and an excellent source of ideas and lessons for the design of other broad-scale monitoring programs.
For instance, BBS data can be used to produce continental-scale maps of relative abundance. When viewed at continental or regional scales, these maps provide a reasonable indication of the relative abundances of species that are well sampled by the BBS (Figure 2.2). Analyzing population change on survey routes is probably the most effective use of BBS data, but these data do not provide an explanation for the causes of population trends. Population trend data have been used, however, to associate population declines with environmental effects such as habitat loss and fragmentation (Askins 1993; Boulinier et al. 1998b, 2001; Donovan and Flather 2002). To evaluate population changes over time, BBS indices from individual routes are combined to obtain regional and continental estimates of trends. Few species, however, have consistent trends across their entire ranges, so spatial patterns in population trends are of particular interest to scientists and managers attempting to identify “hot spots” of regional declines. Route-specific trends can be smoothed to produce trend maps that allow for the identification of regions of increase and decline (Figure 2.3).
Although trends at the species level will always be a basic use of BBS data analyses, combining species into groups with similar life-history traits, known as guilds, provides additional insight into patterns of population trends (Askins 1993, Sauer et al. 1996, Hines et al. 1999). The concept of grouping species based on certain life history characteristics (e.g., breeding habitat, migratory behavior, etc.) can be useful for identifying widespread environmental effects since individual species often differ widely in their response to environmental change. Consistent trends within an entire guild may be indicative of overall changes in an environmental resource (e.g., declining forest birds due to the loss of forests to development).
Environmental Monitoring and Assessment Program (EMAP)
National monitoring programs all share the common challenge of developing a monitoring framework that can scientifically determine and track the condition of a natural resource distributed over thousands of kilometers. Sometimes this need to monitor a natural resource is a legal mandate for a federal or state agency. As an example, under the Clean Water Act the Environmental Protection Agency (EPA) has statutory responsibilities to monitor and assess inland surface waters and estuaries. To achieve this goal, the Environmental Monitoring and Assessment Program (EMAP) was created to develop the science needed for a statistical monitoring framework to determine the condition, and to detect trends in condition, both at the level of individual States as well as for all the nation’s aquatic ecosystems (McDonald et al. 2002). Given its legal responsibility and need to produce legally defensible results, EMAP emphasizes a sampling design guided by both statistical and scientific objectives.
What is the goal of the monitoring?
The primary goal of EMAP is clear and was determined legislatively: to develop a sampling design that provides an unbiased, representative monitoring of an aquatic resource with a known level of confidence. The necessarily general nature of the objective informed a number of other steps in designing the monitoring program and outlined several key challenges. The need to be applicable across the landscape mandated that EMAP’s sampling design rely on a multi-scaled approach of collecting samples with State-based partners and aggregating those local data into broader state, regional, and national assessments. This approach of “scaling up” data from various locales requires EMAP’s research goals to include (1) establishing the statistical variability of EMAP indicators when used in aquatic ecosystems in diverse ecological areas of the country, (2) establishing the sensitivity of these indicators to change and trend detection, and (3) developing indicators and designs that will allow the additional monitoring of high-priority aquatic resources (e.g., Great Rivers, wetlands). The key challenge in this monitoring strategy, and one that is shared with many other national assessments, is how to draw a representative sample from a small number of sites to provide an unbiased estimate of ecological condition over a larger geographic region.
Where and how to monitor?
Choosing sites and methods that adequately addressed the key challenge was not easy. EMAP researchers have spent considerable time and effort in developing a probability-based sampling design to estimate the condition of an aquatic resource over large geographic areas. Probability-based sampling designs have a number of requirements including a clearly defined population, a process by which every element in the population has the opportunity to be sampled with a known probability, and a method by which that sampling can be conducted in a random fashion (Cochran 1977). As is the case with any monitoring project covering a larger geographic region, including the BBS described earlier, samples should be distributed throughout the study area to be maximally representative. EMAP’s design accomplishes this by taking samples at regular intervals from a random start (a systematic random design). To achieve this, EMAP uses hexagonal-shaped grids to add systematic sampling points across a study region (Figure 2.4) (White et al. 1991). The grid is positioned randomly on the map of the target area, and sample locations from within each hexagonal grid cell are selected randomly. Why is this necessary? In short, the use of a sampling grid ensures an unbiased spatial separation of randomly selected sampling units (systematic random sample). Also, the grid allows for the potential of dividing the entire target population into any number of sub-populations (or strata) of interest. Subsequent random sampling within these strata allows statistical inferences to be made about each sub-population. As an example, stratified sampling is often used in a regional stream survey to enhance sampling effort in a watershed of special interest so that its condition can be compared with the larger regional area.
What to monitor?
Once the sampling design was established, the next question to address was a familiar one: what exactly is to be measured? Like BEST’s efforts of monitoring environmental pollutants, an adequate response consisted of more than simply electing one indicator; there are many definitions of an “aquatic resource” that all have unique characteristics. At the coarsest level, EMAP addressed this by dividing aquatic resources into different water body or system types, such as lakes, streams, estuaries and wetlands. Subsequently, they use a second level of strata, ecoregions, to capture regional differences in water bodies. The lowest level of strata in the EMAP design distinguishes among different “habitat types” within an aquatic resource in a specific geographic region. For example, portions of estuaries with mud-silt substrate will have much different ecological characteristics than portions of estuaries with sandy substrates. It is within this lowest stratum that sampling and monitoring is conducted.
EMAP’s sampling design takes one of two very different routes depending on whether the aquatic ecosystem to be sampled is discrete or extensive (McDonald et al. 2002). A discrete aquatic system consists of distinct natural units, such as lakes. Population inferences for a discrete resource are based on numbers of sampling units that possess a measured property (e.g., 10% of the lakes are acidic). For discrete resources, EMAP often uses an intensification of the sampling grid. In some cases where the sampling units are a large enough area, the grid can be used directly by selecting those units in which one or more grid points fall (e.g., estuaries in a state). With this method, the probability that a unit gets into the sample (its inclusion probability) is proportional to the unit’s area (e.g., larger lakes have a higher probability of being sampled). The inferences linking sampling data to the entire population is then in terms of area. Alternatively, a unit of a discrete resource can be treated as a point in space. For example, the center point of lakes could be used. This method of sampling is appropriate for inference in terms of numbers of units in a particular condition (e.g., 7% of Northeastern lakes are chronically acidic).
Extensive resources, on the other hand, extend over large regions in a more or less continuous and connected fashion (e.g., rivers), and do not have distinct natural units. In these cases, population inferences are based on the length or area of the resource. The nature of the ecosystem determines the particular sampling technique that is used. EMAP uses area sampling for extensive systems such as rivers or point sampling for discrete systems like estuaries. In area sampling, the extensive resource is broken up into disjoint pieces, much like a jigsaw puzzle, and sample selection is from a random selection of these pieces. The sampling values that are obtained are then used to characterize or represent the entire resource. To avoid any sampling bias, points are located at random within the extensive resource.
Only once sites and appropriate sampling techniques are selected, can an indicator of ecological condition of the aquatic system be chosen and sampled. Effective aquatic ecological indicators are central to determining the condition of aquatic resources, and EMAP has identified a number of ecological indicators (see McDonald et al. 2002 for a full list). In general, EMAP focuses on combining biological indicators that are able to be sampled through analysis of the fish, benthic macroinvertebrate, and plant communities. EMAP also makes extensive use of an index of biotic integrity (IBI, a multi-metric biological indicator) (Karr 1981) to evaluate the overall fish assemblage, which provides a measure of biotic condition.
Nongovernmental Organizations and Initiatives
Monitoring the Illegal Killing of Elephants (MIKE)
Between 1970 and 1989, half of Africa’s elephants, over 700,000 individuals, were killed due to a surging international ivory trade (Douglas-Hamilton 1989, Blake et al. 2007). This decline prompted the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) to list African elephants on Appendix I of the convention, banning the trade of tusks in international markets. Despite its protected status, the optimal approach to African elephant management and conservation remains a topic of great debate (Blake et al. 2007). In response to the need for better data regarding the status and trends of African Elephants (Figure 2.5), Monitoring the Illegal Killing of Elephants (MIKE) was initiated in 1997. The overall goal of MIKE is to provide the information needed for governments and agencies to make appropriate management and enforcement decisions, and to build institutional capacity for the long-term management of elephant populations. The MIKE program is funded by a diversity of agencies and NGOs including the Wildlife Conservation Society, United States Fish and Wildlife Service, the European Union, and the World Wildlife Fund.
What is the goal of the monitoring program?
MIKE has three specific program objectives including to: 1) measure the levels and trends in the illegal hunting of elephants, 2) determine changes in these trends, and 3) determine the factors associated with these trends. Once again, the clarity of the objectives is central in developing other aspects of the monitoring program. In the case of MIKE, the breadth of the goals meant that a suite of factors needed to be investigated, including habitat type, elephant population levels, human conflicts, adjacent land uses, human access, water availability, tourism activities, civil strife, and development activities. The monitoring objectives of the program also emphasized a need for standardized methodologies, representative sampling, and collecting data on population trends and the spatial patterns of illegal killing (Figure 2.6). The nature of the objectives even clarified what the main benefit of this comprehensive monitoring scheme would be: an increased knowledge base of elephant numbers and movements, a better understanding of the threats to their survival, and an increased general knowledge of other species and their habitats.
Where and how to monitor?
Given the remote location of many of the habitats and populations of interest (Figure 2.7), site selection was of paramount importance for collecting representative and unbiased data. A minimum of 45 sites in 27 states were initially selected in Africa and 15 sites in 11 states in Asia. The methods of site selection were based on a number of variables chosen to make the sites a representative sample, including habitat types, elephant population size, protection status of sites, poaching history, incidence of civil strife, and level of law enforcement. Statistical analysis and modeling have also been used to select sites based on geographical, environmental and socio-economic characteristics.
What to monitor?
In central Africa from 2003-04, Blake et al. (2007) used this approach to implement the first systematic, stratified, and un-biased survey of elephant populations within each MIKE site. The primary data source they elected to use were dung counts based on along line-transects. In addition to the standardized transects, they undertook reconnaissance surveys to provide supplementary information on the incidence of poaching and other human impacts. At each survey site, an attempt was made to sample elephant abundance across a gradient of human impact. Stratification of each site was based on elephant sign encounter rate generated during MIKE pilot studies or on expected levels of human impact as a proxy for elephant abundance. Sample effort was designed to meet a target precision of 25% (coefficient of variation) of the elephant dung density estimate. Density estimates of forest elephants in MIKE survey sites were obtained via systematic line-transect distance sampling that used dung counts as an indicator of elephant occurrence. Advanced data analysis (using distance sampling) provided robust estimates of dung density, relative elephant density, and spatial distributions within each site (Figure 2.8).
The decision to record a diversity of variables allowed researchers to conduct analyses that addressed all of the MIKE objectives and provided other valuable insights. Blake et al. (2007) found that human activities were a major determinant of the distribution of elephants even within highly isolated national parks. In almost all cases the relative elephant abundance interpolated from transect data was the mirror image of human disturbance, and elephant abundance was consistently highest farthest from human settlement (Figure 2.8). They estimated that, despite international attention and conservation status, forest elephants in central Africa’s national parks are losing range at an alarming rate. Twenty-two poached (confirmed) elephant carcasses were found from 4,478 km of reconnaissance surveys walked during the inventory period. The combined inventory, distribution, and reconnaissance data showed little doubt that forest elephants are under imminent threat from poaching and range restriction. This innovative monitoring scheme and analysis demonstrated that even with an international ban of the trade in ivory in place, forest elephant range and numbers are in serious decline.
Learning from Citizen-Based Monitoring
Volunteer-based monitoring efforts have a long history in the United States and throughout the world. For example, Audubon’s Christmas Bird Count (CBC) has been a volunteer-based annual survey of winter bird distributions throughout the United States dating back to the early 1900’s. Although biological surveys based on volunteer effort have a rich history, they are now being increasingly used for monitoring long-term and large-scale changes in animal and plant populations. The combination of current demand for broad-scale, long-term ecological data and an explosion of volunteer-based efforts has resulted in a fairly well-informed movement in which scientists have made great strides in increasing the scientific rigor of monitoring programs that involve citizens. This movement has become so popular in recent years that many of these programs and initiatives are falling under the global label of citizen science.
What is the goal of the monitoring program?
Although citizen science takes many forms and has many objectives (see Cornell Lab of Ornithology’s citizen science programs http://www.birds.cornell.edu/ ), atlas surveys are a globally common example and are widely implemented for many species and taxa. Atlases consist of volunteers documenting the distribution (and often breeding status) of species within a survey grid covering an entire region of interest (Donald and Fuller 1998, Bibby et al. 2000). The goal of many atlas surveys focuses on documenting and monitoring temporal and spatial shifts in species distributions over long time periods (Donald and Fuller 1998). One such example of a regional atlas is the New York State Breeding Bird Atlas (Andrle and Carroll 1988, McGowan and Corwin 2008). This project is sponsored by the New York State Ornithological Association and the Department of Environmental Conservation in cooperation with the New York Cooperative Fish and Wildlife Research Unit at Cornell University, Cornell University Department of Natural Resources, and the Cornell Laboratory of Ornithology. The New York State Breeding Bird Atlas (BBA) is a comprehensive, statewide survey with the specific objective of documenting the distribution of all breeding birds in New York. As with all the preceding monitoring programs, stating the program objective informs and drives other aspects of the monitoring program. For instance, its breadth indicates that substantial planning is needed to collect occurrence data for multiple species over a wide range of habitats and develop a protocol that can be easily followed and adhered to by voluntary participants. Time is an essential component of any monitoring program and atlases are often unique among other monitoring initiatives due to scope of their sampling. In the case of the New York State BBA, the surveys were conducted in two time periods: the first atlas project ran from 1980 to 1985 (Andrle and Carroll 1988) while New York’s second atlas covered 2000 to 2005 (McGowan and Corwin 2008). Broad-scaled distributional surveys, such as atlases, are obviously an attempt to monitor long-term range changes that are beyond the scope of most monitoring programs.
Where and how to monitor?
Given that it was necessary to account for the entire state to meet the objective of the BBA, researchers first had to determine how to make the scale manageable. For the New York State BBA, both surveys used a grid of 5,332 5- x 5-km blocks that covered the entirety of New York State (125,384 km2); representing one of the largest and finest resolution atlas data sets in the world (Gibbons et al. 2007). The state was stratified into ten regions and one or two regional coordinators in each area were responsible for recruiting volunteers in each atlas effort and overseeing coverage of the blocks in their region. Once this system was prepared, efforts were needed to ensure that the volunteers reported quality data despite monitoring independently from one another in different locations. To do this, the researchers assigned atlas surveyors to one or more blocks and instructed them to spend at least eight hours in the block, visiting each habitat represented, and recording data on at least 76 bird species. This “76 species” threshold was treated as a standard of “adequately surveyed” based on experience from previous atlases (Smith 1982). Measures such as these are integral to monitoring programs with multiple observers responsible for sampling different sites and species. Without some form of controlling and documenting variation in sampling effort, the data would be vulnerable to a number of biases.
What to monitor?
The objective of the BBA required that volunteers would survey their atlas block(s) and record every bird species encountered and the observed breeding activity ranging from possible breeding (e.g., singing male in appropriate habitat type), probable breeding (e.g., pair observed in breeding habitat), and confirmed breeding (e.g., nest found). Although the BBA did not provide a definitive statement concerning the absence of a breeding record for a species not listed in a block, absence was interpreted by researchers to mean that species could not be found given adequate effort and observer ability, or that the species occurs in low enough densities to escape detection. In addition, atlasers were asked to submit data on effort including the total number of hours spent surveying and the number of observers. Mandating that volunteers record a variety of data, including data on sampling efforts further reduced the possibility of biases (or at least allowed researchers to account for variation in effort during analyses).
One final important lesson that can be drawn from programs such as the BBA is that researchers must be transparent about the appropriate significance and uses of the data they generate. Whether or not atlases can be used as an effective tool for monitoring animal populations relates to the relationship between changes in regional occupancy (as measured by atlas surveys) and changes in local abundance (Gaston et al. 2000). In macroecology, this relationship is synonymous with the abundance-occupancy rule which predicts that changes in regional occupancy will accurately reflect changes in local abundance. Relatively few studies have addressed the relationship between abundance and occupancy using atlas data, but those that have generally support the use of atlas data for monitoring large-scale population dynamics (Böhning-Gaese 1997, Van Turnhout et al. 2007, Zuckerberg et al. 2009). Once this information and relationship is made explicit, atlas data can be correctly used to make a number of observations and assessments. In the New York State BBA, with its two survey periods, researchers and managers can analyze the changes in regional distribution for over 250 bird species. Bird species demonstrated a wide variation in distributional changes from widespread increases (Figure 2.9) to startling range contractions (McGowan and Corwin 2008). Approximately half of all of the bird species in New York demonstrated significant changes in their distribution between the two atlases. Of those with significant changes, 55 percent increased in their distribution. As a group, woodland birds demonstrated a significant increase in their average distribution between the two atlas periods while grassland birds showed the only significant decrease (Zuckerberg et al. 2009). Scrub-successional, wetland, and urban species showed no significant change in their distribution between the two atlas periods (McGowan and Corwin 2008, Zuckerberg et al. 2009). Within migratory groups, there were significant increases in the overall distribution of permanent residents and short-distance migrants while Neotropical migrants showed no significant change. These trends suggest that certain regional factors of environmental change, such as reforestation or climate change, may be affecting entire groups of species.
Atlases offer an excellent opportunity for monitoring changes in large-scale and long-term population dynamics. Furthermore, the quality of their data will almost certainly increase as future advances in monitoring are applied to atlas implementation and analysis. For instance, improvements in occupancy estimation and modeling will undoubtedly be applied to projects such as the BBA to account for the varying detection probabilities of different species and there are likely to be significant improvements in training models for participants to decrease observer bias even more (MacKenzie 2005, MacKenzie 2006). In addition, repeat atlases for several regions of the United States will be available in the near future (Figure 2.10). These databases will be critical for monitoring changes in species’ distributions in response to relatively broad-scale environmental drivers such as regional climate change.
Summary
Despite their varied interests, funding sources, and target species/communities, all of these monitoring programs share many of the same components and obstacles. Issues such as clearly defined monitoring goals and objectives, where, how, and what to sample are common aspects of many monitoring programs and will be discussed at length throughout this book. Despite the challenges presented to them, these programs represent how careful planning, committed individuals, and thoughtful sampling design and analysis can help answer critical questions and thereby further conservation goals for a variety of types of organizations. Whether it is predicting the effects of environmental contamination, estimating avian declines across an entire country or monitoring elephant populations in remote African forests, these programs serve as encouraging reminders of the power and effectiveness of monitoring information for guiding conservation decision-making. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.02%3A_Lessons_Learned_from_Current_Monitoring_Programs.txt |
Since the time that the Western European civil society natural history organizations undertook formative field studies in the 18th century, to the sportsmen organizations of North America that helped spur the demise of market-hunting in 19th and 20th centuries, to the indigenous peoples of the Amazon currently carrying out GIS mapping initiatives, citizens have often had a significant and meaningful role to play in conservation (Fernández-Gimenez et al. 2008, Reiger 2001, Tripathi and Bhattarya 2004, Withers and Finnegan 2003). Yet just as science in general comes in many shapes and sizes and under a variety of distinct monikers, the manifestations of scientific research that hinge upon citizen involvement are numerous and varied. Community-based monitoring is but one item on this long list that also includes community-science, citizen science, participatory research, community co-management, and civic science (Fernández-Gimenez et al. 2008). The key differences among these endeavors is often found in the degree of influence that resource managers and scientists wield, the manner in which community or citizen is defined, and the specific questions or goals the stakeholders wish to address.
Community-based monitoring, broadly defined, is ecological monitoring that in some manner directly incorporates local community members and/or concerned citizens. The traditional approach is for scientists and resource managers to develop protocols that they deem most likely will generate rigorous data and then transfer the necessary information to communities for them to carry out the protocols (Fernandez-Gimenez 2008). A successful transfer of knowledge either entails the stratified sampling of communities and citizens to ensure that only those most apt to conduct science are invited to participate or the provision of a thorough training in a workshop format (Fernandez-Gimenez 2008). The goals and objectives of such monitoring programs typically address the needs of resource agencies, scientists, and citizens that highly value Western science (Fernandez-Gimenez 2008). This approach, however, perhaps ideal in terms of the rigors of the scientific world, has waned in efficacy in recent years as community-based monitoring programs (CBMP) expand into more remote locales with communities and citizens that are less familiar and comfortable with the objectives and rigors of Western scientific inquiry (Sheil 2001, Spellerberg 2005). In order to implement programs effectively that are viable over the desired space and length of time in these new contexts, non-traditional, arguably less scientific designs have become more common (Fraser et al. 2006).
A Conflict Over Benefits
Ecological monitoring is complex and increasingly sophisticated with each new publication and technological development. To be able to generate convincing inferences grounded in strong data, monitoring program designs require a high level of scientific rigor, powerful statistical design and analysis, and the consideration of specific, science-based questions. This is particularly true as contemporary scientific research reveals the enormous extent of the uncertainties and complexities we confront when we endeavor to monitor or even understand ecosystems and leads us to question many past assumptions and mandate even more powerful, precise techniques (Kay and Regier 2000, Resilience Alliance Website 2008). It should surprise few that the interface between the newer, arguably less rigorous community-based monitoring program designs and the increasing demand for more rigorous science is an area ripe for tensions. Indeed, especially with tenure and promotion driven demands for rigor, many scientists are hesitant to to value monitoring protocols as particularly useful or ecologically meaningful when they are designed to satisfy the objectives of citizens unfamiliar with Western science and its associated monitoring techniques. So why might it be worthwhile to continue working with and encouraging the design of community-based monitoring? Well, because a CBMP’s contribution to science is but one of many important considerations; there are also a variety of economic, ethical, educational, and functional reasons to design and implement a CBMP. In some contexts, these reasons may be strong enough to compensate for deviation from the institutional ideal.
Economic
At times, developing community-based monitoring programs in lieu of scientist-managed programs is either the best fiscal option or, given severe budget constraints, the only option. Natural resource agencies and universities have often been faced with financial constraints. The fiscal challenges have led to notable increases in community-based monitoring. In Canada, for instance, environmental agencies suffered budget declines of 30-60% through the late 20th and early 21st century, an amount substantial enough to begin to compromise their capacity to remain viable institutions (Plummer and Fitzgibbon 2004). Confronted with the threat of becoming an institutional anachronism, considerable expense-cutting actions such as phasing out a number of its programs, including many monitoring initiatives, seemed all but inevitable (Whitelaw et al. 2003). Yet given the agencies’ and the public’s mutual need for information about the local environment, rather than cutting programs altogether, more economically efficient alternatives were sought and found. Since the 1990s, natural resource management across Canada has been marked by the devolution of monitoring and resource management responsibilities to citizens and communities (Whitelaw et al. 2003). This strategy has effectively reduced costs, prevented data gaps in monitoring programs, and allowed resource agencies to retain a fairly comprehensive understanding of Canada’s resource base despite their fiscal crisis (Plummer and Fitzgibbon 2004, Whitelaw et al. 2003).
Although some of the motives of this devolution have been questioned (Plummer and Fitzgibbon 2004), Canadian community-based monitoring has emerged in a fascinating diversity of forms over the past few decades. A large number of communities are involved in the attempt to establish the Canadian Community Monitoring Network (Figure 3.1). From the successful monitoring of bowhead whales by the Inuit (Berkes et al. 2007), to Community Environment Watch’s successful work with school groups (Sharpe et al. 2000), as well as a number of unviable efforts (Fraser et al. 2006, Sharpe and Conrad 2006), Canada’s budget reductions have resulted in a scenario that is ripe for research and driven by an exciting need for scientists, resource managers, and communities to learn and work adaptively in the field of community-based monitoring. In the contemporary economy, monitoring in a sparsely populated country such as Canada would likely be more expensive and less extensive without these initiatives.
Ethical
Ethical considerations can outweigh perceived scientific deficiencies and make community-based monitoring the most appropriate choice. Broadly speaking, the movement over the last several decades away from traditional, top-down techniques toward strategies that involve citizens has not been exclusive to community-based monitoring but has been occurring throughout the world of natural resource and protected area management and conservation (Phillips 2003). One of the fundamental causes of this shift has been the realization by many conservationists and resource professionals that traditional, command-and-control strategies are ineffective in many new conservation frontiers, such as inhabited landscapes and in communities unfamiliar with Western concepts of science and monitoring (Phillips 2003). The need to better navigate the interface between the environment and humans has necessarily led to an array of interdisciplinary approaches to conservation science that incorporate anthropology, psychology, geography, and sociology, and encourage collaboration among researchers from these fields (Berkes 2004, Saunders 2003).
These new conservation partners often make powerful arguments based on democratic and educational theories, that resource managers and conservationists have ethical obligations to involve communities and citizens as comprehensively as possible in the decision-making processes related to our shared, finite resource base (Chase et al. 2004). Further, empirical data have shown that, relative to more exclusive approaches, supporting local governance and empowering communities in the context of resource monitoring and management can have a more desirable impact on social capital, particularly the long-term ability of community members to network and self-organize, can increase local satisfaction with monitoring and resource management in general, and can encourage more sustainable local land-use decisions (EMAN and CNF 2003). Given these positive impacts, in many cases it is the institutional obligation of resource professionals and conservationists to embrace new approaches that involve citizens and communities (Halvorsen 2001, 2003; Meretsky et al. 2006).
Such ethical obligations are often underscored in scenarios involving indigenous peoples. Many resource agencies have controversial pasts in which they evicted or excluded such communities from their traditional lands by forcefully designating the areas as public, erecting literal or figurative fences to forbid access, and assuming full control of management and monitoring (Spence 1999). In the contemporary landscape in which the presidents and prime ministers of developed nations have begun issuing formal apologies to indigenous peoples to atone for these historic injustices, continuing top-down monitoring programs would be inappropriate in many cases (Smith 2008). If resource managers and conservationists are to have any influence on monitoring initiatives on these traditional lands, it should be in the role as a facilitator between the Western science of ecological monitoring and the local ecological knowledge of indigenous communities and any such arrangements must be agreed upon by locals. This is increasingly recognized in conservation circles (Meffe et al. 2002, Phillips 2003).
Education and Community-Enrichment
The topic of human-environment bonds has received considerable attention in academia. For instance, there is an ongoing debate that deals with the causes and implications of the ebbing interaction between our country’s youth and nature (Louv 2006, Stanley 2007). Perhaps the most well-known contributions are those that explore the concept of “nature-deficit disorder” (Louv 2006; 2007). Although this concept remains largely inconclusive, actively nurturing human-environment bonds has been linked to the attenuation of a variety of mental and physical health impairments such as obesity, attention-deficits, and depression; to increases in creativity and community-interaction; and to decreases in aggression (Louv 2007, Stanley 2007, Cornell Lab of Ornithology 2008). Further, many of these results are not exclusive to children, but have also been shown to extend to entire families and communities; the enhancement of these bonds should thus be pursued (Lowman 2006). Community-based monitoring constitutes one way to do this. Indeed, monitoring programs have been found to be an excellent vehicle for family and community-based nature education that fosters social learning and general increases in well-being, and inspires the construction of whole family and community conservation ethics (Fernandez-Gimenez et al. 2008, Lowman 2006). As it has also been determined that the benefits of a healthy relationship with the environment accrue whether the bonds are between fishers and people or pigeons and people, this argument applies to a variety of settings, from urban to rural (Cornell Lab of Ornithology 2008, Dobbs 1999). It is not hard to imagine a situation in which the educational benefits or a high degree of community-enrichment could be enbraced by scientists who are otherwise reluctant to establish a CBMP.
The Cornell Lab of Ornithology’s “Celebrate Urban Birds” project is one example of a monitoring program with the goal of maximizing these benefits. The project trains citizens across the United States to identify 16 species of birds and then conduct 10-minute point counts for them and submit the data online (Cornell Lab of Ornithology 2008, K. Purcell pers. comm.). Although the monitoring protocol is designed in such a manner that it provides insight into the effects of urbanization on avian fauna, the argument could certainly be made that the principal objective of the Urban Birds project is to enrich communities via nature-based, experiential learning. Indeed, the group openly encourages participants to synthesize monitoring with urban-greening projects, artistic and musical events, and a variety of other activities designed to reinforce community-spirit and service; it also seeks to cross cultural boundaries by providing materials and resources in both Spanish and English languages. The Urban Birds project, while a monitoring program, values the education of urban communities in conservation related topics and the improvement of their well-being at least as highly as it does data collection (Cornell Lab of Ornithology 2008).
Some practitioners utilize the educational potential of community-based monitoring to advance a particular conservation agenda (Dobbs 1999). Many of these initiatives are designed to prevent the development of sensitive natural areas and minimize the impact of sprawl (Dobbs 1999). Wildlife ecologist Susan Morse of Keeping Track® in Vermont, for instance, runs workshops in which she trains citizen groups organized by regional conservation agencies and land trusts to locate tracks, scat, and sign of a number of wide-ranging mammal species within their core habitat. Susan further provides the trainees with a primer on the importance of conservation planning (Fig 3.2) (S. Morse, pers. comm., Keeping Track® 2009). This background prepares the groups to conduct Keeping Track®’s science-based track and sign surveys along established transects in their communities once per season on a long-term basis. The year to year detection of the selected mammal species presence within unfragmented, core habitats augments understanding of the species’ local habitat preferences and in some cases provides indices of relative abundance. Perhaps most importantly, for the involved stakeholders, such information attests to the ecological integrity and conservation worthiness of these habitats. Analyzing the data and considering this information in the context of current themes in conservation biology enables more informed decision-making about the appropriate placement of future development (Dobbs 1999, S. Morse pers. comm.). Keeping Track® is originator of the idea that citizens can and should participate in the long term collection of wildlife data with the specific purpose of informing conservation planning at community and eco-regional levels. The protocol is also designed and carried out to enhance the bonds between communities and their ecological surroundings by engaging them in a type of monitoring that maximizes their interaction with the local ecosystems and wildlife (Hass et al. 2000).
Establishing a network of concerned communities that use the same monitoring protocol also creates the potential to scale up the local data and thereby form a cogent argument for increased habitat connectivity for the target species on the regional and national scale. Indeed, Keeping Track® has trained groups of citizens across the entire country (S. Morse, pers. Comm.). Over the years, as data have accumulated, Susan Morse has also developed more rigorous methods of monitoring via tracking, particularly through the detection of scent-marking sign such as felid retromingent scent posts and bear mark trees. These new methods have led Morse to believe that “we can powerfully use scent-marking in our track and sign surveys to predict where to find mammal sign and then deploy remote cameras to photo-capture individual resident animals over time” (S. Morse, pers. comm.). This could increase the power of the tracking-based monitoring, because if groups can identify individuals captured in the photos, conservation planners may be capable of differentiating between resident and non-resident wildlife. Such information would further inform development and conservation planning and facilitate the appropriate application of wildlife laws and regulation.
It is important to underscore that there is a fine line between incorporating environmental education and community-enrichment initiatives into monitoring programs and the incorporation of monitoring into environmental education and community-enrichment initiatives. It is the responsibility of scientists to be fully transparent about how a particular monitoring program should be developed and how data that results from the effort should be appropriately interpreted. In this same vein, it is integral that conservationists and resource managers clearly state the goals and objectives of education-related community-based monitoring programs before design and implementation to reduce the potential for conflict over time.
Effectiveness
Community-based monitoring may simply be the most or only effective approach under some circumstances (Sheil 2001). This appears to be particularly true if the objective of an ecological monitoring program is related to guiding or influencing active management or conservation activities in rural, inhabited landscapes in which communities participate in resource-extraction or agriculture-based economies. Factors such as the intimacy of community relationships with the environment, geographic isolation of the ecosystem under consideration, or the contentious nature of interfering with or manipulating extractive behaviors from the top-down, may mean that some activities are more easily influenced using community- rather than institutionally-based monitoring programs (Sheil 2001). In fact, in some cases strict, top-down monitoring and management initiatives and associated regulations promote local resistance, resource depletion, the deterioration of sustainability, and the undermining of scientist-citizen relationships (Berkes 2007, Bjorkell 2008). This is often true when scientific information is used to manage landscapes such in a manner that supersedes traditional, local programs or paints local-ecological knowledge as illegitimate (Bjorkell 2008, Huntington et al. 2006). Indeed, in certain contexts, community-based and collaborative approaches centered on local institutions and ideas are simply much more informative, more likely to result in effective management, governance, and conservation on a local scale, and more likely to generate monitoring programs that are viable over the desired space and time (Bjorkell 2008, Huntington et al. 2006). In Madagascar, for instance, arranging participatory wetland monitoring programs through local institutions allayed citizen concern that the government fishery agency was using its power to profit from local fisheries (Andrianandrasana et al. 2005). This, in turn, helped legitimize fishery laws and regulations that citizens had previously not respected due to the belief that government officials implemented them in their own self-interest.
The spatial scale of a monitoring program can also make a community-based protocol more effective than one operated by scientists. For projects that span entire regions, countries, or continents, the coordination of a sufficient number of ecologists, biologists, and resource managers to meet project objectives is usually impractical. However, organizing a network of citizens to undertake monitoring activities, although still a challenge, may be more practical. For example, the MEGA-Transect project along the 3,625-km long Appalachian Trail, includes nearly 100 volunteers to “handle equipment, gather data, and record observations” to “monitor environmental trends (Cohn 2008). This project, managed by researchers at the National Zoo’s Conservation and Research Center in Front Royal, Virginia, also includes a 960-km citizen-run motion-sensor camera survey of the trail from Virginia to Pennsylvania (Cohn 2008). Without the aid of citizens and communities, such monitoring and data collection efforts would likely be unrealistic. The North American Breeding Bird Survey and the Breeding Bird Atlas programs discussed below as well as in Chapter 2 provide other examples.
Designing and Implementing a Community-Based Monitoring Program
Although this list of potential benefits is by no means exhaustive (see Fernandez-Gimenez et al. 2008, for instance), it is clear that community-based monitoring has the potential to yield rich, varied results, not all of which are grounded in science. This implicitly reveals that these programs often have a more diverse set of stakeholders than those run entirely by scientists. This can make designing and implementing an effective protocol for a CBMP a very difficult task. Indeed, communities in conjunction with the scientists, resource professionals, and practitioners working with them, are characterized by distinctive amalgamations of needs, desires, opportunities, and education levels that all interact in intricate ways over varying spatial and temporal scales. Just like the ecosystems in which they are embedded, such groups are not homogenous entities, but uniquely complex systems. In light of this, there is no single protocol for the most effective or desirable CBMP; rather, the components of each must be determined based on the specific scientific, ecological, social, and cultural scenario in which it is to be implemented. The existence of different methodological approaches for designing and implementing CBMPs should therefore come as no surprise. It is possible to discuss two markedly different categories that vary in their degree of top-down input from scientists: prescriptive and collaborative. Prescriptive approaches to CBMP design are those in which science professionals craft a protocol to accurately capture ecological data and train citizens to carry it out (Engell and Voshell 2002, Fore et al. 2001). Data-analysis is generally done by scientists, but can also be, and sometimes should be, undertaken by citizens (Engell and Voshell 2002, Fore et al. 2001, Lakshminarayanan 2007). In contrast, the collaborative approach is usually undertaken through the use of a framework that encourages scientists and communities to work jointly and interact as one larger community in the design of a mutually acceptable and useful monitoring program tailored to their specific scenario. However, past and current efforts to design CBMPs rarely fit perfectly into either category; most are a fusion of both, thus the categories are actually two bookends of a continuum rather than discrete types. Locally autonomous monitoring programs are also legitimate and should be respected and institutionally supported, but they are not the main thrust of this chapter. The ideal mix of design techniques depends on a number of factors, including spatial scale and objectives of monitoring and the size, local expertise, and socioeconomic status of the community. Figure 3.3 may prove helpful as a starting point for practitioners and will serve as a useful framework for the remainder of this section.
The Prescriptive Approach
The prescriptive approach to CBMP protocol design is largely focused on the rigor of the monitoring methods, the accuracy and precision of the collected data, and the power of data analysis. One example includes the many Water Watch Organizations within the United States (Fore et al. 2001). In the state of Washington, for instance, over 11,000 citizens have been trained to monitor stream ecosystems using the benthic-index of biological integrity: a measure of the diversity of a stream’s invertebrate organisms often used as an indicator for other stream ecosystem characteristics (Fore et al. 2001). This indicator and its associated collection method was developed by scientists, and the participating citizens were trained by science professionals (Fore et al. 2001). In the particular case discussed by Fore et al. (2001), when scientists later questioned the accuracy and precision of the citizen-derived data, they intervened in a largely top-down way by independently undertaking data collection and analysis and then statistically analyzing the differences between their results and those of the citizens (Figure 3.4). Although they found no significant differences in any case in which the citizens had been properly trained, the process allowed scientists to augment the scientific value of the monitoring program by improving their ability to confidently interpret the citizen’s data (Fore et al. 2001). Top-down, compliance monitoring such as this is generally supported by the scientific community and can be appropriate in the context of prescriptively designed CBMPs, thus it merits consideration (Fore et al. 2001). Another example is the New York State Breeding Bird Atlas (BBA), a project discussed in Chapter 2. Once again, the BBA is a statewide survey in which citizens sample habitat in New York to document the distribution of all breeding birds in New York that was conducted in two time periods: the first from 1980 to 1985 (Andrle & Carroll 1988) and the second from 2000 to 2005 (McGowan & Corwin 2008). Volunteers in this project are given an instructional handbook and other information created by scientists to assist them with atlasing. This is part of a concentrated effort on the part of the researchers to prescribe a particular set of protocols that achieve consistent coverage within each atlas block so that changes in species distributions can be considered true ecological patterns as opposed to some deviation in sampling methodology due to observer bias or differences in training between the two time periods.
While many practitioners refer to programs of this type strictly as “citizen science” rather than community-based monitoring, we have included such initiatives under the umbrella term of community-based monitoring for two reasons. The first is to provide clarity in the sense that citizen science initiatives are by no means limited to ecological monitoring. The second is that the design and implementation processes of prescriptive plans are largely top-down, and can therefore result in excessively top-down, hierarchical designs in which participants are “used” by scientists rather than collaborated with (Lakshminarayanan 2007). This has historically been the case with some geographically broad programs in which community volunteers learned from and appreciated local data collection, but were entirely excluded from the scientists’ meta-analyses (Lakshminarayanan 2007). In the past, this treatment has been justifiably interpreted as skepticism about a public’s intellect, has insulted participants who invested considerable emotion, time, and effort into assisting scientists, and has led to the cessation of monitoring (Lakshminarayanan 2007). As these failed programs were classified as citizen science initiatives, it seems useful to describe prescriptive monitoring programs as community-based monitoring here as a reminder that, in terms of both the long-term viability as well as the ethical basis of the program, it is necessary to interact with the public as social groups and to acknowledge their intellect, efforts, and emotions whenever they are involved. Ways for science professionals to more actively accomplish this include assuming the role of facilitator rather than expert during training; undertaking data calibration, collection, and analysis in a way that embraces “the concepts of open access and freedom;” and establishing a reliable system for citizens to provide feedback to scientists (Meffe et al. 2002, Lakshminarayanan 2007). That being said, the term ‘citizen science’ should not be categorically rejected or criticized and there are numerous inspiring, culturally sensitive, and scientifically impressive “citizen science” initiatives. Furthermore, it is important to keep in mind that the terminology used to classify science involving a public will vary depending on the source (See: Bacon et al. 2005; Cooper et al. 2007, 2008; Fernandez-Giemenez 2008).
In what context does it work?
As mentioned above, the programs designed in this manner focus nearly exclusively on the methods, accuracy, and precision of the science. Consequently, they are often only appropriate and able to engage community volunteers over the long-term in communities that already ascribe a high value to Western scientific inquiry (Cooper et al. 2008). Indeed, although the long-term capacity and willingness of citizens to participate in data collection must be considered in program design, it is often only necessary to do so in terms of the program’s temporal and economic logistics and the scientific utility of data because the epistemological harmony between citizens and scientists makes a science-focused design mutually valuable. It has been argued that communities that are congruous with prescriptive designs are those embedded within societies that offer many opportunities for citizens to enter into a scientific profession, but only after years of training and/or the attainment of academic degrees (Cooper et al. 2007; 2008). In this context, rigorous, scientifically-focused CBMPs provide a desired opportunity for citizens socialized to appreciate scientific fields but trained in others and therefore unable to access science positions, to legitimately contribute to science without the extensive education process. In this sense, local expertise is not necessarily integral to the program because citizens will be open to learning the protocols and adhering to instructions. Communities with a socioeconomic status that fosters a culture of volunteerism and provides a considerable amount of leisure time will be particularly likely to fit this description (Danielsen et al. 2009). In scenarios lacking these social and/or economic characteristics, citizens may need to be incentivized economically or otherwise for undertaking ecological monitoring designed with the prescriptive approach (Andrianandrasana et al. 2005).
It may also be the case that prescriptive designs are needed when the monitoring program’s spatial scale, number of participants, and quantity of data are large. The BBA, for instance, enlisted over 1,200 volunteers over the entirety of New York State during both time periods and resulted in 361,594 records for 246 species in 1980 BBA and 383,051 records for 251 species in 2000. In such scenarios, the design and implementation of a monitoring program as well as the data collection and analysis would likely be chaotic without the strict oversight of scientists, and the ability of researchers to confidently scale up data from the local level would be limited. On a related note, when the goals of a monitoring program include using the data for publication in scientific journals or satisfying a government or institutional mandate, a prescriptive approach may be the only means of attaining them.
The Collaborative Approach
The second prevalent approach to CBMP protocol design and implementation is fully collaborative. As mentioned above, collaborative protocols are often approached with the use of a framework that aims to make initially separated communities and researchers into collaborators. Many such frameworks have been proposed and are readily accessible in academic journals, practitioner’s manuals, and anthologies. The Southern Alliance for Indigenous Resources (SAFIRE) is one example that led to the creation of a design that is adapted to the specific context and appears to have been drafted with rural communities of Africa in mind (Figure 3.5) (Fröde and Masara 2007). This framework creates a forum in which science professionals and citizens are given the opportunity to have significant input. Indeed, it has been suggested that the most meaningful and durable plans that lead to active conservation activities and enjoy multi-layered support are designed in collaborative ways that work with all involved viewpoints. These successful programs must also be sensitive to the differential expertise of involved parties in terms of their natural science aptitude and organizational capacity (Cooper et al. 2007, 2008, Lakshminarayanan 2007, Sheil 2001). Sometimes the most important task for science professionals in the collaborative approach is to maintain a sense of equality during the planning and implementation stages. The varying levels of expertise in both monitoring and in navigating the socioeconomic environment must emerge from within the group and are properly balanced and incorporated into the CBMP.
In what context does it work?
This strategy seems more appropriate than a prescriptive design when there is a measurable degree of epistemological dissonance between the visions of monitoring held by the researcher and the community; this is likely to be the case when a community desires a significant amount of autonomy relative to its natural resources, when there are stark cultural differences between locals and researchers, and when the socioeconomic status of a community makes its members unwilling and/or unable to volunteer simply to meet a scientist’s objectives.
One manifestation of such dissonance is the possession of distinct ideas about acceptable survey methods or indicators. For instance, Jensen et al. (1997) mentioned how some First Nation communities in Canada use the taste of game to monitor the status and health of nearby wildlife populations. As an indicator on which to base game management or policy, this would be unlikely to convince most scientists and politicians. At the same time, a protocol that strictly addresses concerns such as statistical power of methods and biodiversity indicators may not be valued enough by a community in a developing country for them to carry out monitoring, especially if their local livelihoods depend on occupations with high time and energy requirements. Conflicts regarding the desired objectives or other functional aspects of monitoring programs can also arise from epistemological dissonance. In discussing the bowhead whale-monitoring program described above, Berkes et al. (2007) mentioned that “the scientific objectives were about conserving populations and species, the Inuit objectives were about Inuit-bowhead relationships and access to the resource.” In other cases, a community may wish to focus primarily on a program’s educational or culturally enriching components or perhaps even the economic benefits of monitoring game populations while a scientist or resource manager may wish to optimize statistical power for a publication or gather data to conserve a species. In nearly all cases with such dissonance, if having a monitoring program that is locally sustainable and institutionally recognized is the ultimate goal, then involved parties must be willing to accept outside influences and compromises and a collaborative approach is necessary. If the dissonance cannot be reconciled, fundamental differences in world-view and values must be respected rather than forcefully altered or denigrated (Berkes et al. 2007, Sheil 2001). In such cases, a locally autonomous rather than collaborative approach may arise and as mentioned above should enjoy an adequate degree of institutional support.
The collaborative approach also seems more appropriate when the scale of monitoring and the size of the community are at a very local level and scientists have the ability to run workshops to facilitate monitoring-related decision-making processes with all participants. It merits noting, however, that efforts to scale-up data collected across many small communities with protocols designed collaboratively have successfully influenced national resource management (Danielsen et al. 2005).
Despite our specific suggestions, newly proposed CBMP design frameworks vary in how and which ecological and social characteristics are considered and are nearly ubiquitous. There is an extensive body of literature describing and/or advocating alternative approaches to CBMP design and implementation; just as with the monitoring programs themselves, even the approach to design and implementation must be adapted to each specific context (Conrad and Daoust 2007, Fraser et al. 2006, Fleming and Henkel 2001, Fröde and Masara 2007). Once again, important variables to consider when determining an approach to CBMP design include the spatial scale and the objectives of monitoring and the size of the community involved (Figure 3.3).
Suggestions for Scientists
As briefly indicated above, there is much debate about community-based monitoring within the scientific community, usually in terms of its scientific utility. This is particularly the case in scenarios that mandate collaborative design approaches, as they commonly incorporate both biodiversity conservation and livelihood objectives (Fraser et al. 2006, Sheil 2001). Resistance to this is widespread due to the arguments “that social objectives dilute the all-important conservation objectives” and that mixing social-benefits with science ineluctably dilutes the objectivity and therefore rigor of the scientific data collected (Berkes 2007, D. Kramer pers. comm.). Nonetheless, many past monitoring programs have integrated citizens yet failed to integrate local values and livelihood indicators so were not viable over the long-term (Sheil 2001). A number of problems arise in such circumstances, including volunteer “burnout,” a lack of observer objectivity, or simply a dearth of interest and therefore irregular participation that leads to data fragmentation (Sharpe and Conrad 2006). If it is important to scientists that monitoring is conducted in a region where they cannot monitor themselves, where resources are intimately linked to local livelihoods, or where Western science is simply not the local priority, scientists will likely have to be flexible and incorporate local epistemologies if any biodiversity objectives are to be attained. Furthermore, working in this flexible way, has proven worth the effort. Along with the potential benefits described above, scientists generate scientific data and build healthy relationships with citizens. Further, communities gain the capacity and institutional support to monitor locally-valued resources and the opportunity to legitimize their world-views and opinions amongst science professionals, whose activities may have previously been viewed as threats to local livelihoods (Huntington et al. 2006). Open, constructive bonds between scientists and society have an important role to play in the contemporary conservation landscape. Some suggestions and strategies for successfully reaching the necessary compromises include resolving the underlying conflicts between scientists and non-scientific monitoring, using participatory action research, and approaching plan design and implementation in a way that embraces systems-thinking (Bacon et al. 2005, Greider and Garkovich 1994, Castellanet and Jordan 2002, Walker et al. 2006b).
Resolving the Underlying Conflict
Resolution of the ideological discord between our ideas of science, nature, and monitoring and those of a local community can inspire scientists to think and work more flexibly. There are several ways to resolve the conflicts. One is by understanding that ecological monitoring is socially constructed. Applying the core of social constructionism to monitoring is simple enough: our particular needs, values, and interests are what have conceived and reified our processes for monitoring (Boghossian 2001). In the absence of our particular culture, the processes of monitoring have been conceived and developed in distinct forms by other societies with different needs, values, and interests. To these other societies, their monitoring processes are viewed as valid and highly valued, in the same way that ours are to us. The difference and one of the primary sources of conflict, therefore has a cultural base. Realizing this can assist scientists in achieving a philosophy that facilitates the acceptance of local ecological knowledge and social indicators into ecological monitoring programs. In the context of social constructionism, denying the inclusion of disparate needs, values, and interests in monitoring with the argument that it invalidates the process is to erroneously and dogmatically perceive our socially-particular monitoring processes and our culture as sacrosanct and inherently superior to those of a local community.
A second way to resolve the conflict is to confront the so-called “publish or perish” culture of academia. The tradition within the institution is to mandate that professionals publish with regularity in “high-impact” journals in order to attain tenured positions or improve or maintain their standing (Cohen 2006). Given strict publication requirements and the potential for traditional opinions among peer reviewers, there may be hesitancy on the part of some professionals to make the compromises needed to work with communities in a flexible way. Indeed, doing so may hinder publication and put one’s job security at risk. Publicly addressing these potentially negative impacts may lead to a reconsideration of the traditional metrics for evaluating work published in well-regulated interdisciplinary and transdisciplinary publications. Eventually such developments could result in a system that allows for the frequent communication via publication that is integral to our field while encouraging rather than discouraging university scientists to work more collaboratively with communities. A number of alternatives to the traditional system are currently being explored and although there is the potential for huge benefits, the shift is a cautious one (Casati et al. 2007)
Participatory Action Research
Participatory Action Research (PAR) is a style of research that “promotes broad participation in the research process and supports action leading to a more just or satisfying situation for” all “stakeholders” (Bacon et al. 2005). In the context of ecological research this goal is normally attained by designing protocols that ensure that both researchers and other stakeholders are able to improve their respective situations (Bacon et al. 2005). This often involves workshops and extensive, fully transparent dialog between researchers and the community with the purpose of generating goals and objectives that meet the expectations of the maximum number of participants (Figure 3.6) and mandates that an atmosphere of equality is fostered in which the researchers and citizens become components of a larger community linked by the research process itself (Castellanet and Jordan 2002). Indeed, to attain a comprehensive PAR experience, the endeavor must be undertaken “with and by local people” instead of on or for them (Cornwall and Jewkes 1995). PAR techniques are particularly useful in collaborative approaches to CBMP design because they are explicitly implemented to foster a fully collaborative project. Indeed, the techniques are designed to remove scientists from the “linear mould of conventional” research-thinking in which they assume the controlling role of the expert and encourage them to seek outside input (Castellanet and Jordan 2002). It is clear that they have the power to facilitate the acknowledgement and acceptance of the value of integrating non-scientific components into the ecological monitoring program and can encourage scientists to approach subsequent research more holistically.
Systems Thinking
At times, scientists do not accept the input of communities or individual citizens into ecological monitoring plans due to a tendency to think at the national and global scales and to neglect important variables at the local scale. This is predictable in that we, as Western scientists, are often trained to value and prioritize the variables that are most highly regarded by university and government scientists, such as scientific rigor and statistical power, not those valued by locals for their relevance to livelihoods or social wellbeing. If communities and citizens are to be fully integrated into monitoring programs, then this is a flawed approach, because CBMPs are complex, adaptive, social-ecological systems. A social-ecological system, is an “ecological system intricately linked with and affected by one or more social systems” (Anderies et al. 2004). It is sometimes stated that true social-ecological systems are those comprised of multiple social systems that affect one another through independent interactions with the biophysical or ecological system (Anderies et al. 2004). To be complex implies that the system is comprised of multiple subsystems at multiple scales and that those at smaller scales are embedded within those at larger scales. This interrelated structure means that an action undertaken in one subsystem causes feedbacks or reactions in the others. These feedbacks and reactions, in turn, result in the readjustment of the system as a whole (Folke 2006). Finally, adaptability indicates that a system has the capacity to adjust itself in order to increase or maintain survival in the face of environmental perturbation. In other words, an adaptive system will adjust to novelties in the environment in order to retain an appropriate, functional structure despite those novelties. In the context of social systems, it is sometimes argued that adaptability is further defined by the capacity of the actors within the system to influence how such adjustments play out (Walker et al. 2006a).
Most community-based ecological monitoring programs fit this definition. First, they involve ecological systems that are intricately linked, through monitoring activities, to multiple social systems (i.e. the local community, the scientific community, the government, and systems comprised of interacting combinations of individuals from these larger systems). To reveal how they also meet the remaining criteria, let’s look at two examples:
1. Changes in a local community’s attitudes toward monitoring cause an alteration in which aspects of the biophysical world are sampled. This change at the local scale affects the quantity and quality of the data that reach scientists at the national scale, leading them to alter their methods of analysis and interpretation so that they retain the capacity to confidently report the results to the government.
2. Decreases in resource agency funding caused by a global recession lead scientists to de-prioritize the biophysical system surrounding a particular community and to decrease fiscal support for monitoring efforts there– these national and international occurrences impact the capacity of a community to monitor and lead them to reduce the quantity of indicators monitored so that they can continue to afford to monitor their most valued resources.
In both cases, the social systems exhibit an ability to affect one another through otherwise independent interactions with the biophysical system. The social systems also clearly act at different scales, yet not in an isolated manner; some are encompassed within others and all are interdependent to the extent that seemingly independent actions at one scale result in a chain of events that reverberates through the other scales and ultimately leads to the re-adjustment of the monitoring plan as a whole. Finally, the human actors affected by changes at other scales, such as scientists affected by local changes or locals impacted by national and international changes, undertake actions to ensure that the system retains certain necessary functions despite the re-adjustment. The system is therefore complex, adaptive, and a model of social-ecological synthesis.
Viewing CBMPs in this manner, as linked arrangements of mutually important cogs, inevitably leads to the conclusion tha all components of CBMPs have the potential to impact one another and thereby the CBMP as a whole, so all are important, thus all have to be considered. In contexts conducive to collaborative approaches, such broad thinking will probably underscore the importance of incorporating locally-valued components not normally valued by Western scientists, such as those more economically or socially based, into the plan (Bosch et al. 2007, Walker et al. 2002). At the same time, it will also likely prevent an excessively local focus, which can result when scientists and resource agencies overcompensate for past, top-down designs (Giller et al. 2008). There are a variety of systems-based modes of thought, such as resilience-thinking and ecosystem management, and extensive bodies of related literature that can help not simply scientists, but all involved parties to attain a more holistic view of monitoring (Meffe et al. 2002, Walker et al. 2006b).
Summary
Citizen and community involvement in natural resource and conservation science are not novel phenomena. Rather, they have long histories from which many lessons can be drawn and applied to CBMPs. In addition to this, many of the lessons learned from previous non-community-based ecological monitoring programs and the methods and suggestions contained within this book are essential even when monitoring is community-based. One important lesson provided by both of these sources is that the goals and objectives of the plan should be clearly generated and stated before plan design and implementation begins. This may be particularly significant in the context of community-based monitoring as the goals and objectives often diverge markedly from the norm.
Perhaps the most important lesson is that the ideal protocol for monitoring an ecosystem with a community will be adapted to the particular scenario under consideration. Strategies for designing a CBMP protocol can be broadly classified as prescriptive and collaborative, yet choosing an appropriate strategy is a key determinant of the design’s long-term viability, thus previously outlined frameworks should be viewed as two options on a continuum and used as suggestions rather than methodologies to be adhered to; indeed, design strategy itself must also be unique to the protocol’s context.
In many cases, particularly where more collaborative approaches are needed, it is likely that we, as Western scientists, will have to accept social values, livelihood indicators, and epistemologies distinct from those heralded within our field into traditional monitoring protocols if we are to attain both local and institutional acceptance and viability and fulfill the objectives of all participants. For community-based monitoring initiatives with which we are involved to reach their full potential, therefore, we, as ecologists, biologists, and resource managers, must endeavor to think and work in more expansive, interdisciplinary ways. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.03%3A_Community-Based_Monitoring.txt |
Societal values are often the primary factors influencing the goals and objectives of a monitoring or management plan (Elzinga et al. 2001, Yoccoz et al. 2001). Consequently, it is important to understand what goals society has for the resources involved. There are many guidelines available that document how best to identify, engage and understand stakeholders in an issue, empower them in decision-making as the plan is developed, and integrate them as key partners in the adaptive management process. Yet these are far from simple tasks, and even if societal values are fully understood and integrated, these values change, sometimes abruptly. Societies, cultures and the expectations of their members evolve as surely as do species and ecological communities. This presents a daunting challenge for those charged with developing a monitoring plan, because the selection of the species and habitat elements, and the scales over which they are measured, must be selected now in the absence of knowing if these will be the correct parameters to have measured 5, 10, 20, or 100 years from now (Figure 4.1).
In light of this, program managers should work with stakeholders to identify easily understood indicators of state variables (e.g., populations) and their state systems (e.g., habitat) to increase the odds that they will inform the decisions of future managers in a meaningful way. This can be difficult as there are often many options to choose from: Whitman and Hagan (2003) developed a matrix of 137 indicator groups by 36 evaluation criteria as a means of indexing biodiversity responses to forest management actions. A good rule of thumb for ensuring that yours are easily understood is to keep in mind that as indicators begin to span multiple species, multiple times, and multiple areas, clearly articulating goals, objectives, and uses for a program becomes increasingly complex. Although the numerous obstacles and complicated decisions are daunting, making the effort to understand and incorporate societal values is often the only way to develop indicators of change that will be meaningful to society and meet specific monitoring goals and objectives.
Targeted Versus Surveillance Monitoring
Before the process of setting goals and objectives begins, one should have a clear idea of what monitoring is and is not. In their review of monitoring for conservation, Nichols and Williams (2006) argue that monitoring should be equivalent to any scientific endeavor; complete with clearly defined hypotheses that should be produced through deductive logic and be postulated well before any data are collected. They go on to discuss what monitoring is by contrasting two distinct approaches: targeted monitoring vs. surveillance/“omnibus” monitoring (Nichols and Williams 2006). Targeted monitoring requires that the monitoring design and implementation be based on a priori hypotheses and conceptual models of the system of interest. In contrast, they suggest that surveillance monitoring lacks hypotheses, models or sound objectives (Nichols and Williams 2006).
Surveillance monitoring, however, is the more common of the two and often involves data collection with little guidance from management-based hypotheses. In many cases, these types of programs focus on a large number species and locations under the assumption that any knowledge gained about a system is useful knowledge. Surveillance monitoring has been criticized as “intellectual displacement behavior” because it lacks management-oriented hypotheses and clearly defined objectives (Nichols 2000). The primary, often unstated, goal of most surveillance programs is the continuation of past monitoring efforts and the identification of general population trends. Once a trend is detected, usually a decline, management options such as immediate conservation action or undertaking research to identify the cause of these declines are generally implemented (Nichols and Williams 2006). The main limitations of this approach are a dependence on statistical hypothesis testing for initiating management actions (i.e., an insignificant trend would lead to no management), time lags between an environmental change and a population response, costs and resource availability, and a lack of information on the causes of decline (Nichols and Williams 2006).
Despite its limitations, however, surveillance monitoring should not be viewed as a wasted effort. Many of the large-scale monitoring programs covering large geographic regions and estimating changes in numerous species or communities, such as those discussed in Chapter 2, could be considered forms of surveillance monitoring. Proponents of these types of programs emphasize the potential to identify unanticipated problems. For example, the omnibus surveillance of multiple species throughout a region may identify significant population changes for a particular species that are unexpected and perhaps counterintuitive. These changes would then be a starting point for more intensive monitoring and future hypotheses aimed at identifying the magnitude and causes of these changes. Before reaching this stage, however, surveillance monitoring is arguably necessary. It would be difficult to develop adequate hypotheses for a program that monitors the patterns and changes of the hundreds of bird populations throughout the United States, as the USGS Breeding Bird Survey does (Sauer et al. 2006).
In general, targeted monitoring puts less emphasis on finding and estimating population trends and a greater emphasis on monitoring priority species based on taxonomic status, endemism, sensitivity to threats, immediacy of threats, public interest, and other factors (Elzinga et al. 2001, Yoccoz et al. 2001, Nichols and Williams 2006). Targeted monitoring avoids the largest potential pitfall of surveillance monitoring: that significant parameters are missed because they were not identified early in the planning process. In most scenarios that warrant the implementation of a monitoring program, more specific parameters are integral to attaining the goals and objectives. Therefore, we typically advocate the use of targeted monitoring and the development of clear models, hypotheses and objectives it entails.
Incorporating Stakeholder Objectives
Once the concept of monitoring is clearly defined, you can begin to explore the matter of which monitoring priorities and objectives are best for your program. Both are often influenced by multiple stakeholders who bring to the table their own goals, needs, assumptions, and predictions that can conflict, coincide, or be mostly unrelated to yours. One primary goal of any monitoring program, therefore, is to incorporate the concerns and predictions of each party. This can be more art than science and is sometimes a challenge to carry out effectively, but it is certainly an important exercise to perform early in the stages of monitoring. Excluding interested parties from the process may require a re-crafting of monitoring objectives after data have been collected, which could undermine an entire program.
The effort to include multiple stakeholders in the early stages of monitoring could be thought of as a pre-emptive attempt at conflict resolution. Any monitoring program must make several decisions with respect to the objectives, the scale of data collection, and what type of data are to be collected. Your ideas of what final decisions might result from the program are entirely subjective. To set things in stone without considering other points of view can result in serious conflicts with many legal and social implications. Conflicts among stakeholders are common in natural resource management. These conflicts are often the result of differing perceptions, varying interpretations of the law, and self-interests that hold the potential to be reconciled with one another and with scientifically rigorous monitoring (Anderson et al. 2001). Thus, eliciting input from stakeholders in an a priori fashion and attempting to resolve conflicts before they become problems is always recommended. Anderson et al. (1999) suggested a general protocol for conflict resolution in natural resource management that can be easily adapted for incorporating stakeholders in wildlife monitoring:
Participants
A good first step is designating a group of people or committee for identifying stakeholders. Having an unbiased group of people, possibly representing different stakeholder groups, to oversee who to invite to the table leads to greater credibility and transparency. Indeed, the careful consideration of participants may be one of the most important steps in any monitoring plan.
Data
Once a group of stakeholders comes to the table there is likely to be a wide-ranging discussion on what types of data are relevant for monitoring. This is an important step in identifying information needs, assessing the potential costs and feasibility of collecting different data types, and agreeing on important state variables. In addition, stakeholders may already have data in their possession that they would be willing to submit for analysis. If stakeholders are already bringing data to the table, it is advisable that all parties sign a “certification” stating that the data have been checked for errors and come complete with metadata.
Analysis
A lofty goal for any initial discussion on monitoring might include an agreement on what data analyses will or will not be used. Although directions may shift as the analytical process proceeds, an early discussion on potential approaches and important assumptions (e.g., independence, parametric assumptions, and representative sampling) can be extremely useful.
Results
It is important for the stakeholders to agree on the interpretation and reporting of results. In many cases two groups of stakeholders could read the same scientific result and reach two different conclusions with different management implications. A clear understanding of the possible results and their interpretation will avoid confusion in interpretation down the road. Falsely assuming that all stakeholders understand analytical results may lead to the creation of a power hierarchy where those more comfortable with quantitative analysis have greater sway or are dismissed because they do not appreciate the more practical aspects of the monitoring plan.
No Surprise Management
Communication is a key component to any successful collaboration. Changes in project goals, objectives, data acquisition, data analysis, and sampling strategies should be updated to a group of stakeholders on a regular basis. Meetings should occur frequently enough that people can discuss ongoing or unexpected trends, and deliberate. These meetings must be balanced with holding meetings too frequently and simply not discussing anything new. Web site updates and webinars can be a useful way of engaging a large number of stakeholders regularly with less impact on their time.
Identifying Information Needs
Information collected should be designed to answer specific questions at spatial and temporal scales associated with the life history of the species and the scope of the management activities that could affect the species (Vesely et al. 2006). Identifying which factors to measure is usually best understood within a conceptual framework that articulates the inter-relationships among state variables (e.g., number of seedlings), processes influencing those variables (e.g., drought), and the scale of the system of interest (e.g., grassland ecosystem). Initially, such a conceptual model represents a shifting competition of hypotheses regarding the current state of our knowledge of a particular system and target species or communities (Figure 4.2). The development of a conceptual model is intellectually challenging and may take months, but this initial step is critical for developers of the monitoring protocol.
When developing a conceptual model, consider the following:
• It should represent your current understanding of the system that you intend to monitor.
• It should help you understand how the system works. What are the entities that define the structure of the system? What are the key processes? This often yields a narrative model—a concise statement of how you think the system works (i.e., a hypothesis).
• It should describe the state variables. What mechanisms and constraints will be included? Which will be excluded? What assumptions will be made about the system? At what spatial and temporal scales does the system operate? This often results in the construction of a schematic model, perhaps a Forrester diagram (a “box and arrow” model).
The conceptual model should allow the key states or processes that are most likely to be affected by management actions to be identified for monitoring. This will provide a framework for generating hypotheses about how the system works and inform the next step in designing the monitoring program: to develop a set of monitoring objectives that is based on these hypotheses and the results of your stakeholder outreach efforts.
The Anatomy of an Effective Monitoring Objective
Developing a conceptual model and understanding stakeholder values leads to the identification of important state variables and processes from which you can derive a set of effective and well-designed management objectives. The objectives serve as the foundation of the monitoring program. A hastily constructed set of management objectives will ultimately limit the scope and ability of a monitoring program to achieve its goals. A well-constructed set will provide the details for how, when, and who will measure the variables that are necessary for successful monitoring. As part of the larger framework, objectives force critical thinking, identify desired conditions, determine management and alternative management scenarios, provide direction for what and how to monitor, and provide a measure of management success or failure (Elzinga et al. 2001). There are three types of objectives that are pertinent to monitoring (Elzinga et al. 2001, Yoccoz et al. 2001, Pollock et al. 2002):
Scientific Objectives
Scientific objectives are developed to gain a better understanding of system behavior and dynamics (Yoccoz et al. 2001). In this case, a set of a priori hypotheses is developed to predict changes in state variables in response to environmental change. For example, a set of hypotheses regarding the population dynamics of shrubland songbirds in Connecticut may identify several state variables (e.g., bird abundance, presence/absence, reproductive success) and how those variables may change due to changing environmental conditions (e.g., drought, disturbance, land use change). In this case, several hypotheses are generated that readily translate to monitoring objectives. The key to using scientific objectives is to develop competing hypotheses and predictions that can be compared to patterns resulting from data analyses.
Management Objectives
Management objectives incorporate the predicted effects of management actions on system responses. These objectives describe a desired condition, identify appropriate management steps if a condition is or is not met, and provide a measure of success (Elzinga et al. 2001). Not unlike scientific objectives, management objectives should be developed using a priori hypotheses of how a species or population will respond to a given management action. The data collected are then compared to these predictions.
Sampling Objectives
Sampling objectives describe the statistical power that one is attempting to achieve through their management objectives. Many management objectives will seek to estimate the condition and/or a change in a target population (e.g., a 10% increase in juvenile survivorship), but the degree to which that estimate approximates the true condition will, in part, be a function of its statistical power. Consideration of statistical power is critical within a monitoring framework because of the implications of missing a significant effect (Type II error) and not initiating management when it is necessary to do so. In a monitoring program, the perceived condition of a system relates to a target or a threshold in a current state to a desired state. These targets or thresholds are reflected in management objectives. For example, a threshold objective would be limiting the coverage of a wetland site by an invasive species such as common reed to less than 20%. Once that condition (i.e.,< 20%) is reached or exceeded, a management action would be initiated. Management objectives may also relate to an active change in an existing state. That is, a change objective would be decreasing the cover of Common reed to less than 10%. In both of these cases, a sampling objective describes the statistical precision and variation associated with estimating that condition or change, oftentimes using a confidence level (e.g., be 90% confident the coverage of Common reed is estimated to within ± 5%). Sampling objectives relate to the statistical power of your sampling scheme and better inform you about your power to detect significant change (Gibbs et al. 1998).
Whether it is a scientific, management, or sampling objective, all monitoring objectives should consist of several key ingredients (Figure 4.3):
What?
The most important component of a monitoring objective identifies what will be monitored. Will you be monitoring a species or a group of species? Is the focus a specific population? Is the focal species an indicator species serving as a surrogate for another species or habitat type? Also, be clear as to the parameter associated with this target that you will be measuring. Are you collecting information on abundance, occurrence, reproductive success, demographics, or density?
Where?
The site or geographic area should be clearly delineated. Often times, managers cannot apply a monitoring program over the entire area of interest. In these cases, sample areas must be specified and the results of these sampling areas used to draw inference to the rest of the study area (Pollock et al. 2002). It is important that these sampling areas be defined objectively, be representative of the larger study area, be free of biases, and represent an appropriate spatial scale relative to the species or processes of interest.
When?
Providing a time frame is critical for achieving a monitoring objective. Time frames should incorporate species’ life history characteristics (e.g., breeding season, flowering, longevity), logistical constraints, and political schedules. Short time frames are always preferred due to changes in budget, management adaptation, and the uncovering of unexpected information (Elzinga et al. 2001), but may not be useful if dealing with long-lived organisms. When monitoring programs must be necessarily conducted over long time periods, considerable attention should be given to the likelihood of continued funding to support the program.
Who?
Often overlooked, the earlier one can identify who is conducting the monitoring the more likely that the program will be implemented correctly. This avoids the inevitable ambiguity of “passing of the buck”. In addition to the responsibility of conducting the monitoring efforts, is the involvement of stakeholders in the design and interpretation of the data. When continued funding is needed to maintain a monitoring program over long periods of time, key stakeholders include those involved in budgeting. At all stages of monitoring program managers should continually be thinking of who in our society could be affected by these results and ensure that they are kept informed.
Articulating the Scales of Population Monitoring
Another important aspect of setting goals and objectives is to define the scales of space and time over which monitoring should occur. Most populations occupy a landscape representing different habitat patches of varying quality. As a result, individuals in a population are interdependent on a number of areas that are influenced by constantly changing environmental conditions. Population trends are not only dependent on the quality of individual patches and areas, but also by the spatial and temporal distribution of suitable and unsuitable habitat patches. Management and development can have an immediate impact on the accessibility of habitat for a species, but the impact can also be delayed if the habitat changed is utilized seasonally or only in a particular ecological context, or if the manager or developer incorporates a species’ needs into her endeavors. Consequently, a hierarchical approach that takes a broad perspective that is not restricted by politically- and management-imposed boundaries, and allows an examination of population and habitat change across multiple scales should be considered when developing a monitoring plan.
Project or Site Scale
Managers and regulators often want to know what effect a specific management action will have on a population. Indeed, many of the factors that influence populations occur at the site level. For forests this might be a stand, for a town it could be an individual property, or for agriculture, a field. Factors such as resource availability, predation, parasitism, and competition that change as a result of management at these local scales can affect a number of demographic processes including fertility, survivorship, mortality, and dispersal within focal populations. Although these processes are important, the ability to repeatedly monitor them at the site level can be logistically and economically difficult. Even when it is possible, however, the most critical question that pertains to studying of species in small areas must still be addressed: Are the changes that are documented at the site-level are reflective of those occurring in the same species over a wider geographic area? For species with a restricted geographic range such as some plants and fish stocks, this scale may be an accurate representation of population change. In general, if the species is influenced by the same factors (e.g., weather, resources, predation, topography) throughout its geographic range, then fluctuations on a small scale will often accurately represent fluctuations on a wider scale. However, if factors are site-specific, as they often are, then fluctuations in occurrence and abundance will vary from place to place (Holmes and Sherry 1988). In this case, monitoring population change at a larger scale will be more meaningful. It is important to note, however, that as the scale gets larger, identifying the causes of any observed changes can be increasingly difficult.
Landscape Scale
Since many animal populations are dynamic, occupy a heterogeneous landscape, and use multiple resources across that landscape, it is important that population monitoring incorporates the context of any particular site. Indeed, monitoring efforts must incorporate areas surrounding the forest stand, field or other site, to include water bodies, ownership, other habitat types, barriers and corridors. This is especially important for species that have large home ranges and/or use multiple sites during their life history, or for species that depend on dynamic habitats that are influenced by weather, season, or succession.
The arrangement of resources over a large geographic area can be critical for sustaining a population. Monitoring over large complex landscapes may increase your ability to detect long-term changes in abundances, predation rates, extinction rates, patch dynamics, metapopulation dynamics, disturbance effects, and rates of human influences on focal species (Noss 1990). However, monitoring at this scale also presents difficulties in design and logistics, because landscapes, not patches, become the sampling units (McGarigal and McComb 1995, McGarigal and Cushman 2002, Meffe et al. 2002, Pollock et al. 2002).
At the landscape scale, population trends are not only dependent on the quality or extent of individual habitat patches, but also on the spatial distribution, pattern, and connectivity of suitable and unsuitable patches (Meffe and Carroll 1997). Landscape pattern, in turn, is influenced by the type of patches, size of patches, length of surrounding edge, barriers between patches, and nature of corridors (McComb 2001, McComb 2007). Fragmentation, for instance, can lead to the isolation of some important habitat patch types, which can lead to disruptions in species dispersal, and eventually to extinction despite management to conserve a species at a site scale. Whether an area is connected or fragmented ultimately depends on the habitat requirements and dispersal abilities of the organism. Nonetheless, at times even sampling over large landscapes cannot answer key questions because no information is provided concerning the effect of the context of the landscape on a species’ population dynamics. Consequently, sampling at even larger spatial scales may be needed for some species.
Range-Wide Scale
A larger perspective is especially important for sensitive and management-indicator species because many have developed morphological and behavioral adaptations that are unique to certain geographic locations (Cody 1985). Range-wide data and trends provide a perspective into localized population changes. For example, populations of Blue-winged Warblers have been declining in Connecticut at a rate of 3.4% per year over the last 40 years (Figure 4.4). However, the concern over this rate of decline is greatly amplified because an estimated 13% of the global population of this species is found in Connecticut (Figure 4.5, Rosenberg and Wells 1995).
There are few examples of successful long-term monitoring programs that document changes in populations throughout entire geographic ranges, but the North American Breeding Bird Survey, Waterfowl Harvest Surveys, Salmon Escapement monitoring, USDA Forest Service’s Forest Health Monitoring Program, and Agricultural Production monitoring have produced useful results. Ideally, all monitoring protocols would be designed to detect population changes in a species throughout its range; however, this is often logistically and financially prohibitive. This is particularly true for the many species that may have broad geographic ranges. Yet even if active monitoring cannot be undertaken on a range-wide scale, a monitoring program must make an attempt to understand the context of any population changes it documents in the most informed way possible.
Organism-centered Perspective
The most important spatial scale to a species is defined by its life history and habitat requirements. The different habitat requirements between groups of birds, insects, and mammals are clear, but even within these larger groups, species that share similar preferences for food, water, and cover, may have vastly different requirements for space. Species with similar requirements for vegetation and other resources are often affected differently by management actions due to differences in area-sensitivity and home range sizes. An organism-centered view suggests that there is no general definition or perspective of habitat pattern. Therefore the effects of management actions that alter the spatial arrangement of habitat patches across a landscape will ultimately vary from one species to the next. For example, a 10-ha clearcut can have a profound influence on a small forest passerine with a restricted territory size, such as a Black-and-White Warbler, but have relatively no impact on a Cooper’s Hawk whose territory includes hundreds of hectares.
Area requirements and sensitivity to patch size are not the only factors influencing a species’ response to management. The dispersal capabilities of species are a critical component that determines whether or not a population is directly effected by loss of habitat resulting from management or, inordinately affected by fragmentation of its habitat . Species migrate between habitats that are separated by ecological and anthropogenic barriers. However, each species differs in its perception of these “gaps” in habitat and therefore in its ability to successfully cross them (With 1999). A landscape is fragmented if individuals cannot move from patch to patch and are isolated within a single area. Simulations have suggested that species with limited dispersal capabilities are much less likely to successfully cross habitat “gaps” to other habitat clusters relative to species with a higher ability to disperse (With 1999) (Figure 4.6). Whether or not management causes fragmentation, and how monitoring should address this effect, must be addressed from an organismal perspective.
Data Collected to Meet the Objectives
After creating your conceptual model of population persistence for your species and putting this into the proper spatial context, specific questions regarding the potential impacts of management on a species should emerge. The scope of the monitoring program should lead the investigators to identify a set of questions that can be addressed by different data types. For instance, consider the following five questions and the decisions that could be made to meet the information needs associated with each (from Vesely et al. 2006):
1. Given our lack of knowledge of the distribution of a clonal plant species, we are concerned that timber management plans could have a direct impact on remaining populations that have not yet been identified on our management district. How will we know if a timber sale will impact this species?
In this example the plant species may have a geographic range extending well beyond the timber sale boundaries and over multiple National Forests, but populations of this species are patchily distributed and their abundance is poorly known. Based on our conceptual model of persistence, therefore, we are concerned that population expansion and persistence may be highly dependent on movement of propagules among sub-populations and that additional loss of existing patches may exacerbate the loss of the population over a significant portion of its range. Consequently the primary goal of a monitoring effort should be to identify the probability of occurrence of the species in a timber sale. A survey of all (or a random sample of) impending timber sales will provide the land manager with additional information with regard to the distribution of the species. Although information may be collected that is related to fitness of the clone (size, number of propagules, etc.), the primary information need is to estimate the probability of occurrence of the organism prior to and following management actions. Indeed, this survey and manage approach also lends itself well to development of a secondary monitoring approach that utilizes a manipulative experiment. Explained in more detail later, identification of sites where the species occurs can provide the opportunity for random assignment of manipulations and control areas to understand the effect of management on the persistence of the species. This approach may be particularly important when dealing with species, such as cryptic or infrequently apparent species, where the probability of not detecting individuals is relatively high despite the species being present on the site.
1. Given the uncertainty in the distribution of a species of a small mammal species over a management area, we are concerned that planned a timber harvest could have an undue impact on a large proportion of individuals of this species within the management area. We need to have an unbiased estimate of the abundance of the species over the entire planning area to understand if the proposed management activities indeed have the potential to impact a significant portion of the population.
In this example, the species geographic range extends well beyond the boundaries of the management area, but the manager is concerned that the sites under consideration for management may be particularly important for the species’ persistence within her management area. The manager therefore needs to understand the dynamics of the population within the sites, but also the population dynamics within the entire management area, as well as the interplay between these levels to understand the full potential for adverse effects on the species. Based on survey information it is clear that the species occurs in areas that are planned for harvest. But do they occur elsewhere in the management area? With an unbiased estimate of abundance, that extends over the area (or forest, or watershed, etc.) one can estimate (with known levels of confidence) if the proposed management activities might affect 1% of the habitat or population for this species or 80% of the habitat or population. Consider the differences in management direction given these two outcomes. Collecting inventory information following standardized protocols over management units provides the manager with a context for proposed management actions and is integral to a successful hierarchical approach.
1. Given the history of land management on a Refuge, how will the future management actions described by the current Comprehensive Conservation Plan (CCP) influence the abundance and distribution of a sub-population of a salamander species that we know occurs on our Refuge?
In this example, the species again has a geographic range that extends well beyond the boundaries of the Refuge, but there is concern that the relatively immobile nature of subpopulations of this species may make the animals on the Refuge highly important in contributing to its range-wide persistence. If the Refuge’s subpopulation is adversely impacted by management and has shown historical declines in abundance as a result of the past management activities, the CCP may need to be amended. The goal, therefore, is to establish the current status of the species on the Refuge and allow managers to detect trends in abundance over time. Changes in abundance or even occurrence may be difficult to detect at the project scale (e.g, road building), because individuals are patchily distributed, but if data are collected cumulatively over space and time, impacts could become apparent. Consequently, this status and trends monitoring approach should extend over that portion of the Refuge where the species is known or likely to occur and provide an estimate of abundance of the species at that scale at several different time periods. It is important to distinguish between an estimate of abundance over a large area (inventory), and a total count of all individuals in an area (census). Inventories, when conducted following sampling guidelines, and accounting for detection probabilities, can produce estimates with known levels of confidence. Censuses often are not cost effective unless the species occurs in very low numbers and the risk of regional or range-wide extinction is high.
In short, the focus of this monitoring effort would be to document changes in abundance over time over a spatial scale that encompasses the sub-population of concern. One final consideration is that, if at all possible, the abundance estimates should be specific to age and sex cohorts to allow managers to identify potential impacts on population demographics. For instance, reduction in the oldest or youngest age classes, or of females, may provide information on recruitment rates that is significant enough to cause changes in management actions before a significant change in total abundance occurs.
1. Assume that concern has been expressed for a species of neotropical migrant bird whose geographic range extends across an ecoregion. The monitoring plan needs to assess if the history of land management throughout the ecoregion and the multiple plans for future management applicable to the region are contributing to changes in populations over time. In other words, are multiple types of management having an effect on the population?
In this example we are dealing with a species that is probably widely distributed, reasonably long-lived, and spends only a portion of its life in the area affected by proposed management. One could develop a status and trends monitoring framework for this species, but the data resulting from that effort would only indicate an association (or not) with time. It would not allow the manager to understand the cause and effect relationship between populations and management actions.
In this case there are several strata that must be identified relative to the management actions. Can the ecoregion be stratified into portions that will not receive management and others that will receive management? If so, then are the areas in each stratum sufficiently large to monitor abundance of those portions of the populations over time? Monitoring populations in both strata prior to and following management actions imposed within one of the strata would allow the managers to understand if changes occur in the most important response variables from the conceptual model due to management. For instance, if populations in both managed and unmanaged areas declined over time, then the managers might conclude that population change is independent of any management effects and some larger pervasive factor is leading to decline (e.g., climate change, changes in habitat on wintering grounds). On the other hand, should populations in the unmanaged stratum change at a rate different from that on the managed stratum, then the difference could be caused by management actions, and lead managers to change their plan.
1. Finally, say that the conceptual model suggests that the most likely factor affecting the change in population of a wide-ranging raptor is nest site availability. At the ecoregion scale, population density is low and the probability of detecting a change in abundance or fitness at that scale is likewise very low. Rather, managers may wish to monitor habitat elements that are associated with demographic characteristics of the species. How might a monitoring protocol be developed that would allow managers to use habitat elements as an indicator of the capability of an ecoregion to contribute to population persistence?
An unbiased estimate of the availability of habitat elements assumed to be associated with a demographic characteristic of the species and an estimate of the demographic characteristic assumed to be associated with the habitat elements are needed to develop wildlife habitat relationships. Ideally, monitoring of the habitat elements and the demographic processes can be conducted to assess cause and effect relationships (see above), but with rare or wide-ranging species this may not be possible. In these cases, testing a range of relationships through use of information theoretic approaches can help you to identify the ‘best’ relationship given the limitations of the data (Burnham and Anderson 2002). Regardless of the resulting monitoring design, it is important that the monitoring framework for the vegetation component of the habitat relationship is implemented at spatial and temporal scales consistent with those used by the species of interest.
Which Species Should Be Monitored?
If you have several options for species or groups of species that, if monitored, will yield data that meets your objectives, how should you decide which to monitor? Where should you focus time and money? Although the species selected will oftentimes be driven by the values of the stakeholders associated with land use and land management in the area of interest, sometimes characteristics of the species themselves help to focus the list. The following categories of species are some of those most commonly viewed as worthy of special consideration and therefore particularly useful for practitioners when selecting the species to be monitored:
1. Level of Risk – the perceived or real level of risk of loss of the species from the area now and into the future. Risk can be based on previously collected data, expert opnion and stakeholder perceptions.
2. Regulatory status – Species listed under State and/or Federal threatened or endangered species legislation.
3. Government Rare Species or Communities classification –those species or plant communities designated by federal or state agencies as in need of special consideration.
4. Restricted to specific seral stages – species sensitive to loss of a vegetative condition such as a stage of forest, wetland, or grassland succession. Species associated with seral stages or plant communities that are under-represented relative to a reference condition or the historic range of variability often rise to the top when identifying focal species.
5. Sensitivity to environmental change/gradients – species sensitive to environmental gradients such as distance from water, altitude, soil conditions, or characteristics. Under current climate change scenarios, for instance, species associated with high altitudes or high latitudes are of particular concern.
6. Ecological function – species that are particularly important in modifying the processes and functions of an ecosystem. For instance, gophers expose soil in grasslands and voles move mycorrhizal fungal spores in forests.
7. Keystone species — species whose effects on one or more critical ecological processes or on biological diversity are much greater than would be predicted from their abundance or biomass (e.g., beaver, large herbivores, predators).
8. Umbrella species — species whose habitat requirements encompass those of many other species. Examples include species with large area requirements or those that need multiple vegetative conditions, such as raptors, bears, elephants or caribou.
9. Link species — species that play critical roles in the transfer of matter and energy across trophic levels or provide a critical link for energy transfer in complex food webs (e.g., insectivorous birds) or which through their actions influence trophic cascades effects (Ripple and Beschta 2008)
10. Game species – species that are valued by segments of society for recreational harvest.
11. Those for which we have limited data or knowledge – monitoring may provide an information base necessary to understand if continued monitoring is needed.
12. Public/regulatory interest – some species are simply of high interest to the general public because of public involvement (e.g., bluebirds, wood ducks, rattlesnakes). These can include species that are desirable as well as those that interfere with people’s lives.
Intended Users of Monitoring Plans
Monitoring plans can be useful for a variety of users including agency managers and planners, the general public, politicians (to ensure adherence to local, state and federal legislation), non-governmental organizations with similar missions, and also industries with Habitat Conservation Plans on adjacent or nearby lands. Different components of a monitoring plan often are useful to different stakeholders. For instance, a survey prior to a management action may allow a manager to alter the management action to accommodate a species found on the site during the survey. A declining trend in a focal species population in the managed portion of a site compared to an unmanaged portion may allow a Land Planner to make changes in an adaptive management framework over the site. While at a larger scale, regional declines in a species on public land-holdings may lead to legislation or agreements that span ownership boundaries across the species’ geographic range to encourage recovery. Expected products will be dependent on the questions that are asked. Occurrence, abundance, fitness, range expansion/contraction, each may be appropriate to address certain questions. Whatever the measure, whatever the question, and whatever the expected product, the results must be effectively communicated so that the manager, planner or politician can make an informed decision regarding the likely effects of a management action or legislation on the long-term persistence of the species.
Summary
Some biologists distinguish between targeted and surveillance monitoring. Targeted monitoring requires that the monitoring design and implementation be based on a priori hypotheses and conceptual models of the system of interest. Surveillance monitoring oftentimes lacks hypotheses, models or specific objectives. The structure of each approach is driven largely by societal values. Stakeholder involvement in identification of indicators and thresholds for changes in management efforts is a key step in developing a monitoring plan. Suggested steps in stakeholder involvement include:
• Identify the participants.
• Agree on the types of data needed.
• Agree on the types of analysis to be used.
• Agree on how the results will be interpreted.
• Agree on ‘no surprises’ management
Developing a conceptual model and understanding stakeholder values can help to identify important state variables and processes from which management objectives will emerge. Objectives should consider the following questions: What, Where, When, and Who? Objectives also have a scale component. Deciding if the results will address questions at the project, landscape, or geographic range scales influences the utility of the information that is gathered. Alternatively monitoring organisms may be most appropriate. Finally where there is a choice as to which species to monitor, the values of the stakeholders may guide species selections. Rare species invariably rise to the top of a list, but economically important species, keystone species or species that are indicative of ecosystem stresses may also be selected depending on the stakeholder interests. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.04%3A_Goals_and_Objectives_Now_and_Into_the_Future.txt |
Design of a monitoring plan is a process (Figure 5.1) that will ideally lead you through problem identification, to development of key questions, a rigorous sampling design, and analyses that can assign probabilities to observed trends. Finalizing a plan designed as an outcome of this process is a precursor to initiation of data collection. This is probably the single most important step in the monitoring plan. Once you have decided on the design for the monitoring plan, and begun collecting data, there is strong resistance to changing the plan because many changes will render the data collected thus far of less value. So design it correctly from the outset to minimize the need for changes later.
Articulating Questions to Be Answered
It is important to view monitoring as comparable in many ways to conducting a scientific investigation. The first step in the process is to develop a conceptual framework for our current understanding of the system, complete with literature citations to support assumptions. Clearly no monitoring program will have all of the information needed to completely develop a conceptual model for the system under consideration. Available information will have to be extracted from the literature, from other systems and from expert opinion. Nonetheless, the conceptual model needs to be developed in order to identify the key gaps in our knowledge and allow a clear articulation of the most pertinent questions (Figure 5.2).
As you develop the monitoring plan you should pay particular attention to some terms that are commonly used to define the problem and the approach. Within the context of land management and biodiversity conservation, these terms might guide you to the kind of monitoring design that you will choose to use.
These terms relate to the experimental design:
• Cause and effect – Will you be able to infer the cause for observed changes?
• Association or relationship – Will you be able to detect associations between pairs of variables such as populations and changes in area of a habitat type?
• Trend or pattern – Will patterns over space and/or time be apparent?
• Observation or detection – What constitutes having ‘observed’ an individual?
These terms relate to the response variable that you will measure to assess one of the above:
• Occurrence — Was the species present, absent or simply not detected?
• Relative abundance – Did you observe more individuals in one place or time than another?
• Abundance – How many individuals per ha (or square km) are estimated to be present?
• Fitness – Is the species surviving or reproducing better in one place or time than another?
These terms relate to the scope of inference for the effort:
• Stand, harvest unit, field, pasture, project, farm, district, watershed, forest, region — defines the grain and extent of the spatial scale of the potential management effects
• Home range, sub-population, geographic range, stock, clone — defines the grain and spatial extent associated with the focal species.
• Frequency of management or exogenous disturbances affecting the system — helps define the sampling interval
• Return interval between disturbances or other events likely to effect populations of the focal species — helps define the duration of the monitoring framework
• Disturbance intensity or the degree of change in biomass or other aspects of the system as a function of management or exogenous disturbances — helps to understand how effect sizes should be defined and hence the sampling intensity sufficient to detect trends or differences.
Once you have articulated questions based on the conceptual model for the system, then you should use terms from each of the groups above to further define the monitoring plan. Detail and focus are important aspects of a well-designed monitoring system. Use of vague or unclear terms, broad questions, or unclear spatial and temporal extents will increase the risk that the data collected will not adequately address the key questions at scales that are meaningful. Further, clearly articulated questions not only ensure that data collected are adequate to address specific key knowledge gaps or assumptions, they also provide the basis for identifying thresholds or trigger points which initiate a new set of management actions.
If the above terms are considered when the monitoring plan is being designed, and trigger points for management action are described clearly prior to monitoring, then it should be apparent that the universe of questions that could be addressed by monitoring is very broad. Of course, your challenge is to identify the key questions that address the key processes and states in an efficient and coordinated manner over space and time. Given a conceptual model developed for a system, there is a range of questions that could be addressed through monitoring. Prioritization of these questions allows the manager to focus time and money on the key questions.
Inventory, Monitoring, and Research
The questions of concern may be addressed using inventory, monitoring or research approaches (Elzinga et al. 1998). Inventory is an extensive point-in-time survey to determine the presence/absence, location or condition of a biotic or abiotic resource. Monitoring is a collection and analysis of repeated observations or measurements to evaluate changes in condition and progress toward meeting a management objective. Detecting a trend may trigger a management action. Research has the objective of understanding ecological processes or in some cases determining the cause of changes observed by monitoring. Research is generally defined as the systematic collection of data that produces new knowledge or relationships and usually involves an experimental approach, in which a hypothesis concerning the probable cause of an observation is tested in situations with and without the specified cause. Some biologists make a strong case that the difference between monitoring and research is subtle and that monitoring should also be based on testable hypotheses. Nonetheless, these three approaches to gaining information are highly complementary and not really very discrete. And all three approaches are needed to effectively manage an area without unnecessary negative effects.
Are Data Already Available?
You may already have some data that have been collected previously or from a different area. Can you use these data? Should you? What constitutes adequate data already in hand, or how do we know when data are adequate to address a question? Well, that depends on the question! For example, if we want to be 90% sure that a species does not occur in a patch or other area to be managed in some manner in the next year, how many samples are required to reach that level of confidence? Developing a relationship between the amount of effort expended and the probability of detecting species ‘x’ in a patch, can provide insight into the level of effort needed to detect a species 90% of the time when it indeed does occur in the patch. This requires multiple patches and multiple samples per patch over time to place confidence intervals on probabilities (Figure 5.3). Where multiple species are the focus of monitoring, a species-area chart can be quite helpful. For example in Figure 5.4, sampling an area less than 7 hectares in size is not likely to result in a representative list of species for the site.
These sorts of questions require quite different data than would be required to answer the question: What are the effects of management ‘x’ on species ‘y’? Note that the term’ effect’ is used in this example, so the experimental design is ideally in the form of a manipulative experiment (Romesburg 1981). In this case, we would want to have both pre- and post-treatment data collected on a sample of patches that do and do not receive treatment. In the following example, two of the treatments clearly had an effect on the abundance of white-crowned sparrows in managed stands in Oregon (Figure 5.5). Results such as these are base don specific questions. It is the development of the question that is important and the question should evolve from the conceptual model of the system. Clearly the development of a conceptual model to describe the system states, processes, and stressors, should be based to the degree possible on data. So although currently available data are valuable, they must address the question of interest in a manner that is consistent with the conceptual model. It is important to recognize that not all data are equal. Consider the following questions when evaluating the adequacy of a data set to address a question or to develop a conceptual framework:
1. Are samples independent? That is, are observations in the data set representing management units to which a treatment has been applied? Using a forest example, taking 10 samples of densities of an invasive species from one patch is not the same as taking one sample from 10 patches (Hurlbert 1984). In the former example, the samples are sub-samples of one treatment area, in the latter there is one sample in each of 10 replicate units. If the species under consideration has a home range that is less than the patch size, then the patches are reasonably independent samples. If the species under consideration has a home range that spans numerous patches, then the selection of patches to sample should be based on ensuring to the degree possible that one animal is unlikely to use more than one managed patch.
2. How were the data collected? What sources of variability in the data may be caused by the sampling methodology (e.g., observer bias, inconsistencies in methods, etc.)? If sample variability is too high because of sampling error, then the ability to detect differences or trends will decrease. Further if the samples taken are biased then the resulting conclusions will be biased and decisions made based on those conclusions may be inappropriate.
3. Were sites selected randomly? If not, then there may be (likely is) bias introduced in to the data that should raise doubts in the minds of the scientists, managers and stakeholders with regard to the accuracy of the resulting relationships or differences.
4. What effect size is reasonable? Even a well designed study may simply not have the sample size adequate to detect a difference or relationship that is real simply because the study was constrained by resources, rare responses, or other factors that increase the sample variance and decrease the effect size that can be detected. Again, how this is dealt with depends on the question being asked. Which is more important, to detect a relationship that is real or to say that there is no relationship when there really isn’t? In many instances, where monitoring is designed to detect an effect of a management action, the former is more important. In that case, the alpha level used to detect differences or trends may be increased (from say 0.05 to 0.10), but you will be more likely to say a relationship is real when it is really not. Alternatively, you may want to use Bayesian analysis or meta-analysis to examine the data and see if these techniques shed light on your question. See Chapter 11 for a more in-depth discussion of these analytical techniques.
5. What is the scope of inference? From what area were samples selected? Over what time period? Are the results of the work likely to be applicable to your area? As the differences in the conditions under which the data were collected increase compared to the conditions in your area of interest, the less confidence you should have in applying the results in your context.
If, after considering the above factors, you feel that the data can be used to reliably identify known from unknown states and processes in the conceptual model, then you should have a better idea where the model relies heavily on assumptions, weak data, or expert opinion. These portions of the conceptual model should rise to the top during identification of the question that monitoring should be designed to address.
Provided that the cautions indicated above are explored, it is reasonable and correct to use data that are already available to inform and focus the questions to be asked by a monitoring plan. Existing data are commonly used to address questions. For instance, Sauer et al. (2001) provided a credibility index that flags imprecise, small sample size, or otherwise questionable results. Yellow-billed cuckoos have shown a significant decline in southern New England over the past 34 years (Figure 5.6), but the analysis raises a flag with regards to credibility because of a deficiency in the data associated with low abundance (<1.0 bird/route). Further, an examination of the data would indicate that the one estimate in 1966 may be an outlier and may have an over-riding effect on the results. In this example, it would be useful to delete the 1966 data and re-run the analyses to determine if the relationship still holds. Regardless of the outcome of this subsequent analysis, the data will likely prove useful when developing a conceptual model of population change for the species. When the proper precautions are taken, such data may allow the manager to focus on more specific questions with regard to a monitoring plan. For instance, within the geographic range of the species, what factors may be causing the predicted declines? The BBS data reveals that the species is not predicted to have declined uniformly over its range (Figure 5.7). This information may provide an opportunity to develop hypotheses regarding the factors causing the declines.
Recorded trends in abundance for eastern towhees (fig 5.8) provide another clear example. In this case, declines are apparent throughout the entire northeastern United States. Based on our knowledge of changes in land use in the northeast and the association of this species with early successional scrub vegetation, we would hypothesize that the declines are a direct result of the re-growth of the eastern hardwood forests and subsequent loss of shrub-dominated vegetation. Indeed, monitoring the reproductive success of the species prior to and following vegetation management designed to restore shrub vegetation might allow detection of a cause and effect relationship that would lead to a change in monitoring for the species over the northeastern portion of its range. If changes in abundance were related to changes in land cover (and not to parasitism by brown-headed cowbirds or other effects), then an alternative monitoring framework could be developed. Infrequent monitoring of populations with frequent monitoring of the availability of the habitat elements important to the species (shrub cover) may be adequate to understand the opportunities for population recovery (or continued decline). This reveals the potential benefits of applying previously generated data: generally costs associated with monitoring habitat availability are less than costs associated with monitoring populations or population fitness, so if a cause and effect relationship were detected between vegetation and bird populations, then managers could see considerable savings in their monitoring program.
In summary, although there are general guidelines with regards to what constitutes reliable data, adequate data for one question may be inadequate for another. Use of existing data and an understanding of data quality can allow development of a conceptual model where states, processes and stressors can be identified with varying levels of confidence. Those factors that are based on assumptions or weak data and which seem quite likely to be influencing the ability to understand management effects, should become the focus when developing the questions to be answered by the monitoring plan.
Types of Monitoring Designs
Before we provide examples of the types of monitoring designs, recall that there are several main points consistent among all designs:
1. Are the samples statistically and biologically independent?
2. How were the data collected? What sources of variability in the data may be caused by the sampling methodology (e.g., observer bias, inconsistencies in methods, etc.). If sample variability is too high because of sampling error, then the ability to detect differences or trends will decrease.
3. Were sites selected randomly? If not, then there may be (likely is) bias introduced in to the data that should raise doubts in the minds of the plan developers with regard to the accuracy of the resulting relationships or differences.
4. What effect size is reasonable to detect?
5. What is the scope of inference?
Once these questions are addressed, then there are additional considerations depending on the type of monitoring that will be conducted.
Incidental Observations
Opportunistic observations of individuals, nest sites, or habitat elements can be of some value to managers, but often are of not much use in a monitoring framework except to provide preliminary or additional information to a more structured program. For instance, global positioning system (GPS) locations of a species observed incidentally over a three-year period could be plotted on a map and some information can be derived from the map (known locations). The problem with using these data points in a formal monitoring plan is that they are not collected within an experimental design. There undoubtedly are biases associated with where people are or are not likely to spend time; with detectability among varying vegetative, hydrologic, or topographic conditions; and detectability of different age or sex cohorts of the species. Consequently this information should be maintained, but rarely would it be used as the basis for a formal monitoring design.
Inventory designs
Assume that you are concerned that proposed management actions will impact a species that could be present in your management area. How sure do you want to be that the species occurs on the proposed management area? Do you want to know with 100% confidence? Or can you be 95% sure? 90%? The answer to that question will dictate both the sampling design and the level of intensity with which you inventory the site to estimate presence and (presumed) absence.
First, and foremost, you will need to decide what will constitute an independent sample for this design. Are you most concerned that a species does/does not occur on a proposed set of managed patches? If so, sampling of all, or a random sample of proposed managed patches will be necessary. But what if the managed patches are clustered and the species of interest has a home range that overlaps some of the managed patches? Are you likely to detect the same individual on multiple units? If so, is it necessary to detect it on all units within the species home range? Not likely. For species with home ranges larger than a managed patch, you will probably want to sample an area of sufficient size and intensity to have a high probability of detecting the species within that home-range-sized area. Randomly selected areas should be independent with respect to minimizing the potential for detecting the same individual on multiple sites. Random sampling of sites then would be constrained by eliminating those sites where double counting of individuals is likely.
In an inventory design generally you wish to be ‘x’ confident that you have detected the species if it is really there. Consequently a pilot study that develops the relationship between the probability of detecting an individual and sampling intensity will be critical. Consider use of remotely activated recorders for assessing presence/absence of singing male birds in an area. How many mornings would you need at each site to detect a species that does occur at the site? A pilot study may entail 20 or 30 sites (more if the species is rare) to allow you to graph the cumulative detections of the species over the number of mornings sampled (Figure 5.2). Eventually an asymptote should be reached and one could then assume that additional sampling would not likely lead to additional detections. Confidence intervals can be placed on these estimates, and the resulting estimated level of confidence in your ability to detect the species can (and should be) reported. Results of pilot work (or published data) such as this often allow more informative estimates of the probability of a species occurring in an area to be generated in the subsequent sampling during the monitoring program. This is especially the case when estimated levels of confidence can be applied to the monitoring data.
There are several issues to consider when developing a monitoring plan that is designed to estimate the occurrence or absence of a species in an area. First, the more rare or cryptic the species, the more samples that will be needed to assess presence, and the sampling intensity can become logistically prohibitive. In that case other indicators of occurrence may need to be considered.
Consider the following possibilities when identifying indicators of occurrence in an area:
1. Direct observation of a reproducing individual (female with young)
2. Direct observation of an individual, reproductive status unknown (Are these first two indicators of occurrence or something different, such as indicators that management will have an impact?)
3. Direct observation of an active nest site
4. Observation of an active resting site or other cover
5. Observation of evidence of occurrence such as tracks, seeds, pollen
6. Identification of habitat characteristics that area associated with the species
Any of the above indicators could provide evidence of occurrence and hence potential vulnerability to management, but the confidence placed in the results will decrease from number 1 to number 6 for most species based on the likelihood that the fitness of individuals could be affected by the management action.
Finally we strongly suggest that statistical techniques that include data that influence the probability of detection be used. MacKenzie et al. (2003) provide a computer program PRESENCE that uses a likelihood-based method for estimating site occupancy rates when detection probabilities are <1 and incorporates covariate information. They also provide information on survey designs that allow use of these approaches (MacKenzie and Royle 2005).
Status and trend monitoring designs
Long-term monitoring of populations to establish trends over time are coordinated over large areas under several efforts. For instance the US Geological Survey (USGS) Biological Resources Division (BRD) has been involved in monitoring birds and amphibians, as well as contaminants and diseases that may affect populations of these species. Results of these efforts as well as supporting research information provides the basis for understanding why we might be seeing trends in biological resources over large areas (e.g., USGS Status and Trends Reports). Such monitoring systems provide information on changes in populations, but they do not necessarily indicate why populations are changing. For instance, consider the changes in American woodcock populations over a 27-year period (Figure 5.9).
Clearly, the number of singing males has declined markedly over this time period. This information is very important in that it indicates that additional research may be needed to understand why the changes have occurred. Are singing males simply less detectable than they were in 1968? Are populations actually declining? If so, are the declines due to changes in habitat on the nesting grounds? Wintering grounds? Migratory flyways? Is the population being over-hunted? Are there disease, parasitism, or predator effects that are causing these declines? Are these declines uniform over the range of the species or are there regional patterns of decline? Analysis of regional patterns indicates that the declines may not be uniform (Figure 5.10). .Indeed, declines in woodcock numbers are apparent in the northeastern U.S., but not throughout the Lake States. So it would seem that causes for declines are probably driven by effects that are regional. Woodcock provide a good example of the need to consider the scope of inference in design of a status and trends monitoring plan. The Breeding Bird Survey data indicate that there are areas where declines have been significant, and the work by Bruggink and Kendall (1997) indicate that the magnitude of the declines in some areas are perhaps even greater than might be indicated by the regional analyses. Such hierarchical approaches provide opportunities for understanding the potential causes for change in abundance or relative abundance of a species at a more local scale. This insight may allow managers to be more effective in identifying the causes of declines at local scales in a manipulative manner where local, intensive monitoring and research can result in the discovery of a cause and effect relationship.
Consequently the design of a status and trends monitoring plan should carefully consider the scope of inference, generally a large portion of the geographic range, and may necessitate the coordination of monitoring over large areas and multiple agencies. Site-specific status and trends analyses will probably be of limited value in many instances because the fact that species ‘x’ is declining at site ‘y’ is probably not as important as knowing why the species is declining at site ‘y’. In addition, for those species with a meta-population structure (ones with subpopulations maintained by dispersal and recolonization), observed changes at local sites may simply reflect source-sink dynamics in the meta-populations and not the trend of the population as a whole. Using status and trends monitoring to detect increases or declines in abundance is perhaps best applied to identify high priority species for more detailed monitoring, or to allow development of associations with regional patterns of vegetation or urban development. These associations then allow the opportunity for a more informed development of hypotheses that can then be tested in manipulative experiments to identify causes for changes.
One aspect of status and trends monitoring that must be considered carefully is the sampling intensity needed to detect a change in slope over time. Consider the data in figure 5.9. Annual data were quite variable over the 27-year period, but a trend is still detectable because the slope was so steep. Annual variability caused by population fluctuations and sampling variance can prevent detection of a statistically significant change in slope. This problem is exacerbated when the slope is not so dramatic. Consider the trend for whitefish harvest in Lake Erie (Figure 5.11). Annual variability in whitefish harvest was so variable from year to year that detection of a statistically significant trend line is very difficult. Commercial harvest as an indicator of populations is clearly biased due to variability in harvest intensity, resource value and techniques. Use of traditional time-series regression analyses to detect trends may not be the best approach. Use of Bayesian analyses may be more informative (Wade 2000). Nonetheless when commercial harvests reach zero (or nearly so), a threshold is reached where dramatic action must be taken to recover the stocks. Hence there are several factors that must be considered carefully in the design of status and trends plans:
1. What is the spatial scale over which you wish to understand if populations are declining or increasing? If the extent of the monitoring effort is not the geographic range of a species or sub-species, than what portion of the geographic range will be monitored and how will the information be used?
2. Is the indicator (e.g., occurrence, abundance, fitness) that is selected as unbiased as possible and not likely to vary among time periods except those caused by fluctuating populations?
3. Given the inherent variability in the indicator that is being used, how many samples will be needed each time period to allow detection of a slope of at least ‘x’ percent per year over time (Gibbs and Ramirez de Arellano 2007)?
4. Given the inherent variability in the indicator that is being used, at what point in the trend is action taken to recover the species or reverse the trend (what is the trigger point)? Note that this must be well before the population reaches an undesirably low level, because the manager will first have to understand why the population is declining before action can be taken.
5. Will the data be used to forecast results into the future? If so, recognize that the confidence intervals placed on trend lines diverge dramatically from the line beyond the bounds of the data. Forecasting even a brief period into the future is usually done with little confidence unless the underlying cause and effects are understood.
Finally, it is important to recognize that quite often when data are analyzed using time-series regression, auto-correlation among data points (the degree of dependence of one data point on preceding data) is not only likely, it should be expected. Although the chapter 11 provides extensive guidance in analyzing these data, briefly we describe why these factors must be considered during plan design.
Parametric analyses are designed to reject the null hypothesis with an estimated level of certainty (e.g., we reject the null hypothesis that the slope is 0 and conclude that there is a decline). With rare species, variable indicators, or sparse data, we may lack the statistical power necessary to reject that hypothesis, even when a trend line seems apparent. In the Figure 5.12, we may choose to use alternative analyses (Wade 2000) to assess trends in sample B, or increase our alpha level, thereby increasing our likelihood of rejecting the null hypothesis. Changing alpha will increase the risk of stating that there is a trend when there really is not, however, this may be an acceptable risk. If we risk losing a species entirely or over a significant part of its geographic range, we will probably be willing to make an error that results in stating that a population is declining when it really is not. This is an important point, because two individuals approaching trend data with a different perspective (alpha level) may reach very different conclusions.
Cause and Effect Monitoring Designs
Typical research approaches will either assess associations between response variables and predictor variables, or will use a structured experimental design that will assess cause and effect. Monitoring plans can also use this approach. Consider a trend line for white-tailed deer in Alabama that showed a significant decline. Consider also that the manager had just stopped using prescribed burning to manage the area. She might conclude that the cessation of burning caused the decline. But if data from a nearby unburned area were also available and that trend line was also negative, then she might reach a different conclusion and begin looking for diseases or other factors causing a more regional decline.
If the plan being developed is designed to understand the short or long-term effects of some management action on a population, then the most compelling monitoring design would take advantage of one of two approaches to assess responses to those actions: retrospective comparative mensurative designs or Before-after Control-Impact (BACI) designs.
Retrospective Analyses and ANOVA designs
Monitoring conducted over large landscapes or multiple sites may use a comparative mensurative approach to assess patterns and infer effects (e.g., McGarigal and McComb 1995, Martin and McComb 2001). This approach allows comparisons between areas that have received management actions and those that have not and often is designed using an Analysis of Variance (ANOVA) approach. Retrospective designs that compare treated sites to untreated sites raise questions about how representativeness of the untreated sites prior to treatment. In this design, the investigator is substituting space (treated vs untreated sites) for time (pre- vs. post treatment populations). The untreated sites are assumed to be representative of the treated sites before they were treated. With adequate replication of randomly selected sites, this assumption could be justified, but often large-scale monitoring efforts are costly and logistics may preclude both sufficient replication and random selection of sites. Hence doubt may persist regarding the actual ability to detect a cause-and-effect relationship, or the power associated with such a test may be quite low. Further, lack of random selection may limit the scope of inference from the work only to the sites sampled.
McGarigal and McComb (1995) compared bird detections among 6 levels of mature forest abundance and 2 levels of forest pattern using a retrospective ANOVA design (Figure 5.13). Logistics restricted them to only 3 replicates of each condition, and sites were selected randomly from among those available, though in most cases few options were available. Further there was the potential for areas that had been managed to have different topography, site conditions, or other factors that made those sites more likely to receive management than those sites that did not. The patterns of association between bird species and landscape conditions were significant in many instances, and consistent with what we know about the life history of the species. But despite the fact that most of the species in table 5.1 have been associated with older or closed-canopy forests in previous studies (lending support for the fact that their relative abundance should increase with increasing area of old forest) we cannot make any definitive conclusion. Rather, we can only hypothesize that these species should respond positively to increasing area of old forest. Monitoring data on these species collected over time can be used to test that hypothesis.
Table 5.1. Selected results of analyses of bird species showing a positive association between the area of late successional forest and the relative abundance of each species in the Oregon Coast Range (McGarigal and McComb 1995). These relationships suggest that increasing late successional forest in a watershed may lead to increases in abundance of these species, but this is not a cause and effect result. Note that the strength of the association varies among the species.
ANOVA Regression
Species F P R2 (%) P
Gray jay 14.2 <0.001 63 <0.001
Brown creeper 13.4 <0.001 59 <0.001
Winter wren 8.6 <0.001 53 <0.001
Varied thrush 7.8 <0.001 24 0.007
Pileated woodpecker 2.51 0.068 18 0.019
Hermit warbler 1.4 0.271 12 0.063
Before-After Control vs. Impact (BACI) designs
Although the BACI design is usually considered superior to the ANOVA design, BACI designs often are logistically challenging. The BACI design allows monitoring to occur on treated and untreated sites both before and after management has occurred (e.g., Chambers et al. 1999). BACI designs allow detection of cause-and-effect relationships, but within monitoring frameworks, they can often suffer from non-random assignment of treatments to sites. Often the location and timing of management actions do not lend themselves to strict experimental plans. In the following example, Chambers et al. (1999) used a BACI design experiment that included silvicultural treatments in three replicate areas on a working forest (Figure 5.14). The results from this effort again produced predictable responses, but the responses could clearly be linked to the treatments. In figure 5.5, white-crowned sparrows were not present on any of the pre-treatment sites, but were clearly abundant on the clearcut and two-story stands following treatment (vertical bars represent confidence intervals). The treatments caused a response in the abundance of this species. Conversely, hermit warblers declined in abundance on these two treatments but remained fairly constant on the control and group selection treatments (figure 5.15). Consequently we would predict that future management actions such as these would produce comparable results on this forest. However it is important to remember that the scope of inference is this one forest – extrapolation to other similar sites should be done with caution. Further, to fully understand why these changes might have been observed, ancillary data on habitat elements important to these species also could be collected and if the treatments caused changes in important habitat elements, then the reasons for the effects become clearer. These habitat relationships analyses can be particularly informative when developing predictive models of changes in abundance or fitness of an organism based on management actions or natural disturbance.
EDAM: Experimental Design for Adaptive Management
Choosing a design for monitoring can be facilitated using software specifically developed to assess statistical rigor of the plan (e.g., Program MONITOR) and software which can guide design of adaptive management efforts. Anderson (1998) developed EDAM software to guide an adaptive management experiment that may never be repeated, but instead may lead directly to economically significant management decisions. Traditional design recommendations alone may not be helpful in this scenario because manipulating design variables, such as sample size or length of the experiment, often involves very high costs. Also, various stakeholders may have different points of view concerning the impact of possible incorrect inferences (Anderson 1998). There are two versions of the EDAM model: a Before-After-Control-Impact Paired Series (BACIPS) experiment on a landscape scale, and an Analysis of Variance (ANOVA) experiment on a patch scale:
“Each model represents a management experiment on a forest ecosystem, which can be examined from different stakeholders’ points of view. Given a set of design choices, the model demonstrates all possible outcomes of the experiment and their likelihood of occurrence, with a special emphasis on their future economic and ecological impact. The experiments in the EDAM models are thus not primarily statistical exercises; instead, the adaptive management experiment is a 3-stage interaction between people and nature that may stretch far into the future:
Stage 1 — Design and implementation– the experimenters plan and carry out a management plan that probes the forest ecosystem experimentally
Stage 2 — Analysis — the experimenters learn, i.e., they make an inference (correct or incorrect) about the ecosystem based on data from the experiment
Stage 3 — Management response — the experimenters respond to the inference with new management actions, which, as they are projected into the future, will effect both the forest ecosystem and various stakeholders.” (Anderson 1998).
Once you have considered the appropriate monitoring design to answer your key questions(s), then you need to make several additional decisions regarding what you will measure, how you will select sample sites, what level of precision you require, and what your scope of inference will be. These then become steps in the development of a monitoring plan.
Beginning the Monitoring Plan
Within a monitoring plan, the conceptual framework should provide the basis for a written description of the system, how it works and what we do and do not know about it. The culmination of this discussion should be the identification of the key questions that drive the monitoring plan. These key questions should address the processes and stressors about which there are information gaps that keep us from understanding or predicting responses of organisms to management actions. The first step in the process is to identify, clearly and concisely, the question(s) that is to be answered by the monitoring plan. The question(s) must be clearly focused. Once the question(s) has been articulated, and if existing data are insufficient to address the key question(s), then the following steps should be explained and justified based on the conceptual model.
Sample Design
In a research setting we may decide to state our key question as a hypothesis and alternative hypotheses. We can take the same approach in monitoring as well. Indeed, if numerous alternative hypotheses are to be compared using an information theoretic approach, these alternative hypotheses should be generated at this stage so that models reflecting them can be compared.
• Are you predicting occurrence?
• Assessing trends over time?
• Assessing patterns over space?
• Are associations with habitat elements important?
• Do you hope to understand a cause and effect relationship?
The answers to these questions should allow you to develop hypotheses and identify the most useful study design for testing them.
Selection of Specific Indicators
Once you have defined the question of interest, then you will need to decide what will be measured as a reliable indicator of change to address the key question. Noon et al. (1999) described an attribute (indicator) as: “…simply some aspect of the environment which is measurable. When an attribute is measured it takes on a (usually) numeric value. Since the exact value of an attribute is seldom known with certainty, and may change through time, it is properly considered a variable. If the value of this attribute is indicative of environmental conditions that extend beyond its own measurement, it can be considered an indicator. Not all indicators are equally informative — one of the key challenges to a monitoring program is to select for measurement those attributes whose values (or trends) best reflect the status and dynamics of the larger system.”
Questions that will aid you in undertaking this task include:
• What should I measure?
• Why was one indicator better than another?
• What are the benefits and costs associated with each of the potential indicators?
Indicator selection is challenging. The U.S. Environmental Protection Agency (EPA), U.S. Forest Service, and other agencies have tested various indicators for monitoring ecosystems, but there is little consensus on which indicators are best or how best to quantify them. Rather than these specifics, such agencies tend to generate lists of useful indicator characteristics to aid in site-specific indicator selection. The National Park Service (2007), for example, suggests that indicators are most useful when they:
• Have dynamics that parallel those of the ecosystem or component of interest
• Are sensitive enough to provide an early warning of change
• Have low natural variability
• Provide continuous assessment over a wide range of stress
• Have dynamics that are easily attributed to either natural cycles or anthropogenic stressors
• Are distributed over a wide geographical area and/or are very numerous
• Are harvested, endemic, alien, species of special interest, or have protected status
• Can be accurately and precisely estimated
• Have costs of measurement that are not prohibitive
• Have monitoring results that can be interpreted and explained
• Are low impact to measure
• Have measurable results that are repeatable with different personnel
The context of a monitoring program should be carefully considered in the selection of indicators. The largest monitoring program to date has been the EPA’s Environmental Monitoring and Assessment Program (EMAP). In their review of EPA’s EMAP program, the National Research Council (NRC 1995) discussed the relative merits of retrospective monitoring (EMAP’s basic monitoring approach) versus predictive or stressor-oriented monitoring. Retrospective, or effects-oriented monitoring, seeks to find effects by detecting changes in the status or condition of some organism, population, or community. This would include trends in plant or animal populations and it takes advantage of the fact that biological indicators integrate conditions over time. In contrast, predictive, or stressor-oriented monitoring seeks to detect the cause of an undesirable effect (a stressor) before the effect occurs or becomes serious (NRC 1995). Stressor-oriented monitoring will increase the probability of detecting meaningful ecological changes, but it is necessary to know the cause-effect relationship so that if the cause can be detected early, the effect can be predicted before it occurs. The NRC (1995) concluded that in cases where the cost of failing to detect an effect early is high, use of predictive monitoring and modeling is preferred over retrospective monitoring. They concluded that traditional retrospective monitoring was inappropriate for environmental threats such as exotic species effects and biological extinctions because of the large time lag required for mitigation, and recommended that EPA investigate new indicators for monitoring these threats. Planners should keep in mind these approaches and analyses when identifying both the indicators and the likely outcomes of the monitoring effort.
Selection of Sample Sites
This step may seem trivial, but there are a set of questions that should be addressed when designing a monitoring plan. These include:
• How will you assure that sites are independent from one another with respect to the response variable? Are sites sufficiently separated over space to ensure that the same individual is unlikely to be recorded on multiple sites in the same year?
• How did you select the number of sites? Given the pilot study data, was the sample size adequate to detect a desired effect? The process of deciding sample size should be well documented. See Gibbs and Ramirez de Arellano (2007) for assistance with these questions.
• How will you mark the sites on the ground? Sampling locations should be permanently marked and GPS locations recorded, and the degree of accuracy associated with the coordinates should be provided. Will you use flagging? How long will it last? Will flagging or more permanent marks bias your sample? For instance if you are monitoring nest success or fish abundance along streams, could predators be attracted to the marks?
• How will you ensure that the same sites will be found in the future and that the data are collected in the same manner at the same sites?
Detecting the Desired Effect Size
An excellent tool to assist you in assessing the power associated with detecting a trend that is real is the program MONITOR (Gibbs and Ramirez de Arellano 2007). Estimates of variability in the indicators of populations of plants and animals will be necessary to estimate sample sizes and power, so these estimates will have to come from previous studies in similar areas or from pilot studies (Gibbs et al. 1998). Because of the economic impacts of conducting monitoring programs without adequate power to detect trends, it is always wise to consult a statistician for assistance with this task. This step is extremely important because the results will provide insight into the sample sizes and precision of data needed to detect trends. If it is logistically or financially infeasible to achieve the desired level of power, then the entire approach should be revisited.
The Proposed Statistical Analyses
Will the analytical approaches available allow you to detect occurrence, trends, patterns or effects given the data that you will collect? Is the analysis appropriate if data are not independent over space or time? Data collected over time to detect trends or in BACI (Before-After Control-Impact) often have data that are not independent from one time period to the next. Repeated measures designs are often necessary to ensure that estimates of variance between or among treatments reflect this lack of independence (Michener 1997). Concerns regarding independence of data or alternative data analysis approaches (e.g., Bayesian) must be addressed during the planning stages. Too often data are collected and then a statistician is consulted, when the data could be so much more useful if the statistician were consulted at the planning stage for the program.
The Scope of Inference
The sample sites selected for the study will have to be defined to address an appropriately broad or narrow range of conditions. There is a tradeoff that should be discussed in the plan. That tradeoff is to monitor over a large spatial extent, so that results are broadly applicable, vs. sampling over a narrow spatial extent to minimize among-site variance. The variability in the indicator likely will increase as the spatial extent of the study increases. As the variance of the indicator increases, the probability of detecting a difference between treatments, or of detecting a trend over time will decrease.
If it is feasible to do so, collecting preliminary data from a broad range of sites, may help you decide what an appropriately broad scope of inference would be before variance increases dramatically and would therefore influence the power of your test. For instance, if data on animal density were collected from 20 sites extending out from some central location, and the variance over number of samples was calculated, then the variance should stabilize at some number of samples. Even after stabilization, adding more samples from areas that are sufficiently dissimilar from the samples represented at the asymptote may lead to a jump in variance caused by an abrupt change in some environmental characteristic. This change in the variance of the indicator over space may represent an inherent domain of spatial scale for that indicator. Sampling beyond that domain, and certainly extrapolating beyond that domain, may not be warranted. Indeed, broadcasting from the monitoring data (extrapolating to other units of space outside of the scope of inference), and forecasting (predicting trends into the future from existing trends) must be done with great care because the confidence limits on the projects increase exponentially beyond the bounds of the data.
Consideration of the scope of inference is a key aspect of a monitoring program, but it is often not given adequate attention during the design phase. Instead, managers may wish to extrapolate beyond the bounds of the data after data have been collected, when the confidence in their predictions would be much greater if the scope had been considered during program design. Concepts of statistical power, sample size estimation, effect size estimation and scope of inference are discussed in more detail in later sections.
Summary
Development of a monitoring plan must begin with articulating the key question(s) that are the result of careful construction and development of a conceptual framework. Once the question has been clearly articulated, then you can identify the type of monitoring design that you would like to use to address the question(s). Carefully considering the appropriate response variable(s) or indicator(s) will allow you ensure that your results will indeed answer your key question(s). In addition, decisions about your scope of inference and the types of statistical analyses that you might like to conduct should be made during the design process; this is the topic of the next chapter. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.05%3A_Designing_a_Monitoring_Plan.txt |
The previous chapter provides a brief overview of the process of defining key questions, determining the monitoring design, and addressing issues of power and sample size. But there are other aspects of the monitoring plan that should be considered, especially those dealing with how you will analyze the data and how you will decide when a threshold or trigger point is reached. All too often data are collected because it “seems like a good idea” and then months or years later someone sits down to analyze the data and realizes that the resulting interpretation is highly limited and may not indeed address some key question. Hence including aspects of the future analysis and interpretation of the data into the monitoring plan can help ensure that the data will be useful to people in the future.
Effective population monitoring is a critical aspect of adaptive management, and should be designed to test specific hypotheses that are relevant to management and policy decisions (Noss 1990). Unfortunately, monitoring often involves common mistakes such as overlooking explicit hypothesis testing or not paying attention to proper design and analysis (Hinds 1984). A properly constructed and reviewed sampling design will ensure accurate results, and allow users to make inferences to larger areas. In addition to the issues of statistical power and effect size estimation discussed in the previous chapter, there are several factors that should be addressed as a protocol is being developed. Before data collection begins, one must identify the limitations that will be imposed on the sampling techniques by the inherent variability of the animals and habitats being measured.
Use of Existing Data to Inform Sampling Design
Existing data available for the monitoring site or nearby areas can be exceptionally useful when designing the monitoring protocol. The resulting design can be much more robust and the ability to detect differences can be assessed prior to the onset of data collection. A few examples of uses of existing data are:
1. Estimating detectability and detection distances for mobile species (e.g., birds, fish, large mammals).
2. Estimating variance associated with potential indicators to aid in selection of the indicators most likely to detect effects with desired levels of power if they are present
3. Estimating variance to estimate sample sizes needed to achieve desired levels of power
4. Developing tradeoff scenarios to estimate the costs of the monitoring program vs. the effect size that could be detected.
5. Identifying appropriate levels of sampling effort through examination of variance stabilization
6. Maximizing efficiency during adaptive sampling tests
7. Estimating spatial and temporal patterns in habitat elements or populations
Detectability
Since it is often logistically impossible to census an entire population of a species, monitoring generally relies upon a sample of that population. These data are often in the form of presence/not detected (e.g., species occurrence inventories), relative abundance (e.g., number of animals or their sign observed per unit time), or absolute abundance estimates (e.g., mark-recapture). Whether a sampling design collects an accurate sample that is representative of the population is dependent on the ability of the monitoring technique to detect the species. Detectability is defined as the probability that an individual will be observed (e.g., seen, heard, captured, etc.) in a particular habitat at a particular time, and is influenced by factors such as survey method, species, observer, habitat complexity, time of year, weather, density, and breeding phenology (Thomas 1996). These factors can result in missed individuals, multiple counting of individuals, recording an individual where none exists, or the over-counting of conspicuous species. Sampling error, a result of detectability problems, is another source of variation in documenting population change.
The additional stochasticity associated with sampling error can have two major consequences (Barker and Sauer 1995). First, efficiency of the monitoring technique in sampling the species is greatly compromised. Second, the sampling-induced variation can bias estimators of important population parameters. When a sample is collected and analyzed, those results are estimates of population parameters that are used in detecting population changes. Ignoring this sampling error can reduce the likelihood of identifying critical trends in population data.
Population monitoring programs often have a number of different personnel responsible for collecting data. Several studies have suggested that observer error can be a significant source of variation in population data (Sauer et al. 1994, James et al. 1996, Thomas 1996; Barker and Sauer 1995). In fact, observer error has resulted in false population changes (Sauer et al. 1994). A popular approach to addressing detectability problems is by estimating a detection function (Burnham et al. 1980). Consequently, designing an effective and reliable monitoring protocol must emphasize standardized monitoring techniques that take into account species-specific biases, and proper training of data-collecting personnel.
Estimating Detection Distances
When using some types of density estimators (see chapter 7 for more details) such as variable width transects, variable circular plots, or mark-resight estimators, it is important to know what detection distances might be for the species of interest, and more importantly if detection distances vary from one vegetation type to another. Differences in detection distances do not present any particular problems when using these estimators, but if differences do occur among vegetation types, then simple indices to abundance (detection rates, re-sight rates) cannot be used reliably when comparing between or among vegetation types. In a very simple example, consider the detection distances for a salmonid in streams that have and have not been impacted by streamside activities leading to increased sediment loads. Or detection distances for olive-sided flycatchers in old-growth forests vs clearcuts. The function describing the detection decay curve will very likely differ between these two conditions and must be used to estimate abundance in an unbiased manner. Even estimates of abundance of patchily distributed plants may have different detection distances among vegetation types and this should be considered during design of the monitoring protocol, especially when distributing transects or points over an area to ensure complete, but not overlapping coverage.
Estimating Variance Associated with Indicators
The ability to detect a difference between conditions, or a slope different from 0, will depend on the sampling error associated with the chosen indicator. Clearly an indicator should be chosen which is meaningful to the question being asked, but there may very well be options to choose among. For instance, consider estimating the densities of a specific age class of fish from stream surveys vs. electro-shocking mark-recapture estimates. Both techniques may produce similar numbers of observations, but if the stream survey work produces more consistent (less variable) estimates of abundance, then the ability to detect differences or trends would be greater (assuming similar sample sizes) with that technique than the mark-re-sight technique (or vice versa).
Estimating Sample Size
The ability to detect a difference will increase with decreasing sampling error and increasing sample size. In a very simple example, consider N = s2t2/d2, where N = the estimated sample size, s2 = the sample variance, t = the t-statistic for a specified alpha level, and d = the effect size or difference that you wish to detect. Sample sizes increase as (1) the variance increases, (2) the t-statistic increases (decreasing alpha level), or (3) the effect size decreases (you want to detect smaller differences). Knowing in advance what the variance might be for a sampling effort can allow the developer of the protocol to understand if it would even be possible to detect a difference given a limited amount of time and money. See Program Monitor for more information on calculating sample sizes (Gibbs and Ramirez de Arellano 2007).
Logistical Tradeoff Scenarios
Given a limited budget with which to work, a knowledge of the variance in a potential indicator can be useful in deciding what statistical power will be associated with the sampling design, at a given effect size and sample size. Conversely knowledge of the variance can allow you to estimate the effect size that could be detected given the logistics of funding, and a desired level of power. It should become quickly apparent that identifying indicators with low sampling error can mean considerable savings in sampling effort for intensive field studies.
Variance Stabilization
You will need to make a decision regarding how many samples are sufficient to estimate variance for a monitoring protocol. Too few samples and the estimate may be unusually high and lead to an inability to detect differences. Too many samples and you are not being efficient with time and resources. One approach to understanding when sampling intensity is sufficient to provide a reasonable estimate of variance is to plot variance over number of samples (figure 6.1). If you want to estimate the mean and variance for a set of values, one might ask how many data points would be needed to develop a reasonable estimate of variance and a mean. Variances and means fluctuate among just a few samples, but stabilize eventually; at some point additional data are not likely to appreciably change the estimate. In the examples above (figure 6.1), variance stabilizes at about 10-15 samples and the estimate of the mean stabilizes at about 15 samples. Clearly using less than 10 samples could lead to a poor estimate of the mean and variance. More than 30 samples are probably not necessary.
In Figure 6.2, estimates of dead wood from four 50-m transects at sample plots in young Douglas-fir stands show a high degree of variability over sample size and stabilization is observed only after a large number of plots are used in the analysis. Given such a large sample size needed to characterize the mean and variance, one would have to ask if some other indicator of this habitat element might be more efficiently characterized. For some habitat elements and populations that are highly patchy in nature, use of variance stabilization may be problematic because jumps in variance may occur as sampling efforts encounter new patches.
Spatial Patterns
Populations and individuals can be dispersed throughout a habitat or a landscape in various patterns. Monitoring protocols must incorporate species-specific patterns in density and distributions. The three basic population spatial patterns are random, clumped, and regular (Figure 6.3; Curtis and Barnes 1988, Krebs 1989). Random dispersion is found in populations in which the spacing between individuals is irregular, and the presence of one individual does not directly affect the location of another individual. Clumped populations are characterized by patches or aggregations of individuals, and the probability of finding one individual increases with the presence of another individual. Regularly distributed populations have individuals that are distributed more or less evenly throughout an area, and the presence of one individual decreases the probability of finding another nearby individual.
The spatial distribution within populations is an important constraint on sampling designs. A number of factors influence the distribution of individuals across a habitat or landscape. Factors such as resource distribution (e.g., water, food, and cover) and habitat quality can affect the dispersion of individuals and populations (McComb 2007). A random distribution is often found in species that are dependent on ephemeral resources. Species that depend on temporary or seasonal resources may exhibit different types of distribution at different points in their life histories. In vertebrates, social behavior and territoriality can affect distribution. Highly territorial species tend to follow a regular distribution, while more gregarious and colonial nesting species tend to occur in clumps (Curtis and Barnes 1988, Newton1998). In addition, the scale of observation is critical in determining the distribution of a population. Populations may appear regularly distributed at a fine scale, such at the site level, but may show a more random or clumped distribution throughout part or all of their geographic range.
Spatial patterns of organisms and populations can complicate sampling design, but there are a number of techniques to address these constraints. Nested quadrat sampling is often used to define a species-area curve for a population or community of organisms (Krebs 1989). The number of species will expectedly rise as the size of the quadrats increase, but a plateau in species number should eventually be reached within a patch type. This plateau is considered the minimum sampling area for that community. This technique has been used successfully for plant communities (Goldsmith and Harrison 1976). However, quadrats are not natural sampling units and one must decide on a number of factors including size, shape, and number of quadrats. Refer to species area curves in the previous chapter to understand how numbers and sizes of plots can influence results. .
A useful approach for determining the spatial distribution of a population is “plotless sampling”. There are two general approaches to plotless sampling (Krebs 1989):
1. select random organisms and measure distance to nearest neighbors
2. select random points and measure distance from each point to nearest organisms
Plotless sampling has two major advantages. First, if the spatial pattern of the population is random, one can use plotless sampling to estimate the density of the population. Conversely, if the population density is known then one can determine the spatial pattern of that population. Both of these applications may prove valuable in the preliminary stages of monitoring. A first step is to estimate if a population has a random, clumped or regular distribution; approaches for estimating these distributions are given in Table 6.1.
Table 6.1. Commonly used methods to assess the distribution of individuals in a population.
Methods Data Types
Nearest-Neighbor Methods
(Clark and Evans 1954)
Population density is known; spatial map of population is available
Byth And Ripley Procedure
(Byth and Ripley 1990)
Sample of a population over a large area; independency of sample points
T-Square Sampling Procedure
(Besag and Gleaves 1973)
Favored by field studies; random point assignments
Point-Quarter Method
(Cottam and Curtis 1956)
Random point assignments; typically transect data
Change-in-Ratio Methods
(Seber 1982)
Change in sex ratios data; population data
Catch-Effort Methods
(Ricker 1975)
Exploited population data; catch per unit effort with time
Temporal Variation
Spatial variation is a critical limitation of successful monitoring, but sample design must also consider temporal fluctuations in populations. A sampling design that does not emphasize a dynamic and repeatable monitoring scheme will not be able to accurately estimate populations or their response to management.
The temporal variation observed in populations is often the result of environmental variation (Akcakaya 1999). Environmental changes will have both direct and indirect effects on populations. Although we can often calculate probabilities regarding environmental fluctuations based on past records and averages (e.g., rainfall, flooding, etc.), it is often difficult, if not impossible, to predict when these changes might occur. In cases were population rates and demographics depend on environmental variables, population fluctuations are likely to occur (Akcakaya 1999). Sometimes these environmental changes can indirectly influence populations through predator densities, herbivory, sedimentation, nest predation, food resource availability, and cover. For example, a study on acorn production by oaks found that populations of white-footed mice, eastern chipmunks, and gray squirrels were significantly correlated with annual fluctuations in acorn crop (McShea 2000). In addition, these changes in small mammal populations were correlated to the nesting success of several ground-nesting birds. In eastern North America, Carolina wrens suffered a population crash following several severe winters in the mid 1970s (Figure 6.4; Barker and Sauer 1995; Sauer et al. 2001).
Analysis and interpretation of long-term monitoring should recognize and evaluate the effects of these patterns on population data. Monitoring over extended time periods and careful documentation of environmental changes (including management actions) is the only effective method for determining the change and status of a population.
Cost
A proper sampling design emphasizes cost-effectiveness, and improves the interpretation and presentation of results. Knowledge of the sample design promotes understanding and communication between project leaders and administrators, and further elucidates the critical goals of the program. Conversely, failure to consider a proper sampling design can reduce monitoring efficiency, inflate costs, and lead to inaccurate results. The inventorying and monitoring process consists of a hierarchy of decisions and events (see Chapter 5 and Jones 1986). Following the hierarchy of planning decisions, as well as constructing a reliable conceptual model, will allow managers to construct a cost-efficient sampling scheme. These decisions and goals will also dictate which type of inventory method is appropriate. Different monitoring techniques vary in their costs and intensity. For example, inventories relying on presence/not-detected data can be inexpensive because personnel with minimum training can sample fairly large areas. Comparatively, monitoring which relies on relative abundance or absolute abundance data (e.g., mark-recapture studies) demands highly skilled personnel and are generally more site-intensive. Thus, a proper sampling design, constructed through a hierarchy of decisions and input, is critical to limiting costs and collecting relevant data.
Stratification of Samples
Stratified random site selection can be an excellent method for limiting bias and collecting representative data. Although this topic will be discussed in greater detail in Chapter 11, considering stratification in your monitoring design is an important step. A stratum is an aggregation of mapping units that have similar abiotic or biotic characteristics (Jones 1986). Selecting appropriate strata is a critical step in habitat type and study site classification. In many cases, strata are based on existing vegetation and landforms. However, like many aspects of habitat assessment, strata selection can also be species-specific. For example, if it is important to collect data on a particular species, a stratum can be created that encompasses several of the habitat components that are necessary for that species. Stratification of habitats can be based on dominant or subdominant vegetation types, topographical characteristics, soil composition, ichthyologic provinces, or management areas. However, monitoring efforts and sampling is designed to be repeatable and creating strata based on vegetation can be problematic since these habitat boundaries may change over time (e.g., succession). If the characteristics used to create strata are variable over time, such as vegetation types, then it is may be necessary to reevaluate strata classification, boundaries, and criteria every year.
Adaptive Sampling
Quite often during surveys of rare plants or animals, the species of interest is observed on very few of the sampling units, and units where the species is detected are in close proximity. Many common species also have a tendency to occur in population clusters because of dispersal mechanisms, behavior patterns (e.g., herding, colonialism), or habitat associations. Under these conditions, it is predictable that surveys conducted according to conventional designs will expend most of the sampling effort at locations where the species is unobserved. Adaptive sampling designs offer an approach to concentrate sampling units in the vicinity of population clusters, thus improving the efficiency of parameter estimation. The theoretical origins of adaptive sampling extend back at least 50 years (Wald 1947, Zacks 1969) and S.K Thompson has written extensively on the application of adaptive sampling designs to plant and wildlife surveys (Thompson and Ramsey 1983, Thompson 1990, Thompson 1992, Thompson and Seber 1996). Adaptive cluster sampling has been applied to surveys of rare trees (Roesch 1993), freshwater mussels (Box et al. 2002), tailed frogs (Vesely and Stamp 2001), among other species and assemblages.
Adaptive cluster sampling refers to designs in which sample selection depends on the values of counts or other variables observed during the course of the survey. Initially, a probability procedure is used to select a set of sampling units in the study area. When any of the selected units satisfy some predetermined criterion, additional units are sampled in the vicinity of the qualifying unit. Sampling is extended until no further units satisfy the criterion. Typically the criterion is a count value of the target species.
For rare or highly aggregated populations, adaptive cluster sampling can greatly increase the precision of population size or density estimates when compared to a simple or stratified random design of equal cost (1992). Adaptive cluster sampling can be applied to surveys conducted on quadrats, belt transects, variable circular plots, among other types of sampling units. Thompson and Seber (1996) provide a comprehensive review of adaptive sampling designs and data analysis. There are two different considerations that may limit the applicability of adaptive sampling designs for some inventory and monitoring studies. First, adaptive sample selection may cause biases in conventional estimators for the population mean, variance, and total population size. Unbiased estimators have been described for simple and stratified adaptive sampling designs, but cannot be automatically computed with commonly-used statistical software. Calculation of design-unbiased estimators for adaptive sampling designs requires a thorough understanding of statistics and the ability to program the estimators into one of the advanced statistical software packages (e.g., SAS®, S+®). A statistical consultant can aid in developing analytical methods appropriate for adaptive sampling, and provide similar assistance in performing data analysis. The second consideration in planning for adaptive sampling is the operational uncertainty surrounding the number of sampling units required for the survey. Unlike conventional designs in which the sample size is typically determined before starting fieldwork, there is no precise knowledge prior to data collection as to the number of units that will trigger secondary surveys. This uncertainty can be minimized by conducting pilot studies to estimate the mean and variance for sample sizes. Alternatively, survey protocols can limit the maximum number of sampling units visited in a study area, after making appropriate modifications to the population estimators.
Peer Review
Once a sampling design has been developed based on existing data or a pilot study, there is still some doubt that the data collected as part of the monitoring effort will adequately address all potential biases or inherent fluctuations in conditions over time. One step that can be extremely valuable in the development of a protocol is to draft the sampling design, providing the preliminary data analyses and rationale for indicators selected, sampling intensity, effect sizes, and power. This draft should be reviewed by both a statistician and an expert on the biology of the organism(s) and ecosystem(s). Recall that statistics are merely a tool to help make decisions. The design must be statistically sound, but it must also be biologically meaningful. External review of the design can help to identify features of the sampling design that may limit the usefulness of the data in the analytical phase of the monitoring program. It is much better to be thorough in development of the design phase and minimize the risk of making errors now then to find out after a year or more of data collection that the results are biased, not independent, or too variable to make inferences.
Summary
In addition to developing clear objectives, having a random sample, and having adequate power in your design to detect trends, the monitoring plan should include a framework for analyzing and interpreting the data. Existing data from other studies or a pilot study may be particularly useful when estimating detectability, variance in potential indicators, estimating costs of monitoring, maximizing efficiency during adaptive sampling tests, and estimating spatial and temporal patterns in habitat elements or populations. These and other ancillary data may aid in the identification of strata as monitoring plans are designed. Stratified random site selection can be an excellent method for limiting bias and collecting representative data. For rare or highly aggregated populations, adaptive cluster sampling can greatly increase the precision of population size or density estimates when compared to a simple or stratified random design of equal cost. Finally, the monitoring plan should be subjected to rigorous peer review prior to implementation. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.06%3A_Factors_to_Consider_When_Designing_the_Monitoring_Plan.txt |
To accurately monitor changes in habitat and populations, long-term monitoring programs must utilize a repeatable sampling scheme. Making inferences about a population from a sample taken over time depends on the ability of a monitoring plan to guide personnel to re-sample and re-visit the same set of sample units (often points or plots) from one time period to the next in a standardized manner. Documentation of sample units throughout the study area and details for replicating sampling techniques are therefore critical. It is vitally important that there is proper documentation and storage of site locations and all notes pertinent to the sampling scheme for ensuring the long-term and repeatable success of monitoring plans. In this chapter we outline the steps that should be considered when establishing a monitoring scheme to ensure that it is consistently implemented over time.
Creating a Standardized Sampling Scheme
Selecting Sampling Units
Monitoring plans should clearly identify the methods necessary for biologists to translate the conceptual sampling design into field practices that can be implemented even under challenging conditions. Methods for randomly selecting the locations or individual organisms to be included in the sample should be described in detail. Criteria or rules for establishing boundaries of the sampling area (extent) to match the spatial scale specified in the planning and design section should be identified. Also the procedures to stratify the sampling effort or to exclude certain regions (e.g., areas that are not habitat for species of concern) within the sampling frame should be described if these steps are required by the design.
Size and Shape of Sampling Units
The size and shape of the sampling units have both logistical and statistical implications. Counting individual plants on plots delineated by a sampling frame was among the earliest approaches used by ecologists to estimate the frequency or density of plant populations. The technique may also be used for sedentary animals (e.g., mollusks, terrestrial salamanders). But researchers realized that count data obtained from plots are affected by the size and shape of the sampling unit. The optimum size and shape of a plot will differ according to the species, environmental conditions, and monitoring program objectives. Typically, the optimum plot configuration will be one that provides the greatest statistical precision (i.e., lowest standard error) for a given area sampled. Several investigators have developed approaches for determining the most appropriate plot size and shape for a particular population monitoring program (e.g., Hendricks 1956, Weigert 1962). Krebs (1989) provides a useful review of standardized plot methods.
There are, however, many important general concepts to consider when determining plot size and shape. Square plots, also known as “quadrats”, and circular plots have smaller boundary:interior ratios compared to rectangular shapes of equal area. Plots having an exaggerated length are sometimes referred to as “strip transects” or “belt transects”. In some sampling conditions, it may be difficult for the surveyor to determine whether organisms occurring near the boundary of a plot are “in” or “out” of the plot and counting errors can result. In these circumstances, compact plot shapes are preferred. Boundary:interior ratios also decrease with increasing plot size, thus larger plots seemingly offer another approach for reducing counting errors. However, the tedious nature of counting organisms on a large plot under difficult field conditions may also cause surveyors to make mistakes. Counting errors are not the only factor to consider when determining plot size and shape. In heterogeneous habitats, count or abundance data collected on long plots often have been found to have lower statistical variance among plots than data from compact plots of the same total area (Krebs 1989).
While the usual notion of a plot is an area delineated by a frame or flagging, other techniques may be used count organisms in a given area. Line transect and point transect sampling are specialized plot methods in which a search for the target organism is conducted along a narrow strip having a known area. See Chapter 8 for a more thorough discussion of application of transect sampling.
Population abundance also can be estimated by a variety of “plotless” monitoring methods that utilize measurements to describe the spacing of individuals in an area. These techniques are based on the assumption that number of individuals in a population can be determined by measuring the average distance among individuals in the population or between individuals and randomly selected points. Distance methods have been commonly used for vegetation surveys, and are easily adapted to inventories of rare plants or other sessile organisms. The approach may also be useful for population studies of more mobile animal species by obtaining abundance estimates of their nests, dens, roosting sites, or scat piles. Indeed, sometimes the optimal option when considering your plot size and shape is to have no plots at all! Collecting data for monitoring programs based on distance methods may have some practical advantages over plots or transects:
1. Distance methods are not susceptible to counting errors that often occur near plot boundaries, thus may yield more accurate abundance estimates, and
2. The time and effort to attain an adequate sample of distance measurements in an area often is less then that required to search for every target organism on a plot, thus increasing the efficiency of the monitoring program.
Field techniques vary depending upon the distance method selected for the monitoring program. All distance methods employ random selection procedures to choose points and compass bearings. Equipment requirements are minimal, usually only a compass, flagging, and a measuring device appropriate to the scale of the population and monitoring area are needed, but a detailed list of equipment used and descriptions of the protocol for using it must still be documented. Cottam and Curtis (1956) recommended a minimum of 20 measurements for estimating population density or abundance using Point-Centered Quarter Method. However, data collection plans may be relatively complicated and sample size calculations may need to be performed in the field. To keep this from translating into biased results, a rigorous training program is recommended for personnel conducting the monitoring program. Two useful references for designing inventories based on distance methods are Seber (1982) and Bonham (1989).
Selection of Sample Sites
A proper sampling design ensures that samples taken by a monitoring plan are representative of the population under study, and that any conclusions that are reached can be inferred and extrapolated to other areas and populations. The goal of the sampling design is to maximize efficiency by providing the best statistical estimates with the smallest amount of variance at the lowest cost (Krebs 1989). The sampling methods described below are three of the most popular methods for selecting sample sites when developing monitoring plans.
Simple Random Sampling
Simple random sampling occurs when a random subset of sampling units are selected as samples from a population in such a way that every unit has an equal chance of being chosen (Krebs 1989). For example, a set of randomly located points is placed throughout a study area. At each point, information is collected on some aspect of the species of interest, such as its reproductive success. The data collected from this randomly generated set of points can be considered representative of the population within the study area. However, users often need large sample sizes with this approach because sampling schemes tend to be spatially unbalanced, and there is no attempt to reduce the effect of variability on estimates (Fancy 2000). Consequently, simple random sampling is generally not appropriate for large-scale monitoring because it is cost-ineffective.
Nonetheless, randomization is essential in reducing bias and estimating the parameters of a population. In cases where it is important to have an adequate sample size from a limited area (e.g., watershed), samples can be distributed using a grid, cell design, or tessellation procedure (Stevens 1997). Most statistical analyses assume that sampling units were collected in a random fashion to reduce bias and maintain independence among samples (Krebs 1989). Although independence in ecological settings is difficult to ensure, randomization is an important aspect of any sampling design.
Systematic Sampling
Systematic sampling allows for simple and uniform sampling across an area, and is often conducted using a line transect or belt transect procedure. For example, biologists often use point counts along pre-established transects to determine avian occupancy, density, and community composition across a habitat type. In this case, the starting point of the transect must be random, and point counts are placed at equal distances along the length of the transect (Figure 7.1).
Another common procedure is centric systematic area sampling. The study area is subdivided into equal squares and a sampling unit is taken from the center of each square (Krebs 1989). Systematic sampling provides an even coverage of the study area and is relatively cost-efficient. However, if there is an environmental gradient (e.g., a moisture gradient, roads, fences, etc.) that happens to align with the orientation of a transect or grid, then estimates from this technique can be biased. In general, systematic sampling remains a popular method in monitoring programs and studies due to its ease of implementation and efficiency and is useful for sampling ecological data, but users must be aware of the potential for bias in some settings.
Stratified Random Sampling
Stratified random sampling is a powerful technique for collecting reliable ecological data. This method consists of separating the population into subpopulations (strata) that do not overlap and are representative of an entire population (Krebs 1989). Strata are constructed based on criteria such as population density, habitat features, habitat quality, home range, or topography. The decision is often made using prior knowledge of the sampling situation in different areas. In some cases, however, what constitutes a stratum is not as clear and it may be necessary to use preliminary data as a statistical basis for strata delineation. Iachan (1985) discussed several approaches for deciding strata boundaries. Once the strata are delineated, each stratum is sampled separately, and then samples are chosen randomly within the strata. In 1967, Stewart and Kantrud (1972) estimated populations of breeding birds in North Dakota by dividing the state into eight strata based on biotic characteristics (Figure 7.2). These biotic regions were relatively homogenous and the number of sampling units in each stratum was proportional to the area of the biotic region. Sample units were selected randomly from each region. This design proved useful for other projects in the same area (Nelms et al. 1994). Stratified random sampling is favored in ecological studies for the following reasons (Cochran 1977):
1. Separate estimates for means and confidence intervals can be derived for each subpopulation allowing for comparisons among strata.
2. Cost per observation is typically reduced.
3. If strata are chosen well, then confidence intervals may be narrowed appreciably. This allows for a greater precision and confidence in the parameter estimates for the whole population.
4. Stratification may be administratively convenient if different organizational units are responsible for different parts of the sampling.
Although stratification represents an excellent sampling method for many monitoring plans, users should be aware of some of the inherent problems in creating strata. Recently, it has been suggested that designs based on the stratification of areas by “habitat types” derived from vegetation maps is not recommended (Fancy 2000). The reasoning is that habitat type boundaries, especially those based on vegetation, can change over time, and this will cause problems for future sampling since strata are permanent classifications. A stratum is an area for the purpose of distributing a sample, and any changes will bias the sampling design. These changes in strata boundaries restrict the ability of biologists and managers to include new information into the sampling framework. Consequently, it is considered more appropriate to delineate special areas of interest based on physical features (e.g., terrain, geology, soil, topography, or ecoregions). However, many monitoring plans continue to base strata selection on habitat types due to their influence on animal abundance and distribution.
Yet this does not mean that we can’t draw lessons from past and current monitoring designs. Monitoring agencies have different philosophies on sampling designs and framework. The National Park Service advocates sampling designs that emphasize areas of special interest, such as rare or declining habitat types (Fancy 2000). In many of their sampling designs, areas of special interest are sampled with higher frequencies using either stratification or a general approach of defining the units within the areas of interest and varying their selection probabilities (unequal probability approach). The USDA Forest Inventory and Analysis program’s base grid is randomly located, and users can use this grid as a means of initial sampling. The North American Amphibian Monitoring Program uses a stratified random block design (Weir et al. 2005). Overall, although many monitoring programs differ in the specifics of their sampling framework, most do emphasize critical considerations such as random sampling, a grid or system that allows for the initial sampling of all areas, and documenting limitations to their sampling designs.
Logistics
Careful attention to the personnel, equipment, and permissions that are required for fieldwork is crucial. Incomplete data sets, unreliable measurements, and budget overruns are the common consequences of poorly implemented monitoring programs. Failure to prepare adequate safety plans for fieldwork may even jeopardize the welfare of the survey crew. The following are several steps that can help increase the logistical viability of a monitoring program:
1. Ensure consistent implementation of the monitoring plan among different units within an agency or among agencies conducting coordinated monitoring programs,
2. Maintain the scientific credibility of the project by standardizing materials and methods used during data collection and analysis, thus facilitating independent review and replication of the monitoring program, and
3. Support the development of annual budgets and operation plans that biologists or contractors will be required to submit for the monitoring program to their unit supervisor.
Safety plan
All federal and state and most industry organizations are required to prepare a safety plan. Gochfeld et al. (2006) provide an example of development of a Health and Safety Plan for marine work, but the ideas and approaches are easily adaptable to other circumstances. Some biological monitoring programs may involve special procedures for hazards affecting the safety and welfare of personnel that are not typically covered in standard safety plans for natural resources organizations. Examples include:
1. Exposure to animal-borne diseases (e.g., rabies, hantavirus),
2. Risk of injury from handling wild animals (e.g., capturing large carnivores),
3. Risk of injury from special equipment or materials (e.g., electroshocker), and
4. Hazardous activities (e.g., tree climbing, spelunking).
The U.S. National Center for Infectious Diseases provides factsheets for many diseases for which biological technicians may be at risk (NCID 2003). Similar resources are available for a number of other safety considerations and should be sought out when applicable.
Resources needed
Proper equipment and adequate supplies are essential to the operation of monitoring programs. Your monitoring plan should therefore include a list of equipment and supplies needed for implementation. The list should provide a detailed description (including manufacturer and model number to allow future replacements), minimum functional specifications, and suppliers for specialized instruments and materials used in data collection and analysis. Any specialized laboratory or storage facilities that are required should also be described. Biologists in charge of implementing monitoring programs should include a checklist of equipment and supplies required for fieldwork in the operation plans and to survey crews. Monitoring plan developers should also identify special software packages necessary for performing data analysis or laboratory procedures. Data collected by different units within an agency conducting the same program may not be comparable if equipment and supplies are widely inconsistent. Developers of monitoring plans can minimize this possibility by ensuring the standardization of monitoring program materials.
Permits
Obtaining the proper permits can be integral to the implementation or continuation of a monitoring program. Most states require surveyors to possess scientific collecting permits for studies involving the removal of rare plants or capturing native wildlife. Most studies of federally protected species such as migratory birds, endangered species, or CITES species also requires obtaining specific permits from the US Fish and Wildlife Service. Permits must likewise be acquired to use controlled substances or materials such as prohibited trap types (leg-hold traps in some states), and certain immobilizing agents (e.g, ketamine) and the syringes, dart guns or other equipment used to administer the agents. When using radio transmitters, approved frequencies must be used as based on Federal Communications Commission regulations. Anytime that monitoring is conducted on private lands, written permission allowing entry should be acquired from the landowner. Failure to receive permission from a landowner can lead to dropping a plot from the sampling scheme in addition to creating ill will toward personnel involved in field sampling. A replacement technique that ensures randomization of plot locations should be developed. For instance, if a list of random plot locations is developed and permission is refused for one of the selected plot locations then the next random plot in the list for that stratum should be selected. Nonetheless, if the reasons for refusing access rights is in some way related to the species of interest (a landowner does not want you to know that the species occurs on her/his land) then there is the potential for bias to creep into your sample.
Biological Study Ethics
If the monitoring is conducted in conjunction with a University then the monitoring plan will need to be approved by the Institutional Animal Care and Use Committee (IACUC). Having an IACUC approval process that is well documented is required by universities but also should be used in other organizations as well. Capture, marking, and observation techniques may cause the subject animals to experience pain, permanent injuries, and increased mortality rates. In fact, some animal inventories and monitoring studies depend on lethal traps for the collection of voucher specimens or population data. The justification for such studies must balance the benefits of knowledge to be acquired with the welfare of individual animals and populations subjected to study methods. Most wildlife, fisheries, and zoological professional societies have adopted guidelines to assist field biologists in minimizing the adverse impacts on individual animals and populations (e.g., American Society of Mammalogists 1998; AFS, ASIH, and AIFRE 1987; Gaunt et al. 1997). Supervisors and field personnel should receive animal use training (required by most university scientists) and also become familiar with the standards for use of animals in field studies. In most cases, investigators must have explored alternative options to animal capture and handling and be prepared to justify any proposals to capture, restrain, harm or kill and animal. The monitoring plan should ensure that methods used explicitly consider these standards.
Voucher Specimens
Techniques for the preparation of pressed plants for archiving in a herbarium, or preparation of animal skins and skulls for archiving in a museum are provided in Anderson (1965) and Carter et al. (2007). The methods used to handle, prepare, and store plant or animal specimens collected in the field should be described. If laboratory analyses are required for the monitoring plan, the facility where the analyses will be conducted should be identified along with appropriate shipping methods. The museum or university collection that will ultimately house voucher specimens should also be identified. A lack of such considerations can physically fragment data and present obstacles to future analyses of specimens (e.g. subsequent genetic analysis).
Schedule and Coordination Plan
The schedule for sampling on a daily, weekly, monthly and annual basis should be well documented to ensure consistency over the tenure of the monitoring plan. This schedule should include the major logistical activities, data collection and fieldwork periods, and timing of analytical procedures. This will facilitate the estimation of reporting deadlines. It is particularly crucial that the monitoring plan describe factors that influence the appropriate season for conducting field work. Examples of these factors include: climatic or weather conditions, latitude or elevation, and animal activity patterns such as those relating to reproduction. The plan should also describe procedures that require coordination with other agencies and monitoring programs. Examples include the establishment of permanent monitoring plot monuments, determining radio frequencies to be used for monitoring program communication, and contracting arrangements. The deadlines for acquiring the necessary permits should likewise be noted.
Qualifications for Personnel
One of the most important considerations in planning a monitoring program is to ensure that data collection and analytical procedures are performed by trained staff under the supervision of qualified biologists. Technological tools such as electronic data-loggers improve the efficiency of field technicians, but these tools cannot compensate for short-comings of inexperienced or poorly trained personnel. The monitoring plan should specify the minimum qualifications and responsibilities of biologists, crew leaders, and crew members involved in conducting the monitoring program to ensure reliable and efficient data collection. Establishing written qualifications for personnel is particularly important for multi-year monitoring studies during which there is likely to be a significant amount of turnover among the monitoring program participants.
Sampling Unit Marking and Monuments
Careful consideration should be given to selecting methods to mark sampling units and to install monuments at permanent plots. There are numerous marking systems available and the final decision should be based on an assessment of the vulnerability of sampling units to vandalism and natural disturbance and the particular strengths and weaknesses of each system.
Plastic flagging and pin flags are inexpensive and suitable for temporary marking. However, plastic deteriorates in sunlight and may attract browsing by deer or cattle. Many large landowners reserve certain flagging colors for specific types of management activities; therefore flagging guidelines should be reviewed prior to marking sampling sites. Polyvinylchloride (PVC) pipe and wood stakes are vulnerable to vandalism and can be lost during wildfire or floods. These materials should be used as short-term (<1 year) markers only and should not be used at all near locations frequently visited by humans or livestock.
Steel reinforcing rod (rebar) and T-posts are more durable materials for monumenting sampling units. They can be driven deeply into the ground to prevent all but the most determined vandals from removing them. Steel rebar and T-posts can also be relocated with a metal detector if they are buried during a flood or land management activities. If vandalism is not likely at the site, high-visibility paint or flagging can be used to make posts more detectable by field crews. Rebar can be fitted with a commercially available plastic cap or bent into a loop if the protruding end presents a hazard to cattle or humans. Electric or manually powered rock or masonry drills (available at rock climbing equipment retailers or masonry suppliers) can be used to insert a bolted marker into rock substrate when bedrock or boulders prevent the use of posts or stakes.
Trees can be marked with a paint ring to indicate a sampling point or as an aid for relocating an individual sample tree. Periodic re-painting will be required at long-term monitoring sites. As with plastic flagging, tree marking guidelines vary by landowner and will be inappropriate on some sites. Trees can be provided a unique identifier by fastening two numbered tags (available at forestry supply companies) to the bole; one at breast height (1.5 m, 4.5 ft) and another at the base of the tree. Tags should be fastened with an aluminum nail to prevent rusting and loss of the tag. Two tags should be used in case the tree is harvested, then the basal tag will remain. Nails should be angled slightly downward and have a minimum of 3” of the shaft protruding from the tree to prevent diameter growth from damaging the tag. At permanent tree inventory plots, tree tags are customarily nailed to the aspect of the bole facing the plot center.
Whatever types of visual markers are used in the field, sampling unit locations should be recorded on a topographic map and with distances and compass bearings to permanent landmarks. Locations are typically determined using global positioning systems (GPS), geographic information systems (GIS), and other computer-based systems for data analysis, storage, and retrieval. GPS is a valuable tool for conducting field surveys and relocating sample sites. Using GPS, users can geo-reference sample site locations using latitude, longitude, or Universial Transverse Mercator (UTM) coordinates. Along with GPS locations, careful notes taken on the location and description of sample sites can aid in relocation at future times. These notes should be reported in a consistent manner and held in office records. The details that must be recorded to ensure that sampling techniques can be replicated include equipment used, permits obtained, schedule for sampling, etc. Data management and documentation remains a critical component of project supervision.
But it should not be assumed that the crew will always be able to relocate the sampling units using a GPS. Rugged terrain or dense canopy cover may prevent reception of the satellite signal, or the GPS may fail to operate once in the field. At long-term monitoring sites, landmark references should be recorded for every sampling unit. For short-term surveys and sites where sampling units are uniformly positioned along a transect or grid, landmark references only need to be recorded to the first unit. The crew can then rely on the site map and standardized spacing distances to navigate among sampling units at the site. Even this can take time though especially if sufficient time has elapsed between samples to allow vegetation to obscure permanent markers. Maps, UTM coordinates, and landmark references for sampling unit locations should be included as an appendix in the project report.
A number of other practices are helpful in maintaining consistent sampling units. For instance, the dimensions of plots, transects, or other sampling units should be described. Efficient techniques for positioning and measuring sampling units under field conditions should be identified. Providing a diagram or map to indicate the spacing and configuration of sampling units is also useful. For long-term monitoring projects, recommendations for marking and establishing monuments that are resistant to natural disturbances and vandalism should be provided. Elzinga et al. (2001) provided an excellent review of such techniques.
Documenting Field Monitoring Plans
A comprehensive description of field methods for sampling the target species or habitat element is particularly important. The monitoring plan should address all of the following issues relevant to the population or habitat element being sampled:
1. Observational or capture techniques: include a description of the equipment used and the rationale for the equipment chosen, pointing out the advantages and disadvantages of the chosen method with regards to precision and repeatability of the technique. Subtle details of techniques such as guidelines for trap placement, binoculars used, mensuration equipment used, and weather conditions may be very useful in reducing inter-annual variability in estimates.
2. Timing of sampling in terms of days, months, and years: explain how the temporal framework for sampling interfaces with periods of activity, movement, growth, or reproduction for the species of interest or how it is associated with the function of the habitat element of interest. Point out the advantages and disadvantages of the proposed timing with regards to the precision and repeatability of estimating the index of interest.
3. Duration of sampling: include a written explanation of why and how the sampling effort is adequate to develop a precise estimate over a period of time meaningful to the population of concern. Consider providing data from the literature or a pilot study that makes it clear that the additional sampling effort beyond what is proposed is unlikely to add additional information (e.g., species detection curves).
4. Frequency of sampling: Document the periodicity of sampling that reflects the likelihood that the index to the population or habitat element is as precise as possible and that bias due to sampling at times when individuals are more or less detectible has been minimized. The advantages and disadvantages of the proposed sampling frequency should be pointed out relative to achieving precision and repeatability within the context of the annual and inter-generational changes in the populations. For instance, highly dynamic populations may need more frequent sampling than populations that are relatively stable and change slowly over time.
5. Data collection: Document exactly how data are to be collected, including reference to the significant digits with which data are recorded. Clearly state the taxonomic level expected, the degree of precision of the measurement, and the specific techniques used to acquire the datum.
6. Plant or animal marking techniques must be considered carefully. Any marking technique that introduces bias into estimates of survival or reproduction can lead to highly unreliable monitoring information, thus they must be considered carefully. References to support methods used to sample and mark plants and animals should be provided. In the case of radio transmitters, make it clear that transmitter mass should not exceed specific guidelines provided in the literature. Bands, ear tags, passive integrated transponder (PIT) tags, and other markers must not unduly modify the organism’s mobility, survival, reproductive potential, or other functions that may result in an unreliable estimates of demographic parameters.
7. Use of equipment and materials should be precisely described. It is better to provide too much detail than too little regarding how equipment should be used, maintained, and stored.
The monitoring plan should receive peer review and be tested thoroughly before being implemented.
Quality Control and Quality Assurance
Data collection tasks that are vulnerable to observer error should include both a training program and compliance monitoring to ensure that the data are collected as accurately and precisely as possible. Data verification tests are highly recommended. For example, re-surveys could be conducted by an independent examiner on a subset of sampling units to measure error rates. Monitoring plans should also establish criteria for acceptable levels of observer error, and describe remedial measures when data accuracy is not acceptable.
Critical Areas for Standardization
Projects designed to identify population distribution or abundance patterns across space and time must control for measurement biases and observer variability that could confound interpretation of the data analysis. This process is referred to as standardization and consists of those aspects of the data collection monitoring plan intended to ensure that observations and measurements are conducted using identical methods and under the same conditions across all sampling units included in the monitoring program. The primary objective of standardization is to make certain that the field techniques employed do not cause detection probabilities to vary among sampling units. Standardization is particularly critical for monitoring plans that utilize relative abundance indices, that is, counts of individuals per unit of time or effort. If the techniques do influence detection probabilities, then it cannot be assumed that counts or other field measurements accurately represent variation in the population parameter of interest (e.g., population size or population density). Formal parameter estimation procedures (e.g., sighting-probability models) utilize different pilot studies to permit analysis of detection probabilities according to age class, habitat, monitoring program personnel, and other factors. These different detection probabilities are then incorporated into the calculation of the estimator, instead of assuming that detection probabilities are fixed. Monitoring plans should consider the following factors when identifying critical areas of standardization.
Season and Elevation
Most plants occurring in temperate climates demonstrate a predictable pattern of growth, reproduction, and senescence in response to changing environmental conditions throughout the year along moisture gradients and elevational gradients. Animals also often exhibit seasonal periodicity in habitat use and behavior patterns. These biological responses to the environment clearly influence detection probabilities in association with location, but may also strongly alter detection probabilities across different months of the year. Birds are an excellent example. Territorial male passerines sing regularly when establishing a territory and attracting a mate. During incubation and after hatching however, singing drops off and indeed adults feeding young are not only quiet but cryptic. And when fledglings emerge from the nest then they often call but do not sing. Hence sampling during the beginning, middle and end of the nesting cycle can produce quite different estimates of abundance. Therefore, a monitoring plan should specify the appropriate season for sampling. If the monitoring plan is designed to be applied across a wide geographic range, it must indicate how sampling periods are to vary by region, latitude, or elevation.
Diurnal Variability
Activity patterns of wildlife and fish species often change in a relatively predictable manner throughout the 24-hour day. Using our example of bird sampling, males sing on territories most aggressively early in the morning and the activity subsides during mid day. On the other hand, some observational and capture techniques are insensitive to diurnal patterns of behavior because they rely on a trap or other device that is always ready to capture an animal or record a detection (e.g. screw traps for migratory fish, track plates for medium-sized carnivores). However many field techniques are designed toward certain target behaviors that increase the detectability of some individuals in a population or their vulnerability to capture at particular periods throughout the day. Biologists developing monitoring plans should assess the significance of diurnal activity patterns on detection probabilities and, if necessary, specify the appropriate time of day to sample the target population.
Clothing observers wear while monitoring
Simply considering the clothing worn during field sampling can have an effect on the observations of some species. Standardizing field appearance and behaviors can be quite important. For instance, when sampling breeding birds, wearing red or orange can cause hummingbirds to be attracted to the observer, thereby biasing the estimates of abundance of this species. Wearing clothing that blends into the background to the degree possible may minimize such biases.
Budgets
After a monitoring program is designed, a budget request must be made to ensure that the plan can be implemented as designed. Typically this becomes an iterative process because the budget request for monitoring to achieve a certain statistical power to detect a given trend over time may exceed the capacity of the funding organization. The inability to procure adequate funding for a monitoring program often results in concessions being made to the effect size that can be detected by reducing the sample size, or changing the confidence level with which a trend can be detected. Program MONITOR (Gibbs and Ramirez de Arellano 2007) provided a tool for assessing the costs associated with each sampling plot while simultaneously estimating the power associated with detecting a trend given a certain sample size. Hence the implications of modifying the design on the funding levels needed to support the design can be explored prior to initiating the monitoring program. If funds are so limiting as to not provide an acceptable level of power, then changes can be made in the response variables, sampling techniques, or other design factors that may allow a revised form of the monitoring plan to be implemented. In a worst case scenario, if the funding is simply not sufficient to provide an acceptable level of power to detect a trend, the monitoring program will likely have to be abandoned.
Budget planning is often broken into two components: fixed costs and variable costs. Fixed costs are costs which are not affected by the extent of the monitoring effort, and are typically those associated with equipment that is needed during the first year of the program, such as vehicles, capture or recording equipment. These items are necessary to purchase to begin the program, but can be used in subsequent years. It is important to estimate the life of this equipment so that there are funds for replacements as certain pieces cease to work adequately.
Variable costs are those that vary with the sampling intensity. Cumulative personnel expenses (salaries, benefits, and indirect costs) are often the largest portion of the budget and these vary depending on the number of sampling locations measured. In addition it is important to calculate increased personnel costs over time due to raises and increased costs associated with benefits. Supplies are expendable items such as bait and flagging that must be replaced each year, so they also represent variable costs.
The greatest challenge to building and requesting a budget for a monitoring program is ensuring that funding will be available at the necessary time period (usually each year) over time. Given annual fluctuations in agency budgets, simply having the money allocated on a consistent basis becomes problematic. Most often the program leader will have to make an effective argument regarding the importance of the information during each budget cycle. This should become easier over time as results are summarized and the value of the data increase. A related difficult decision for a program leader or an agency to make however is when to stop a monitoring program. The tendency is to try to keep it operational for as long as possible, but one must begin to ask what the return is on the investment. Monitoring programs that have been ongoing for years or decades can become institutionalized and there can be considerable resistance to ending them. Yet this could come at the cost of taking funding from other more critical monitoring programs. It is therefore important to design monitoring programs with trigger points are included in the monitoring plan (e.g., the population reaches a certain level of growth for a certain number of years) that clearly indicate the program’s termination point. This will help facilitate the timely cessation of monitoring.
Summary
The logistics associated with implementing a monitoring plan may seem overwhelming but are integral to ensuring that the plan is implemented correctly and that the data will be useful. Adhering to random sampling monitoring plans, monumenting points, and using consistent plot designs from one time period to the next is critical. If stratification can reduce variance in estimates, then it should be used, but basing strata on vegetative characteristics should normally be avoided since vegetation structure and composition will likely change over time. Geographic or geologic features may be more useful and consistent strata.
Ensuring that personnel are trained, and that the necessary state, federal and institutional permits have been acquired take considerable time. How and when these activities will be conducted should be included in planning documents. Where sampling occurs on private land, time must be allotted to determine landownership and contact land owners for access rights.
Monitoring plans should be developed and followed to ensure ethical treatment of animals, and standardization in timing, techniques and locations over time. Personnel should be trained to follow these monitoring plans as closely as possible in order to reduce sampling error.
Finally, once the plan is designed and the costs associated with the logistics of the plan are estimated, a budget must be developed. Where budget constraints arise, then choices must be made regarding tradeoffs between data quality, response variables used, and statistical power to detect a trend. If these tradeoff analyses are not conducted before embarking on a monitoring program, then the end result could be data that are simply insufficient to detect a trend in the desired response variable, and funding and monitoring will likely end. On the other hand, collecting data consistently and estimating adequate power to detect trends has the potential to create a positive feedback loop in which acquiring funding for continuation of the program becomes easier over time as the value of the data increases. Including a trigger point in the monitoring plan that dictates when the monitoring should end is important, however, to avoid the monitoring program from becoming institutionalized and funded for its own sake. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.07%3A_Putting_Monitoring_to_Work_on_the_Ground.txt |
Field techniques refer to the standardized methods employed to select, count, measure, capture, mark, and observe individuals sampled from the target population for the purpose of collecting data required to achieve study objectives. The term also includes methods used to collect voucher specimens, tissue samples, and habitat data. The choice of field techniques to use for a particular species or population is influenced by five major factors:
1. Data needed to achieve inventory and monitoring objectives
2. Spatial extent and duration of the project
3. Life history and population characteristics
4. Terrain and vegetation in the study area
5. Budget constraints
Data Requirements
The types of data required to achieve inventory or monitoring objectives should be the primary consideration in selecting field techniques. Four categories of data collection are discussed below along with some suggestions for electing appropriate field techniques for each.
Occurrence and distribution data
For some population studies, simply determining whether a species is present in an area is sufficient for conducting the planned data analysis. For example, biologists attempting to conserve a threatened salamander may need to monitor the extent of the species’ range and degree of population fragmentation on a land ownership. One hypothetical approach is to map all streams in which the salamander is known to be present, as well as additional streams that may qualify as the habitat type for the species in the region. To monitor changes in salamander distribution, data collection could consist of a survey along randomly selected reaches in each of the streams to determine if at least one individual (or some alternative characteristic such as egg mass) is present. Using only a list that includes the stream reach (i.e., the unique identifier), the survey year, and an occupancy indicator variable, a biologist could prepare a time series of maps displaying all of the streams by year and distinguish the subset of streams that were known to be occupied by the salamander. Such an approach could support a qualitative assessment of changes in the species distribution pattern, thereby attaining the program’ objectives, and generate new hypotheses as to the cause of the observed changes.
It is far easier to determine if there is at least one individual of the target species on a sampling unit than it is to count all of the individuals. Determining with confidence that a species is not present on a sampling unit also requires more intensive sampling than collecting count or frequency data because it is so difficult to dismiss the possibility that an individual eluded detection. Probability of occurrence can be estimated using approaches such as those described by MacKenzie and Royale (2005). MacKenzie (2005) offered an excellent overview for managers of the trade-off between number of units sampled per year and the number of years (or other unit of time) for which the study is to be conducted. The variation in the estimated trend in occupancy decreases as the number of years of data collection increases (Fig. 8.1). A similar level of precision can be achieved by surveying more units over fewer years vs. surveying fewer units over a longer period.
Population size and density
National policy on threatened and endangered species is ultimately directed toward efforts to increase or maintain the total number of individuals of the species within their natural geographic range (Suckling and Taylor 2006). Total population size and effective population size (i.e., the number of breeding individuals in a population; Lande and Barrowclough 1987) most directly indicate the degree of species endangerment and effectiveness of conservation policies and practices. Population size or more accurately density per unit area is usually used as the basis for trend analyses because changes in density integrate changes in natural mortality, exploitation, and habitat quality. In some circumstances, it may be feasible to conduct a census of all individuals of a particular species in an area to determine the population density. Typically however, population size and density parameters are estimated using statistical analyses based on only a sample of population members. Population densities of plants and sessile animals can be estimated from counts taken on plots or data describing the spacing between individuals (i.e. distance methods) and are relatively straightforward. Population analyses for many animal species must account for animal response to capture or observation, observer biases, and different detection probabilities among sub-populations. Pilot studies are usually required to collect the data necessary to address these factors in the analysis. Furthermore, mark-recapture studies, catch-per-unit effort surveys, and other estimation methods require multiple visits to sampling units (Pradel 1996). These considerations increase the complexity and cost of studies designed for population parameter estimation.
Abundance indices
The goals and objectives of some biological inventories and monitoring studies can be met with indices of population density or abundance, rather than population estimators. The difference between estimators and indices is that the former yield absolute values of population density while the latter provide relative measures of density that can be used to compare indices to populations among places or times. Indices are founded on the assumption that index values are closely associated with values of a population parameter, although the precise relationship between the index and parameter usually is not quantified. Examples of abundance or density indices are: plant canopy cover, numbers of individuals captured per 1000 trap nights, counts of individuals observed during a standardized unit of time, among many others. From a data collection perspective, density indices often require less sampling intensity and complexity than population estimation procedures. However, population indices are not comparable among different studies unless field techniques are strictly standardized. Furthermore, the assumption that an abundance index closely approximates population density is rarely tested (Seber 1982).
Fitness data
For rare or declining populations, estimates of survival in each life stage as well as reproductive rates are required. These data not only provide useful trigger points for estimating rates of decline (lambda) they also allow trigger points for removal of a species from a threatened or other legal status. Collecting these sorts of data is often labor intensive and expensive. In a study on northern spotted owls, for instance, millions of dollars have been spent collecting these types of data (Lint 2001). This is not particularly surprising as the types of data that would be necessary to understand the population dynamics of a bird are numerous and complicated to generate. Nest densities, clutch sizes, hatching rates, fledging rates, and survival rates to maturity and survival rates as reproductive adults would be a minimum data set. New approaches to estimating individual contributions to population growth and changes in distributions of quantitative traits and alleles include genetic analyses, which can lead to even more detailed understanding of the potential for a population to adapt to variations in environmental factors (Pelletier et al. 2009).
Research studies
Studies of habitat relationships or cause-and-effect responses require coordinated sampling of the target population and environmental measurements or stressors to which the population may respond. Data collection efforts tend to be complex, requiring multiple sampling protocols for the target population, study site attributes, and landscape pattern metrics. The funding required to conduct research studies typically limits their application to species or populations in greatest need of management planning such as those listed as threatened or endangered. Manipulative studies are often carried out to generate the necessary data, but when these focus on a threatened species, ethical questions regarding the conduct of the experiment placing the species at even great risk, at least locally, often emerge. Hence it is often monitoring of both environmental conditions and aspects of population density or fitness that are used to assess associations in trends between population parameters and environmental parameters.
Spatial Extent
Clearly the scope of inference will influence the type of sampling technique used. Breeding bird atlas techniques commonly use large grids placed over entire states to assess the occurrence of species in a grid cell. Such approaches and those of the Breeding Bird Survey (Sauer et al. 2008) can be conducted through volunteer efforts. On the other hand, monitoring the trends in reproductive rates of northern spotted owls, northern goshawks, or grizzly bears over their geographic ranges requires a huge budget to collect the level of population data over large areas needed to understand trends. Great care must be taken when deciding what technique to use because both budgets and sample size requirements enter into logistics. Indeed, it is often the tradeoff between more detailed data and the cost of producing those data that drive decisions regarding monitoring designs for species at risk.
Frequently Used Techniques for Sampling Animals
The array of techniques available to sample animals is vast and summarized elsewhere in techniques manuals (e.g., Bookhout 1994). We summarize a few examples of commonly used techniques, but strongly suggest that those of you developing monitoring plans do a more complete literature search on sampling of the species that are of most concern in your monitoring program. We first provide a brief overview of techniques used to sample vertebrates and then point out which techniques are commonly used among various taxonomic groups.
Aquatic Organisms
Some aquatic organisms can and have been monitored using techniques that are essentially identical to those used for terrestrial vertebrates. For instance, in Brazil, arapaima have been monitored using a point count technique that counts individuals as they surface for aerial breathing (Castello et al. 2009). Point counts were more logistically and economically feasible, were determined to more accurately represent population changes over time and led to more effective management, but a conventional mark-recapture technique was also attempted with the same fish species (Castello et al. 2009).
Yet cases such as the arapaima are uncommon because this species is detected when surfacing for aerial breathing, has a low enough population density in a small enough area to be counted effectively, and possesses certain subtle visual and acoustic characteristics that allow for the identification of individuals (Castello et al. 2009). Most techniques used to sample aquatic organisms are conceptually similar to those used to sample terrestrial organisms. But constraints placed on observers of dealing with sampling in or on the water and at various water depths require that many techniques be more specialized. There are a variety of techniques commonly used to sample fish and aquatic amphibians as well as aquatic invertebrates (Slack et al. 1973). A systematic assessment of stream reaches using either snorkel surveys (Hankin and Reeves 1988) or electrofishing equipment is commonly used in shallow streams and rivers (Cunjak et al. 1988).
In estuaries and large rivers, quantitative studies are often confounded by the high variability of fish populations and the high efficiency of fish sampling gear (Poizat and Baran 1997). In light of this, Poizat and Baran (1997) undertook a study assessing the efficacy of surveying fishermen compared with a scientist-managed gill-net sampling approach and determined that combining both approaches is the best way to increase confidence that observed trends are real. In other words, if both sets of survey data suggest the same trend, it is safer to infer that the trends are real than if the data sets suggest different trends or there exists but one type of data.
Manta tows, which are comparable to line-transect methods but must account for uniquely marine conditions such as turbidity of water, tides, and sea-condition characteristics, are often utilized to monitor general characteristics of coral reefs and their associated populations. The technique, which has been employed in both scientist-run and community based programs, consists of towing a snorkeler trained to observe certain variables behind a boat at constant speed along a pre-determined stretch of reef (Bass and Miller 1996, Uychiaoco et al. 2005). In one study along the Great Barrier Reef, where manta tows have been employed since the 1970s, the sampled line is broken up into zones that take two minutes to sample and every two minutes, the boat stops for the observer to record data on an aquatic data sheet (Bass and Miller 1996). In these surveys, data often include counts of conspicuous species, such as giant clams, or of entire assemblages, such as carnivorous and herbivorous fish, but the technique is also used for monitoring habitat (Bass and Miller 1996, Uychiaoco et al. 2005). Indeed, observations of suites of variables designed to inform practitioners about the state of coral reefs over time such as reef slope, dominant benthic form, dominant hard coral genus, and structural complexity of coral are also commonly recorded (Bass and Miller 1996, Uychiaoco et al 2005).
Welsh et al. (1987) proposed a habitat-based approach for amphibians in small headwater streams and time-constrained and area-constrained approaches have also been used for headwater species (Hossack et al. 2006). Pond-breeding species or species that inhabit deeper water are often sampled using minnow traps, nets, or call counts of vocalizing frogs and toads (Kolozsvary and Swihart 1999, Crouch and Paton 2002).
Tracking of individual animals through tags, passive integrated transponders (PIT tags) and similar techniques are expensive but provide information on animal movements and estimates of population size and survival. Such approaches have been used with species of high interest such as coho salmon in the Pacific Northwest (Wigington et al. 2006).
Terrestrial and Semi-Aquatic Organisms
The diversity of forms, sizes, and life histories among terrestrial vertebrates has led to the development of hundreds of field techniques designed for different species and survey conditions. Table 8.1 lists the most widely used field techniques for collecting wildlife data, but it is by no means an exhaustive list of all inventory and monitoring methods. Techniques are separated into observational, capture, and marking methods and by the mode by which data are collected. A comprehensive review of all the different field techniques for terrestrial and semi-aquatic organisms is a separate book in itself (see Bookhout 1994). Here we provide a brief overview of some of the commonly used techniques.
Kuenzi and Morrison 1998 TagsBirds/MammalsNietfeld et al. 1994
Table 8.1. Field techniques for inventories and monitoring studies of terrestrial and semi-aquatic vertebrates. References can be found in the Literature Cited section.
Mode Technique Target Groups of Species References
Observational Direct Quadrats; fixed-area plots Sessile or relatively immobile organisms Bonham 1989
Avian point counts Bird species that sing or call on territories Ralph et al. 1995
Spot mapping & nest searches Territorial bird species Ralph et al. 1993
Line transect Large mammals, birds Anderson et al. 1979
Call playback response Wolves, ground squirrels, raptors, woodpeckers Ogutu and Dublin 1998
Standardized visual searches Large herbivores, Cook and Jacobsen 1979
Census Cave-dwelling bats; large herbivores Thomas and West 1989
Animal
Sign
Foot track surveys Medium-large mammals Wilson and Delahay 2001
Pellet & scat counts Medium-large mammals Fuller 1991
Food cache searches Large carnivores Easter-Pilcher 1990
Structures (e.g., dens, nests) Arboreal mammals; fossorial mammals; bears Healy and Welsh 1992
Remote Sensing Track plates Medium-large mammals Wilson and Delahay 2001
Photo & video stations Medium-large mammals Morruzzi et al. 2002
Ultrasonic detectors Bats Thomas and West 1989
Audio monitoring Frogs Crouch and Paton 2002
Hair traps Small-medium mammals, large carnivores McDaniel et al. 2000
Radio telemetry Limited by animal body size (>20 g) ? USGS 1997
GPS telemetry Limited by animal body ( >2000 g) ? Girard et al. 2002
Marine radar Bats, migrating birds Harmata et al. 1999
Harmonic radar Bats, amphibians, reptiles Pellet et al. 2006
Capture Passive Pitfalls Salamanders, lizards, small mammals Enge 2001, Mengak and Guynn 1987
Snap traps Small mammals Mengak and Guynn 1987
Box traps Small-medium mammals Powell and Proulx 2003
Funnel-type traps Snakes, turtles Enge 2001
Leg-hold & snares Large mammals Bookhout 1994
Mist nets
Active Drives to an enclosure Medium-large mammals with predictable flight response deCalesta and Witmer 1990
Cannon nets Medium-large mammals Bookhout 1994
Immobilizing agents Large mammals Bookhout 1994
Hand capture Salamanders Kolozsvary and Swihart. 1999
Marking
Mutilation Small mammals Wood and Slade 1990
Pigments Small mammals Lemen and Freeman 1985
Collars & Bands Birds/mammals Nietfeld et al. 1994
For certain species and conditions, it may be feasible to determine a count of individual members of the population on quadrats (sample plots) randomly or systematically positioned in the study area. Searches can be conducted on foot, all-terrain vehicles, or airplane depending on the scale and circumstances of the survey. Quadrat sampling is commonly used for plants and habitat elements, but with animals quadrat sampling poses some challenges. If animals are mobile during the sampling period, then there needs to be some reasonable assurance that an individual is not double-counted at multiple quadrats as it moves. Size, spacing, and mobility of the organisms must all be considered.
Point counts are perhaps the most extensively used technique for measuring bird abundance and diversity in temperate forests and on rangelands but have also been used to estimate abundance of other diurnal species such as squirrels. Variations in the technique have been described for different species and to meet different data needs (Verner and Ritter 1985, Verner 1988, Ralph et al. 1995, Huff et al. 2000). Ralph et al. (1995) provided a collection of papers examining sample size adequacy, bird detectability, observer bias, and comparisons among techniques.
Spot mapping, also referred to as territory mapping, often is used to estimate avian population densities by locating singing males during a number of visits to the study area and delineating territory boundaries. The technique is further described in Ralph et al. (1995). Nest searches can be used to assess reproductive success in an avian population by monitoring the survival of eggs and nestlings over the course of a breeding season. Both techniques are labor intensive and are not commonly used for inventories, but the information gained from these methods (i.e., territory densities, productivity) may be better indicators of population trends and habitat quality than simply counts of individuals.
Line transect and point transect sampling are specialized plot methods in which a search for the target organism is conducted along a narrow strip having a known area. Rarely can it be assumed that all animals are detected along the transect. However, if the probability of detection can be predicted from the distance between the animal and the centerline of the transect, then a detection function can be used to estimate population density. The approach can be adapted to surveys conducted by foot, snorkeling, and ground or air vehicles. Buckland et al. (1993) provided a complete, though highly technical, introduction to line transect and point transect methods. The approach has been widely applied to surveys of vertebrates, including desert tortoise (Anderson et al. 2001), marbled murrelets (Madsen et al. 1999), songbirds in oak-pine woodlands (Verner and Ritter 1985), and mule deer (White et al. 1989).
Audio recordings of animal vocalizations have been used to elicit calls and displays from species otherwise difficult to detect. The technique has been applied in studies of blue grouse (Stirling and Bendell 1966), northern spotted owls (Forsman 1988), ground squirrels (Lishak 1977), and others. The number of responses by the target species elicited by the recording is tallied during a prescribed interval and provides a population density index.
Standardized visual searches refer to techniques used to determine species occurrence, species richness, or relative density values, where sampling effort is standardized by space or time. Examples include road counts for large mammals (Rudran et al. 1996), raptor migration counts (Hussell 1981), and visual encounter surveys for terrestrial amphibians (Crump and Scott 1994) (Figure 8.2). Some visual search techniques do not necessarily equalize the amount of survey effort among sampling units. Instead, animal counts or species detected are standardized during analysis by dividing the number of observations by a unit of area or time. Variability among observers and environmental conditions may be significant sources of error unassociated with the sampling technique and should be assessed prior to data collection to minimize biases and improve precision.
Under certain circumstances, it may be possible to effectively observe all individuals in the target population. In such cases, population size can be determined directly from the count of individuals; no statistical procedures are necessary. Accurate counts on individuals depend upon a natural tendency of population members to aggregate, at least during predictable periods (e.g., cave-roosting bats). Furthermore, all locations where the individuals aggregate must be known in the study area, and there must be adequate surveyors available to make simultaneous counts at all locations.
In many cases, the target population is highly cryptic or too wary to be observed directly and budget constraints prevent the investigator from utilizing capture methods for data collection. In these situations, it is often possible to infer the presence of a species or determine an index value for population density by observing animal signs. Signs are tracks, scat piles, fecal pellets, scent-marking posts, or animal constructions (e.g., arboreal nests, beaver lodges, burrow openings) that can be accurately identified as evidence of a particular species. If searches for such evidence are conducted on standardized transects or quadrats, then observations may provide a reliable index to population density. Data analyses are similar to that for direct observations. Davis and Winstead (1980) and Wemmer et. al (1996) provide an overview of methods based on animal sign.
Elusive species can be sampled using remote sensing devices positioned across the study area. Track plates (Zelinski and Stauffer 1996) and hair traps (Scotts and Craig 1988, McDaniel et al. 2000) are inexpensive and suitable for determining the occurrence and distribution of rare mammals in the study area. Ultrasonic detectors can be used to monitor bat populations (Kunz et al. 1996), however it is not always possible to reliably distinguish among all bat species. Remote camera stations with data-loggers (Cutler and Swann 1999, Moruzzi et al. 2002) not only detect occurrence of the species, but also may yield information about sex, age, and activity patterns of individuals. Baits at a track plate or camera station can be used to increase the probability on detecting a cryptic or rare species, but can also bias any estimates made or disproportionately attract common omnivorous species, such as Virginia opossum or northern raccoon (Figure 8.3).
Radio-telemetry has been used for many years to collect data on wildlife and fish movement, home range size, and habitat selection (Figure 8.4). Transmitters weighing <1.0 g are now commercial available making it possible to track all but the smallest vertebrates. Tracking systems utilizing global positioning system (GPS) satellites permit monitoring of animal locations in real-time without requiring surveyors to determine radio signal directions in the field and are becoming more reasonably priced. A collection of abstracts on wildlife telemetry methods (USGS 1997) provides a useful introduction to the topic for terrestrial studies. Marine band radar has been used to count migratory birds at observation points (Harmata et al. 1999) and monitor activity patterns of marbled murrelets (Burger 2001).
Finally genetic analyses of tissue collected from hair traps, scat or other tissues have led to an explosion of approaches to assess populations, dispersal, and evolutionary patterns (Haig 1998, Mills et al. 2000).
Life History and Population Characteristics
Certain techniques are more commonly used with some taxonomic groups than others. In this section we provide guidance as to the types of techniques that you might consider depending on the species included in your monitoring program.
Amphibians and Reptiles
The small size, cryptic nature, and fossorial habits of salamanders make data collection particularly difficult. Many terrestrial amphibians move only short distances and are not susceptible to passive capture techniques. These species are usually sampled using visual searches and hand capture techniques with sampling effort standardized by area (Jaeger and Inger 1994, Bailey et al. 2004) or a time constraint (Crump and Scott 1994) (Figure 8.2). Species that migrate between aquatic breeding ponds and terrestrial habitat types may be susceptible to pitfall traps with drift fences (Corn 1994). For pond-breeding species, egg masses are often more detectable than adults of the same species, making egg masses more suitable for population monitoring studies. Shaffer et al. (1994) and Olson et al. (1997) provided an excellent introduction to techniques for amphibian inventories in ponds.
Cover-board surveys have been widely adopted for estimating the relative abundance of amphibian and reptile populations in different habitat types (Grant et al. 1992, Harpole and Haas 1999, Engelstoft and Ovaskake 2000). Cover-boards are objects such as boards or metal roofing that provides daytime cover for animals and when lifted reveals a sample of the animals in the area that use it (Figure 8.5). Hence it is a sample of a plot for those species that seek cover.
Birds
As a group, many species of birds are sampled using distance sampling because they are so mobile and vocal (Rostenstock et al. 2002, and see Buckland et al. 1993 for an overview of distance sampling). Consequently there are two primary means of detecting many species of birds, increasing the likelihood that they may be detected, especially during the breeding season when males are often territorial. Diurnal species sampled in grasslands, marshes or other rather uniform vegetation conditions often can be sampled using transects (e.g., Ribic and Sample 2001). Samples taken in areas where rugged terrain or other factors prevent the use of transects rely on point counts (Buckland 1987). Other commonly used techniques include spot mapping to understand territory densities (e.g., Dobkin and Rich 1998), nest searches to understand nest densities, and variations on the Mayfield method of calculating nest success (Johnson and Shaeffer 1990). Nocturnal species present additional challenges, but point counts for owls during their mating season can be effective especially if call back recordings are used to elicit responses (Hardy and Morrison 2000). But call back recordings can introduce biases when recordings are played in areas having different vegetative structure or topography. Finally, banding and band returns can be used to estimate longevity and age structures of populations (Pollock and Raveling 1982).
Mammals
Small mammals are often sampled using traps of various forms (Figure 8.6). Live traps are often used as they are suitable for mark-recapture estimates of population size, or live or kill traps can be used to estimate catch per unit effort estimates of relative abundance. When any kind of trap is used, animal welfare guidelines should be reviewed and followed.
Detection probabilities are influenced by the number of trap-nights (the number of traps multiplied by the number of nights sampled). Capture rates are easily influenced by factors such as density-dependent intra-specific interactions, weather, and habitat, so capture probabilities must be calculated to allow an unbiased estimate of relative abundance (Menkens and Anderson 1988). This is particularly important when assessing trends over time during circumstances where weather and other conditions affecting catchability vary from year to year.
Larger mammals, especially those that form social aggregations or occur as clustered populations may be more effectively surveyed by observational techniques than capture methods. Aerial surveys for ungulates are often conducted using distance sampling procedures, but again observability among vegetation types, weather conditions, and topographies need to be considered to ensure unbiased estimates of abundance (Pollock and Kendall 1987).
Occurrence and indices to abundance for mid-size mammals are often addressed using remotely activated cameras, scent stations, track counts or track plates, or spotlight surveys (Figure 8.3; Gese 2001). Each of these techniques has advantages of being reasonably low cost and effective at detecting certain species (see Gese 2001), but estimation of population size is usually not possible.
Bats present a unique sampling problem. Using ultrasonic recordings of their feeding calls can help in distinguishing some species occurring in an area (O’Farrell et al. 1999), but estimates of abundance are often conducted at roost or maternity sites.
Effects of Terrain and Vegetation
Imagine that you are counting all the birds that you can see or hear along a transect that extends from the center of a forested patch to the center of an adjacent field. You wish to determine if the relative abundance of birds differs between the two habitat types. You detect 28 birds in the forest and 34 in the field. Are there more birds in the field than in the forest? Perhaps. But probably not. Your ability to detect birds in the forest is hampered by the decreased visibility in the forest compared to a more open field. Hence if you corrected for the differences in detectability as a function of the vegetation type (using techniques common in distance sampling) then the number of birds detected per unit area might be much greater in the forest than in the field. Consequently simply raw counts of animals without considering the distance from the observer to the animal are often biased and should not be used as response variables in monitoring programs. This is particularly important where vegetation structure is likely to change over the course of the monitoring time frame.
On human time-scales, terrain does not (usually) change appreciably from one time period to another, but observations must still be standardized by their detectability in various settings.
Merits and Limitations of Indices Compared to Estimators
Indices are often used to assess changes in populations over time based on an assumption that some aspect of detection is related to actual animal density. For instance, the following are a few examples of indices to abundance:
• track counts (Conner et al. 1983)
• pellet group counts (Fuller 1991)
• capture rates (Cole et al. 2000)
• detection rates of singing male birds (McGarigal and McComb 1998)
• relative dominance (plant populations)
• counts of squirrel leaf nests (Healy and Welsh 1992)
• counts of beaver lodges or caches (Easter-Pilcher 1990)
These examples do not provide estimates of populations, rather, an index is measured with the assumption that the index is related to the population or its fitness in a known manner and that observed changes in the index measurement over time will reflect changes in population according to this relationship. Assumptions such as the more tracks seen, the more individuals present; or the more male birds heard singing, the more birds reproducing at the site are often made. But the reliability of these assumptions is brought into question, and indeed the opportunity for bias associated with indices to abundance is quite high. For instance, track counts may be related to animal abundance or to animal activity levels, but on the other hand, they could be related to the characteristics of the substrate, the weather, or any combination of these options. Likewise, counts of singing male birds may represent trends in abundance of territorial males, but if some males do not attract a mate, then numbers of singing males may not indicate abundance of nesting females nor reproductive output. Capture rates of animals over space and time can be related to animal abundance or to their vulnerability to capture in different areas of habitat quality. Consequently, although indices to abundance are often used because of logistical constraints, considerable caution must be exercised when interpreting the results. Indeed, it is often useful to conduct a pilot study that will allow you to state with a known level of certainty what the relationship is between the index and the actual population (or fitness) for the species being monitored. To do so requires an estimate of the population.
Estimators provide additional information to the user and can help to address some of the biases inherent in many indices. Fortunately there are a number of tools available to estimate abundances that are based on sampling theory and can result in known levels of confidence placed around the estimates. For instance, distance estimators provide a mechanism for estimating abundance of organisms from points or transects where detectability might differ among vegetative types or stream reaches. Population estimators are generally available as free software: https://www.usgs.gov/software/wildlife-software-and-models
A variety of information is used as the basis for estimates of populations (capture-recapture and band returns), some of which can also provide estimates of survival and reproduction. The overwhelming advantage of using population estimators is that estimates of abundance, survival, and age class distribution can be made with estimates of confidence. Clearly with replicate sampling of independent sites, indices to abundance can be calculated with confidence intervals, but there is still doubt regarding the assumption of unbiased association between the index and the population characteristic of interest. Consequently it is important when designing monitoring protocols to ensure that estimators are considered, and if it is not logistically possible to use estimators as a response variable in the monitoring program, then the selected index should be justified relative to its known association with the population characteristic of interest. If this cannot be done, then both the assumptions and the implications of violating those assumptions should be clearly stated.
Estimating Community Structure
Although much of this book focuses on monitoring species and the environmental conditions in which they live, at times managers may be concerned with maintaining or developing conditions that promote diverse or functional communities, or be able to detect declines in functional diversity in the face of environmental stressors. Diversity metrics have evolved over decades and provide a means of comparing complexity between or among places or times. Unfortunately most diversity metrics also bury information on individual species responses within one or a few numbers. To understand what is really happening within a community, a diversity metrics must be deconstructed to see changes in individual species or populations. The devil is indeed in the detail. Nonetheless diversity metrics are still used as a guide to community structure and function. Typically, a diversity metric consists of an estimate of the number of species in a unit of space and time (species richness) and the distribution of individuals among those species (evenness). In most evenness metrics, the maximum is achievable value is 1.00 (an equal number of individuals per unit area represented among all species in the community; i.e., no species dominates the community). But consider the example in table 8.2. The hypothetical forest and grassland have the same diversity and evenness. So are they the same community? Do they function in a similar manner? Obviously not. In fact the degree to which the two communities are similar in species representation and distribution of individuals among species in common between the two communities indicates that the percent similarity between the two communities is 0. In fact, each community has more in common with a more species rich and more even community represented in a savannah than in the forest or grassland. So is the savannah better because it is more species rich and more diverse? No, it is just different. In short, these metrics of community structure can be very difficult to interpret without digging into the details that comprise the metrics.
Table 8.2. Example of estimates of species diversity and community similarity for three hypothetical communities.
Community
Forest Savannah Grassland
Black-capped chickadee 10 4 0
Song Sparrow 2 4 0
American robin 4 3 0
Grasshopper sparrow 0 3 4
Marsh wren 0 1 2
Savannah Sparrow 0 1 10
___ ___ ___
Species Richness 3 6 3
Number of individuals 16 16 16
Simpson’s Evenness 0.797 0.956 0.797
Simpson’s Species Diversity1 0.567 0.850 0.567
Community similarity (%)2
Forest-Savannah 0.563
Forest-Grassland 0.000
Savannah-Grassland 0.313
1 White (1986)
2 Itow (1991)
Sampling communities in a manner that produces unbiased estimates of community structure also can be problematic. Species richness assessments may be as simple as developing a list of species detected in an area using standardized techniques. But some species are likely more easily detected than others. Some are active at different times of the day, and some move more than others. So estimates of richness are confounded by differences in detectability. When diversity metrics are calculated using these data, additional complications arise because estimates of abundance for each species in the community must be unbiased and based on the same unit of space and time. Again, differential detectability of species and biases resulting from movement arise making evenness estimates confounded between actual differences in abundance among species and differences in detection among species. Surveys to determine the presence of a species in an area typically require less sampling intensity than fieldwork necessary to collect other population statistics.
Another metric that can be calculated from data collected within a monitoring framework deals with unequal sampling efforts when trying to estimate the number of species in an area. Because rare species are often less likely to be detected than common species, one can estimate the number of species based on rarefaction curves so that you can compare the number of species found in two areas when the sampling effort differed (Simberloff 1972).
Estimating biotic integrity
Karr (1981) developed and index to biotic integrity (IBI) that was designed to be used to compare aspects of fish communities among sites in a standardized manner that reflected the water quality of the site with regards to its capacity to support fish communities. It included aspects of species richness, fish health, and a number of other parameters. Researchers have since adapted this technique for other taxa including aquatic macroinvertebrates and birds (Bryce et al. 2002). Although the general structure of IBIs is similar to that developed by Karr (1981), each IBI is typically crafted to a reference condition typical of the ecoregion within which a sampled area occurs. Hence an IBI developed for the mixed mesophytic forest of the Appalachians may have a similar structure to that of one in the Cascades mountains of Oregon, but the parameters measured would be based on a very different set of reference conditions. For that reason IBIs are not typically used in terrestrial monitoring protocols and like diversity indices they can bury information that must be extracted by deconstructing the index.
Standardization Protocol Review
Regardless of the approach taken, certain aspects of a sampling design should be standardized to minimize bias in the resulting data. See chapter 7 for a more detailed overview of standardization techniques. At the very least specific attention should be paid to consistently sampling the same location over time, sampling during the same season and time of day and using the same equipment from one sampling period to the next.
In addition to consistency in sampling techniques, locations and times, most of the approaches described in this chapter will need approval by an Institutional Animal Care and Use Committee (IACUC) or comparable review board at universities and agencies. Standards of Care for animals when conducting research are rigorous and should be applied to monitoring programs as well (see Laber et al. 2007 and Hafner 2007 for a perspective on limitations to such reviews).
Budget Constraints
The choice of which sampling technique to use when presented with options and a set of goals and objectives is as often driven my constraints of time and money as by the ideal technique to acquire the data needed. For instance, while information on survival of juveniles in the face of climate change may be a primary consideration for a long-lived species, a suitable surrogate might be an index to abundance of young of the year and adult animals in the population. Since budget decisions are often made based on the social seriousness of the issue, and since social values change over time, so do budgets. Consequently it often is wise to develop a monitoring program using techniques that are robust to concerns regarding bias and precision and that are cost effective, even if they do not result in the ideal level of fitness data that would be needed to answer demographic questions more definitively. More detailed demographic information may be collected in a supplementary manner if the level of social concern reaches a point where it is mandated.
Summary
There is a huge array of methods available to detect, enumerate or assess the fitness of organisms. Matching the appropriate approach with the goals and objectives of the study is a key first step in designing a monitoring program. The data needed to achieve inventory and monitoring objectives is often the driving factor in deciding which techniques will be used in a monitoring program. In addition the scale of the monitoring program may also influence the methods used. For narrowly focused programs on highly valued species, detailed measurements of fitness may be appropriate. As the scale of the project over space and time increases, then estimates of abundance or occurrence may be the most feasible approach.
Furthermore, different taxa vary in their propensity to be sampled using different methods. Whereas sessile animals can be sampled using quadrat sampling, wide-ranging species may more easily be sampled using cameras or hair traps that may provide information on occurrence or individual movements. In a similar way, simply the logistics associated with sampling in inhospitable (to humans) terrain limits the choices of sampling strategies available. Finally, budgetary and logistic restrictions oftentimes mean that the ideal sampling system may not be feasible because the time or money is not available to implement the technique to adequately meet the goals and objectives.
Amidst all of the decisions regarding which technique to employ, you should continually be aware of the need to standardize approaches over space and time and seek to minimize any biases in your sampling methods. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.08%3A_Field_Techniques_for_Population_Sampling_and_Estimation.txt |
We define habitat as the resources necessary to support a population over space and through time (McComb 2007). Species depend on a number of environmental resources within a specifc unit of space for their long-term persistence; these resources comprise a species’ habitat. All of these resources play an important role in the quality of habitat, and any fluctuation in these resources can affect a species at both the individual and population level (Pulliam 1988). Legislative mandates in the US make it legally necessary to monitor habitats, as well as populations of species that are designated as management indicator or endangered species (e.g., National Environmental Policy Act, Endangered Species Act, National Forest Management Act). Repeated inventories or long-term monitoring programs are excellent approaches to determine the interactions and dynamics of habitat use by a broad suite of species (Jones 1986). A properly designed monitoring protocol is appropriate for understanding and evaluating the long-term dependency of selected species on various habitat components. Management that modifies or reduces habitat quality can change the overall fitness of an organism, and consequently affect the growth of the population as a whole (McComb 2007). Consequently, managers will want to identify and incorporate the interactions between habitat and population change in order to make informed management decisions through an adaptive management process (Barrett and Salwasser 1982).
Resource availability is dynamic for most if not all species. Consequently, the challenge when developing a monitoring protocol is assessing whether changes in occurrence, abundance, or fitness in a population is independent from or related to changes in habitat availability and quality (Cody 1985). To assess the responses of animals or plants to changes in habitat quality, monitoring protocols must measure and document appropriate habitat elements. Many of these attributes could be incorporated into existing monitoring efforts associated with vegetation changes (e.g., USDA Forest Service Forest Inventory and Analysis efforts). A number of techniques exist for measuring site-level habitat characteristics, composition, and structural conditions. For example, point sampling and line sampling (e.g., line-intercept method) are two excellent methods for collecting data on a number of habitat characteristics such as percentage of plant cover, substrate type, and horizontal or vertical complexity (Jones 1986, Krebs 1989). Plot and plotless sampling (e.g., point-center-quarter method) are more intensive techniques for determining the density, composition, and biomass of various habitat components in an area (Krebs 1989). These data can be used to characterize the composition and frequency of habitat components for an area. Furthermore, if these sampling points are permanent, then it is possible to document changes in habitat components over time. This is especially important, since the carrying capacity of a habitat is dynamic and depends on a number of resources that can fluctuate due to natural (e.g., food, hurricanes, disease, etc.) and/or anthropogenic (e.g., silviculture, water management) disturbances. These disturbances can occur at a coarse scale, affecting hundreds of hectares and multiple patches within a landscape, or at a finer scale, affecting only a small area within a larger patch type. How a population responds to disturbances and the resultant environmental changes depends on the species’ habitat requirements. Whether or not a monitoring protocol can determine causes of population change will be a direct result of its ability to monitor that species’ habitat.
It is important to differentiate between habitat, which is species-specific, and a habitat type, which is a biophysical classification of the environment that can be useful for understanding possible effects on a suite of species. Habitat types are often used as surrogates for a species habitat but this approach must be viewed with caution. Habitat for one species rarely if ever represents habitat for another species given the multiple factors involved in defining a species’ habitat (Johnson 1980).
Selecting an Appropriate Scale
Knowing how a species selects habitat can provide clues as to which habitat elements to measure at what scale to ensure independence among samples and to more accurately characterize habitat for a species. Habitat selection is a set of complex behaviors that individuals in a population have developed over time to ensure fitness. These behaviors are often innate and have evolved to allow populations to be resilient to the variations in conditions that occur over time (Wecker 1963). These behaviors are also often evolved such that each species selects habitat in a manner that allows it to reduce competition for resources with other species. So the evolutionary selection pressures on each species, both abiotic and biotic, have led species to develop distinct strategies for survival and have thereby linked habitat selection and population dynamics.
Some species are habitat generalists and can use a broad suite of food and cover resources. These species tend to be highly adaptable and occur in a wide variety of environmental conditions. Other species are habitat specialists. These species are adapted to survive by capitalizing on the use of a narrow set of resources, which they are adapted to use more efficiently than most other species. Consider where you might find spring salamanders in the eastern US or torrent salamanders in the western US. Both species occur in clear, cold headwater streams and they tend to be most abundant where predatory pressure from fish is minimal or non-existent. Changes over time in the occurrence and abundance of both species are of interest to managers due to the concern that forest management activities that reduce canopy cover and raise stream temperatures could threaten populations of these species (Lowe and Bolger 2002, Vesely and McComb 2002). Clearly though, habitat generalists and specialists are simply two ends of a spectrum of species’ strategies for survival in landscapes faced with variable climates, soils, disturbances, competitors, and predators.
Hierarchical Selection
Many studies have been conducted to assess habitat selection by wildlife species. Johnson (1980) suggested that many species select habitat at four levels and called these levels, first-, second-, third-, and fourth-order selection (Figure 9.1). First order selection is selection of the geographic range. The geographic range defines, quite literally, where in the world this species can be found. In our example from figure 9.1, pileated woodpeckers are found in forests throughout the eastern and western North America. Considering two extremes underscores the significance of understanding first-order selection: Figure 9.2 shows geographic range maps for two species, Weller’s salamander, found in spruce forests above 1500 m (5000 feet) in the southern Appalachians, and black-capped chickadees found throughout the northern US and southern Canada. These two species have widely divergent geographic ranges and any monitoring protocols developed must consider these differences.
Consider the importance of populations of a species at the center vs the periphery of its geographic range. Populations at the periphery may be in lower quality habitat if either biotic or abiotic factors are limiting its distribution. But recall that environments are not static. They are constantly changing. Climate changes, earthquakes change the topography, some species arrive while others leave. It is those populations at the periphery of their geographic range that are on the front line of these changes. Hence although it may be tempting to think of these peripheral populations as somewhat expendable, they may be critical to population maintenance as large scale changes in habitat availability occur. Given the contemporary rate of climate change, these peripheral populations may be even more important over the next few hundred years (McArty 2001).
Although Johnson (1980) did not describe metapopulation distribution as a selection level, it is important to realize that within the geographic range, populations oftentimes are distributed among smaller, interacting sub-populations that contribute to overall population persistence. In this structure, defined as a metapopulation, the growth, extinction, and recolonization of and by sub-populations is an adaptation to habitat quality changes caused by iterative disturbance and regrowth. The distribution of the sub-populations is important to consider during development of a monitoring plan to ensure that not only the sub-populations are included in the monitoring framework, but suitable habitat patches not currently occupied, as well as the intervening matrix are also included.
Johnson (1980) described second-order selection as the establishment of a home range: the area that an individual or pair of individuals uses to acquire the resources that it needs to survive and reproduce. Not all species have established home ranges, but most do. Individuals which have nests, roosts, hibernacula, or other places central to their daily activities move in an area around that central place to acquire food, use cover, drink water, and raise young. Home ranges are not the same as territories. A territory is the space, usually around a nest, that an individual or pair defends from other individuals of the same species and occasionally other individuals of other species. Territories may be congruent with a home range, smaller (if just a nest site is defended), or may not be present at all.
Species with larger body mass need more energy to support that mass than smaller-bodied species. Herbivores tend to have smaller home ranges than carnivores of the same size, both because energy available to herbivores is more abundant and because with each increase in trophic level there is a decrease in energy availability. Home range sizes also vary among individuals within a species. Generally speaking, if food resources are less abundant or more widely distributed, home range size increases. But within a species the home range size has an upper limit that is governed by balancing energy input from food with energy loss by movement among food patches. For instance, Thompson and Colgan (1987) reported larger home ranges for American marten during years of low prey availability than in years of high prey availability. In this example, to ensure that observations of American marten are independent from one another, sample sites should be distributed in a manner that no individual marten is likely to visit more than one site. Because marten can be difficult to detect in some settings, however, sub-samples within sample sites may be used to ensure that the species is detected if it is present.
Third order selection is the use of patches within a home range where resources are available to meet an individual’s needs. Biologists often can delineate a home range based upon observed daily or seasonal movements of individuals going about their business of feeding, resting, and raising young. But this area is not used in its entirety. Rather there are some places within the home range that are used intensively and other parts of the home range that are rarely used (Samuel et al. 1985). Selection of these patches is assumed to represent the ability of the individual to effectively find and use resources that will allow it to survive and reproduce. Sampling in these patches can influence the detectability of a species to the extent that sampling says more about the habitat elements and resources important to the species of interest rather than a species’ density or abundance.
Fourth order selection is the selection of specific food and cover resources acquired from the patches used by the individual within its home range. Given the choice among available foods, a species should most often select those foods that will confer the greatest energy or nutrients to the individual. Which food or nest site to select is often a tradeoff among availability, digestibility, and risk of predation (Holmes and Schultz 1988). Factors that influence the selection of specific food and cover resources most often tend to be related to energetic gains and costs, but there are exceptions. The need for certain nutrients at certain times of the year can have little to do with energetics and much to do with survival and fitness. For instance, band-tailed pigeons seek a sodium source at mineral springs to supplement their diet during the nesting season (Sanders and Jarvis 2000).
Collectively, these levels of habitat selection influence the fitness of individuals, populations and species. Habitat quality is dependent not only on the food and cover resources but also the number of individuals in that patch. Many individuals in one patch means that there are fewer resources per individual. Habitat quality and habitat selection is density dependent. Hence sampling of habitat elements must consider the likely effects of population density on the probability of detecting a resource. Sampling browse in a forest with high deer densities will result in an estimate of browse availability only in relation to that population size, and not to the potential of the forest to provide browse biomass.
Remotely Sensed Data
Some information on habitat availability for selected species can be efficiently collected over large areas using remotely sensed data. In the very simplest form, maps allow users to better define their sampling framework by locating and delineating important areas and habitat types. Users can classify areas based on a variety of physiographic characteristics, and are able to document site-specific information, such as winter roosts, vernal pools, and breeding grounds. Data for maps can be based on a number of sources including aerial photographs, satellite imagery, orthophotos, or planimetric maps (Kerr 1986).
Aerial Photography
Monitoring and inventorying programs often use aerial photography for creating maps. Generally, these programs use aerial photos from scales of 1/2,000 to 1/60,000 for the purposes of classification and planning (Kerr 1986). Aerial photographs should not be considered as maps because they contain inherent degrees of radial and topographical distortions. Thus, aerial photographs must be corrected for geometric and directional inaccuracies. However, many Geographic Information Systems (GISs) are capable of correcting these problems. Orthophoto maps are commonly used for large-scale monitoring projects (covering 8,000-400,000 ha). These maps are corrected aerial photos with topographic information superimposed. If available, these types of data can be very useful during design of a sampling scheme. Aerial photography is usually available in black and white, true color, and color-infrared (Figure 9.3).
Color-infrared aerial photography is useful for identifying riparian vegetation and seasonally dominant vegetation (Cuplin 1986, Kerr 1986). The primary use of color infrared photographs is for analyzing and classifying vegetation types. This is because healthy green vegetation is a very strong reflector of infrared radiation and appears bright red on color infrared photographs. Often times, aerial photography is taken at different times in the year, allowing for seasonal comparisons of vegetation types (i.e., leaf-on and leaf-off photography). Yearly differences can be documented to describe changes in habitat area and composition over time.
Although aerial photography can be essential in creating maps for habitat types and area classification, the accuracy of these maps depends on photo interpretation by humans. Misclassification of habitat types is one common result of human error during photo interpretation. Consequently, although aerial photography is an indispensable tool for creating a sampling framework over large geographic areas, the accuracy, reliability, and usefulness of the map is influenced by the expertise of those responsible for interpreting and classifying the photography.
Satellite Imagery
Satellite imagery has become a popular method for describing gross vegetation types over large geographic areas (Figure 9.4). The majority of satellite imagery data comes from the LANDSAT program. The LANDSAT program refers to a series of satellites put into orbit around the earth to collect environmental data about the earth’s surface (Richards and Jia 1999). The U.S. Department of Interior and NASA initiated this program under the name Earth Resources Technology Satellites. Spatially, these data consist of discrete picture elements, referred to as pixels, and is radiometrically classified into discrete brightness levels (Richards and Jia 1999). This reflected light is recorded in different wavelength bands, the number of which depends on the type of sensor carried by the satellite. For instance, LANDSAT 7 was launched in April 1999 and carries the Enhanced Thematic Mapper Plus (ETM+), which produced data in 7 specific bands and 1 panchromatic band (Richards and Jia 1999).
The area each pixel covers on the ground is referred to as that image’s resolution. The pixel size for Landsat image data is typically 30 m2. Using the digital reflectance data, these images can be initially classified by humans, but later extrapolated through computer classification, to the rest of the image. Satellite imagery produces digital data, which carries the distinctive advantage of being able to be processed by computers that can distinguish small differences in color in a consistent, easily repeatable way.
There are, however, several drawbacks to using satellite imagery. In general, satellite imagery does not provide the detail that is found in aerial photography (Kerr 1986). Computer interpretation and classification often has difficulty in separating vegetation species or areas of the same reflectance. This may pose a problem if one is attempting to classify areas based on a species of plant. The scale of image resolution may not be sufficient to address the needs of the monitoring protocol. Although satellite imagery has proved useful for regional analyses (see Scott et al. 1993), the level of spatial detail and resolution may not be appropriate for small-scale monitoring programs.
Accuracy Assessment and Ground-truthing
The accuracy of satellite imagery depends on ground-truthing and subsequent accuracy assessment. The process of classifying such broad ranges of environmental features into specific, and often simplified, land use and land cover classes leads to inevitable errors in classification. Having a well-distributed grid of Global Positioning System(GPS) field surveys is a useful method for rectifying such problems. This process, ground-truthing, is an absolute necessity for any map, whether or not the map is based on satellite imagery or aerial photography. However, this method can be relatively expensive if there are a large number of ground points across an extensive geographic area. Recently, aerial videography has become a useful method for assessing the accuracy of Landsat imagery. This method consists of airborne video data systems that tag each frame of video with geographic coordinates from a GPS, providing a cost- and time-effective method for obtaining data on vegetative communities over large geographic areas (Graham 1993). This method can be combined with ground-truthing procedures, but allows for a decreased dependency on ground-based field surveys. These methods of accuracy assessment, and others like them, allow for rigorous statistical analyses to produce acceptably accurate land use and land cover maps. It is important to stress that to legitimately use and create accurate maps based on satellite imagery or aerial photography, monitoring protocols must incorporate ground-truthing and accuracy assessment.
Vegetation Classification Schemes
Vegetation classification is a common use of map data. Although vegetation can change over time and may not be a particularly useful means of stratifying samples, vegetation structure and composition are often highly related to a species occurrence or abundance. Biologists and managers often use a hierarchal approach to stratify vegetation types based on dominant and subdominant vegetation, landform, soil composition, or other factors that they deem pertinent (Kerr 1986). Once a classification criterion is determined, the landscape can be separated into discrete units so that samples can be distributed into an adequate number of habitat types which represent strata in a stratified random sample. Vegetation stratification can yield important information about the use of different types by a species. The Resource Inventory Committee of British Columbia has outlined a good approach to vegetation stratification (Robinson et al. 1996):
1. Delineate the project area boundary.
2. Conduct a literature review of the habitat requirements of the focal species. If there is enough available and accurate information on the habitat requirements of the species, then it may be possible to identify those vegetation components that relate to habitat quality. However, caution should be used when relying on habitat associations from previous studies since many studies may not be applicable to the region of study.
3. Develop a system of habitat stratification that you expect will coincide with species habitat requirements.
4. Use maps, aerial photographs, or satellite imagery to review and select sample units that are reflective of the study area.
5. Evaluate the availability of each habitat strata within the study area. If there are any habitat types that are inaccessible, then no inferences can be made to similar habitat types throughout the project area.
Consistent Documentation of Sample Sites
To accurately monitor changes in habitat and populations, long-term monitoring protocols must emphasize a repeatable sampling scheme. Making inferences about a population from a sample taken over time depends on the ability of a protocol to re-sample and re-visit the same set of points from one year to the next. Monitoring protocols should incorporate consistent documentation of sample sites throughout the study area. This typically involves the use of GPSs, GISs, and other computer-based systems for data analysis, storage, and retrieval. GPS is a valuable tool for conducting field surveys and relocating sample sites. Using GPS, researchers can geo-reference sample site locations using latitude, longitude, or UTM coordinates. Along with GPS, careful notes should be taken on the location and description of sample sites. These notes should be reported in a consistent manner and held in office records. Data management and documentation remains a critical component of project supervision. It is vitally important that there is proper documentation and storage of sample site locations for ensuring the long-term and repeatable success of monitoring protocols.
Ground Measurements of Habitat Elements
Oftentimes a monitoring framework will be based on remotely sensed data as a first coarse-scale approach to documenting change followed by more detailed ground-based sampling. Changes in resource availability for species often are predicted using measurements of habitat elements and habitat types. Habitat measurements include abiotic and biotic features such as rock, soil, elevation, vegetation types, snags, ground cover, and litter. These data apply to a specific habitat type, which is defined as an area that is characterized by consistent abiotic and biotic features (Jones 1986). To assess habitat availability, a number of measurements are documented at various scales and include (Jones 1986):
• size of sites (area);
• location and position of habitat sites, including distance between habitat sites and heterogeneity within an area;
• edge influences created by habitat size interfaces and ecotones;
• temporal availability of habitat sites.
These data are collected over various scales; however, the relevant scale at which to collect and interpret these data will be defined by the organism (see previous section).
Information that relates to the abiotic or biotic influences on the species is considered a habitat element or component (Jones 1986). These elements can be highly significant measurements in terms of the distribution, fitness, and stability of a population throughout their range. Habitat elements are characterized both spatially and temporally, and can represent an entire habitat type or a specific area occupied by the species. Examples of abiotic and biotic data that are typically included are described by a number of authors: Cuplin 1986, Cooperrider 1986, Jones 1986 (Table 9.1):
Table 9.1. Examples of habitat elements that should be considered when identifying vegetation types and sampling designs.
Habitat Feature Habitat Components
Landform and physical features Average elevation, slope, and aspect
Average surface rock cover, talus and rock outcrop abundance and size
Soil depth and composition
Vertical and horizontal heterogeneity of soils and rocks
Vegetation-derived features Average leaf and litter cover per unit area
Snag density and size
Dead and down woody debris
Average height, density, and composition of vegetation types
Vertical and horizontal heterogeneity of litter, snags, and live vegetation
Aquatic physical features Streamflow pattern (riffles, pools, glides and cascades)
Streamflow volume
Stream width, depth and gradient
Water temperature
Turbidity
Surface acreage
Stream channel stability
The measurement and interpretation of habitat elements is central to understanding current conditions and desired future conditions in patches and landscapes. In the subsequent sections we describe a few simple techniques for measuring the availability of key habitat elements, but more comprehensive information on field sampling of habitat elements can be found in Bookhout (1994), James and Shugart (1970), Hays et al. (1981), and Noon (1981).
Methods for Ground-Based Sampling of Habitat Elements
Some habitat elements are particularly important to many species depending on their size, distribution and abundance. These include: percent cover, height, density, and biomass of trees, shrubs, grasses, forbs, and dead wood. Other habitat elements are associated with only a few species, such as stream gradients (e.g., beaver; Allen 1983) and tree basal area (e.g., downy woodpecker, Schroeder 1982). The following constitutes suggestions for an exercise that will train you in some of the more common habitat sampling methods:
Visit two areas with very different management histories such as a recent clearcut and an unmanaged forest. First, compare habitat elements between the two stand types. Then choose a particular organism and, using life history information, a habitat suitability index model, and a geographic information system, assess the habitat quality of each for that species.
Random Sampling
Probably the most important part of sampling habitat is to sample randomly within the area of interest (stand, watershed, stream system, etc.). Systematic or subjective sampling can introduce bias into your estimates and lead to erroneous conclusions. In this example you will be sampling two forest stands, but it could be wetlands, prairies, or any other unit of land or water. Within your stand you should collect a random sample of data describing the habitat elements. For the purposes of this exercise, you will collect data from three or more randomly located points in each stand.
1. Using a random numbers table (nearly all statistics books have these) first select a 3-digit number that is a compass bearing (in degrees) that will lead you into the stand. If the number that you select does not lead you into your stand then select another number until you have a bearing that will work.
2. Select another 3-digit number that is a distance in meters. Using your compass to establish the bearing and either a 30-m tape measure or pacing, walk the randomly selected distance in the direction of the assigned bearing and establish a sample point. You will collect habitat data at this point. Once you have completed collecting data at this point, you repeat the process of random number selection three or more times in this stand and then three or more times in the second stand.
Vegetation Sampling
Measuring density
One of the most common habitat elements that you will measure is density of items, usually trees, snags, logs, shrubs, or other plants. Density is simply a count of the elements over a specified area. Counting individual plants on plots delineated by a sampling frame is the most commonly used approach to estimate the frequency or density of plant populations. Measurements of plant biomass also can be obtained from the dry weights of vegetation clipped on plots having standardized heights, as well as width and length. Standardized photographic methods (i.e., photoplots) can be used to capture a visual record of a sampling unit that is useful for monitoring studies (Elzinga et al. 1998).
Data collected from plots are affected by the size and shape of the sampling unit. Square plots, known as “quadrats”, and circular plots have smaller boundary/interior ratios compared to rectangular shapes of equal area. In heterogeneous habitats, data collected on long plots often have been found to have lower statistical variance than data from compact plots of the same total area (Krebs 1989).
The optimum size and shape of a plot will differ according to plant life-form, environmental conditions, and survey objectives. Typically, the optimum plot configuration will be one that provides the greatest statistical precision (i.e., lowest standard error) for a given area sampled. Several investigators have developed approaches for determining the most appropriate plot size and shape for a particular population survey (Hendricks 1956, Weigert 1962). Krebs (1989) provided a useful review of standardized plot methods.
When estimating the density of trees, you usually will count all the trees in a circular plot, usually 0.04 ha (0.1 acre) in size. Saplings and tall shrubs are usually measured in a 0.004-ha (0.01-acre) plot. Small shrubs and tree seedlings are usually measured in a 0.0004-ha (0.001-acre) plot.
1. From plot center, measure out in each cardinal direction (N, E, S, W) 11.3 m (37.2 feet) (the radius of a 0.04 ha [0.1-acre] plot). Mark these places with flagging.
2. Using a diameter tape or a Biltmore stick, measure the diameter at 1.3 m (4.5 feet) above ground of all live trees in the plot that are > 15 cm (6 inches) in diameter at breast height (dbh) and record the species of each tree. Repeat this procedure for all dead trees > 15 cm dbh. Expand this sample to a ha (or acre) by multiplying the estimates by the proper conversion factor, in this case using 25/1 converts our number to a per ha estimate (10/1 will generate a per acre estimate). This procedure, with the appropriate conversion factors, can be repeated for smaller plot sizes to estimate more tediously sampled habitat components such as seedling numbers.
Estimating Percent Cover
Use your four 11.3-m (37.2-foot) radii as transects, by walking along each and stopping at five equidistant points to estimate canopy cover. There are a number of techniques available to estimate canopy cover including moosehorns (Garrison 1949) and densitometers (Lemmon 1957). A simple approach to estimating cover is to estimate the presence or absence of vegetation using a sighting tube (a piece of PVC pipe with crosshairs) (James and Shugart 1970). At each of the 20 points on your transects, look directly up and see if the crosshairs intersect vegetation (if so record a ‘1’) or sky (if so, record a ‘0’). Repeat this at each of the five points on each of the four transects. Tally the number of ‘1’s recorded from these points. Divide by 20 to estimate the proportion of the plot covered by vegetation. A similar approach to estimating cover can be used by looking down rather than up, but estimates of ground covered by grasses and forbs often use somewhat different techniques. One method of measuring ground cover for a plant species is to calculate the percentage of points in contact with the target species from a standardized arrangement of points on the sampling unit. The technique utilizes marks at fixed intervals along a tape, or pins held along a linear frame positioned above the sampling unit (i.e., point frame). Points are particularly useful for estimating the cover of short grasses, dense patches of forbs, and other low plant species. Bonham (1983) reviews several types of simple apparati to standardize point observations and greatly improve the precision of cover measurements.
Ground and shrub cover can also be measured using a fiberglass measuring tape stretched tautly between two end poles. The surveyor proceeds along the tape, recording each point where the tape first intercepts the vertical plane of any above-ground plant part of the target species, and then the point where interception with the target species is interrupted. Cover is estimated as a percentage of the total length of tape intercepting the target species. Interception points can be reliably observed along the tape to approximately eye-level; a staff or contractors level held vertically and moved along the tape by the surveyor can extend the effective height of measurements to 4 m or more. The position of the end poles should be permanently monumented to ensure re-measurements are reliably positioned.
Estimating tree height
Use a clinometer with a percent scale (look through the view finder and you should see two scales, with units given on them if you look straight up or straight down).
1. Walk 30 m (100 feet) from the base of the tree or other object that you wish to measure.
2. Looking through the view finder, align the horizontal line in the view finder with the top of the tree. Record the number on the percent scale (top).
3. Looking through the view finder, align the horizontal line in the view finder with the base of the tree. Record the number on the percent scale (bottom).
4. If the top number is positive and the bottom number is negative (< 0) then add the absolute values of these two numbers together to estimate height in feet.
5. If the top number is positive and the bottom number is also positive (> 0), then subtract the absolute value of the bottom number from the top number to estimate height in feet.
Estimating basal area
Basal area is the cross-sectional area of all woody stems at 1.3 m (4.5 feet) above ground. It is a measure of tree dominance on a site. The higher the basal area, the greater the dominance by trees. There are two ways to estimate basal area. First, you can use your estimates of dbh from your sample of trees (see estimating density, above) to calculate the area of each stem (A=3.1416*r2, where r = dbh/2). By summing the areas on a 0.04-ha (0.1-acre) plot and then multiplying the total by 25, you arrive at an estimate of basal area per hectare (multiply by 10 to estimate basal area per acre).
Alternatively, you can use a wedge prism (Figure 9.5) using a plotless method for estimating basal area. Holding the prism over the plot center (do not stand at the center), look at a tree through the prism. If the image that you see through the prism is connected to the image of the tree outside of the prism then tally the tree and record its species. If the image that you see through the prism is disconnected from the image outside the prism, then do not record the tree. Moving in a circle around the prism that you continue to hold over plot center, record all trees that have the prism image connected to the image outside of the prism regardless of whether they fall in the 0.04-ha (0.1-acre plot) or not. Tally the number of trees that were recorded. Generally you will use a 10-factor prism, that is, each tallied tree represents 10 other trees per acre. Multiply the number of trees tallied by 10 and this estimates the basal area in square feet per acre for this site. Other factor prisms do exist, however, and may be more appropriate for your survey depending on the specific characteristics of the habitat being sampled (Wensel et al. 1980).
Another class of “plotless” techniques utilizes measurements to describe the spacing of individuals in an area to estimate population density. Commonly referred to as “Distance Methods”, these techniques are founded on the assumption that number of individuals in a population can be determined by measuring the average distance among individuals, or between individuals and randomly selected points. Two of the most widely used techniques include the Point-Centered Quarter Method (Cottam and Curtis 1956) and the Wandering-Quarter Method (Cantana 1963). Distance methods have been commonly used for vegetation surveys, and are easily adapted to inventories of rare plants or other sessile organisms. Collecting data for surveys based on distance methods may have some practical advantages over plots or transects. First, distance methods are not susceptible to counting errors that often occur near plot boundaries, thus may yield more accurate density estimates. Secondly, the time and effort to attain an adequate sample of distance measurements in an area often is less than that required to search for every target organism on a plot, thus increasing the efficiency of the survey. Cottam and Curtis (1956) recommended a minimum of 20 measurements for estimating population density or abundance using Point-Centered Quarter Method. However, it is always prudent to assess the adequacy of the sample size empirically using widely available formulas (Bonham 1989).
Sampling Dead wood
Dead wood has been recognized as a habitat element important to many species (McComb 2007). There are a number of methods for sampling dead wood, but the most comprehensive uses line intercept sampling to generate estimates of a variety of dead wood characteristics (Harmon and Sexton 1996). The line transects often radiate out from a plot center and the diameter of logs on which they fall is measured at the point of intersection. Usually an estimate of decay class (1-5) is also made (McComb 2007). Diameters of elliptically-shaped logs should be measured in two dimensions and then averaged to get a single value. These measurements are then used. Volume, projected area, and surface area of small and large CWD can be calculated using the following equations (Marshall et al. 2000; Marshall et al. 2003):
• Volume/ha (m3/ha) = (π2/(8*transect length)) * ∑(log diameters2)
• Total projected area/ha (m2/ha) = ((50* π)/transect length) * ∑(log diameters)
• Total surface area (m2/ha) = ((50* π2)/transect length) * ∑(log diameters),
where transect length is in meters and log diameter is in centimeters.
Estimating biomass
Biomass of vegetation is usually estimated to provide information on winter food availability for herbivores. A number of species, including deer, moose, elk, and hare, depend most on these browse resources after the vegetation senesces. Herbivores usually will only eat woody growth resulting from the most recent growing season, and during winter, this includes the twigs and buds, but not leaves.
Within a 1.1-m (3.7-foot) radius plot, use clippers to clip all of the twigs within the plot that have resulted from the most recent growing season. Remove and discard the leaves and place the twigs in a bag. Return to the lab and weigh the bag with the twigs. Remove the twigs and weigh the empty bag. Subtract the bag weight from the bag + twigs weight to estimate biomass per 0.0004-ha (0.001-acre) plot. Multiply this number by 2500 to estimate biomass (kg) per ha (or 1000 to generate a per acre estimate). Because the proportion of the food biomass composed of water can vary from one period of the growing season to the next and from one year to the next, usually the sampled are oven dried and then weighed to standardize estimates of biomass.
Using Estimates of Habitat Elements to Assess Habitat Availability
The aggregate data on habitat element abundance, sizes, and distribution can now be used to estimate habitat availability. Using table 9.2 and the downy woodpecker as an example (if you are carrying out this exercise, you can use your own numbers and species information from your field samples and research), consider how you would interpret these data. DeGraaf and Yamasaki (2001) described habitat for downy woodpeckers as: ”…woodlands with living and dead trees from 25-60 cm dbh; some dead or living trees must be greater than 15 cm dbh for nesting.” Although both sites contain trees and snags of sufficient size, the canopy cover data in table 9.2 would suggest that the clearcut is not functioning as a woodland. Thus, we would probably not consider it suitable habitat for downy woodpeckers (though they certainly do use snags in openings at times). Similar descriptions of habitat are available for many species in North American and Europe sp this type of subjective assessment of habitat availability can be easily accomplished.
Table 9.2. Comparison of average and range of habitat elements between clearcut (with a legacy of living and dead trees) and uncut forests, Cadwell Forest, Pelham, MA.
Clearcut Mature Forest
Trees > 15 cm/ha 3 (0-6) 308 (234-412)
Snags > 15 cm/ha 1 (0-2) 22 (4-43)
Basal area/ha 2.4 (0-3) 16 (12-18)
Canopy cover (%) 4 (0-7) 95 (90-100)
Canopy height (m) 23 (18-34) 27 (23-33)
Browse (kg/ha) 1234 (554-2600) 387(122-788)
Using Estimates of Habitat Elements to Assess Habitat Suitability
In addition to using your data to understand if a site might be used by a species, habitat suitability index models have been developed to understand if some sites might provide more suitable habitat than others (e.g., Schroeder 1982). Very few of these models have been validated, especially not using fitness as a response variable. Nonetheless they do represent hypotheses based on the assumption that there is a positive relationship between the index and habitat carrying capacity. In the case of the downy woodpecker, its habitat suitability is based on two indices: tree basal area (Figure 9.6) and density of snags > 15 cm dbh (Figure 9.7). Considering first the uncut stand Table 9.2), note that there is an average of 16 m2/ha of basal area and 22 snags per ha (8.8 per 0.4 ha). The corresponding suitability index score for each variable is 1.0 and the overall habitat suitability is calculated (in this case) as the minimum of the two values. Hence this should be very good habitat for downy woodpeckers. In the recent clearcut however, the suitability index for snags is approximately 0.1 and for basal area is approximately 0.2. Hence the overall suitability in the recent clearcut for this species is 0.1; according to this index, it is both unsuitable in general and much less suitable relative to the uncut stand. Further, in the recent clearcut, snag density, which has the lowest index score, is the factor most limiting habitat quality for downy woodpeckers. The best way to use these types of models is to compare the habitat suitability of one site to another rather than as definitive data pertinent to species abundance, density, or fitness. It is also not justifiable to use habitat suitability scores as the basis for value judgments; indeed, if we were use this technique to assess habitat suitability for snowshoe hares then we might find the recent clearcut to be much better habitat.
Assessing the Distribution of Habitat Across the Landscape
It is often as imtortant to know if patches are suitable habitat for a species and how they are arranged on a landscape. In figure 9.8, a 490-ha forest has been broken into habitat types based on overstory cover and stand structure. Field samples were taken at 117 points distributed across the forest and habitat elements were sampled at each point. Habitat suitability index values are then calculated at each point and extrapolated to the habitat types as portrayed in this figure to illustrate how habitat availability for a species can be displayed over a landscape. A different pattern would emerge for other species using this same approach, and these would have to be overlain on patches used as the basis for management. In addition to synthesizing monitoring information to display changes in spatial patterns, these types of maps can guide planning for management activities in order to achieve habitat patterns leading to a desired future condition for the landscape.
Linking Inventory Data to Satellite Imagery and GIS
Ohmann and Gregory (2002) described a technique called gradient nearest neighbor (GNN) approaches to populate raster cells in satellite imagery with ground plot data (Figure 9.9). They used direct gradient analysis and nearest-neighbor imputation to ascribe detailed ground attributes of vegetation to each pixel in a digital landscape map (Figure 9.10). The gradient nearest neighbor method integrates vegetation measurements from regional grids of field plots, mapped environmental data, and Landsat Thematic Mapper (TM) imagery (Ohmann and Gregory 2002). The accuracy of maps created with this approach is normally questioned, but at the regional level, mapped predictions represent the variability in the sample data very well and predict area by vegetation type accurately in many forests where the approach has been tested. For instance, prediction accuracy for tree species occurrence and several measures of vegetation structure and composition was good to moderate in the Oregon Coast Range (Ohmann and Gregory 2002). Vegetation maps produced with the gradient nearest neighbor method are often used for regional-level monitoring, planning, and policy analysis. Their utility decreases as they are used over smaller spatial scales.
Results of the maps generated using the GNN approach can then be reclassified in a nearly infinite number of ways to represent habitat availability for various species over large areas (figure 9.11). With repeated monitoring of ground plots and synchronous acquisition of satellite image data, new projections of habitat availability can be developed over time to understand trajectories of change. In addition, by linking the ground plot data to vegetation growth models, changes in vegetation structure and composition and resulting habitat can be projected into the future under various assumptions regarding land use, natural disturbances or other environmental stresses (Spies et al. 2007).
Measuring Landscape Structure and Change
In addition to assessing habitat elements at various spatial scales over space and time, the pattern of patches across landscapes can be monitored. The assumption often made by landscape ecologists is that pattern influences process and processes create patterns. Consequently, knowledge of aspects of landscape patterns such as characteristics of patches (size, shape, edges, etc.) and among patches (richness, diversity, arrangement) can be informative when inferring how processes might be influenced by changes in landscape pattern. One often-used tool used to generate measurements of landscape pattern is FRAGSTATS (McGarigal et al. 2002). FRAGSTATS quantifies the extent and configuration of patches in a landscape. The user must define the basis for the analysis, including the extent (outer bounds) and grain (the finest level of detail) in the landscape. All patches in a landscape must be classified in a manner that is logical to the objectives of the analysis (e.g., related to habitat for a species or group of species). FRAGSTATS computes 3 groups of metrics. For a given landscape mosaic, FRAGSTATS computes several metrics for: (1) each patch in the mosaic; (2) each patch type (class) in the mosaic; and (3) the landscape mosaic as a whole (McGarigal et al. 2002. These metrics can easily become the basis for long term monitoring to assess changes in landscape patterns and allow inference to changes in landscape processes.
Summary
Effectively sampling habitat within a monitoring framework requires that the key habitat elements for the species (or species’) be defined. Habitat is a species-specific concept so unless monitoring is focused on habitat types (a biophysical classification of the environment), then a set of habitat elements must be identified as important to one of four levels of habitat selection: geographic range, home range, resource patches or habitat resources. Sampling these habitat elements must consider these scales of habitat selection when defining the grain and extent of a monitoring framework for the species of interest. Often remotely sensed data are used as a first assessment of habitat patches, but ground plot data are usually stratified by patch types identified from remotely sensed data. Ground plot data can provide more detailed information on the availability of habitat elements when extrapolated to specific patch types, or can be used to populate a GIS layer using gradient nearest neighbor approaches. Remotely sensed data, ground plot data and GIS layers interpreted as habitat for the species of interest can all be used to monitor changes over time in habitat availability for a species. Similarly, changes in the pattern of landscape structure can be assessed over time to understand how changes in pattern might influence key ecological processes on the landscape. FRAGSTATS is a commonly used tool to conduct such assessments. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.09%3A_Techniques_for_Sampling_Habitat.txt |
For many monitoring projects, data management is often considered a nuisance and of less importance than sampling design, objective setting, and data collection and analysis. Yet a proper database management system is a critical component of any monitoring plan and should be considered early in the planning process. In many ways, such a system serves as the ship’s log of a monitoring mission and should detail every step of data collection, storage, and dissemination. Sound data management is so vital because a monitoring project adapts and changes over time and as such, so might the data. Furthermore, because most monitoring projects are conducted over many years and include the inevitable changes in staff, data collection and methodologies, land ownership and accessibility, and shifting technologies, improper data management can fail to document these changes and undermine the entire monitoring initiative. In addition, because online data dissemination and digital archives are becoming increasingly popular (if not necessary), data management serves as a much needed blueprint of instructions for future users of the data who might not have been involved in any aspect of the original monitoring plan.
The Basics of Database Management
The data generated from monitoring programs are often complex and the protocols used to generate these data can change and adapt over time. Consequently, the system used to describe these data, and the methods used to collect them, must be comprehensive, detailed and flexible to changes. In a perfect world, monitoring data are collected and often entered into a database (as opposed to being stored in a filing cabinet). A comprehensive database should include six basic descriptors of the data that detail how they were collected, measured, estimated and managed. Ultimately, these basic descriptors ensure the long-term success of a monitoring effort because they describe the details of data collection and storage.
The six essential descriptors are: what (the type of organism), how many (units of observation for individual organisms or colonies, presence/absence, detection/non-detection, relative abundance, distance measurements), where (the geographic location at which the organism was recorded and what coordinate system was referenced), when (the date and time of the recording event), how (what sort of record is represented and other details of data-collection protocols; e.g., 5-minute point counts, mist-netting, clover trap, etc.), and who (the person responsible for collecting the data). Each of these components represents an important aspect of data collection that facilitates future use. For example, information on how a recording event was made allows someone separate from the data collection to properly account for variation in effort and detection probability, deal with data from multiple protocols, and determine whether the data are from multiple species or single-taxon records.
The General Structure of a Monitoring Database
Unfortunately, there is no “one size fits all” solution to the basic structure of a monitoring database. Monitoring programs are diverse and so are the data they collect. There are, however, several basic and standardized templates that can be used when creating a monitoring database (Huettmann 2005, Jan 2006). As an example, the Darwin Core is a simple data standard that is commonly used for occurrence data (specimens, observations, etc. of living organisms) (Bisby 2000). The Darwin Core standard specifies several database components including record-level elements (e.g., record identifier), taxonomic elements (e.g., scientific name), locality elements (e.g., place name), and biological elements (e.g., life stage). Jan (2006) provided another excellent example of a functional structure for an observational database. Using the terminology of Jan (2006), biological sampling information relates to field site visits, and each of these visits is considered a Gathering. Each Gathering event is to be described by the occurrence and/or abundance of a species and additional site information including site name, the period of time, the name of the collector, the method of collection, and geography. The geography field should indicate using the country codes using the International Standardization Organization (ISO) standards (www.iso.org), and it should have an attribute detailing whether this information is currently valid because political boundaries and names change over time (e.g., new countries form, their names can change) (Jan 2006). Geospatial data are stored under the heading of GatheringSite and includes coordinate data (e.g., latitude and longitude, altitude), gazetteer data (e.g., political or administrative units), and geo-ecological classifications (e.g., geomorphological types). It is important that this field allows for high-resolution geo-referencing for subsequent integration with a GIS (e.g., using 5 significant digits for latitude and longitude coordinates). The Unit field includes organisms observed in the field, herbarium specimens, field data, taxonomic identifications, or descriptive data. An Identifications field details the species’ common name, species’ scientific name, and a species code (using the Integrated Taxonomic Information System [ITIS; www.itis.gov]) to a Unit (specimen, observation, etc.). Identifications can then be connected to a taxon database using a TaxIdRef field. The organization of any monitoring database should have these necessary information fields (although field names may vary) and will likely require the use of a digital database for storage and manipulation.
Digital Databases
Digital databases are now considered an invaluable and commonly used tool for storing data generated from monitoring programs. Even in remote field sites, researchers are using mobile GPS (Global Positioning System) and PDA (Personal Digital Assistant) units to record georeferenced census tracks and species observations (Travaini et al. 2007) (Fig. 10.1). Using any laptop computer, these data can then be quickly integrated into database management software such as CyberTracker (cybertracker.org), Microsoft Excel (office.microsoft.com/en-us/excel), or Microsoft Access (office.microsoft.com/en-us/access). By using a digital database, researchers gain the ability to georeference census points for later integration into a GIS, such as ArcGIS (esri.com/software/arcgis/), allowing for additional analytical options such as predictive species distribution modeling (Fig. 10.1). Travaini et al. (2007) provided an excellent review and application of a field-based database framework for using digitally-stored data to subsequently map animal distributions in remote regions. A key advantage to recording data into a digital database during the collection event itself is the ability to develop and maintain multiple databases. Digital databases also increase the capacity to integrate data into online data management programs and thereby to access data at later dates.
In addition to this, database managers often use online and digital databases because they can be readily linked to other databases for greater functionality. Connecting multiple databases results in a relational databases management system (RDMS) (Fig. 10.2), which allows for queries to be made among multiple databases. In light of these developments, the structure and framework of many large monitoring databases are increasingly sophisticated and data on demographic rates, abundance, and species occurrences can be linked with other geographic information stored in ancillary databases. For example, a standard relational database can consist of sub-tables of data that are connected through a common record ID number (Fig. 10.2). A Main table normally contains information on the sampling units, the units used for data presentation, the years of the study, and notes on sampling design. Other frequently used tables include a Taxon table (information about the organism sampled in each data set; see ITIS (see www.itis.org for globally accepted species names), a Biotope table (habitat of the organism), a Location table (geographical details of the monitoring site), a Datasource table (reference to the original source of the data), and the actual Data table (original population data). In this case, a relational database and a common record identifier enable the user to perform multiple queries based on species, taxonomic group, habitats, areas, latitudes or countries. This is particularly powerful because a user can query a unique identifier that refers to a specific study site and then extract data on that site from multiple data tables. In practice, developing, maintaining and retrieving data from a RMDS often requires knowledge of SQL (Structured Query Language; http://en.Wikipedia.org/wiki/SQL), a widely used database filter language that is specifically designed for management, query and use of RMDS. SQL is a standardized language with a huge user community that is recognized both by the American National Standards Institute (ANSI) and International Organization for Standardization (ISO; [iso.org/iso/home.htm]). It is implemented in many popular relational database management systems including Informix (ibm.com/software/data/informix), Oracle (oracle.com/index.html), SQL Server (microsoft.com/sql/default.mspx (inactive link as of 05/18/2021)), MySQL (mysql.com) and PostreSQL (postgresql.org).
Data Forms
All data collectors should use a standard data form that is approved by stakeholders in the monitoring program (Table 10.1). Copies of these data forms should be included as an appendix to the planning document. The appendix should also provide a data format sheet that identifies the data type, unit of measurement, and the valid range of values for each field of the data collection form. The data format sheet should also identify all codes and abbreviations that may be used in the form.
Time Begin__________________Time End _________
Table 10.1. Example of a field data sheet used in association with a project designed to monitor the occurrence and number of detections of birds in agricultural lands in the Willamette Valley of Oregon. The inset photograph is used not only to locate sample points but also to plot locations of bird observations.
Date __________ Sample point________ Landscape__________________ Observer __________
Weather ____________________
Obs. Num. Species Number Distance(m) Repeat (Y/N) Behavior Patch type
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Species = use 4-letter code
Number = number of individuals
Repeat = enter “Y” only for repeat observations of the same bird
Behavior = F(eeding), R(esting), O (flyover),
Patch type = P(lowed), G(rass), W(Grassed waterway), S(hrubby), T(reed)
Data Storage
For many monitoring programs, hardcopy data are still collected despite the increasing availability of digital formats. In general, there are three primary obstacles to the shift of hard copies to digital formats. First, significant amounts of (historical) hardcopy data remain to be digitized (e.g., in archives, libraries, and filing cabinets). Second, although technological advances are making the collecting of digital data in the field more feasible (Travaini et al. 2007), many field data are still collected in field notebooks when field conditions are difficult and the field-site is remote. Third, many digital datasets are still getting printed as hardcopy for cultural and logistical reasons.
In many cases, even when data are compiled digitally, hardcopies are collected as an important back-up for many monitoring programs, or such data are retained and maintained as critical sources of information for legacy programs that have been running for decades. Yet despite this, and although other examples of obstacles associated with the transition to digital documentation doubtless exist, there are many reasons why monitoring data should be collected and stored in a digital format (with necessary back-up systems). The advantages of using digital field data collection methods include immediate data availability (e.g. real-time online data entry), lack of labor-intense data key-in sessions afterwards, and automated metadata and processing. Given these benefits, a more universal use of digital data collection would be ideal, but many universities, governments, NGOs and agencies are hesitant to embrace current technologies. Reasons for reluctance to go entirely digital are varied but typically include a lack of computational training and insufficient infrastructure for using and storing digital data.
Metadata
Databases resulting from biological inventories and monitoring studies can benefit other scientific research efforts and facilitate species conservation programs for many decades. The usefulness of a database for these purposes, however, is determined not only by the rigor of the methods used to conduct the monitoring program, but also by the ability of future investigators to decipher the variable codes, measurement units, and other details affecting their understanding of the database. When a potential user of a database is interested in deciphering the details of that database, they often refer to the metadata. Metadata are “data about data” and are an essential aspect of any database because they serve as a guide provided by the developer of the database. Metadata facilitate information sharing among current users and are crucial for maintaining the value of the data for future investigations. Indeed, if monitoring data are placed online or meant to be shared among participatory stakeholders, then there needs to be a clear description documenting every relevant step of data curation and processing. There are few things more frustrating for potential data users than receiving a database or map with little or no information on what the variables represent or how the data were collected. The standardized metadata that accompany monitoring databases should be highly valued as one of the principal means for improving transferability of biological monitoring information among different programs, management units and future data users.
With respect to metadata, the Federal government has developed several systems, standards, and templates for database documentation that can be applied to any monitoring database. Since 1995, all Federal agencies have adopted a content standard for geospatial data called Content Standard for Digital Geospatial Metadata (CSDGM; Tsou 2002)). This standard was developed by the Federal Geographic Data Committee (FGDC), which is also responsible for reviewing and updating the standard as needed. The currently approved FGDC standard is CSDGM Version 2 – FGDC-STD-001-1998 and was developed to be applicable to all geospatial databases. The standard includes seven major elements. Certain GIS packages include software tools that automate a number of these metadata documentation tasks, however, the originator of the database must manually complete most fields. The process of describing data sources, accuracy tests, geo-processing methods, and organizational information can be tedious and add many hours to the preparation of a data set. This initial cost of the labor and time, however, will ensure that the data can be used for many years into the future, possibly for research or conservation purposes not anticipated by the originator of the data set.
Although prescient, the generic nature of the CSDGM, does not provide for standardization of many attributes commonly shared among biological databases. To extend the effectiveness of the CSDGM framework to biological sampling, the FGDC’s Biological Data Working Group has standardized the use of terms and definitions in metadata prepared for biological databases with the development of the Biological Metadata Profile (FGDC 1999). The Biological Metadata Profile falls under the broader National Biological Information Structure (NBII) (>www.nbii.gov) profile and applies to topics such as taxonomic classification, voucher specimens, environmental attributes, and others not considered in the CSDGM. The Biological Metadata Profile is also applicable to non-geospatial data sets. Considering that most monitoring programs collect biological information, database managers should consult the Biological Metadata Profile before and after data collection.
The FGDC standard and its profiles are widely embraced by the U.S. Federal Government and international initiatives (e.g., International Polar Year (IPY)). Nonetheless, several other metadata standards exist, including: a) Directory Interchange Format (DIF) for a short telephone entry description, which is still widely used by BAS (British Antarctica Service), b) EML (Ecological Metadata Language) for a rather detailed description of relational databases, which is used by Long Term Ecological Research sites in the U.S., and c) SML (Sensor Metadata Language) for a very powerful and progressive description of high-performance Sensors Networks. There is also a wide array of metadata standards that have local relevance only, and are not compatible with global metadata standards. There is a current movement, however, towards the development and implementation of a more global standardization. Variation among studies in metadata standards impedes global data availability, and deviating from the FGDC NBII standard often results in large information loss. The idea that more local, simpler metadata concepts can simply be mapped, and then cross-walked through automatic parsing software to other standards such as FGDC NBII in order to satisfy delivery needs, can prove fatal to data quality because once an information field is missing, its content can likely never again be filled in a way that maintains the rigor of the database as a whole.
Over 50 collective years of database experience in monitoring populations have led to one major conclusion: the lack of metadata make databases entirely unusable. Thus, metadata and data management needs to occupy a major section of the project budget and should be considered early in the planning process.
Consider a Database Manager
As you may be able to tell from the preceding sections, database management is not a simple task. It requires an understanding of complicated metadata standards and, in the case of many digital databases, a skill set pertaining to computer programming (e.g., SQL language). Unfortunately, perhaps because of the considerable training and effort that are necessary, database management does not receive sufficient attention in terms of time and budgetary allocations in many monitoring efforts. Tasks associated with database management are often given to lower ranking members of the research team, and considered ‘technician work’; not part of “real” science or monitoring. In other settings, databases are simply contracted out to others, and it is hoped that any problems can be fixed that way. Due to these practices, many monitoring databases exist in raw or clumsy formats, are published as dead-end PDFs, or are stored in older Excel-type worksheets. The worst-case scenario involves the consignment of years of hard copy data to a filing cabinet, then to a box, and eventually to the local recycling center (often when the original data manager retires). This situation is particularly discouraging considering that data management has critical implications in the monitoring process and data dissemination and that the proper storage and documentation of years of monitoring data is of utmost relevance for the future use of monitoring data. To overcome this situation, monitoring programs need to make the budgetary commitment necessary to ensure that they have the expertise required for excellent data management. This normally entails hiring experienced database managers.
An Example of a Database Management System: FAUNA
As an example of a recent database management system, the US Forest Service requires that all monitoring data be stored in the Forest Service’s Natural Resource Information System (NRIS) FAUNA database (see Woodbridge and Hargis 2006 for an example). All Forest Service monitoring plans outline several steps in preparing data for entry into the FAUNA database that are intended to be addressed during the development of an inventory or monitoring protocol. Although these basic steps are designed for Forest Service protocols, they can be incorporated into any monitoring initiative:
1. All data collected in the field must be reviewed for completeness and errors before entry into FAUNA. The concerns and techniques specific to the protocol being developed should be discussed.
2. Protocol development teams should become familiar with the major elements of the FGDC-CSDGM, Biological Metadata Profile (FGDC 1999) to better understand metadata standards.
3. Complete descriptions and bibliographic citations for taxonomic, population, or ecological classification systems should be provided, including identification of keywords consistent with the Biological Metadata Profile where appropriate.
4. Sources of maps, geospatial data, and population information that are used to delineate the geographic boundaries of the monitoring program or to locate sampling units should be identified.
5. Units of measurement should be identified.
6. The authors of the protocol and the personnel responsible for maintaining and distributing data resulting from the monitoring programs should be identified (i.e., data steward).
7. The anticipated schedule for data reviews and updates should be described.
8. All data codes, variable names, acronyms, and abbreviations used in the protocol should be defined.
9. An outline or template of the structure of tabular databases in which monitoring program data will be held should be provided.
Summary
Database management is often an afterthought for many monitoring programs, but proper database management and documentation is critical for the long-term success of a monitoring program. An effective database management details six essential components of data collection including what, how many, where, when, how, and who collected the data. If possible, data should quickly be incorporated into a digital database either during data collection or shortly thereafter. Digital formats allow for the building of relational database management systems, often automated metadata documentation, and compatibility with current and global metadata standards. Given the increasing sophistication of database management systems, monitoring programs should place a greater emphasis on consulting or hiring a database manager with the necessary skill set needed for maintaining and querying large databases. The failure to develop a strong database management system early in the monitoring program can lead to information loss and an inability to properly analyze and implement the results of a monitoring initiative in the future. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.10%3A_Database_Management.txt |
Plant and animal data come in many forms including indices, counts, and occurrences. The diversity of these data types can present special challenges during analysis because they can follow different distributions and may be more or less appropriate for different statistical approaches. As an additional complication, monitoring data are often taken from sites that are in close proximity or surveys are repeated in time, and thus special care must be taken regarding assumptions of independency. In this chapter we will discuss some essential features of these data types, data visualization, different modeling approaches, and paradigms of inference.
This chapter is designed to help you gain bio-statistical literacy and build an effective framework for the analysis of monitoring data. These issues are rather complex, and as such, only key elements and concepts of effective data analysis are discussed. Many books have been written on the topic of analyzing ecological data. Thus, it would be impossible to effectively cover the full range of the related topics in a single chapter. The purpose, therefore, of the data analysis segment of this book is to serve as an introduction to some of the classical and contemporary techniques for analyzing the data collected by monitoring programs. After reading this chapter, if you wish to broaden your understanding of data analysis and learn to apply it with confidence in ecological research and monitoring, we recommend the following texts that cover many of the classical approaches: Cochran (1977), Underwood (1997), Thompson et al. (1998), Zar (1999), Crawley (2005, 2007), Scheiner and Gurevitch (2001), Quinn and Keough (2002), Gotelli and Ellison (2004), and Bolker (2008). For a more in-depth and analytical coverage of some of the contemporary approaches we recommend Williams et al. (2002), MacKenzie et al. (2006), Royle and Dorazio (2008) and Thomson et al. (2009).
The field of data analysis in ecology is a rapidly growing enterprise, as is data management (Chapter 10), and it is difficult to keep abreast of its many developments. Consequently, one of the first steps in developing a statistically sound approach to data analysis is to consult with a biometrician in the early phases of development of your monitoring plan. One of the most common (and oldest) lamentations of many statisticians is that people with questions of data analysis seek advice after the data have been collected. This has been likened to a post-mortem examination (R.A. Fisher); there is only so much a biometrician can do and/or suggest after the data have been collected. Consulting a biometrician is imperative in almost every phase of the monitoring program, but a strong understanding of analytical approaches from the start will help ensure a more comprehensive and rigorous scheme for data collection and analysis
Data Visualization I: Getting to Know Your Data
The initial phase of every data analysis should include exploratory data evaluation (Tukey 1977). Once data are collected, they can exhibit a number of different distributions. Plotting your data and reporting various summary statistics (e.g., mean, median, quantiles, standard error, minimums, and maximums) allows the you to identify the general form of the data and possibly identify erroneous entries or sampling errors. Anscombe (1973) advocates making data examination an iterative process by utilizing several types of graphical displays and summary statistics to reveal unique features prior to data analysis. The most commonly used displays include normal probability plots, density plots (histograms, dit plots), box plots, scatter plots, bar charts, point and line charts, and Cleveland dotplots (Cleveland 1985, Elzinga et al. 1998, Gotelli and Ellison 2004, Zuur et al. 2007). Effective graphical displays show the essence of the collected data and should (Tufte 2001):
1. Show the data,
2. Induce the viewer to think about the substance of the data rather than about methodology, graphic design, or the technology of graphic production,
3. Avoid distorting what the data have to say,
4. Present many numbers in a small space,
5. Make large data sets coherent and visually informative,
6. Encourage the eye to compare different pieces of data and possibly different strata,
7. Reveal the data at several levels of detail, from a broad overview to the fine structure,
8. Serve a reasonably clear purpose: description, exploration, or tabulation,
9. Be closely integrated with the numerical descriptions (i.e., summary statistics) of a data set.
In some cases, exploring different graphical displays and comparing the visual patterns of the data will actually guide the selection of the statistical model (Anscombe 1973, Hilborn and Mangel 1997, Bolker 2008). For example, refer to the four graphs in Figure 11.1. They all display relationships that produce identical outputs if analyzed using an ordinary least squares (OLS) regression analysis (Table 11.1). Yet, whereas a simple regression model may reasonably well describe the trend in case A, its use in the remaining three cases is not appropriate, at least not without an adequate examination and transformation of the data. Case B could be best described using a logarithmic rather than a linear model and the relationship in case D is spurious, resulting from connecting a single point to the rest of the data cluster. Cases C and D also reveal the presence of outliers (i.e., extreme values that may have been missed without a careful examination of the data). In these cases, the researcher should investigate these outliers to see if their values were true samples or an error in data collection and/or entry. This simple example illustrates the value of a visual scrutiny of data prior to data analysis.
Table 11.1. Four hypothetical data sets of X-Y variable pairs (Modified from Anscombe 1973).
A B C D Analysis output
X Y X Y X Y X Y N = 11
Mean of Xs = 9.0
Mean of Ys = 7.5
Regression line:
Y = 3 + 0.5X
Regression SS = 27.50
r = 0.82
R2 = 0.67
10.0 8.04 10.0 9.14 10.0 7.46 8.0 6.58
8.0 6.95 8.0 8.14 8.0 6.77 8.0 5.76
13.0 7.58 13.0 8.74 13.0 12.74 8.0 7.71
9.0 8.81 9.0 8.77 9.0 7.11 8.0 8.84
11.0 8.33 11.0 9.26 11.0 7.81 8.0 8.47
14.0 9.96 14.0 8.10 14.0 8.84 8.0 7.04
6.0 7.24 6.0 6.13 6.0 6.08 8.0 5.25
4.0 4.26 4.0 3.10 4.0 5.39 19.0 12.50
12.0 10.84 12.0 9.13 12.0 8.15 8.0 5.56
7.0 4.82 7.0 7.26 7.0 6.42 8.0 7.91
5.0 5.68 5.0 4.74 5.0 5.73 8.0 6.89
The fact that, under some circumstances, visual displays alone can provide an adequate assessment of the data underscores the value of visual analysis to an even greater extent. A strictly visual (or graphical) approach may even be superior to formal data analyses in situations with large quantities of data (e.g., detailed measurements of demographics or vegetation cover) or if data sets are sparse (e.g. in the case of inadequate sampling or pilot investigations). For example, maps can be effectively used to present a great volume of information. Tufte (2001) argues that maps are actually the only means to display large quantities of data in a relatively small amount of space and still allow a meaningful interpretation of the information. In addition, maps allow a visual analysis of data at different levels of temporal and spatial resolution and an assessment of spatial relationships among variables that can help identify potential causes of the detected pattern.
Other data visualization techniques also provide practical information. A simple assessment of the species richness of a community can be accomplished by presenting the total number of species detected during the survey. This is made more informative by plotting the cumulative number of species detected against an indicator of sampling effort such as the time spent sampling or the number of samples taken (i.e., detection curve or empirical cumulative distribution functions). These sampling effort curves can give us a quick and preliminary assessment of how well the species richness of the investigated community has been sampled. A steep slope of the resulting curve would suggest the presence of additional, unknown species whereas a flattening of the curve would indicate that most species have been accounted for (Magurran 1988, Southwood 1992). Early on in the sampling, these types of sampling curves are recommended because they can provide some rough estimates of the minimum amount of sampling effort needed.
Constructing species abundance models such as log normal distribution, log series, McArthur’s broken stick, or geometric series model can provide a visual profile of particular research areas (Southwood 1992). Indeed, the different species abundance models describe communities with distinct characteristics. For example, mature undisturbed systems characterized by higher species richness typically display a log normal relationship between the number of species and their respective abundances. On the other hand, early successional sites or environmentally stressed communities (e.g., pollution) are characterized by geometric or log series species distribution models (Southwood 1992).
The use of confidence intervals presents another attractive approach to exploratory data analysis. Some even argue that confidence intervals represent a more meaningful and powerful alternative to statistical hypothesis testing since they give an estimate of the magnitude of an effect under investigation (Steidl et al. 1997, Johnson 1999, Stephens et al. 2006). In other words, determining the confidence intervals is generally much more informative than simply determining the P-value (Stephens et al. 2006). Confidence intervals are widely applicable and can be placed on estimates of population density, observed effects of population change in samples taken over time, or treatment effects in perturbation experiments. They are also commonly used in calculations of effect size in power or meta-analysis (Hedges and Olkin 1985, Gurevitch et al. 2000, Stephens et al. 2006).
Despite its historical popularity and attractive simplicity, however, visual analysis of the data does carry some caveats and potential pitfalls for hypothesis testing. For example, Hilborn and Mangel (1997) recommended plotting the data in different ways to uncover “plausible relationships.” At first glance, this appears to be a reasonable and innocuous recommendation, but one should be wary of letting the data uncover plausible relationships. That is, it is entirely possible to create multiple plots between a dependent variable (Y) and multiple explanatory variables (X1, X2, X3,…,XN) and discover an unexpected effect or pattern that is an artifact of that single data set, not of the more important biological process that generated the sample data (i.e., spurious effects) (Anderson et al. 2001). These types of spurious effects are most likely when dealing with small or limited sample sizes and many explanatory variables. Plausible relationships and hypotheses should be developed in an a priori fashion with significant input from a monitoring program’s conceptual system, stakeholder input, and well-developed objectives.
Data Visualization II: Getting to Know Your Model
Most statistical models are based on a set of assumptions that are necessary for models to properly fit and describe the data. If assumptions are violated, statistical analyses may produce erroneous results (Sokal and Rohlf 1994, Krebs 1999). Traditionally, researchers are most concerned with the assumptions associated with parametric tests (e.g., ANOVA and regression analysis) since these are the most commonly used analyses. The description below may be used as a basic framework for assessing whether or not data conform to parametric assumptions.
Independence of Data Points
The essential condition of most statistical tests is the independence and random selection of data points in space and time. In many ecological settings, however, data points can be counts of individuals or replicates of treatment units in manipulative studies and one must think about spatial and temporal dependency among sampling units. Dependent data are more alike than would be expected by random selection alone. Intuitively, if two observations are not independent then there is less information content between them. Krebs (1999) argued that if the assumption of independence is violated, the chosen probability for Type I error (a) cannot be achieved. ANOVA and linear regression techniques are generally sensitive to this violation (Sokal and Rohlf 1994, Krebs 1999). Autocorrelation plots can be used to visualize the correlation of points across space (e.g., spatial correlograms) (Fortin and Dale 2005) or as a time series (Crawley 2007). Plots should be developed using the actual response points as well as the residuals of the model to look for patterns of autocorrelation.
Homogeneity of Variances
Parametric models assume that sampled populations have similar variances even if their means are different. This assumption becomes critical in studies comparing different groups of organisms, treatments, or sampling intervals and it is the responsibility of the researcher to make these considerations abundantly clear in the protocols of such studies. If the sample sizes are equal then parametric tests are fairly robust to the departure from homoscedasticity (i.e., equal variance of errors across the data) (Day and Quinn 1989, Sokal and Rohlf 1994). In fact, an equal sample size among different treatments or areas should be ensured whenever possible since most parametric tests are overly sensitive to violations of assumptions in situations with unequal sample sizes (Day and Quinn 1989). The best approach for detecting a violation in homoescedasticity, however, is plotting the residuals of the analysis against predicted values (i.e., residual analysis) (Crawley 2007). This plot can reveal the nature and severity of the potential disagreement/discord between variances (Figure 11.2), and is a standard feature in many statistical packages. Indeed, such visual inspection of the model residuals, in addition to the benefits outlined above, can help determine not only if there is a need for data transformation, but also the type of the distribution. Although several formal tests exist to determine the heterogeneity of variances (e.g., Bartlett’s test, Levine’s test), these techniques assume a normal data distribution, which reduces their utility in most ecological studies (Sokal and Rohlf 1994).
Normality
Although parametric statistics are fairly robust to violations of the assumption of normality, highly skewed distributions can significantly affect the results. Unfortunately, non-normality appears to be the norm in ecology; in other words ecological data only rarely follow a normal distribution (Potvin and Roff 1993, White and Bennetts 1996, Hayek and Buzas 1997, Zar 1999). Moreover, the normal distribution primarily describes continuous variables whereas count data, often the type of information gathered during monitoring programs, are discrete (Thompson et al. 1998, Krebs 1999). Thus, it is important to be vigilant for large departures from normality in your data. This can be done with a number of tests if your data meet certain specifications. For instance, if the sample size is equal among groups and sufficiently large (e.g., n > 20) you can implement tests to assess for normality or to determine the significance of non-normality. The latter is commonly done with several techniques, including the W-test and the Kolmogorov-Smirnov D-test for larger sample sizes. The applicability of both tests, however, is limited due to the fact that they exhibit a low power if the sample size is small and excessive sensitivity when the sample size is large. To overcome these complications, visual examinations of the data are also undertaken. Visual examinations are generally more appropriate than formal tests since they allow one to detect the extent and the type of problem. Keep in mind, however, that when working with linear models the aim is to “normalize” the data/residuals. Plotting the residuals with normal-probability plots (Figure 11.3), stem-and-leaf diagrams, or histograms can help to understand the nature of the non-normal data (Day and Quinn 1989).
Possible Remedies if Parametric Assumptions are Violated
Data transformations or non-parametric tests are often recommended as appropriate solutions if the data do not meet parametric assumptions (Sabin and Stafford 1990, Thompson et al. 1998). Those developing monitoring plans, however, should repeatedly (and loudly) advocate sound experimental design as the only effective prevention of many statistical problems. This will keep unorganized data collection and questionable data transformations to a minimum. There is no transformation or magical statistical button for data that are improperly collected. Nonetheless, a properly designed monitoring program is likewise not a panacea; ecosystems are complex. Thus even proper designs can produce data that confound analysis, are messy, and require some remedies if parametric models are to be used.
Data Transformation
If significant violations of parametric assumptions occur, it is customary to implement an appropriate data transformation to try to resolve the violations. During a transformation, data will be converted and analyzed at a different scale. In general, researchers should be aware of the need to back-transform the results after analysis to present parameter values on the original data scale or be clear that their results are being presented on a transformed scale. Examples of common types of transformations that a biometrician may recommend for use are presented in Table 11.2. A wisely chosen transformation can often improve homogeneity of variances and produce an approximation of a normal distribution.
Table 11.2. The most common types of data transformation in biological studies (Modified from Sabin and Stafford 1990).
Transformation type When appropriate to use
Logarithmic Use with count data and when means positively correlate with variances. A rule of thumb suggests its use when the largest value of the response variable is at least 10 x the smallest value.
Square-root Use with count data following a Poisson distribution.
Inverse Use when data residuals exhibit a severe funnel shaped pattern, often the case in data sets with many near-zero values.
Arcsine square root Good for proportional or binomial data.
Box-Cox objective approach If it is difficult to decide on what transformation to use, this procedure finds an optimal model for the data.
Nonparametric Alternatives
If the data violate basic parametric assumptions, and transformations fail to remedy the problem, then you may wish to use nonparametric methods (Sokal and Rohlf 1994, Thompson et al. 1998, Conover 1999). Nonparametric techniques have less stringent assumptions about the data, are less sensitive to the presence of outliers, and are often more intuitive and easier to compute (Hollander and Wolfe 1999). Since nonparametric models are less powerful than their parametric counterparts, however, parametric tests are preferred if the assumptions are met or data transformations are successful (Day and Quinn 1989, Johnson 1995).
Statistical Distribution of the Data
As mentioned above, plant and animal data are often in the form of counts of organisms and this can present special challenges during analyses. The probability that organisms occur in a particular habitat has a direct bearing on the selection of appropriate sampling protocols and statistical models (Southwood 1992). Monitoring data will most likely approximate random or clumped distributions, yet this should not be blindly assumed. Fitting the data to the Poisson or negative binomial models are common ways to test if they do (Southwood 1992, Zuur 2009). These models are also particularly appropriate for describing count data, which are, once again, examples of discrete variables (e.g., quadrat counts, sex ratios, ratios of juveniles to adults). The following subsections briefly describe how to identify whether or not the data follow either a Poisson or negative binomial distribution model.
Poisson Distribution
Poisson distributions are common among species, where the probability of detecting an individual in any sample is rather low (Southwood 1992). The Poisson model gives a good fit to data if the mean count (e.g., number of amphibians per sampling quadrat) is in the range of 1–5. As the mean number of individuals in the sample increases, and exceeds 10, however, the random distribution begins to approach the normal distribution (Krebs 1999, Zar 1999).
During sampling, the key assumption of the Poisson (random) distribution is that the expected number of organisms in a sample is the same and that it equals μ, the population mean (Krebs 1999, Zuur 2009). One intriguing property of the random distribution is that it can be described by its mean, and that the mean equals the variance (s2). The probability (frequency) of detecting a given number of individuals in a sample collected from a population with mean = μ is:
Pμ = eμ/μ!)
Whether or not the data follow a random distribution can be tested with a simple Chi-square goodness of fit test or with an index of dispersion (I), which is expected to be 1.0 if the assumption of randomness is satisfied:
I = s2 / ̅x̅,
where ̅x̅ and s2 are the observed sample mean and variance, respectively.
Zurr et al. (2009) provided excellent examples of tests for goodness of fit for Poisson distributions. In practice, the presence of a Poisson distribution in data can also be assessed visually by examining the scatter pattern of residuals during analysis. If we reject the null hypothesis that samples came from a random distribution, s2 < μ, and s2/ μ < 1.0, then the sampled organisms are either distributed uniformly or regularly (underdispersed). If we reject the null hypothesis but the values of s2 and s2/ μ do not fall within those bounds, then the sampled organisms are clumped (overdispersed).
Negative Binomial Distribution
An alternative approach to the Poisson distribution, and one of the mathematical distributions that describe clumped or aggregated spatial patterns, is the negative binomial (Pascal) distribution (Anscombe 1973, Krebs 1999, Hilbe 2007, Zuur 2009). White and Bennetts (1996) suggested that this distribution is a better approximation to count data than the Poisson or normal distributions. The negative binomial distribution is described by the mean and the dispersion parameter k, which expresses the extent of clumping. As a result of aggregation, it always follows that s2 > μ and the index of dispersion (I) > 1.0. Several techniques exist to evaluate the goodness-of-fit of data to the negative binomial distribution. As an example, White and Bennetts (1996) give an example of fitting the negative binomial distribution to point-count data for orange-crowned warblers to compare their relative abundance among forest sites. Zero-inflated Poisson models (ZIP models) are recommended for analysis of count data with frequent zero values (e.g., rare species studies) or where data transformations are not feasible or appropriate (e.g., Heilbron 1994, Welsh et al. 1996, Hall and Berenhaut 2002, Zuur 2009). Good descriptions and examples of their use can be found in Krebs (1999), Southwood (1992), Faraway (2006), and Zurr et al. (2009). Since the variety of possible clumping patterns in nature is practically infinite, it is possible that the Poisson and negative binomial distributions may not always adequately fit the data at hand.
Analysis of Inventory Data – Abundance
Absolute Density or Population Size
National policy on threatened and endangered species is ultimately directed toward efforts to increase or maintain the total number of individuals of the species within their natural geographic range (Carroll et al. 1996). Total population size and effective population size (i.e., the number of breeding individuals in a population) (Harris and Allendorf 1989) are the two parameters that most directly indicate the degree of species endangerment and/or effectiveness of conservation policies and practices. Population density is informative for assessing population status and trends because the parameter is sensitive to changes in natural mortality, exploitation, and habitat quality. In some circumstances, it may be feasible to conduct a census of all individuals of a particular species in an area to determine the total population size or density parameters. Typically, however, population size and density parameters are estimated using statistical analyses based on only a sample of population members (Yoccoz et al. 2001, Pollock et al. 2002). Population densities of plants and sessile animals can be estimated from counts taken on plots or data describing the spacing between individuals (i.e., distance methods) and are relatively straightforward. Population analyses for many animal species must account for animal response to capture or observation, observer biases, and different detection probabilities among sub-populations (Kery and Schmid 2004). For instance, hiring multiple technicians for field-work and monitoring a species whose behavior or preferred habitat change seasonally are two factors that would need to be addressed in the analysis. Pilot studies are usually required to collect the data necessary to do this. Furthermore, the more common techniques used for animal species, such as mark-recapture studies, catch-per-unit effort monitoring programs, and occupancy studies, require repeated visits to sampling units. This, along with the need for pilot studies, increases the complexity and cost of monitoring to estimate population parameters relative to monitoring of sessile organisms.
For animal species, mark-recapture models are often worth the extra investment in terms of the data generated as they may be used to estimate absolute densities of populations and provide additional information on such vital statistics as animal movement, geographic distribution, and survivorship (Lebreton et al. 1992, Nichols 1992, Nichols and Kendall 1995, Thomson et al. 2009). Open mark-recapture models (e.g., Jolly-Seber) assume natural changes in the population size of the species of interest during sampling. In contrast, closed models assume a constant population size. Program MARK (White et al. 2006) performs sophisticated maximum-likelihood-based mark-recapture analyses and can test and account for many of the assumptions such as open populations and heterogeneity.
Relative Abundance Indices
It is sometimes the case that data analyses for biological inventories and monitoring studies can be accomplished based on indices of population density or abundance, rather than population estimators (Pollock et al. 2002). The difference between estimators and indices is that the former yield absolute values of population density while the latter provide relative measures of density that can be used to assess population differences in space or time. Caughley (1977) advocated the use of indices after determining that many studies that used estimates of absolute density could have used density indices without losing information. He suggested that use of indices often results in much more efficient use of time and resources and produces results with higher precision (Caughley 1977, Caughley and Sinclair 1994). Engeman (2003) also indicated that use of an index may be the most efficient means to address population monitoring objectives and that the concerns associated with use of indices may be addressed with appropriate and thorough experimental design and data analyses. It is important, therefore, to understand these concerns before utilizing an index, even though indices of relative abundance have a wide support among practitioners who often point out their efficiency and higher precision (Caughley 1977, Engeman 2003). First, they are founded on the assumption that index values are closely associated with values of a population parameter. Because the precise relationship between the index and parameter usually is not quantified, the reliability of this assumption is often brought into question (Thompson et al. 1998, Anderson 2001). Also, the opportunity for bias associated with indices of abundance is quite high. For instance, track counts could be related to animal abundance, animal activity levels, or both. Indices often are used because of logistical constraints. Capture rates of animals over space and time may be related to animal abundance or to their vulnerability to capture in areas of differing habitat quality. If either of these techniques are used to generate the index, considerable caution must be exercised when interpreting results. Given these concerns, the utility of a pilot study that will allow determination, with a known level of certainty, of the relationship between the index and the actual population (or fitness) for the species being monitored is clear. Determining this relationship, however, requires an estimate of the population.
Suitability of any technique, including indices, should ultimately be based on how well it addresses the study objective and the reliability of its results (Thompson 2002). It is also important to consider that statistical analyses of relative abundance data require familiarity with the basic assumptions of parametric and non-parametric models. Some examples of the use and analysis of relative density data can be found in James et al. (1996), Rotella et al. (1996), Knapp and Matthews (2000), Huff et al. (2000), and Rosenstock et al. (2002).
Analyses of relative abundance data require familiarity with the basic assumptions of parametric models. Since the focus is on count data, alternative statistical methods can be employed to fit the distribution of the data (e.g., Poisson or negative binomial). Although absolute abundance techniques are independent of parametric assumptions, they nevertheless do have their own stringent requirements.
When a researcher decides to use a monitoring index, it is important to remember that statistical power negatively correlates with the variability of the monitoring index. This truly underscores the need to choose an appropriate indicator of abundance and accurately estimate its confidence interval (Harris 1986, Gerrodette 1987, Gibbs et al. 1999). An excellent overview of a variety of groups of animals and plants for which the variability in estimating their population is known is given in Gibbs et al. (1998). It is also important to keep in mind that relative measures of density can be less robust to changes in habitat than absolute measures. For instance, forest practices may significantly affect indices that rely on visual observations of organisms. Although these factors may confound absolute measures as well, modern distance and mark-recapture analysis methods can account for variations in sightability and trapability. See Caughley (1977), Thompson et al. (1998), Rosenstock et al. (2002), Pollock et al. (2002) and Yoccoz et al. (2001) for in-depth discussions of the merits and limitations of estimating relative vs. absolute density in population monitoring studies.
Generalized Linear Models and Mixed Effects
Recently, generalized linear models (GLM) have become increasingly popular and take advantage of the data’s true distribution without trying to normalize it (Faraway 2006, Bolker 2008, McCulloch et al. 2008). Often times, the standard linear model cannot handle non-normal responses, such as counts or proportions, whereas generalized linear models were developed to handle categorical, binary, and other response types (Faraway 2006, McCulloch et al. 2008). In practice, most data have non-normal errors, and so GLMs allow the user to specify a variety of error distributions. This can be particularly useful with count data (e.g., Poisson errors), binary data (e.g., binomial errors), proportion data (e.g., binomial errors), data showing a constant coefficient of variation (e.g., gamma errors), and survival analysis (e.g., exponential errors) (Crawley 2007).
An extension of the GLM is the Generalized Linear Mixed Model (GLMM) approach. GLMMs are examples of hierarchal models and are most appropriate when dealing with nested data. What are nested data? As an example, monitoring programs may collect data on species abundances or occurrences from multiple sites on different sampling occasions within each site. Alternatively, researchers might also sample from a single site in different years. In both cases, the data are “nested” within a site or a year, and to analyze the data generated from these surveys without considering the “site” or “year” effect would be considered pseudoreplication (Hurlbert 1984). That is, there is a false assumption of independency of the sampling occasions within a single site or across the sampling period. Traditionally, researchers might avoid this problem by averaging the results of those sampling occasions across the sites or years and focus on the means, or they may simply just focus their analysis within an individual site or sampling period. The more standard statistical approaches, however, attempt to quantify the exact effect of the predictor variables (e.g., forest area, forb density), but ecological problems often involve random effects that are a result of the variation among sites or sampling periods (Bolker et al. 2009). Random effects that come from the same group (e.g., site or time period) will often be correlated, thus violating the standard assumption of independence of errors in most statistical models.
Hierarchal models offer an excellent way of dealing with these problems, but when using GLMMs, researchers should be able to correctly identify the difference between a fixed effect and a random effect. In its most basic form, fixed effects have “informative” factor levels, while random effects often have “uninformative” factor levels (Crawley 2007). That is, random effects have factor levels that can be considered random samples from a larger population (e.g., blocks, sites, years). In this case, it is more appropriate to model the added variation caused by the differences between the levels of the random effects and the variation in the response variables (as opposed to differences in the mean). In most applied situations, random effect variables often include site names or years. In other cases, when multiple responses are measured on an individual (e.g., survival), random effects can include individuals, genotypes, or species. In contrast, fixed effects then only model differences in the mean of the response variable, as opposed to the variance of the response variable across the levels of the random effect, and can include predictor environmental variables that are measured at a site or within a year. In practice, these distinctions are at times difficult to make and mixed effects models can be challenging to apply. For example, in his review of 537 ecological studies that used GLMM analyses, Bolker (2009) found that 58% used this tool inappropriately. Consequently, as is the case with many of these procedures, it is important to consult with a statistician when developing and implementing your analysis. There several excellent reviews and books on the subject of mixed effects modeling (Gelman and Hill 2007, Bolker et al. 2009, Zuur 2009).
Analysis of Species Occurrences and Distribution
Does a species occur or not occur with reasonable certainty in an area under consideration for management? Where is the species likely to occur? These types of questions have been and continue to be of interest for many monitoring programs (MacKenzie 2005, MacKenzie 2006). Data on species occurrences are often more cost-effective to collect than data on species abundances or demographic data. Traditionally, information on species occurrences has been used to:
1. Identify habitats that support the lowest or highest number of species,
2. Shed light on the species distribution, and
3. Point out relationships between habitat attributes (e.g., vegetation types, habitat structural features) and species occurrence or community species richness.
For many monitoring programs, species occurrence data are often considered preliminary data only collected during the initial phase of an inventory project and often to gather background information for the project area. In recent years, however, occupancy modeling and estimation (MacKenzie et al. 2002, MacKenzie et al. 2005, Mackenzie and Royle 2005, MacKenzie 2006) has become a critical aspect of monitoring animal and plant populations. These types of categorical data have represented an important source of data for many monitoring programs that have targeted rare or elusive species, or where resources are unavailable to collect data required for parameter estimation models (see Hayek and Buzas 1997, Thompson 2004).
For some population studies, simply determining whether a species is present in an area may be sufficient for conducting the planned data analysis. For example, biologists attempting to conserve a threatened wetland orchid may need to monitor the extent of the species range and proportion of occupied area (POA) on a National Forest. One hypothetical approach is to map all wetlands in which the orchid is known to be present, as well as additional wetlands that may qualify as the habitat type for the species within the Forest. To monitor changes in orchid distribution at a coarse scale, data collection could consist of a semiannual monitoring program conducted along transects at each of the mapped wetlands to determine if at least one individual orchid (or some alternative criterion to establish occupancy) is present. Using only a list that includes the wetland label (i.e., the unique identifier), the monitoring year, and an occupancy indicator variable, the biologists could prepare a time series of maps displaying all of the wetlands by monitoring year and distinguish the subset of wetlands that were found to be occupied by the orchid.
Monitoring programs to determine the presence of a species typically require less sampling intensity than fieldwork necessary to collect other population statistics. It is far easier to determine if there is at least one individual of the target species on a sampling unit than it is to count all of the individuals. Conversely, to determine with confidence that a species is not present on a sampling unit requires more intensive sampling than collecting count or frequency data because it is so difficult to dismiss the possibility that an individual missed detection (i.e., a failure to detect does not necessarily equate to absence). Traditionally, the use of occurrence data was considered a qualitative assessment of changes in the species distribution pattern and served as an important first step to formulating new hypotheses as to the cause of the observed changes. More recently, however, repeated sampling and the use occupancy modeling estimation has increased the applicability of occurrence data in ecological monitoring.
Possible analysis models for occurrence data
Species diversity
The number of species per sample (e.g., 1-m2 quadrat) can give a simple assessment of local, α diversity, or these data may be used to compare species composition among several locations (β diversity) using simple binary formulas such as the Jaccard’s index or Sorensen coefficient (Magurran 1988). For example, the Sorensen qualitative index may be calculated as:
CS = 2j / (a +b),
where a and b are numbers of species in locations A and B, respectively, and j is the number of species found at both locations. If species abundance is known (number individuals/species), species diversity can be analyzed with a greater variety of descriptors such as numerical species richness (e.g., number species/number individuals), quantitative similarity indices (e.g., Sorensen quantitative index, Morista-Horn index), proportional abundance indices (e.g., Shannon index, Brillouin index), or species abundance models (Magurran 1988, Hayek and Buzas 1997).
Binary Analyses
Since detected/not-detected data are categorical, the relationship between species occurrence and explanatory variables can be modeled with a logistic regression if values of either 1 (species detected) or 0 (species not-detected) are ascribed to the data (Trexler and Travis 1993, Hosmer and Lemeshow 2000, Agresti 2002). Logistic regression necessitates a dichotomous (0 or 1) or a proportional (ranging from 0 to 1) response variable. Yet in many cases, logistic regression is used in combination with a set of variables to predict the detection or non-detection a species. For example, a logistic regression can be enriched with such predictors as the percentage of vegetation cover, forest patch area, or presence of snags to create a more informative model of the occurrence of a forest-dwelling bird species. The resulting logistic function provides an index of probability with respect to species occurrence. There are a number of cross-validation functions that allow the user to identify the probability value that best separates sites where a species was found from where it was not found based on the existing data (Freeman and Moisen 2008). In some cases, data points are withheld from formal analysis (e.g., validation data) and used to test the relationships after the predictive relationships are developed using the rest of data (e.g., training data) (Harrell 2001). Logistic regression, however, is a parametric test. If the data do not meet or approximate the parametric assumption, alternatives to standard logistic regression can be used including General Additive Models (GAM) and variations of classification tree (CART) analyses.
Prediction of species density
In some cases, occurrence data have been used to predict organism density if the relationship between species occurrence and density is known and the model’s predictive power is reasonably high (Hayek and Buzas 1997). For example, one can record plant abundance and species richness in sampling quadrats. The species proportional abundance, or constancy of its frequency of occurrence (Po), can then be calculated as:
Po = No. of species occurrences (+ or 0) / number of samples (quadrats)
Consequently, the average species density is plotted against its proportional abundance to derive a model to predict species abundance in other locations with only occurrence data. Note, however, that the model may function reasonably well only in similar and geographically related types of plant communities (Hayek and Buzas 1997).
Occupancy Modeling
Note that without a proper design, detected/not-detected data cannot be reliably used to measure or describe species distributions (Kery and Schmid 2004, MacKenzie 2006, Kéry et al. 2008). Although traditional methods using logistic regression and other techniques may be used to develop a biologically-based model that can predict the probability of occurrence of a site over a landscape, occupancy modeling has developed rapidly over the past few years. As with mark-recapture analysis, changes in occupancy over time can be parameterized in terms of local extinction (ε) and colonization (γ) processes, analogous to the population demographic processes of mortality and recruitment (Figure 11.4) (MacKenzie et al. 2003, MacKenzie 2006, Royle and Dorazio 2008). In this case, sampling must be done in a repeated fashion within separate primary sampling periods (Figure 11.4). Occupancy models are robust to missing observations and can effectively model the variation in detection probabilities between species. Of greatest importance, occupancy (ψ), colonization (γ), and local extinction (ε) probabilities can be modeled as functions of environmental covariate variables that can be site-specific, count-specific, or change between the primary periods (MacKenzie et al. 2003, MacKenzie et al. 2009). In addition, detection probabilities can also be functions of season-specific covariates and may change with each survey of a site. More recently, program PRESENCE has been made available as a sophisticated likelihood-based family of models that has been increasingly popular using species occurrence in for monitoring (www.mbr-pwrc.usgs.gov/software/presence.html). Donovan and Hines (2007) also present an explanation of occupancy models and several online exercises (www.uvm.edu/envnr/vtcfwru/spreadsheets/occupancy/occupancy.htm).
Assumptions, data interpretation, and limitations
It is crucial to remember that failure to detect a species in a habitat does not mean that the species was truly absent (Kery and Schmid 2004, MacKenzie 2006, Kéry et al. 2008). Cryptic or rare species, such as amphibians, are especially prone to under-detection and false absences (Thompson 2004). Keep in mind that occasional confirmations of species presence provide only limited data. For example, the use of a habitat by a predator may reflect prey availability, which may fluctuate annually or even during one year. A more systematic approach with repeated visits is necessary to generate more meaningful data (Mackenzie and Royle 2005).
Extrapolating density without understanding the species requirements is also likely to produce meaningless results since organisms depend on many factors that we typically do not understand. Furthermore, limitations of species diversity measures should be recognized, especially in conservation projects. For example, replacement of a rare or keystone species by a common or exotic species would not affect species richness of the community and could actually ‘improve’ diversity metrics. Also, the informative value of qualitative indices is rather low since they disregard species abundance and are sensitive to differences in sample size (Magurran 1988). Rare and common species are weighted equally in community comparisons. Often this may be an erroneous assumption since the effect of a species on the community is expected to be proportional to its abundance; keystone species are rare exceptions (Power and Mills 1995). In addition, analyses that focus on species co-occurrences without effectively modeling or taking into account the varying detection probabilities of the species can be prone to error, although new occupancy models are beginning to incorporate detectability in models of species richness (MacKenzie et al. 2004, Royle et al. 2007, Kéry et al. 2009).
Analysis of Trend Data
Trend models should be used if the objective of a monitoring plan is to detect a change in a population parameter over time. Most commonly, population size is repeatedly estimated at set time intervals. Trend monitoring is crucial in the management of species since it may help:
1. Recognize population decline and focus attention on affected species,
2. Identify environmental variables correlated with the observed trend and thus help formulate hypotheses for cause-and-effect studies, and
3. Evaluate the effectiveness of management decisions (Thomas 1996, Thomas and Martin 1996).
The status of a population can be assessed by comparing observed estimates of the population size at some time interval against management-relevant threshold values (Gibbs et al. 1999, Elzinga et al. 2001). All monitoring plans, but particularly those designed to generate trend data, should emphasize that the selection of reliable indicators or estimators of population change is a key requirement of effective monitoring efforts. Indices of relative abundance are often used in lieu of measures of actual population size, sometimes because of the relatively reduced cost and effort needed to collect the necessary data on an iterative basis. For example, counts of frog egg masses may be performed annually in ponds (Gibbs et al. 1998) or bird point-counts may be taken along sampling routes (Böhning-Gaese et al. 1993, Link and Sauer 1997a,b; 2007). Analysis of distribution maps, checklists, and volunteer-collected data may also provide estimates of population trends (Robbins 1990, Temple and Cary 1990, Cunningham and Olsen 2009, Zuckerberg et al. 2009). To minimize the bias in detecting a trend, such as in studies of sensitive species, the same population may be monitored using different methods (e.g., a series of different indices) (Temple and Cary 1990). Data may also be screened prior to analysis. For example, only monitoring programs that meet agreed-upon criteria may be included, or species with too few observations may be excluded from the analysis (Thomas 1996, Thomas and Martin 1996).
Possible Analysis Models
Trends over space and time present many challenges for analysis to the extent that consensus does not exist on the most appropriate method to analyze the related data. This is a significant constraint since model selection may have a considerable impact on interpretation of the results of analysis (Thomas 1996, Thomas and Martin 1996).
Poisson regression is independent of parametric assumptions and is especially appropriate for count data. Classic linear regression models in which estimates of population size are plotted against biologically relevant sampling periods have been historically used in population studies since they are easy to calculate and interpret. However, these models are subject to parametric assumptions, which are often violated in count data (Krebs 1999, Zar 1999). Linear regressions also assume a constant linear trend in data, and expect independent and equally spaced data points. Since individual measurements in trend data are autocorrelated, classic regression can give skewed estimates of standard errors and confidence intervals, and inflate the coefficient of determination (Edwards and Coull 1987, Gerrodette 1987). Edwards and Coull (1987) suggested that correct errors in linear regression analysis can be modeled using an autoregressive process model (ARIMA model). Linear route-regression models represent a more robust form of linear regression and are popular with bird ecologists in analyses of roadside monitoring programs (Geissler and Sauer 1990, Sauer et al. 1996, Thomas 1996). They can handle unbalanced data by performing analysis on weighted averages of trends from individual routes (Geissler and Sauer 1990) but may be sensitive to nonlinear trends (Thomas 1996). Harmonic or periodic regressions do not require regularly spaced data points and are valuable in analyzing data on organisms that display significant daily periodic trends in abundance or activity (Lorda and Saila 1986).
For some data where large sample sizes are not possible, or where variance structure cannot be estimated reliably, alternative analytical approaches may be necessary. This is especially true when the risk of concluding that a trend cannot be detected is caused by large variance or small sample sizes, the species is rare, and the failure to detect a trend could be catastrophic for the species. Wade (2000) provides an excellent overview of the use of Bayesian analysis to address these types of problems. Thomas (1996) gives a thorough review of the most popular models fit to trend data and assumptions associated with their use.
Assumptions, Data Interpretation, and Limitations
The underlying assumption of trend monitoring projects is that a population parameter is measured at the same sampling points (e.g., quadrats, routes) using identical or similar procedures (e.g., equipment, observers, time period) at regularly spaced intervals. If these requirements are violated, data may contain excessive noise, which may complicate their interpretation. Thomas (1996) identified four sources of variation in trend data:
1. Prevailing trend – population tendency of interest (e.g., population decline),
2. Irregular disturbances – disruptions from stochastic events (e.g., drought mortality),
3. Partial autocorrelation – dependence of the current state of the population on its previous levels, and
4. Measurement error – added data noise from deficient sampling procedures.
Although trend analyses are useful in identifying population change, the results are correlative and tell us little about the underlying mechanisms. Ultimately, only well designed cause-and-effect studies can validate causation and facilitate management decisions.
Analysis of Cause and Effect Monitoring Data
The strength of trend studies lies in their capacity to detect changes in population size. To understand the reason for population fluctuations, however, the causal mechanism behind the population change must be determined. Cause-and-effect studies represent one of the strongest approaches to test cause-and-effect relationships and are often used to assess effects of management decisions on populations. Similar to trend analyses, cause-and-effect analyses may be performed on indices of relative abundance or absolute abundance data.
Possible analysis models
Parametric and distribution free (non-parametric) models provide countless alternatives to fitting cause-and-effect data (Sokal and Rohlf 1994, Zar 1999). Excellent introductory material to the design and analysis of ecological experiments, specifically for ANOVA models, can be found in Underwood (1997) and Scheiner and Gurevitch (2001).
A unique design is recommended for situations where a disturbance (treatment) is applied and its effects are assessed by taking a series of measurements before and after the perturbation (Before-After Control-Impact, BACI) (Stewart-Oaten et al. 1986) (Figure 11.5). This model was originally developed to study pollution effects (Green 1979), but it has found suitable applications in other areas of ecology as well (Wardell-Johnson and Williams 2000, Schratzberger et al. 2002, Stanley and Knopf 2002). In its original design, an impact site would have a parallel control site. Further, variables deemed at the beginning of the study to be relevant to the management actions would be planned to be periodically monitored over time. Then any differences between the trends of those measured variables in the impact site with those from the control site (treatment effect) would be demonstrated as a significant time*location interaction (Green 1979). This approach has been criticized since the design was originally limited to unreplicated impact and control sites (Figure 11.5), but it can be improved by replicating and randomly assigning sites (Hurlbert 1984, Underwood 1994).
Assumptions, data interpretation, and limitations
Since cause-and-effect data are frequently analyzed with ANOVA models, a parametric model, one must pay attention to parametric assumptions. Alternative means of assessing manipulative studies may also be employed. For example, biologically significant effect size with confidence intervals may be used in lieu of classic statistical hypothesis testing. An excellent overview of arguments in support of this approach with examples may be found in Hayes and Steidl (1997)), Steidl et al. (1997), Johnson (1999), and Steidl and Thomas (2001).
Paradigms of Inference: Saying Something With Your Data and Models
Randomization tests
These tests are not alternatives to parametric tests, but rather are unique means of estimating statistical significance. They are extremely versatile and can be used to estimate test statistics for a wide range of models, and are especially valuable in analyzing non-randomly selected data points. It is important to keep in mind, however, that randomization tests are computationally difficult even with small sample sizes (Edgington and Onghena 2007). A statistician needs to be involved in choosing to use and implement these techniques. More information on randomization tests and other computation-intensive techniques can be found in Crowley (1992), Potvin and Roff (1993), and Petraitis et al. (2001).
Information Theoretic Approaches: Akaike’s Information Criterion
Akaike’s information criterion (AIC), derived from information theory, may be used to select the best-fitting model among a number of a priori alternatives. This approach is more robust and less arbitrary than hypothesis-testing methods since the P-value is often predominantly a function of sample size. AIC can be easily calculated for any maximum-likelihood based statistical model, including linear regression, ANOVA, and general linear models. The model hypothesis with the lowest AIC value is generally identified as the ’best‘ model with the greatest support (given the data) (Burnham and Anderson 2002). Once the best model has been identified, the results can then be interpreted based on the changes in the explanatory variables over time. For instance, if the amount of mature forest near streams were associated with the probability of occurrence of tailed frogs, then a map generated over the scope of inference could be used to identify current and likely future areas where tailed frogs could be vulnerable to management actions. In addition, one of the more useful advantages of using information theoretic approaches is that identifying a single, best model is not necessary. Using the AIC metric (or any other information criteria), one can rank models and can average across models to calculate weighted parameter estimates or predictions (i.e., model averaging). A more in depth discussion of practical uses of AIC may be found in Burnham and Anderson (2002) and Anderson (2008).
Bayesian Inference
Bayesian statistics refers to a distinct approach to making inference in the face of uncertainty. In general, Bayesian statistics share much with the traditional frequentist statistics with which most ecologists are familiar. In particular, there is a similar reliance on likelihood models which are routinely applied by most statisticians and biometricians. Bayesian inference can also be used in a variety of statistical tasks, including parameter estimation and hypothesis testing, post hoc multiple comparison tests, trend analysis, ANOVA, and sensitivity analysis (Ellison 1996). Bayesian methods, however, test hypotheses not by rejecting or accepting them, but by calculating their probabilities of being true. Thus, P-values, significance levels and confidence intervals are moot points (Dennis 1996). Based on existing knowledge, investigators assign a priori probabilities to alternative hypotheses and then use data to calculate (“verify”) posterior probabilities of the hypotheses with a likelihood function (Bayes theorem). The highest probability identifies the hypothesis that is the most likely to be true given the experimental data (Dennis 1996, Ellison 1996). Bayesian statistics has several key features that differ from classical frequentist statistics:
• Bayes is based on an explicit mathematical mechanism for updating and propagating uncertainty (Bayes theorem)
• Bayesian analyses quantify inferences in a simpler, more intuitive manner. This is especially true in management settings that require making decisions under uncertainty
• Takes advantage of pre-existing data, and may be used with small sample sizes
For example, conclusions of a monitoring analysis could be framed as: “There is a 65% chance that clearcutting will negatively affect this species,” or “The probability that this population is declining at a rate of 3% per year is 85%.” A more in-depth coverage of the use of Bayesian inference in ecology can be found in Dennis (1996), Ellison (1996), Taylor et al. (1996), Wade (2000), and O’Hara et al. (2002). Even though Bayesian inference is easy to grasp and perform, it is still relatively rare in natural resources applications (although that is quickly changing) and sufficient support resources for these types of tests may not be readily available. It is recommended that it only be implemented with the assistance of a consulting statistician.
Retrospective Power Analysis
Does the outcome of a statistical test suggest that no real biological change took place at the study site? Did the change actually occur but was not detected due to a low power of the statistical test used, in other words, was a Type II (missed-change) error committed in the process? It is recommended that those undertaking inventory studies should routinely evaluate the validity of results of statistical tests by performing a post hoc, or retrospective power analysis for two important reasons:
1. The possibility of falsely accepting the null hypothesis is quite real in ecological studies, and
2. A priori calculations of statistical power are only rarely performed in practice, but are critical to data interpretation and extrapolation (Fowler 1990).
A power analysis is imperative whenever a statistical test turns out to be non-significant and fails to reject the null hypothesis (H0); for example, if P > 0.05 at 95% significance level. There are a number of techniques to carry out a retrospective power analysis well. For instance, they should be performed only using an effect size other than the effect size observed in the study (Hayes and Steidl 1997, Steidl et al. 1997). In other words, post hoc power analyses can only answer whether or not the performed study in its original design would have allowed detecting the newly selected effect size.
Elzinga et al. (2001) recommends the following approach to conducting a post hoc power analysis assessment (Figure 11.6). If a statistical test was declared non-significant, one could calculate a power value to detect a biologically significant effect of interest, usually a trigger point tied to a management action. If the resulting power is low, one must take precautionary measures in the monitoring program. Alternatively, one can calculate a minimum detectable effect size at a selected power level. An acceptable power level in wildlife studies is often set at about 0.80 (Hayes and Steidl 1997). If the selected power can only detect a change that is larger than the trigger point value, the outcome of the study should again be viewed with caution.
Monitoring plans may also encourage the use of confidence intervals as an alternative approach to performing a post hoc power analysis. This method is actually superior to power analysis since confidence intervals not only suggest whether or not the effect was different from zero, but they also provide an estimate of the likely magnitude of the true effect size and its biological significance. Ultimately, for scientific endeavors these are rules of thumb. In management contexts, however, decision making under uncertainty where the outcomes have costs, power calculations and other estimates for acceptable amounts of uncertainty should be approached more rigorously.
Summary
Even before the collection of data, researchers must consider which analytical techniques will likely be appropriate to interpret their data. Techniques will be highly dependent on the design of the monitoring program, so a monitoring plan should clearly articulate the expected analytical approaches after consulting with a biometrician. After data collection but before statistical analyses are conducted, it is often helpful to view the data graphically to understand data structure. Assumptions upon which certain techniques are based (e.g., normality, independence of observations and uniformity of variances for parametric analyses) should be tested. Some violations of assumptions may be addressed with transformations, while others may need different approaches. Detected/non-detected, count data, time series and before-after control impact designs all have different data structures and will need to be analyzed in quite different ways. Given the considerable room for spurious analysis and subsequent erroneous interpretation, if possible, a biometrician/statistician should be consulted throughout the entire process of data analysis. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.11%3A_Data_Analysis_in_Monitoring.txt |
The information that monitoring generates can only be put to use if it is made available in a timely way. Shortly after the monitoring program is terminated, therefore, a formal final report must be developed. Yet this should ideally be the final step in a continual process of communication. Interim monitoring reports should also be provided frequently throughout the duration of monitoring. This may occur annually (e.g., USGS Breeding Bird Survey data; Sauer et al. 2008), or periodically (Forest Inventory and Analysis data; Smith et al. 2004) depending on the program, but must be done often enough for the reporting of monitoring data to allow for rapid response within an adaptive management framework. Frequent communication of monitoring data is also important because it helps inform research approaches. In a sense, the data represent a middle ground between research and monitoring (Figure 12.1).
Aside from the temporal aspects, the successful reporting of data has two components. First, all potential users of the data must be given a means to readily access the report. Web-based dissemination certainly is the most likely way of getting information out, especially with powerful search engines now available, but providing copies directly to stakeholders is also necessary. If a report is made available, but some stakeholders are not aware of its availability, then the information is not of use, and worse, the stakeholder may feel marginalized. Proprietary restrictions (if they exist) can hinder the communication process, thus it is best to avoid them provided that doing so does not decrease the quality of the report.
Second, and perhaps most important, the report and the data within them must be presented in a well-organized and visually appealing (i.e., a picture if worth a thousand words) format that is easy for stakeholders to understand. The format is an important consideration given that even if an effective means of disseminating the reports is chosen, an unclear or otherwise poor format may make the data inaccessible.
Format of a Monitoring Report
Some web-based reports are simply interpretations of data in text form for the general public. Others use web interfaces to provide summaries in a variety of ways for various time periods over various areas, all specified by the user (e.g., annual summaries from the Audubon’s Christmas Bird Count). Most however, are pdf files and have a standard format to allow the users to find the information that they need quickly while still understanding any potential biases, limitations or interpretations of the data.
Both interim and final reports and other products such as predictive or conceptual models should be designed in the way that best meets the particular information requirements for which the project was intended to address. Hence there is no single format that should be followed. Within this chapter, we provide an annotated list of elements that together comprise a generalized, commonly used format, but these pieces should be adapted to meet the needs of a particular client or set of stakeholders.
Title
The title should concisely state what, when and where the monitoring data were collected. Avoid long titles. “Southwestern willow flycatcher 2002 survey and nest monitoring report” is a perfectly acceptable title. Or is it? Albeit succinct and to the point, we do not know where the monitoring occurred. Throughout the range of the species? In one state? In part of one state? Making such a distinction could make the difference between a potential user reading or not reading the report. In this instance, the results are synthesized range wide so simply adding that term would clarify the scope of the monitoring effort and report (Sogge et al. 2003).
Abstract or Executive Summary
Although it may be very important to do so, most readers of a monitoring report will not dig into the details of the methods and results. Providing a brief informative abstract or executive summary is therefore essential. An executive summary is a very concise version of the report that includes brief descriptions of data, analysis, and interpretations. An executive summary should provide an understanding of:
• The goals and objectives of the monitoring work
• What important decisions or actions these data could help inform
• How the data can (or cannot) answer these questions
• Limitations of the data including scope of inference both in space and time
• Implications of the trends and recommendations, if appropriate
• Future needs
An abstract is similar to an executive summary but is usually more of a condensed overview of just the objectives and the findings and includes little in the way of interpretation. Generally an executive summary for a monitoring report is 2-3 pages while an abstract is about a page or less.
Introduction
The introduction should outline the reasons for inventorying and/or monitoring the population, species, community or ecosystem of interest. It is useful to include ample contextual information that communicates to the reader precisely why monitoring or inventorying was ecologically, economically, culturally, or otherwise justifiable. Suggestions for this section include:
1. A statement of the management problem or policy that prompted the inventory and/or monitoring project,
2. A summary of current knowledge about the population, species, community or ecosystem that is relevant to the management problem or policy driving the monitoring plan,
3. A statement of the goals and objectives for the monitoring plan, and
4. Hypotheses and conceptual models that guided sampling, data analysis, and data interpretation.
Study Area
This section should first establish the general spatial and temporal scales of the project and the rationale for the scope. Then, more specifically, the grain, extent and context for the study should be described in detail. The grain refers to the finest level of detail measured in the study (i.e., patch size) and you should indicate why this grain size was chosen. The extent is the outer bounds of the sampling framework. This may be a species’ geographic range, a watershed, or a property boundary. You should make an effort to describe the chosen extent relative to the space used or needed by the populations, species, communities or ecosystems of interest, especially if the outer bounds are delineated based on anthropogenic criteria. A map should also be included with sufficient detail to allow the reader to understand the context within which the extent is embedded; exactly which components of the broader landscape are and are not included in the sampling effort is often highly significant to stakeholders.
Typically the geology, soils, climate, and physiognomy or vegetation is described in this section to reinforce the broad spatial overview. Without describing biophysical factors that could have an influence on the patterns of results seen over space and/or time in sufficient detail, the reader may not understand why patterns were observed. Any pertinent land management actions such as roads, development, timber harvest, or agricultural practices should also be described in sufficient detail so that the reader can understand how these actions may influence results. It is particularly helpful to map how these anthropogenic disturbances relate to the area being monitored and to then provide copies in the report (Figure 12.2). Also, as anthropogenic disturbances typically change in their intensity and location over time, it is important to describe the temporal context of current maps and the implications this history has for the surrounding ecosystem. This can be succinctly done through the use of a chronosequence.
Finally, background information on the population, species, community or ecosystem of interest should also be provided. Descriptions of the geographic range of the species, its home range, habitat elements, competitors and predators allow the reader to interpret the results more completely. For example, a report on the monitoring of amphibians in the Mt. Hood National Forest may be particularly important with regards to changes in the abundance or distribution of Larch mountain salamanders but may be less important with regards to species such as Pacific chorus frogs due to differences in geographic distribution (Figure 12.3). To understand trends in the latter species, coordinated monitoring efforts among many land management agencies and owners would be needed.
Methods
The gold standard for the methods section is that a reader be able to use it to repeat exactly what was done and produce comparable results. This necessitates considerable attention to detail in documenting the sampling and analytical procedures. This section should include:
1. The rationale for selecting sampling units. Be sure to indicate if sampling was random or systematic and if not random, then indicate what biases may be inherent in the resulting data. Any irregularities in selection of sampling sites such as failure to acquire permission to enter private lands, access to the sites, or other biases need to be described in detail and interpreted in the Discussion section.
2. A description of the sampling design. Explain the overall sampling design and which state variables were measured (e.g., presence-absence, correlative, Before-After Control-Impact), the rationale for using that design, as well as the analytical model that the data was expected to populate. For instance, if data were collected from random sites among 3 strata, be clear as to how the strata were defined. Explain if any treatment effects were nested within other ‘treatments’, and what type of statistical approach was appropriate for analysis. Of particular importance is an explanation of the determination of an appropriate sample size used in the monitoring effort. Clearly discuss the sample size from both a statistical power standpoint as well as from a logistical standpoint. Should the sample size be less than optimal based on power analysis, then also note the influence of the reduced sample size on the statistical power. In many cases, a repeated sampling design may have been used to develop detection probability estimates. The report should be clear as to whether the sampling design was of a repeated nature, and if so, in what fashion were the repeated visits standardized.
3. A summary of field methods for locating sampling units and collecting data. Much of this could be included in an appendix containing copies of the field protocols, data sheets and detailed maps, but give enough detail here to ensure that easily avoidable biases will not be overlooked. Some of the most common biases are a result of differences in observers, or weather, temporal or spatial factors; explicitly addressing these topics is suggested.
4. Identification of ancillary data used in the analysis. Describe all outside information used, such as satellite imagery or timber inventory data. If remotely sensed data were used, record the time that the images were taken. Similarly, if FIA or other forest inventory data were used, provide the dates of data collection, reference to specific field methods, and the location of the data. If data were acquired or downloaded from an external GIS warehouse and database, then details should be provided regarding the exact URL or appropriate contact information.
5. A description of analytical methods. Provide the specific statistical methods and software platform used to calculate descriptive and comparative statistics. In cases where complex model structures are used, include the programming code used to generate the statistics. Although software changes over time it is usually far easier to recreate the model structure in another software package from an existing program than from text. If the data are stored in a relational database system, then one should also consider including the exact SQL code for querying these databases and extracting the data. Keep in mind that monitoring programs are often considered legacy projects, and a future user should be able to replicate all steps of data extraction and analysis.
6. A description of measures to assure data quality. Describe personnel training and sampling activities used to minimize biases in the observation process. The results of observer skill tests, effort data, and detection probability estimates should also be reported so that the reader can understand the degree to which observation biases were included in data collection and analysis. Remember that observation biases, which may increase due to inter-observer variability among other things, diminishes the ability to detect trends and estimate state variables. In addition, address data entry, proofing and cleaning activities in detail.
Results
This section should describe the results of data collection and analysis with little to no interpretation. The findings should be summarized verbally and statistically and may also be presented in the form of tables, figures, or maps. Report all relevant aspects of the statistical results (central tendency, variance, drop in deviance, and other parameters) not only so that the information can be clearly interpreted but also so that the information can be used in meta-analysis (Gurevitch and Hedges 1999). Anderson et al. (2001) provided guidance on presenting statistical summaries in scientific papers, particularly with regard to information theoretic approaches to data analyses as well as Bayesian analyses.
It is important to remember that all tables and figures should be able to stand alone. In other words, they should be easily interpretable even if extracted from the report. Hence the table and figure titles should clearly state what information is being displayed, where the data came from (location) and over what time period (Figure 12.4). Additional explanatory information may be placed in a footnote to the table or figure. When maps are used, be sure that legends are provided that include an explanation of the map features, scale and orientation (e.g., a north arrow).
Discussion
Because one set of data can be interpreted a number of ways depending on the goals and objectives of the party using it, some may argue that it makes sense to allow each individual to interpret the data. It can also be tempting to provide tables and figures that summarize the results without undertaking much interpretation of those results as a means of quickly disseminating monitoring data. Nonetheless, we believe that the individuals best able to interpret the data as objectively as possible are those with the most knowledge about the monitoring program: those responsible for carrying out the actual monitoring work. We suggest that the discussion, therefore, include an interpretation of the results along with an account of the pertinent knowledge accrued by the parties that undertook the monitoring. Although this may be a comparatively labor-intensive, time-consuming process, it will also make for a fully transparent and more comprehensive presentation and is generally worthwhile.
One important component of such a presentation is to compare the monitoring findings with the results of previous research and monitoring efforts for the species within the study area, as well as comparable efforts elsewhere. You may have read the pertinent literature, but it is unlikely that every user has. For instance, Holmes and Sherry (1988) compared long term monitoring of a number of bird species on a 10-ha plot to regional patterns of abundance. In this case, generalized trends were remarkably similar (Figure 12.6). But these consistencies among scales are not a rule. In a subsequent study, Holmes and Sherry (2001) identified 7 species that exhibited inconsistent trends between local monitoring sites and regional patterns. A brief comparison of these studies within the Discussion section of the latter’s report helped to place the results in the appropriate context and potentially serves to make the reader more informed than she would have been otherwise.
Yet not all monitoring projects have similar precedents. Important questions to address in any Discussion section include:
• Did the project satisfy the objectives?
• In what ways did the work extend our knowledge about the species in the study area?
• Do the results support or challenge hypotheses and conceptual models stated in the introduction?
• What should the reader know about these results before using them to make decisions?
The answer to the last question is a key part of a responsible monitoring report. Explicitly informing your reader of the scope and limitations of the results provides a clear frame with which to view interpretations and thereby allows her to interpret the data in a manner that does not overstate the conclusions. Common limitations include scope of inference (both spatial and temporal), potential biases and unexpected problems encountered during the project.
Management Recommendations
This section should discuss how the results of the monitoring effort can or cannot be used to improve or otherwise influence resource management, including future monitoring activities. If the trends or differences in populations or habitats has reached or is approaching a threshold or ‘trigger point’ identified in the monitoring plan, corrective management measures should also be proposed (Noon et al. 1999, Moir and Block 2001). With regards to monitoring, it is in this section that recommendations for improvements in methods, changes in parameters monitored and/or termination of some aspects of monitoring should be proposed.
To decide what to include in a Management Recommendation section, you may have to re-visit some of your files from the design and implementation stage of your monitoring program and juxtapose that information with the monitoring results. Information dealing with the program’s goals and objectives and potentially the results of any pilot studies are particularly helpful. For instance, in a study carried out by McDonnell and Williams (2000), the general goal was to maintain a species-diverse grassland. Early in the research process, they collected a range of diversity values from a number of grassland sites and were able to derive a more specific management objective that defined species-diverse in a way that was pertinent to monitoring: to maintain diversity above 40 species within the grassland (Figure 12.7). From this objective, the researchers determined an appropriate management ‘trigger’ point: ‘if measured diversity falls below 50 species for two consecutive years, then the site should be burned within the next two years to restore the grassland structure and composition.’ (McDonnell and Williams 2000).
Given this context, if monitoring data reveal that the threshold level of 50 species is reached for two consecutive years, the Management Recommendations section should be used to encourage the development of a burning plan. All of the data that informed the original decisions should be cited to justify the proposal. Conversely, if the data indicate that the threshold has not been reached for two consecutive years, the Management Recommendations section should be used to discourage the development of a burning plan. Once again, all data that informed the original decisions should be cited. This example also underscores the importance of documenting all monitoring decisions and archiving any data or outside sources used in making them.
It is important to realize, however, that monitoring data, especially when it is collected on a long-term basis, may suggest that previously derived objectives and trigger points are unhelpful or unrealistic. Or they may suggest that monitoring itself is ineffective. For instance, if, using the same example, the researchers were to detect only 3 species in the first two years of sampling, there would likely be an inconsistency between the management plan and the ecosystem, the trigger point and the ecosystem, or the sampling techniques and the species being monitored (provided that nothing has drastically changed since the pilot studies were undertaken). In this scenario, the Management Recommendations section should be used to encourage further research such as a new set of pilot studies to recalibrate management and monitoring.
List of Preparers
In this section, the authors of the report should identify themselves and other biologists that had supervisory roles in the project by name, title or position and provide contact information. Usually a section of acknowledgements lists those who assisted with some aspect of the monitoring design, data collection, or data analysis.
Appendices
Appendices are especially useful for reporting highly detailed information that may not be necessary for most readers, but which may be critical if other managers or scientists wish to replicate or further interpret the monitoring work. Copies of detailed field data collection protocols, data sheets, programming language used in analyses, detailed statistical summaries, field study site maps, and similar information that may be needed by others in the future can be included in appendices.
Summary
At times a summary of the findings may be included if it constitutes more than the reiteration of the Executive Summary. Whereas the Executive Summary precedes the text and provides a brief synopsis of the approach and results, a summary at the end of the document truly focuses on results and implications of the results. The summary should be informative with enough detail to allow the reader to walk away knowing the ‘bottom line’ from the monitoring program to date.
Summary
In summary, timely communication of monitoring results helps to ensure that the results will be used and that decisions based on the results can be evaluated by all stakeholders. A well structured report that allows others to understand how data were collected, what biases might exist, and how reliable inferences from the analyses might be are all key to effective use of the data. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.12%3A_Reporting.txt |
Imagine the following scenario. You have just spent nearly \$500,000 over the past five years collecting information on changes in the abundance of sharptail snakes in the foothills of the Willamette Valley in Oregon. Data were collected from 30 randomly selected sites on public land managed to restore Oregon oak savannahs, and on another 30 sites on private lands that are grazed. The data are presented in figure 13.1.
So given this information, what do you do? Continue to monitor? Use the information to make changes? What are the risks of changing vs. continuing on with the status quo? Can these data be integrated with monitoring data from other programs to create a broader picture of the state of Oregon’s ecosystems? We will follow this example through a few key steps in interpreting monitoring data and see how decisions might be made.
Thresholds and Trigger Points
Clearly there are a number of issues that must be considered not only by managers but also by stakeholders before making any changes. One approach is to agree with stakeholders at the outset of the monitoring program that if a particular threshold or trigger point is reached then alternative management actions are to be implemented. Block et al. (2001) differentiated between trigger points that initiate a change to enact recovery, and thresholds, that indicate success in a recovery action. In the case of figure 13.1, a trigger point may be recording < 5 snakes/10ha for two or more consecutive years. If such a trigger point is reached, it could be agreed with stakeholders beforehand that a series of steps would be taken by the responsible agency to restore habitat for the species. Or in the case of endangered species, the decision may be made to capture individuals and initiate a captive breeding program. But in our hypothetical case after 5 years, sharptail snake detections meet the trigger point at year 5, so at that point the public management agency biologists may begin meeting with private landowners to explore the following options to restore habitat for the species:
• Provide landowner assistance on habitat restoration
• Provide incentives to landowners to alter grazing and other land use practices.
• Explore purchase of a conservation easement that allows public biologists to manage land
• Explore purchase of key properties and begin habitat restoration
Any one of the above options may be acceptable to one landowner but not to another. As these or other options are implemented then continued monitoring can allow detection of the point at which a threshold of recovery, say >10 snakes/10 ha for >2 years, is surpassed and maintained. Monitoring a control area to understand changes in abundance on public conservation land will provide a point of comparison to help ensure that the patterns seen on private lands using the above approaches are more likely caused by management actions than to other extraneous effects. For instance, if the abundance on both the public and private lands declined over time despite changes in management practices on the private lands then declines are more likely due to factors unassociated with management such as changes in climate or disease.
One possible problem with the identification of thresholds is that they are the result of social negotiation and although they may be based in biology they may also simply represent an agreed upon, socially acceptable point by managers and stakeholders. Thresholds based on biology may represent population density, probability of occurrence, a change in reproduction or survival (or lambda), genetic heterozygosity, or other population parameters, but the threshold(s) are set jointly by biologists and stakeholders. Use of genetic markers to assess changes in effective population size and other aspects of population ecology have become increasingly popular (Schwartz et al. 2007). Schwartz et al. (2007) described two categories of monitoring using genetic markers: Category I which can identify individuals, populations, and species; and Category II which monitors population genetic parameters allowing insights into demographic processes and ‘retrospective monitoring’ to better understand historical changes (Figure 13.2). Thresholds may also, however, constitute more of a reflection of society’s tolerance of or desires for a particular species. For instance, the threshold for the number of cougars in a residential area of California may be the level that the public can tolerate rather than what is most significant in terms of the population dynamics of the species.
Forecasting Trends
With 5 years of data, trends can begin to emerge from the data (Figure 13.3) that provide information to guide management actions. In our hypothetical example, trends on public lands are rather stable, whereas those on private lands are declining. If we forecast the trend from private lands into the future we can see that in 2.5 years the x intercept for the trend will reach 0. The degree of precision in estimating the x intercept decreases dramatically as forecasts are extended further into the future, so forecasting attempts should be viewed as one tool to guide decision making. It is not clear if the x intercept will be reached in 1 year, 2.5 years or 10 years, or at all, but the trend line does raise concerns about the long term viability of the species on private lands and may initiate a more rapid response than if the trend line had an x intercept of 15 years. Dunn (2002) used an approach similar to this and categorized over 200 bird species into conservation alert categories.
But these are simply linear trends and the variability associated with trends, especially for rare species, is often very high. Indeed, the power associated with detecting a significant trend is often very low with rare species, thus statistical trend lines must be interpreted cautiously to avoid making an error of concluding that no trend exists when it actually is in a decline. This is especially problematic when populations have already reached very low levels and the probability of detecting an additional decline is very low (Staples et al. 2005). In these cases it may be more useful to employ risk assessments based on population viability analyses (PVA, Morris et al. 2002, Lande et al. 1993). If the data collected in monitoring can be used to aid in parameterizing a PVA model, then at least relative changes in future population abundance or time-to-extinction can be estimated (Dennis et al. 1991, Morris and Doak 2002). Staples et al. (2002) proposed a viable population monitoring approach in which yearly risk predictions are used as the monitoring indicator. Staples et al. (2002) defined ‘risk’ as “the probability of population abundance declining below a lower threshold within a given time frame.” Predicting that risk will increase over time could constitute a trigger point and prompt alternative management actions.
Predicting Patterns Over Space and Time
Clearly managers would like to know where on a landscape species are likely to occur so that management actions can be taken to increase, or decrease populations or at least have minimal effects on desired species. Monitoring occurrence of organisms across a landscape can provide information in the spatial distribution of individuals within populations and can provide a better understanding of metapopulation structure and connectivity among subpopulations. If information on reproduction and survival are also included in the monitoring effort then additional information on the value of subpopulations as sources or sinks can also be gained. And if this information is collected over time then information on the probabilities of subpopulations becoming locally extinct in patches and subsequent recolonization can also be understood through long-term monitoring.
Although this baseline information on the distribution and fitness of organisms over a planning area is valuable information for understanding the impacts of managing landscapes, issues such as land use and climate change make the information even more valuable. In the face of such changes, the risk of species loss from an area, or even overall extinction, depends on the rate at which a species can adapt to changing conditions. Monitoring information can provide evidence to more fully understand both the rates of change in the biophysical environment and the associated fitness of organisms. In the following sections we use monitoring in the context of climate change as an example to show how environmental stressors can influence how managers act to attempt to conserve biodiversity, but also the difficulties of confronting such comprehensive ecological changes.
If we continue to pump CO2 into the atmosphere at current rates, then approximately 20-30% of plant and animal species assessed by the IPCC (2007) are likely to be at increased risk of extinction as global average temperature increases by 1.5 to 2.5°C or more. Hence understanding certain aspects of the environment and species responses through monitoring is key to providing opportunities for species to adapt to or recover from climate change. But climate change is probably one of the more difficult environmental stressors to respond to even with good monitoring data because it is global – the opportunity for comparisons between sites affected by climate change and those unaffected by change are rare if they exist at all. Indeed, we are not usually given the opportunity to use BACI or comparative mensurative approaches when designing a monitoring plan affecting regional or global stressors, so we must rather rely on associations over time. To be more specific, effect may be inferred from these data only with care since other factors associated with change may have a greater or lesser effect in any observed trends. Nonetheless there are a number of potential factors that are often assessed when trying to understand effects of global changes like climate change on loss of biodiversity.
Geographic Range Changes
If global average temperature increases exceed 1.5 to 2.5°C, then major changes in ecosystem structure and function, species’ ecological interactions and shifts in species’ geographical ranges, are anticipated, with predominantly negative consequences
for biodiversity (IPCC 2007). Because geographic ranges of species are often dictated by climatic conditions (or by topographic barriers) that influence physiological responses, changes in geographic ranges of species are frequently predicted using bioclimate envelopes (Pearson and Dawson 2003), and observed changes are used as an early indicator of a species’ response and ability to adapt to climate change. But bioclimate envelopes are coming under scrutiny and being questioned because biotic interactions, evolutionary change, and dispersal ability also influence the ability or inability of a species to respond to changes in its environment (Pearson and Dawson 2003). One can easily imagine how the impacts of climate change on subpopulations could be exacerbated by land use change that leads to their isolation; indeed these subpopulations would become more vulnerable to local extinction through inability to disperse, infectious disease, or competition with invasive species as their habitat changes in response to climate change.
Zuckerberg et al. (2009) used the New York State Breeding Bird Atlas surveyed in 1980–1985 and 2000–2005 to test predictions that changes in bird distribution are related to climate change. They found that 129 bird species showed an average northward range shift in their mean latitude of 3.6 km (Zuckerberg et al. 2009) and that the southern range boundaries of some bird species moved northward by 11.4 km. Clearly these monitoring programs can provide evidence for associations between climate change and changes in geographic ranges, yet other factors should not be ruled out. Human population density has changed over that time as have land use patterns and both could have had similar effects on the geographic range of certain species. Nonetheless the compelling fact is that all of the 129 species that they examined showed a northward shift in distribution, thus in this case, the data suggest that the driving influence is something more global and consistent in its impact. Similar efforts at using monitoring information over time can elucidate changes for less mobile species such as plants, invertebrates and amphibians (Walther et al. 2002).
Home Range Sizes
Resource availability is related to home range size for many species. Climate change quite likely will influence the dispersion or concentration of available food and cover resources for many species (McNab 1963). Therefore, monitoring home range sizes also constitutes a method for assessing ecological effects of climate change on some species.
Documenting the sizes of home ranges can be costly and estimates can suffer from low precision for a number of reasons (Borger et al. 2006). Estimating the effect size that could be detected (a power analysis would help determine this, Zielinski and Stauffer 1996), can allow a better understanding of the actual risks of losing species.
Some effects are obvious in the higher latitudes. As sea ice is lost and shifts in its locations, polar bears must extend their foraging bouts into new locations (Derocher et al. 2004). If the energy that they expend in foraging exceeds the energy they gain from catching prey then they will die. With polar bears and other species, expanding home range size can be an early warning indicator of decreased or dispersed resources availability and an indication that the species may be facing imminent population declines. Changes in home range sizes hence can be an important aspect of risk analysis. If home range sizes are expanding then risk of population decline is greater than if they are stable to contracting and changes in hope range size may be detectable prior to a decline in abundance.
Phenological Changes
Another early warning sign of impending impacts of climate change on populations are changes in the phenological patterns of plants and animals. Indeed, events such as the arrival at breeding or wintering sites from migrations, onset of flowering or other reproductive activities, leaf-out, or leaf fall function as indicators because they tend to be influenced at least in part by temperature (Parmesan 2007). Phenological studies have been conducted for years (e.g., Menzel 2000), but not on the global scale necessary for monitoring global climate change. Schwartz (1994) provided a discussion on the detection of large-scale changes using phenological information. He commented on how past efforts at recording phenological patterns have often been done at small scales, and then suggested that by integrating ground-based data collection with remotely-sensed data, local patterns can be appropriately scaled to ecoregions, continents and ideally the globe, allowing larger scale patterns to be inferred. White et al. (2005) proposed a global framework for monitoring phenological responses to climate change using remotely sensed data. If White et al.’s (2005) approach can be implemented effectively then the physical mechanisms responsible for observed patterns can be used to assess the effectiveness of global-scale models in predicting changes in phenological events (Schwartz 1994).
Habitat Structure and Composition
For some purposes, simply understanding changes in the availability of habitat for a species may be sufficient to infer likely changes in a species potential abundance or distribution. The devil is in the details however. For many species, knowledge of abundance and spatial arrangement of fine scale habitat elements such as large trees, snags, logs, or shrubs is important. But gathering this knowledge on a large scale can pose problems; satellite imagery will not detect many of these features. LIDAR or other remotely sensed data, however, can often provide information at a fine enough scale to detect habitat components (Hyde et al. 2006). LIDAR in particular can provide information on the fine-scale vertical complexity of a forest including canopy heights and canopy biomass (Hyde et al. 2006). For those species associated with vegetative layers in forests, remotely-sensed data may be useful. For species associated with dead wood or other habitat elements that are not detectable using remote techniques then combining remotely sensed data with ground plot data becomes the only logical approach. These fine scale habitat elements can be imputed to pixels from known locations of ground plots using nearest-neighbor techniques (Ohmann and Gregory 2002).
Synthesis of Monitoring Data
Monitoring data can be integrated with other information on terrain, climate, disturbance probabilities, land use, land ownership, and infrastructure to paint a generalized integrated picture of the state of a landscape. These approaches allow managers to monitor not only the individual pieces of the landscape but also the integrated whole over time. For instance, changes in the structure and composition of forest stands in Oregon with and without certain silvicultural practices can be incorporated into maps of forest age classes and habitat types (Spies et al. 2007). These can then be linked to models of forest growth and development (many of which are based on continuous forest inventory monitoring plots), and to transition probabilities associated with land management decisions, allowing projections of possible future conditions for planning purposes and to better understand the implications of possible changes in land use policy (Spies et al. 2007). Other approaches have not explicitly used vegetation growth models but have developed scenarios of past conditions, current conditions and likely alternative future conditions of landscapes (Baker et al. 2004). It is important to stress that these approaches not only use monitoring information to parameterize many of the spatial and temporal projections, but also to improve our understanding of possible future conditions. Indeed, it is the ability to use data to create models that allow projections of conditions into the future based on interacting stressors such as climate change (IPCC 2007) and land use planning (Kaiser et al. 1995). These model projections not only raise the potential for developing ‘what-if’ scenarios to compare alternative policies, but they can identify key parameters that should be monitored into the future to help stakeholders understand if the results of a policy change are being realized as projected. There are so many interacting assumptions that enter into these complex landscape projections that without monitoring data, the projections are at best a likely future condition and at worst an artifact of an incorrect assumption. Some practitioners also attempt to integrate ecological monitoring data with economic, social, and institutional information in order to create bodies of data that function as sustainability indicators. This has often been done for agricultural systems and for communities in developing countries but is expanding to include other regions, such as highly developed urban environments (Olewiler 2006, Van Cauwenbergh et al. 2007). Not all of these initiatives necessarily include the monitoring of populations or habitat, but many do. For instance, to assess the sustainability of the terrestrial resource use of communities in tropical ecosystems, several researchers have integrated wildlife monitoring and the mapping of hunting kill-sites with data regarding the use of other terrestrial resources, access to new technologies, and changing local land uses (Koster 2008, Parry et al. 2009). In the Sustainability Assessment of Farming and the Environment (SAFE) framework for developing a set of variables that indicate the sustainability of agro-ecosystems, variables that measure the retention of biodiversity and the “functional quality of habitats” are considered an integral component of the monitoring framework (Van Cauwenbergh et al. 2007). While monitoring wildlife and habitat is not explicitly discussed within the framework guidelines, it would be difficult to make such assessments without doing so. It is also important to realize that the concept of “sustainability indicators” and previous attempts at deriving them has its share of critics. Scerri and James (2009), for instance, discuss how many practitioners reduce the complex concept of sustainability and the generation of sustainability indicators that is likely context specific to a very technical, quantitative task.
PVA models typically compare the estimated risk of a species or population going extinct among several management alternatives. PVA models are notoriously data-hungry requiring age- or stage-specific estimates of survival, reproduction and movements with associated ranges of variability for each parameter estimate (Beissenger and Westphal 1998, Reed et al. 2002). As with projections of landscape models, monitoring aspects of PVA projections allow not only an assessment of risk associated with not achieving an expected result but also highlight the weaknesses in the model assumptions. Monitoring programs that inform the validity of assumptions can provide the opportunity for developing more reliable model structures and resulting projections. Deciding which assumptions or parameters to monitor based on a model structure can be problematic, especially with large complex models such as the two described above. Identification of variable to monitor may be based on subjective assessment of the reliability of the underlying data or through more structured sensitivity analyses that identify variables that have an over-riding influence on the model results (McCarthy et al. 1995, Fieldings and Bell 1997). Quite often the least reliable parameters in these models are those that are the most difficult to measure. This can create a dilemma for a program manager developing a monitoring program since these data may be the most important to lead to a decrease in uncertainty in future predictions but they may also be the most expensive to acquire. Hence a benefit:cost assessment will need to be made with stakeholders to develop a priority list of variables.
Despite the ability to develop more reliable estimates of key variables from monitoring data, projections into the future are always faced with the inability to predict unknown threshold events that would not have been foreseen at the outset. For instance, barred owl invasions into spotted owl habitat were not seriously considered as much of a threat as habitat loss when early PVAs for spotted owls were developed (Peterson and Robins 2003). And even when models can consider new or confounding variables, the inter-relationships among the variables can give rise to new states or processes that could not be foreseen.
Climates have always changed on this earth but the rate of change likely to be seen in the next century could be unprecedented. Changes in vegetative community structure and inter-specific relationships are likely to change, but their ability to adapt to changing climatic conditions is in question. Williams and Jackson (2007) provided an overview of no-analog plant communities associated with historic “novel” climates and future novel climates which are likely to be warmer than any present. Ecological models such as forest dynamics models and PVA models are at least partially parameterized from relatively recently collected data, so they may not accurately predict responses to novel climates (Williams and Jackson 2007). The uncertainty raised by the potential development of no-analog conditions must be explicitly considered during risk analyses.
Risk Analysis
Risk analyses have been formally developed with regards to direct and indirect effects of pollutants on wildlife species. The Environmental Protection Agency defines Ecological Risk Assessment (ERA) as, “an evaluation of the potential adverse effects that human activities have on the living organisms that make up ecosystems. The risk assessment process provides a way to develop, organize and present scientific information so that it is relevant to environmental decisions. When conducted for a particular place such as a watershed, the ERA process can be used to identify vulnerable and valued resources, prioritize data collection activity, and link human activities to their potential effects. ERA results provide a basis for comparing different management options, enabling decision-makers and the public to make better informed decisions about the management of ecological resources”(http://epa.gov/superfund/programs/nrd/era.htm). The steps used by the EPA are outlined in Figure 13.4, and could be adapted for use in other situations where risks from other environmental stressors or disturbances may be of key importance to managers (e.g., fires, land use, floods, etc.). For instance, Hull and Swanson (2006) provided a stepwise process for assessing risk to wildlife species from exposure to pollutants. Similar approaches have been proposed to assess risk to loss of biodiversity. Kerns and Ager (2007) described risk assessment as a procedure to assess threats and understand uncertainty by “…providing: (1) an estimation of the likelihood and severity of species, population, or habitat loss or gain, (2) a better understanding of the potential tradeoffs associated with management activities, and (3) tangible socioeconomic integration.” They proposed a quantitative and probabilistic risk assessment to provide a bridge between planning and policy that includes stakeholder involvement (Kerns and Ager 2007). Such formal approaches are needed within ecological planning processes if both managers and stakeholders are to understand uncertainty, and the costs associated with the risks of not achieving the intended results.
Decision Making
From a logical standpoint, decisions should be made using a sequence of steps: characterize the problem or question, identify a full range of alternatives and determine
criteria for selecting one, collect information about each option and rate it on the criteria, then make the final decision based on the rating (Lach and Duncan 2007). But Klein (2001) found that only 5% of all decisions are made using such a logical approach. Individuals often make their decisions using intuition and mental simulations (quickly relating the outcome of a decision to some experience) (Lach and Duncan 2007). Groups may make decisions differently and groups are better able to make better decisions on complex problems than individuals (Lach and Duncan 2007). People with different world views structure the world around them in different ways and in so doing bring a different perspective to a group decision. Ensuring that a range of world views is represented in a group can be particularly useful when trying to reach a balanced decision on a complex issue, though discussions needed to reach that decision may necessarily become protracted.
Summary
Considerable time and money are invested in many monitoring programs so not only must the design of these programs be scientifically and statistically rigorous, it must be clear to the managers and stakeholders how the information will be used to make decisions. During the design phase, trigger points or thresholds should be identified to ensure that managers know when changes in management approaches should be considered. In many circumstances it is easy for managers to simply wait for more information without taking an action, not realizing that waiting places greater risk on achievement of desired outcomes. Using monitoring data as the basis for forecasting trends over space and time can allow managers to understand the implications of waiting too long before taking remedial actions. Factors such as changes in climatic characteristics, phenology, geographic ranges, and home range sizes of some species can be particularly informative in the face of global changes to climate for which the only reference condition is the past. Using monitoring information as a means of parameterizing models of landscape or climate change allows projections over space and times of more complex conditions. Such integrative approaches further allow comparisons among alternative management strategies or policies and can be an important component of a risk analysis, a formalized approach to identifying uncertainties and assessing direct and indirect effects of stresses on organisms and ecosystems. The results of monitoring, modeling and risk analysis are then used to make decisions by individuals or by groups. Although we typically assume that decisions are made in a logical manner many decisions are made based on intuition or as the result of group discussions among people with various world views. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.13%3A_Uses_of_the_Data-_Synthesis_Risk_Assessment_and_Decision_Making.txt |
Despite the best efforts at designing a monitoring plan, it is nearly inevitable that changes will be made to the monitoring strategy sooner or later. Indeed, if monitoring data are used as intended in an adaptive management framework, the information gained should be used to refine the monitoring approach and improve the quality and utility of the data that are collected (Vora 1997). Marsh and Trenham (2008) summarized 311 surveys sent to individuals involved with monitoring programs in North America and Europe and estimated that 37% of the programs made changes to the overall design of the monitoring program at least once and that data collection techniques changed in 34% of these programs. Adding novel variables to measure is also often incorporated into monitoring programs as information reveals new, perhaps more highly valued, patterns and processes. Another change, dropping variables, oftentimes must accompany these additions simply due to increased costs associated with measuring more things. And clearly the vagaries of budget cycles can cause variables to be dropped for one or more monitoring cycles and then re-added if budgets improve. But changes to monitoring programs can result in some or all of the data collected to date being incompatible with data collected after a change is made. Increased precision in data collection is always a goal, but if data are collected with two levels of precision over two periods of time, then pooling the data becomes problematic. Similarly, changing the locations or periodicity of sampling can lead to discontinuities in the data; this makes analyses more challenging. Given these concerns, changing a monitoring program should not be done lightly and is a process that necessitates as much preparation as establishing the initial monitoring plan. Despite this, there is remarkably little information available to inform monitoring program managers when they consider changing approaches within their program.
General Precautions to Changing Methodology
In light of the paucity of references, it is important to carefully consider those that do exist. For instance, Shapiro and Swain (1983) noticed the enormous impact a change in methodology had on data analysis in a monitoring program involving water quality in Lake Michigan. Indeed, the apparent decline in silica concentration between 1926 and 1962 was an artifact of having changed methods and not a result of increased phosphorus loads as had been reported prior to their work (Shapiro and Swain 1983). Strayer et al. (1986) described this classic example of the dangers associated with changing methodology during a monitoring program further and used the experience to suggest several general precautions to take when changing methodology in the middle of a long-term monitoring program.
1. Calibrate the new methods against the old methods for a sufficient period of time.
2. Maintain a permanent detained record of all protocols used
3. Archive reference samples of materials collected in the field where appropriate. Voucher specimens, soil or water samples, and similar materials should be safely and securely archived for future reference. Consider collecting hair, feather, scale or other tissues form animals for future DNA analyses.
4. Change methods as infrequently as possible.
When to Make a Change
Although alterations should certainly be minimized, there will be instances in which a change will make monitoring more valuable than maintaining the original design. There will also be instances in which changes are unavoidable due to data deficiencies or stakeholder desires. Changes made to the design, in the variables measured, in the sampling techniques or locations, in the precision of the samples, or in the frequency of sampling are all potentially helpful. Yet they also all have the potential to detract from a monitoring program in unique and powerful ways. Determining when or if to change your program, therefore, can be a difficult task. So, when should a monitoring program be changed? The following examples describe some potentially appropriate or necessary scenarios, but it is important to keep in mind that all potential changes merit careful consideration
Changing the Design
The initial stages of a monitoring program result in a series of data points and associated confidence intervals that describe a trend over space or time. Once that trend is established, new questions often emerge or, as new techniques are developed that are more useful or precise, a change in the design might be warranted. For example, the pattern observed in Figure 14.1 represents a positive trend, but the precision of the estimates may come into question since the data in time periods 4, 5 and 6 reflect a plateau. This realization leads to a number of questions that would undermine the monitoring program if left unanswered: Is this plateau real or a function of imprecise data collection? Are other variables such as fecundity or survival better indicators of population response than simply population sizes? If a change in design can answer these questions and make data more useful, and staying the course cannot, managers and stakeholders may decide that it is time to make some changes even after only 5 years of data collection.
Changing the Variables that are Measured
Changing the variables measured may be considered for a number of reasons, but should be undertaken prudently because it can set a monitoring program back to the very beginning. One legitimate reason to change the variables, however, is a failure to meet the goals and objectives of the project or a sudden change in the desires of stakeholders. If goals and objectives are not being met by the data being collected, it is obvious that changes must be made. In such a case, data collected to date may still be very useful to decision makers. These data may help to inform decisions made regarding how the changes ought to be made (altering variables measured or intensity of sampling). Using data in post-hoc power analyses has also become quite popular when trying to understand why a significant trend was not observed, but the logic behind post-hoc power analysis has been considered inherently flawed by some authors because the point of power analysis is to ensure during the design phase of a project that if a trend is real then there is an ‘x’ percent chance that it can be detected (Hoenig and Heisey 2001). Data analyses that include confidence intervals on parameter estimates are particularly useful in understanding the deficiencies of the underlying data and informing decisions regarding what changes to make and how and when to make them. This is especially true when failure to reject a null hypothesis (e.g., unable to detect a trend) could be erroneous and jeopardize a population.
Once the data have been analyzed, and the uncertainty associated with parameter estimates is understood, then all stakeholders can be informed about the changes that could be made in the monitoring plan to better meet their goals and objectives and then ensure that they are involved in the decision-making process.
Returning to our example, (Figure 14.1), positive trends may be encouraging, but if the data are needed to describe the degree of recovery and potential delisting under the Endangered Species Act, then stakeholders likely would suggest that population parameters describing reproductive rates and survival rates may also need to be measured. In this case, an entirely new monitoring program may be added to the populations monitoring program or monitoring of demographic parameters may simply be added to the existing protocol. Alternatively, sampling animal abundance may even be dropped and replaced with estimates of animal demographics, and hence truncating the continued understanding of population trends. The extent and form the changes take will depend on budgets, logistics, and stakeholder support and will ultimately be determined by assessing the potential costs associated with change relative to the perceived benefits and opinions of the stakeholders and funders.
Changing the Sampling Techniques
As new techniques become available that provide more precise or more accurate estimates of animal numbers, habitat availability or demographic parameters, the tendency is to use the new methods in place of less precise or less accurate methods used to date. This can also be a very appropriate scenario in which to change a monitoring program, but should be undertaken with a controlled approach if at all possible.
What does this entail? Consider the pattern in Figure 14.2a. Changing techniques in year 5 results in a higher R2 and an abrupt change in population estimates. Because changes over time are confounded with changes in techniques, we cannot be sure if the observed trend line is real or an artifact of the changes in techniques.
Using a more controlled approach by making the change to the new technique in year 5 but also continuing to use the old technique as well for years 5-9, however, has the potential to inform managers of the effect due to technique change (Sutherland 1996). This is especially true if a statistical relationship (regression) between the data collected using both techniques allows the managers to standardize the data points for years 0-4 (Figure 14.2b). Such an approach requires extrapolation to years where only one technique was used (not both), and such extrapolations are accompanied by confidence intervals that describe the uncertainty in the data.
This more controlled process has been taken by others and led to informed, helpful changes to already established monitoring programs (Buckland et al. 2005). When the Common Bird Census (CBC) in the United Kingdom were established, the proposed techniques were state of the art. Over time however the methods were questioned and increasingly viewed as obsolete. Despite these concerns, the flawed methods were still used due to a fear of that any change would undermine the value of the long time series (Buckland et al. 2005). Eventually it became obvious that changing the methods had the potential to rectify the problem of misleading and unhelpful data and was therefore necessary. The British Trust for Ornithology decided to replace the CBC with a Breeding Bird Survey (BBS) in the United Kingdom that was similar to the North American BBS. Yet they also decided to conduct both approaches simultaneously for several years to allow calibration of CBC data to BBS data to provide a bridge in understanding how the results from one technique was associated with another which then allowed them to move to the BBS approach (Buckland et al. 2005). Strayer (1986) also advised employing new and old techniques simultaneously for a calibration period when changing techniques.
Changing the Sampling Locations
Changing the sampling locations over time can introduce variability into the data that may make detections of patterns difficult or impossible and many practitioners would therefore be very hesitant to do so. Nonetheless, in several cases it may be required for monitoring to be meaningful. First, not changing sampling location in environments that change more rapidly than the populations that are being monitored will confound data so much that analysis may be impossible unless the location is changed. Consider sampling beach mice on coastal dune environments. If a grid of sample sites are established and animals are trapped and marked year after year, the trap stations may become submerged as the dune location shifts over time. Similar problems arise when sampling riparian systems. Moving the sampling locations is required in these instances. In order to reduce the variance introduced into the sample by continually changing locations, stratification of sampling sites based on topographic features or (if necessary) vegetation structure or composition can help to reduce variability. Nonetheless such stratification will not entirely compensate for increases in variability due to changing sampling locations. It is important to keep this in mind at the outset of a monitoring program designed to sample organisms in dynamic ecosystems. Unless the variability in samples due to changing locations is considered during experimental design, it is possible, and indeed likely, that the statistical power estimated from a pilot study that does not sample new places each year will be inadequate to detect patterns. The pilot study should explicitly consider the variability associated with changing sampling locations from year to year.
The second case in which the sampling location may warrant a change is due to a deficient or misleading pilot study and involves a one-time alteration. While organisms may behave according to certain trends over time or space, one can never be certain that the data from a pilot study embodies those trends. To be more specific, if the goal of a monitoring program is to collect data on a particular population of a particular organism, it is likely necessary to choose a sampling location that either constitutes or is embedded within the home range of that population. A pilot survey is therefore necessary to choose the location. Yet, as organisms are normally not physically restricted to their home range, it is possible that survey data from a pilot study could suggest a sampling location that is hardly ever frequented by the focal species. This may be particularly likely for wide-ranging species such as the white-lipped peccary. Given this species’ tendency to travel in herds of several hundred animals over an enormous area, the presence of individuals or of sign at one point in time, even if abundant, may not be a good indication of the frequency with which a location is used (Emmons and Feer 1997). If the sampling location chosen inhibits the collection of the desired population parameters, an alteration to the sampling location is necessary.
Changing the Precision of the Samples
Despite having collected pilot data and designed a monitoring protocol to detect a given rate of change in a population, unexpected sources of variability may arise (human disturbances, climate, etc.) that reduce your ability to detect a trend. Increasing sample size or reducing sampling error can lead to more precise estimates as illustrated in Figure 14.3 after year 5. After making this change the fit of the line to the points is considerably tighter and the variance about the points is considerably less, leading to greater assurance that the population is indeed increasing. Such changes increase the R2 somewhat (0.74 to 0.78) but the R2 rose from 0.58 for the first 5 years to 0.99 during the second 5 years after improving precision.
But given the risks of altering a monitoring program, is it worth making a change just to increase precision? At what level is an increase in precision worth the risks of making a change? There is no simple answer to these questions; the program managers and stakeholders would need to decide if the added costs associated with increasing precision are worth the increased level of certainty associated with the trend estimates.
Changing the Frequency of Sampling
Given constraints on time, money and people, a decision might have to be made to reduce the level of effort associated with monitoring. Consider the trend in Figure 14.4 where the trend over the first 5 years was positive (R2 = 0.58). In this case, program managers and stakeholders might agree that given the slope of the line there is little need to be concerned about this population, but that they want to continue some level of monitoring to ensure that the population does not begin to decline in the future. They may decide to reduce the frequency with which monitoring is conducted to every other year with the agreement that should there be more than 2 consecutive samples showing a decline that they would then revert back to annual sampling.
Such an approach should not be taken lightly, however. For instance, in our example, the reduced sampling did continue to demonstrate continual increases in abundance, but the R2 associated with the trend declined. Such a decline in explanatory power may not be particularly important to the stakeholders so long as the population is increasing, but the level of certainty in that trend should also be valuable information to certain stakeholders and therefore carefully considered before making the change. It is also necessary to consider that high precision now may be important for the future. Should the population show declines over time, maintaining the sampling frequency and the high precision of the estimates now may facilitate future management decisions. Changes such as these come at a cost in certainty, money, and time and truly must be made prudently.
Logistical Issues With Altering Monitoring Programs
One other key component of prudently changing a monitoring program is that the program manager consider the logistical constraints associated with those changes. Training personnel in new techniques requires added time prior to the field sampling season. Where data standardization is necessary then collecting data using both the old and the new techniques adds considerable time and effort to field sampling. Changing locations may mean re-establishing sampling points and recording new GPS locations.
Changing variables that will be measured may require new equipment, additional travel, or different sampling periods. For example, sampling survival of post-fledging birds will require different techniques, sampling strategies, and sampling times than estimating abundance of adults from variable circular plot data. These new logistical constraints will need to be evaluated relative to the societal and scientific value of the monitoring program to determine if the making the changes is a tenable endeavor.
Economic Issuess With Altering Monitoring Programs
Changing monitoring programs in any way usually results in at least an initial expenditure of funds for equipment, travel, or training. It is thus important to address the economic questions of whether the change will result in increased costs, and if so, are the new data worth the increases in costs. This clearly must be done prior to making the change.
Keep in mind that a modest increase now will tend to compound itself over time, especially in the case of added per-diems or salaries for new staff, which must be iteratively increased to reflect cost of living trends, or added fuel consumption, which will almost certainly bring increasing costs over time due to rising fuel prices. A simple cost:benefit analysis is a useful way to estimate the marginal increases (or decreases) in costs associated with alternative changes in the monitoring program. The ultimate question that must be addressed is, “Where will you be getting the best information at the least cost and still stay within your budget”?
Terminating the Monitoring Program
The decision to terminate a monitoring program is probably the most difficult decision that a program manager can make. Obviously you end a program when you have answered the questions associated with your goals and objectives, correct? But how do you know when that is?
Consider the information in Figure 14.1. It seems quite obvious that the population is increasing. What if we extended the monitoring program another 4-5 years? Perhaps we would see the population approach an asymptote, which we would expect if a carrying capacity was reached (Figure 14.5). At this point, if the monitoring program was established to determine when and if a certain population target was attained, it would be logical to terminate the monitoring program; or if any monitoring was to be continued, it would be appropriate to only maintain it at a minimal level and a low cost.
Alternatively, if the data showed a different trend, such as a decline (Figure 14.6), it would be unwise to assume that the population was increasing or even remaining stable. The decline in population during the last 5 years could simply be due to chance, or to a population cycle, or to some biophysical factor leading to a true long-term decline. Unless comparable data had been collected on reference sites, we would not know if this pattern is likely a cyclic population or if a local event had occurred that would lead to a continued decline. In this case, key questions have not been answered, the goals and objectives of the monitoring program have not been attained, and there is a strong argument for the continuation of monitoring.
Summary
Changing a monitoring program is done frequently and has significant consequences with regards to the utility of the data, costs, and logistics. If the data that are collected and analyzed suggest that the goals and objectives are not being met adequately as determined by program management and stakeholders, then revisions in the protocol will be required. Adding or deleting variables, altering the frequency of data collecting, altering sample sizes or changing techniques to increase precision can all improve a monitoring program and help to meet goals and objectives more comprehensively. Yet all of these changes can also lead to changes in costs, in power to detect trends, or other patterns, thus any potential alteration to a monitoring program must be carefully considered. | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.14%3A_Changing_the_Monitoring_Approach.txt |
Our world is a dynamic place. This constant, change, has myriad manifestations, some of which we view as negatively impacting on us and others as positively impacting on us. It should come as no surprise, therefore, that monitoring these changes to understand and prepare for their implications is not a novel endeavor, but a human enterprise that has undergone a long evolutionary process.
Perhaps the earliest form of what we would consider statistically based monitoring arose around the turn of the 17th century in the midst of the worst years of the plague. During this time, the lord mayor of London mandated that parish clerks compile “bills of mortality” to keep track of the ravages of the disease (Mlodinow 2008). From this monitoring data, a man by the name of John Graunt not only created the first life table, but also reached several groundbreaking conclusions about the prevalence and utility of the normal distribution (Mlodinow 2008). Over time as our values have shifted and we have been forced to confront distinct changes and challenges in our environment, the targets of monitoring have expanded. We still monitor human health, of course, but now also monitor the economy, our education systems, technological advances, and wildlife and their habitat.
The latter has been the topic of this book and we have attempted to provide a fairly consummate and practical overview of the current state of monitoring wildlife and their habitat. We are not the first group to have tackled this topic, neither was the author before us, nor the author before that publication, nor the one before that; indeed, every few years a new monitoring book is published to concisely update practitioners, researchers, and interested parties of the developments in the field. In other words, just like monitoring in a general sense, the monitoring of wildlife and habitat has undergone a long process of evolution that continues unabated even today. In fact, we are currently living in a time during which climate change, the state of international politics, and rapid scientific and technological advancement make the number of changes in our environment and the rate at which they occur astonishing. Thus, over the past thirty years, ecological monitoring and ecology in a more general sense have developed at a particularly impressive pace and incorporated a number of novel monitoring methods and mathematical ways of thinking (Moore et al. 2009).
So given these historical precedents and the volatility of our reality, where is the field headed? What techniques, technology, and mathematics are going to usurp those popular amongst today’s scientists? Will there be any changes in how monitoring data are applied? In this final chapter, we attempt to tackle some of these difficult questions and provide our interpretation of what the indicators of the present might mean for the future of monitoring.
Emerging Technologies
Genetic Monitoring
Monitoring populations over time through the use of genetic analyses is not necessarily a cutting-edge idea, but the increasing affordability and precision of testing DNA, along with the increasing prevalence of fully sequenced genomes, are slowly creating a more practical, defensible, and widely used system for monitoring animal populations (Schwartz et al. 2006). Increased use frequently begets increased innovation and this certainly appears to be the case with genetic monitoring.
Schwartz et al. (2006) discuss the field as having two distinct approaches. The first is to undertake diagnostic assays in order to identify “individuals, populations, species and other taxonomic levels” (Schwartz et al. 2006). Data generated from iteratively sampling DNA and undertaking such assays for a population can be used in traditional population models estimating abundance or vital rates. In comparison with many traditional Capture-Mark-Recapture (CMR) techniques, this can be done in a relatively non-invasive manner (i.e. through using hair from hair snares or fecal samples) and may help to both reduce biases associated with capturing animals and to resolve the controversy and difficulty of capturing rare and elusive species. Diagnostic assays may also prove increasingly helpful in the monitoring of species’ range shifts and rates of hybridization as alterations in habitat and forced migration due to anthropogenic changes such as urban sprawl and climate change become more acute (Schwartz et al. 2006).
The second approach uses the monitoring of population genetic metrics such as effective population size, changes in allele frequencies, or estimates of changes to genetic diversity based on expected genetic heterozygosity, as indicators of more traditional population metrics (Schwartz et al. 2006). This approach will be particularly helpful if evolutionary principles can be reliably correlated to population dynamics such that inferences can be made about wild populations. For instance, think of the implications of being able to defensibly compare characteristics of DNA extracted from museum specimens with the DNA of wild specimens; this would allow retrospective monitoring and, potentially retrospective BACI experimental designs.
There are many other exciting potential applications of genetic monitoring. As a recent example, researchers used genetic analysis to estimate the population density and distribution of grizzly bears in and around Glacier National Park (Kendall et al. 2008, Kendall et al. 2009). Hair samples were collected through two sampling methods including systematically distributed, baited, barbed-wire hair traps and unbaited bear rub trees found along trails. The researchers estimated there was an average number of over 240 bears in the study area resulting in a density of 30/bears/1,000 km2. These non-invasive genetic methods provided critical baseline information for managing one of the few remaining populations of grizzlies in the contiguous United States, and holds promise for monitoring other large mammals through similar methods (Kendall and McKelvey 2008).
Genetic information could provide state wildlife agencies with an abundance of new information on how hunters are affecting game populations over time. This could allow them to more carefully regulate hunting in a way that maintains more genetically diverse and economically desirable populations. Using DNA analyses to monitor mixed-species fish stocks (i.e. some species of salmon), bird flocks (i.e. black ducks vs. mallard ducks), or mammal populations (i.e. New England cottontail vs. Eastern cottontail) that include rare and common species that are difficult to differentiate from one another but are nonetheless harvested due to their economic value could also lead to improved hunting regulations. Indeed, DNA analyses could provide insight into temporal or spatial patterns that are unique to each species, which could serve as a basis for more specific harvest regulations that effectively conserve the rare species. A similar approach has been effective with sockeye salmon in British Columbia (Beacham et al. 2004).
Kilpatrick et al. (2006) used DNA analyses to monitor the blood inside mosquitoes and were able to correlate a shift in feeding behavior from birds to mammals with patterns in West Nile virus outbreaks in North America. Using a genetic monitoring approach to other zoonotic diseases has enormous potential, especially if recent upward trends in urban wildlife populations and the transmission of their diseases to urban citizens are substantiated (Tsukada et al. 2000). Finally, the application of evolutionary principles to genetic monitoring in a general sense will almost certainly provide invaluable insights into how we manage and conserve populations and their habitat.
Despite the enormous potential, there are still a number of limitations to the use of DNA in monitoring. These range from the additional expense of iteratively undertaking DNA assays, the ease with which fraudulent samples can be inserted into the collected data, the prevalence and implications of genotyping errors on any inferences derived from monitoring, and a lack of powerful statistical tools to assess genetic metrics (Schwartz et al. 2006). Yet as additional research is undertaken and more sophisticated simulation software that models these metrics is derived, genetic monitoring will almost certainly help us to carry out wildlife and habitat monitoring more comprehensively.
Monitoring Environmental Change with Remote Sensing
Regardless of one’s personal opinions or conclusions concerning climate change, that its current and potential impact on our world is an increasing societal, political, and economic concern is undeniable. Further, the science linking climate change to inflated atmospheric levels of greenhouse gases is incontrovertible (IPCC 2007). In light of this, many governments and environmental organizations have either mandated or proposed tighter restrictions on society’s CO2 emissions via cap and trade systems, carbon taxes, stricter automobile regulations, or international treaties (Stavins 2008). As discussed in the Introduction to this textbook, these governments and organizations are going to want to know if the money spent designing and implementing these strategies to curb emissions is attaining their objectives. An increase in the monitoring of CO2 emissions in terms of prevalence and strategies, therefore, can only be expected.
One of the most recent innovations involves the use of satellite technology designed specifically for this purpose. In 2009, the Japanese government launched the Greenhouse Gases Observing Satellite (GOSAT), which is expected to collect useful data on global patterns of greenhouse gas emissions (GOSAT Project 2008). A similar U.S. initiative ended in failure (the satellite went into the ocean rather than space), but it seems likely that further efforts will be undertaken (Morales 2009).
Directly related to CO2 emissions is the carbon sequestration capacity of forests. This has historically been monitored to assess the impacts of deforestation on atmospheric CO2 levels, but also represents a way to monitor a locale’s contributions to mitigating carbon emissions through conservation and a means to generate data to justify programs to pay for this ecological service. The traditional approach is to undertake limited destructive harvesting in order to measure the capacity of individual trees to store carbon, carry out a ground-based forest inventory, and then use these two sets of data in conjunction with one another to make inferences about an entire forest’s, region’s, or country’s carbon sequestration capacity (Gibbs et al. 2007). Yet given that forest inventories are almost always local in extent by necessity, and that small changes in a tree’s characteristics may translate into large changes in carbon sequestration capacity, this approach is rife with potential biases. Although techniques to reduce them based on empirical studies of soils, topography, or climate have been advanced, extrapolating these local data across larger scales can still be tenuous (Gibbs et al. 2007). This has resulted in efforts to more effectively utilize remotely sensed data, which allows for the collection of information specific to each individual habitat type across a region. The typical approach to derive estimates for a forest’s capacity to sequester carbon with remotely sensed data is to measure proxies, such as all individual tree heights and crown diameters, and then apply allometric relationships between these proxies and carbon sequestration generated from ground-based studies (Gibbs et al. 2007). Nonetheless, this approach is also vulnerable to several biases and the reliability of such remotely sensed data in dense forests, such as many of those in the tropics, is questionable (Gibbs et al. 2007). Thus, despite significant advances, especially with the use of Radar sensors and light detection and ranging systems (LiDAR), significant work remains to be done before a comprehensively reliable system is created.
Such advances regarding the monitoring of carbon sequestration, as well as more general advances regarding the monitoring of greenhouse gas emissions in terms of sampling techniques and methods of analyzing data that is global in its extent should be expected. If the monitoring of climate change continues to reveal the enormous importance of the ocean in mitigating the impacts of this global phenomenon, we may also see the design of a rigorous system to measure and monitor the ocean’s capabilities as a carbon sink.
Advances in Community Monitoring and the Internet
If, as indicated in Chapter 3, community-monitoring becomes even more prevalent than it currently is, it is likely that monitoring techniques designed to attain a high degree of scientific rigor in the hands of the public as well as capture and keep the attention of non-scientists will become even more common. Many such community-oriented innovations to date have simply been variations of time-tested monitoring approaches such as avian syrveys (e.g. atlases) or simplified tools to measure a river’s nitrate and phosphate levels. There are also a number of efforts underway to increase the rigor of techniques historically popular amongst citizens, yet frowned upon by scientists. For instance, track-based monitoring has become increasingly adapted in recent years as sign, such as black bear bites and claw marks on trees, has been incorporated into designs previously based solely on track and scat counts (S. Morse, pers. comm.). Such efforts to include indicators that can withstand precipitation and are not as strongly impacted by variations in substrate reduce the potential for certain biases that have always plagued tracking techniques.
Several entirely novel innovations have come about with increases in the public availability of satellite imagery, increasing internet access, and the ease with which many citizens can now undertake sophisticated mapping exercises. For instance, the Green Map System enables citizens to create maps of their hometowns and insert data indicating the area’s most sustainable options for visitors and citizens alike (Green Map). Open source style maps on the system’s website allow users to monitor changes in these locales on the ground and update maps when needed. These projects are akin to the monitoring of communities by communities, and researchers have only begun to scratch the surface of using social networking internet sites (e.g., Facebook) for community-based monitoring projects.
The internet will continue to allow communities to monitor their own natural resources and local animal populations in novel and exciting ways. As Google Maps, Google Earth, and Google Oceans are refined, more of these interactive, democratic community-monitoring and mapping projects will likely evolve in unexpected ways. The participatory monitoring of wildlife populations and their habitats in a public forum is one way for humankind to conceptualize and rigorously keep abreast of our impacts on the ecosystems in which we are embedded and the enormous scale on which they act.
A New Conceptual Framework for Monitoring
Although the monitoring of wildlife and their habitat and the particular scientific theories that inform it draw heavily from current ideas in ecology, there is also a clear disconnect between ecologists in academia and many who design and implement monitoring programs. Indeed, there tends to be a time lag between the implementation of new ideas in strict ecological research and the subsequent implementation of those ideas in ecological monitoring and management. This is likely due to the conflict between the inevitable uncertainty and theoretical basis of many new concepts in ecology and the need for land managers and practitioners carrying out monitoring to be confident in their protocols and to accomplish specific objectives that are planned far in advance (Moore et al 2009). To put it simply, land managers and those given a mandate to monitor often have to minimize the risk involved with their projects to maximize their job security. Given this relationship between ecological thinking and monitoring and management, will the key concepts in contemporary ecological thinking manifest themselves in the world of monitoring wildlife and their habitat? If so, how?
A Reflection on Ecological Thinking
Moore et al (2009) undertook a Delphi study using a panel of professional ecologists to determine where those concepts currently stand. The most unanimously agreed upon ideas were that:
1. Disturbances are extremely prevalent and historically contingent phenomena that can impact ecosystems,
2. Considering multiple levels and how each impacts on the ecosystem and on one another is integral to understanding an ecosystem, and finally,
3. Simple biodiversity is a poor measure and functional diversity is largely what determines the future characteristics of the ecosystem (Moore et al 2009).
These ideas, particularly the concept of ecosystems changing via disturbance and consisting of multiple levels, have supported a strong movement toward conceptualizing ecosystems as complex, dynamic, open systems rather than the more parochial views of the past (Moore et al 2009).
There is, of course, no means of telling how or if these concepts will be involved in future monitoring programs. However, if not only ecological thinking, but also contemporary societal values are taken into account, it seems likely that many of these ideas will be integrated into ecological monitoring. In a general sense, contemporary societal values relative to wildlife and their habitats are increasing in complexity due to the global scale on which our current environmental crises and issues act. Global climate change, the globalization of our economy, and an increasing desire to buy “green” products has citizens more carefully monitoring how their everyday behaviors impact on the global environment. In other words, citizens are beginning to incorporate many of the ecological science ideas discussed by Moore et al (2009) in their lives. For instance, citizens have begun to display the belief that the actions that cause disturbances today will partially determine the state of the ecosystem in the future. Indeed, many strive to emit less CO2 under the assumption that it will make for a more agreeable global climate with fewer health complications in the future (Fay Cortez and Morales 2009, Terrapass 2009). Also, citizens are behaving in ways that display a belief that an ecosystem is impacted by several different interacting levels; there is a strong movement, for example, to buy “green” products that advertise how their producers support conservation elsewhere (UPFRONT 2009). There is a consumer movement based on the idea that environmentally friendly producers in a particular locale can be supported by broader economic activity and that the interaction of and activity on both levels impacts the environment. There is also a strong movement to eradicate invasive species based on the assumption that native species are more ecologically healthy and support higher diversity than invasive species (Ruiz and Carlton 2003). Finally, the breadth of these conservation activities, which occur in the grocery market, the gas station, and the local farm, indicate that citizens are implementing, whether consciously or not, a more systems-based approach to the global environment. Conservation and preservation are no longer defined by fencing off protected areas and strictly regulating access and use, but by a variety of consumer behaviors, personal decisions, and lifestyle changes.
Given that both ecologists and citizen behaviors and beliefs, which are driven by their values, are largely congruous, and that these are important determinants of the current state of monitoring wildlife and their habitats, it seems highly likely that monitoring will also begin to exhibit similar trends. This means that a more systems-based approach to monitoring may become prevalent. Such approaches monitor indicators at different scales and levels and seeks to integrate not simply components of the local ecosystem, but a broader ecosystem that involves the impacts of human beings on several levels. The typical scale of monitoring may become even larger given widespread concern about global warming and the shifts in flora and fauna that it will cause.
To be sure, monitoring has already exhibited some of these trends. The Breeding Bird Atlas and TRANSECT programs, for instance, have very large geographical scopes. Project BudBurst, albeit designed for younger students, enlists citizens across the United States to monitor the phenophases of their local plants over time, which they hope will create an informative series of maps that describe trends in plant growth that can be compared with climate data to look for correlations (Project Budburst 2009). Further, as indicated earlier in this chapter, the indicators that wildlife and habitat monitoring programs utilize and the manner in which they do so are expanding. This includes looking at novel indicators on a small scale (DNA) to those on a larger scale (CO2 emission). If a systems-based approach becomes the norm, monitoring programs that include a variety of both new and old techniques that all address different levels impacting a locale may become the norm.
Dealing with Complexity and Uncertainty
The likely transition of ecological monitoring to a more holistic endeavor that seeks to track changes in multiple animal populations and ecosystems will undoubtedly have a number of analytical challenges in the future. As has been discussed throughout this book, natural systems and populations are dynamic and complex. This complexity changes over time, and in an unpredictable fashion, yet scientists are expected to make predictions of these systems based on the data they collect and their management actions. This is the ultimate moving target in a system full of uncertainty.
Recently, ecologists have turned to advanced mathematics and statistics to aid them in dealing with this dynamic uncertainty. As an example, Chades et al. (2008) proposed partially observable Markov decision processes (POMDP) as an approach for placing resource allocation and monitoring decisions into an objective decision-making process. The authors model three possible scenarios regarding the management of the Sumatran tiger within the Kerinci Seblat region including population management, population surveys to assess whether it is still extant in the region, or cease all conservation efforts and focus resources elsewhere (Chades et al. 2008). The approach identifies which approach should be made each year, for a series of years, given the current belief about the state of the population (extinct or extant). The POMDP approach has several advantages to decision-making in monitoring and may have much to offer population monitoring and adaptive management in the future (MacKenzie 2009). What is becoming increasingly clear, however, is that the monitoring of animal populations and their habitats will rely on quantitative and statistical advancements for dealing with uncertainty. This poses a significant problem for many ecologists and managers who are not professionally trained in advanced statistics or computational mathematics, but are responsible for studying and managing natural resources. Consequently, the future of monitoring may involve non-traditional collaborations between ecologists, managers, computational scientists, and statisticians. As an example, Computational Sustainability is an emerging field that aims to apply techniques from computer science, information science, operations research, applied mathematics, and statistics for balancing environmental, economic, and societal needs for sustainable development. This field promises to have a major influence in ecological research and monitoring in the near future and in the development of computational and mathematical models for decision making in natural resources management. The advantage of these types of collaborations and approaches is that it often involves combinatorial decisions for the management of highly dynamic and uncertain environments. The first annual conference in Computation Sustainability was held in June 2009 at Cornell University and brought together over 200 computer scientists, applied mathematicians, statisticians, biologists, environmental scientists, biological and environmental engineers, and economists. The future of monitoring and predicting complex ecological systems may very well depend on these types of partnerships.
Summary
Monitoring is a process of gaining in formation and revising approaches to management based on the information gained. This book and others like it have been and will continue to be a part of the monitoring process. Recent approaches that show considerable promise for expansion and proliferation in use among monitoring processes are DNA approaches, community monitoring systems, and systems-based frameworks for collecting and synthesizing monitoring data. Open source monitoring frameworks allow direct input and utilization of monitoring data on that benefits many stakeholders simultaneously and allow many minds to contribute solutions to complex problems based on the data available.
Analytical approaches also will have to adapt to these changing systems to allow rigorous analysis of a steady flow of incoming data so that stakeholders can interpret results to address their goals and objectives. Results will need to directly quantify uncertainty, and they will need to be easily synthesized into systems based projections of current and likely future conditions. Synthetic approaches must extend beyond biologists and ecologists to economists, social scientists, and mathematicians, among others, to build team approaches to addressing the complex challenges facing wildlife populations and the habitats on which they survive.
02: Appendix 1. Scientific names of species mentioned in the text
Common Name Scientific name
Plants
common eeed
oak-pine
Oregon oak
San Diego ambrosia
Phragmites australis
Quercus-Pinus
Quercus garryana
Ambrosia pumila
Invertebrates
Giant clam Tridacna gigas
Fish
Arapaima
brown trout
coho salmon
sockeye salmon
whitefish
Arapaima sp.
Salmo trutta
Oncorhynchus kisutch
Oncorhynchus nerka
Coregonus lavaretus
Amphibians
Ensatina salamander
Larch mountain salamanders
Pacific chorus frog
spring salamander
tailed frog
torrent salamander
Weller’s salamander
Ensatina eschscholtzii
Plethodon larselli
Hyla regilla
Gyrinophilus porphyriticus
Ascaphus truei
Rhyacotriton spp.
Plethodon welleri
Reptiles
desert tortoise
gopher snake
rattlesnake
sharp-tailed snake
Gopherus agassizii
Pituophis catenifer
Crotalus spp.
Contia tenuis
Birds
American robin
American woodcock
band-tailed pigeon
barred owl
black duck
black-and-white warbler
black-capped chickadee
blue grouse
bluebirds
blue-winged Warbler
brown creeper
brown-headed cowbird
Canada goose
Carolina Wren
Cooper’s Hawk
downy woodpecker
Eastern Meadowlark
eastern towhee
grasshopper sparrow
Gray jay
Hermit warblers
hummingbird
mallard
marbled murrelets
marsh wren
northern goshawk
northern spotted owl
olive-sided flycatcher
orange-crowned warblers
pigeon
Pileated woodpecker
red-cockaded woodpecker
song sparrow
Varied thrush
western bluebird
white-crowned sparrow
willow flycatcher
Winter wren
wood ducks
wood thrush
yellow-billed cuckoo
Turdus migratorius
Scolopax minor
Columba fasciata
Strix varia
Anas rubripes
Mniotilta varia
Poecile atricapilla
Dendragapus obscurus
Sialia spp.
Vermivora pinus
Certhia americana
Molothrus ater
Branta canadensis
Thryothorus ludovicianus
Accipiter cooperii
Picoides pubescens
Sturnella magna
Pipilo erythrophthalmus
Ammodramus savannarum
Perisoreus canadensis
Dendroica occidentalis
Archilochus spp.
Anas platyrhinchos
Brachyramphus marmoratus
Cistothorus palustris
Accipiter gentilis
Strix occidentalis caurina
Contopus cooperi
Vermivora celata
Columba livia
Dryocopus pileatus
Picoides borealis
Melospiza melodia
Ixoreus naevius
Sialia mexicana
Zonotrichia leucophrys
Empidonax traillii
Troglodytes troglodytes
Aix sponsa
Hylocichla mustelina
Coccycus americanus
Mammals
African elephant
American marten
beaver
black bear
bowhead whale
caribou
cheetah
eastern chipmunk
eastern cottontail
fisher
gophers
gray squirrel
grizzly bear
ground squirrel
mule deer
New England cottontail
northern flying squirrel
northern raccoon
polar bear
red tree vole
snowshoe hare
Sumatran tiger
Virginia opossum
white-footed mouse
white-lipped peccary
white-tailed deer
Loxodonta africana
Martes americana
Castor canadensis
Ursus americanus
Balaena mysticetus
Rangifer tarandus
Acinonyx jubatus
Tamias striatus
Sylvilagus floridanus
Martes pennanti
Thomomys spp.
Sciurus carolinensis
Ursus arctos
Spermophilus spp.
Odocoileus hemionus
Sylvilagus transitionalis
Glaucomys sabrinus
Procyon lotor
Ursus maritimus
Arborimus longicaudus
Lepus americanus
Panthera tigris sumatrae
Didelphis virginiana
Peromyscus leucopus
Tayassu pecari
Odocoileus virginanus | textbooks/bio/Ecology/Monitoring_Animal_Populations_and_their_Habitats%3A_A_Practitioner's_Guide/1.15%3A_The_Future_of_Monitoring.txt |
Thumbnail: www.pexels.com/photo/animals-apiary-beehive-beekeeping-928978/
01: A Radicalize the Hive Manifesto
For an abbreviated, animated version of this Manifesto, watch my TedX talk “What bees can teach us about social change” below.
A YouTube element has been excluded from this version of the text. You can view it online here: http://openbooks.library.umass.edu/radicalizethehive/?p=5
The Manifesto section of Radicalize the Hive provides the reader with context about my perspective on beekeeping in the 21st Century. It examines where we are and how we got here by taking a look at the historical significance of honey bees in North America. This section is based on my own experience as a radical and queer beekeeper over the last decade.
Beneath ideas of “industriousness” and “productivity,” honey bees are translators of sweetness and light. They are facilitators of pollination – nature’s fluffers humming between stamens and pistols, full up with pleasure and drunk on sunshine.
Right now the honey bee/human relationship is transactional. We want to “save the bees.” If we want a reciprocal relationship with these creatures, we have to ask what we LEARN from the bees to begin to shape change so we can be more responsive to each other and our ecological allies.
To move back into a more symbiotic relationship with the honey bee, we have to examine how entangled this sweet bee is with the historical relationship between colonization and industrial agriculture. We have to acknowledge that relationship. We also have to look closer at the honey bees’ system of cooperation and ask what we can learn from honey bees as a “social super-organism.”
We can take lessons from inside the hive to begin the process of building new resilient worlds together, worlds that honor natural rhythms and lessons.
In this section I examine lessons from the hive:
• The root cause of the plight of the honey bee
• How honey bees effectively collaborate
• What humans can learn from honey bees to be more effective collaborators:
a. Review lessons that can help us shape change in OUR own exploitative industrial culture so we can be more responsive to each other and our ecological allies
i. Setting terms, sharing power, building collective understanding, working towards building consensus while being compassionate and forgiving ourselves
ii. Sharing purpose, AND sharing joy
• How we can apply this in our work to build networks of collective care and shared power. To me true collaboration is sharing power with each other rather than holding and manipulating power over one another, or over another species. This is how I have shaped my own iterative practice and my work, and in this section I share that with you.
The Story of this Book
The story of this book started in the spring of 2017 when, in the midst of a major life upheaval, I fled to Vermont to deepen my beekeeping practice with Kirk Webster. Inspired by my time at Kirk’s, I told a friend, “I’m going to write a zine about bees.” At the time, this “zine” was nothing more than a discombobulated collection of sketches and tools of the craft that I had gleaned from mentors and modified through my own experience.
After I spoke the words, I started thinking of the pollinator protection movements and where we are. I wondered who has the microphone in this movement? Who needs it? Who has access to bees and who doesn’t? I reflected on the story of how we got here and what momentum we need to move in a new direction.
The story of this book also started over a decade ago, when an uproar arose from within the national and international pollinator community about massive bee die-off. Pollinator die-off is a complex ecological issue that involves more than honey bees, and in fact, impacts native pollinators, butterflies and bats. But the 2.66 million honey bee colonies in the United States became the central actor in our collective conscious. Within the honey bee colonies, the issue was distilled down to “Colony Collapse Disorder,” a “root cause” and no clear solution.
Over time, we’ve discovered the problem is complex — due to loss of a diverse habitat, the over-use of toxic pesticides, aggressive viruses and rapidly changing climate, honey bees as a species, are in danger.
This is a problem for honey bees, but also for humans because bees are a keystone species. Which means, we rely on them for our survival. Every 1 in 4 bites of food we take is thanks to honey bees. Imagine if bees ceased to exist. How would we pollinate foods like apples, avocados and almonds?
The parasites, viruses and pesticides that are impacting our honey bees, and our ecosystem are complex, and the challenges are constantly mounting as climate changes. Amidst these mounting challenges, a movement to “Save the Bees” has risen up in the collective conscious to help the important and charismatic microfauna — the honey bee. This rally call has built a movement of people engaged with the honey bee. Our relationship with this creature dates back over 8,000 years. Honey bees appear in ritual across the world from the Himalayas to Eastern Europe.[1]
Humans and honey bees are deeply intertwined, and because they are deeply entwined, we need to examine the use of the word “save.” According to the Merriam-Webster dictionary, the word “save” means to rescue or deliver from danger or harm and to preserve or guard from injury, destruction or loss.
What are we saving bees from? Our desire to save any single creature limits our vision and makes it hard for us to see the connections and relationships between ourselves and the creature we’re trying to “save.” The use of the word “save”puts us in a position of “savior.” Assuming the role of “savior” removes our actions and behaviors from the equation, giving us plausible deniability for why honey bees need saving in the first place. Authentic learning relationships can’t take place when we are trying to “save” those we seek to learn from. By claiming to be the hero, we are “othering” and creating a divide. Failing to honor the relationship between ourselves and the honey bee limits us to inadequate solutions to a larger systemic problem of environmental destruction and systemic oppression for capital gain. It defeats our capacity to see the whole story and respond in a way that speaks to our full humanity as living beings on this planet.
Our current economic model is based on endless growth, consumption and permanent race for profit. This economic system threatens the ecological balance of our planet and has multiplied inequities. As humans participating in this system, we stand on the precipice of ecological crisis. The idea that we will be the “saviors” is a grand self-delusion. A movement built on “saviorism” and the individualizing of a problem to one sub-group or species is one ignorant to the need for systemic change. If we can not imagine systemic change, we can not begin to abolish the systems that have perpetuated the oppression of people, land, water and animals since the United States became a country.
As Wendell Berry wrote in In Distrust of Movements:
“I must declare my dissatisfaction of movements to promote soil conservation or clean air or wilderness preservation or sustainable agriculture or community health or the welfare of children…I am dissatisfied with such efforts because they are too specialized, they are not comprehensive enough, they are not radical enough, they virtually predict their own failure by implying that we can remedy or control effects while leaving causes in their place. Ultimately, I think, they are insincere, they propose that the trouble is caused by other people, they would like to change policy but not behavior…To make ourselves into a practical wholeness with the land under our feet is maybe not altogether possible—how would we know?—but, as a goal, it at least carries beyond hubris, beyond the groundless assumption that we can sub-divide our present great failure into a thousand separate problems that can be fixed by a thousand task forces of academic and bureaucratic specialists. That program has been given more than a fair chance to prove itself, and we ought to know by now that it won’t work.”
Over the last 10 years, I’ve worked and learned through honey bees. I’ve come face to face with an ecological collapse brought on by the abuse and misuse of our planet fueled by an ever-expansive model of capitalism. The only way capitalism can be profitable is through a process of “primitive accumulation” — where things like slavery and colonialism are utilized to extract free labor and resources from people and planet. It’s not some innate quality of humans that has destroyed the planet, it’s a product of how the system of capitalism operates. If we aim to live in cooperative symbiosis with the planet, then we need to name the systems that cause planetary destruction. Labeling them helps us separate humans from the behemoth systems. Labeling helps us make room for humans generating potential solutions to the climate crisis that aren’t about exploiting nature but are about entering into a much more balanced relationship to the web of life. Honey bees are not the ones out of balance with the ecosystem, humans are.
The Earth and her fauna and flora have much to teach us. We need to remember that we are a part of a place, a history and a solar system of planets much bigger than ourselves. When I listen to the bees, I hear the stories of an organism ready to teach us lessons about successful cooperation AND the dangers of industrialized expansion.
In the year 2020, it is difficult to deny that each of us exists within the framework of systemic oppression that actively impacts our lives, our work and how we move through the world. With practice, we can actively examine how oppressive patterns show up in our minds and in our daily lives. It’s inside of us, and if we’re not actively doing the work to root it out and build awareness of it and deconstruct it through healing and equity building, we are not doing the work of radicalizing or abolishing the systems of oppression.
But we can! We can shape change if we remember Audre Lorde’s well-known declaration that “the master’s tools will never dismantle the master’s house.”
Two of the primary tools of human complacency in the face of climate disaster are despair and shame. Despair and shame are not effective tools for learning. They are tools of oppressive forces, like patriarchy, white supremacy, colonization and settler culture. Despair and shame incapacitate our search for collective, systemic solutions — the only solutions that will truly work. By participating in shame and fear we are adhering to a dysfunctional culture instead of shaping our own. We need to practice building a new culture, while leaving room for our roles to be fluid. We need this practice so people can breathe enough to fight with passion and not from a disempowered space. So energetically we can ebb and flow like the hive, contract and expand and SWARM when the time is right.
I’m proposing in this moment we have an opportunity to plant our courage and our hope in the deep soil we’re standing in. We need to use our courage to address our collective needs by turning to our natural and elemental allies and ask:
“What can we learn?”
“What can we BE together? What can we DO together?”
So, what if instead of looking to modernity for solutions, we turn our attention towards the indigenous, ancestral and ecological ways of being in relationship with our surroundings? I think we stand to unlearn unsustainable patterns of expansion inherent in capitalism.
The honey bee and human relationship is old. There is evidence that humankind was gathering honey in the late Paleolithic times, ten to fifteen thousand years ago. An 8,000-year-old rock painting discovered at Arana Cave near Valencia, Spain, depicts a person climbing a ladder to gather honey from a hive on a cliff face. This picture was made when humans were still in the hunting and gathering as their primary source of sustenance, before they had begun to farm or domesticate animals.
Radicalize the Hive is the idea that we can start to work in reflective practice in ourselves, our communities and our organizations. We can use this charismatic microfauna as an example of the cooperative energy and momentum it takes to engage in change making work OR shift systems.
I’m going to say things that are critical of the beekeeping industry and draw attention to how many of us serve within and rely on that system for capital, resources and equipment. We’re going to look at the challenges and the reality that we’re all playing into the challenges and how we begin the work of radicalizing using the hive as a model.
While Colony Collapse Disorder was being labeled the culprit of a widespread honey bee collapse, I was in Dedham, Massachusetts in an itchy white suit with my French beekeeping mentor Jean-Claude holding a dolly with one hand and staring at an old whiskey barrel brimming full of bees. According to Jean-Claude, our instructions were to “remove it.” Jean Claude and I sealed up the entrance of the “whiskey hive”, packed the whiskey barrel into the back of my small pick-up strapped down with several carefully placed rachets and dropped it off at the apiary at dusk. The next morning, again packed tightly into a bee suit, gloves and pull-up galoshes, I helped Jean-Claude carefully cut and band the hexagon shaped layers of brood and honeycomb and rubber band them into the wooden frames of a new bee hive.
Tens of thousands of honey bees hummed around us peacefully as we worked to rehome this wild hive. The scent of nectar was thick in the air. This was a moment of connection to land, air, water, plants and mycelium — all of these systems honey bees bind together. I was struck by how much honey bees have to teach us. Jean-Claude was studying wild hives and asking, “What are the bees doing to adapt?” and trying to mimic bee behaviors in his hive management strategies. From the very beginning of my beekeeping career, I was taught to look to honey bees for the answers.
Figure 1.1 Honeybees
Industrialization of the Honey Bee
Before we discuss strategies for dismantling systems or become lost in the “magic of bees”, let’s look at the industrialization of the honey bee on the North American continent.
In the current agricultural system, with their pollination power, honey bees are responsible for pollinating 1 in 4 bites of our food in North America. Honey bees and the practice of keeping them or “beekeeping” is rooted deeply in the US agricultural system. And the United States (US) Agricultural system is rooted in racism, a social construct designed to exploit labor of black and African heritage people through slavery. Slavery launched modern capitalism and turned the US into one of the wealthiest countries in the world.
Honey bees aren’t endemic or indigenous to the North American continent. They were introduced to the US colonies in 1622 on board a ship that landed in Richmond, Virginia. Honey bees were and continue to be used to support agricultural expansion in North America.
According to CW Weber’s book, Sam or the History of Mystery[2], Indigenous peoples on Turtle Island quickly realized the advent of the honey bee was an indicator of coming colonizers. In 1820, the first honey bees made their appearance on the Braxos and Colorado rivers in Texas. Five years later, the Austin settlement began to rise on the banks of these two rivers, and Indigenous tribes were displaced from their land. White settlers stole indigenous land and displaced the Indigenous tribes in and around Austin, rendering them exiles on their native soil.
Throughout the growth and expansion of the so-called United States, honey bees were used to support monocropping agricultural models, and rapidly became a key player in the industrialization of agriculture.
Today honey bees are employed in migratory beekeeping practices, moved across the US via 18-wheeler (semi-trailer truck). Migratory beekeeping is an industry that begins with almond pollination in Southern California. Each year 1.7 million hive boxes full of bees are transported to California from all over the US via tractor trailer truck and set down in the 1.3 million acres of almonds.
This accounts for close to 85 percent of all the honey bee hives in the United States. California’s almond bloom is the largest pollination gig anywhere in the world. Those truckloads of bees don’t stay put in California’s Central Valley all year though. The almond bloom typically lasts just a few weeks in February. These bees and their keepers engage in an endless summer of chasing nectar producing plants. They crisscross the nation 10 months a year, working tirelessly to pollinate everything from oranges to blueberries. This industrial model of agriculture uses 388 million pounds of Glyphosate annually, a pesticide (and key ingredient in RoundUp) so toxic it is banned in the European Union, China and Brazil.
This work, as you can imagine, is taxing for both honey bees and beekeepers, because, just like capitalism, it relies on consistent expansion to be successful, leaving no room for contraction, rest or recovery.
Approximately a decade ago, we began to see the impact of this agricultural system on our pollinators. Honey bee hives began “failing” or dying out completely by the thousands. And so, like canaries in the coal mine, honey bees are giving us a warning about the impact of these expansive systems on our environment.
Today we know the biggest parasite honey bees face is the Varroa destructor mite. In 2018, Sam Ramsey of the University of Maryland discovered that varroa mites feed on the lymphatic system of the honey bee — resulting in a weakened immune system and the rapid spread of viruses and diseases within the hive. We now know that these viral loads are combined with a loss of pollen and nectar based forage. Loss of forage is due to climate change. Systemic use of pesticides and herbicides used to maintain our food system poses a major threat to the immune system of the honey bee, making honey bees more susceptible to bacterial and viral infections manifesting in the hive.
Last year, according to a national survey by the Bee Informed Partnership, 40 percent of managed hives in the United States were lost to viruses and Varroa mites. This is an alarming rate of loss. These losses were experienced throughout the season. What does that mean? It means hives were lost not only during the long cold winter months, but also during the active honey bee keeping season across the continental United States.
From this industrialized model of beekeeping we can see that mimicking systems of expansion and exploitation is not a generative way to build new worlds. So where do we find hope and change amidst this catastrophic environmental crisis?
Honey bees have taught me that hope and change can begin very small.
Figure 1.2 A queen bee
This is a queen bee (see image above). A queen bee is no bigger than the thumbnail on my right hand, but she can lay over 2,000 eggs a day. Each and every one of those eggs is a hope of a future generation, laid with the hope that flowers will bloom, and nectar will flow and each bee will have enough food to grow into an adult honey bee.
For more on this, see video link below.
A YouTube element has been excluded from this version of the text. You can view it online here: http://openbooks.library.umass.edu/radicalizethehive/?p=5
Strategies
Activist and facilitator adrienne maree brown says “Small is all.” Leopold Kohr coined the term “Small is beautiful.” And when it comes to honey bees I have to agree.
Small-scale beekeepers are already working with the honey bees’ natural systems of adaptation to find ways to support bees and radicalize the beekeeping industry. It takes incredible commitment and careful work to build change at this small scale, especially when you’re facing down behemoths like “industrial agriculture.” But beekeepers are hoping to build a new culture of beekeeping by working with the adaptive capacity of honey bees that they observe in the wild.
Figure 1.3 Melanie Kirby
“You have to act as if it were possible to radically transform the world. And you have to do it all the time.” – Angela Davis
Beekeepers like Melanie Kirby of Zia Queen Bees of New Mexico are raising adaptive bees that can deal with disease and rapidly changing climate. Melanie refers to her work as “seed saving, with bees.” These “seed queens” are adapted to the bioregion where they were raised, making them more resilient than bees imported from outside the region.
Figure 1.4 Kirk Webster
Kirk Webster, a beekeeper in the hills of Vermont raises “survivor stock” honey bees using no chemicals or treatments in his hives. Kirk’s bees can survive long harsh winters while successfully resisting diseases.
As a small-scale beekeeper myself, I’m looking into ways to build resilient community while fostering a connection between humans and honey bees. Last fall, my friends and I hosted the first Queer and Trans (QT) bee field day at my farm in Western Massachusetts. Together, we gathered 18 new, or aspiring queer and trans beekeepers to foster an affirming space to share skills and resources. We gathered to build a deeper relationship with honey bees and practice interdependence with one another.
Figure 1.5 Inflatable skep beehive model created by artist & beekeeper Maria Molteni
At the inaugural bee day we opened up bee hives, and learned about what happens inside. On plant walks we learned about plants bees pollinate in the ecosystem. Facilitators told stories of how both humans AND honey bees can use each plant. We used hand crafted guidebooks to identify plants, made by our rad planning team of QT organizers from across a wide spectrum of identities, sharing a collective purpose. Through QT Bee Day events, we’re making bees a gateway bug for shaping new relationships with the natural world by queering our understanding of bees. What does that mean? It means we’re reclaiming a forgotten relationship with the natural world that moves beyond binaries. We are shaping relationships with the natural world built on reciprocity.
Figure 1.6 Inflatable skep beehive model created by artist & beekeeper Maria Molteni
Small actions like these are building a culture of “small-scale” beekeeping. These practices collectively reframe the value of honey bees — rather than using bees as a tool for pollinating industrial agriculture, we’re using bees as a model for building community.
At my farm, we are supporting aspiring beekeepers and teaching skills like swarm catching and how to raise queens. Through actions like these, small-scale beekeepers are building new beekeeping communities that are collaborative, while supporting thriving hives.
Figure 1.7 Queer & Trans Bee Day organizers gather around inflatable skep beehive model created by artist & beekeeper Maria Molteni.
When my collaborators and I facilitate small groups of aspiring beekeepers, we reflect on our visible and invisible social identities including race, ethnicity, class, gender, sexuality and ability. We name where people hold power and privilege because you can’t share power if you don’t know you have it. Diverse perspectives and identities are important, but they can only become powerful when we make space for them to be heard, valued and integral to the collective. Because we’re not bees, we have to make space for humanity which means making space for our differences AND our traumas. We have to make room for healing and repair. The decision-making we engage in within our communities has to be accessible for those marginalized by our current system. It has to call in our survivors and create space for compassionate listening and the bravery to share diverse perspectives and experiences as a group.
When we build high trust groups like this, we can be very coherent and effective. Bees trust innately, it is part of their biology. But we have to build it, just like we build new neural pathways in our brain when we learn new habits. Then we can be agile and adaptive in a complex and rapidly changing environment, while sharing power.
Lessons from the Hive
You don’t have to be a beekeeper to start sharing power. You can address big issues by starting with small actions to combat environmental injustice in the small groups you’re a part of today. The lessons we can learn from the hive are lessons on iterative process. Iteration is the repetition of a process. In a healthy hive, we see some basic essential functions and lessons we can adapt to our own groups from each.
Essential Function:
In a balanced ecosystem, honey bees are facilitators of pollination — transforming sunlight into sweetness by transmuting nectar and pollen into resources for their young. They are facilitators of interspecies sex humming between stamens and pistils. When hives are gathering these important resources from nectar producing plants, they are full up with pleasure and drunk on sunshine. They are in a reciprocal relationship with the ecosystem in which they are pollinating. They draw resources from and contribute to the plants’ capacity to thrive. Honey bees pollinate food they’ll never eat, store nectar and pollen for young they’ll never meet and swarm to locations they decide upon while suspended in midair.
LESSON:
Relationship with our surroundings can be joyful, purpose-filled and interdependent.
Internally, when we look into a hive, we see individuals working in roles, practiced with ritualistic precision by each bee, for the collective benefit of the hive’s longevity. Every hive is made up of 30,000+ worker bees, one queen and several drone bees.
Essential Function:
Worker bees are the force of collaboration in a honey bee hive. They play a very important role in the hive. Workers begin as cleaner and nurse bees who prepare wax cells for their sisters’ birth by cleaning, polishing and adding food to each cell. They care for the young bees of the hive. Young bees also spend time as builders. They engage in an act called festooning, in which they hang off of one another secreting wax from scales on their bellies and passing it arm to arm to mouth and chewing it into hexagons in which to store young, food and water. Foragers gather resources for the hive. They can travel 5-8 miles to collect pollen, nectar, propolis and water that will feed and hydrate the hive.
LESSON:
We can play many roles and move between them fluidly.
Essential Function:
Wax is the foundation of a healthy hive. It is the architecture upon which the entire hive is built, the central nervous system of the hive. Hexagons hold the most weight with the least amount of material.
LESSON:
Work together to build solid foundations on which to collaborate.
Essential Function:
Pollen and nectar are collected from flowers by forager bees. These resources are transmuted into food, called bee bread, for the current young, and stored as resources for the next generation in the form of honey.
LESSON:
Share in the abundance, store it for moments of contraction.
Essential Function:
Propolis is collected by forager bees as resins collected from evergreen trees. Propolis is mixed with enzymes in a honey bee gut — it seals the inside of the hive, making it a sterile space for the young, and seals the hive from moisture, cold and predatory insects.
LESSON:
Cultivate a space that is healthy for everyone to thrive.
One of the most crucial elements of a healthy hive is clear, consistent and collaborative communication.
Honey bees communicate through several methods:
• Pheromones – a form of scent-based communication through glands on the honey bees’ head and butt
• Vibration
• Dance
• Consensus building
We can look to the hives to see a clear mechanism for communication and consensus building. Honey bees reproduce by swarming. During a swarm, honey bee communication is collaborative and embodied. Honey bees make cooperative decisions through listening and responsiveness.
The most profound example is a swarm of bees.
During a swarm, honey bees collectively embrace change.
Swarms happen in Spring — when the bees have collected an abundance of nectar and pollen and the hive is FULL of workers. The bees begin to outgrow their space and prepare to split 1 hive into 2.
The bees will begin to raise a new queen by feeding tiny larva a special diet of royal jelly and pollen. The queen, much like a butterfly, spins a small cocoon inside beeswax and begins to pupate — or grow into an adult. When the new queen emerges from her cocoon, half of the bees in a hive will leave the hive with the old queen. They leave behind a newly hatched queen, young bees and plenty of food.
During a swarm, the bees cluster around the queen and hang from a branch. The swarm of bees then begin their search for a new home.
A YouTube element has been excluded from this version of the text. You can view it online here: http://openbooks.library.umass.edu/radicalizethehive/?p=5
This past summer while conducting field work with a collaborator, I was stopped dead in my tracks by a swarm in action. We watched as tens of thousands of bees flew out of a hive collectively and hovered in a cloud all around us. They quickly clustered on the limb of a nearby maple tree, and we watched as “scout bees” began to search out new places to call home. It’s a fascinating process. Scout bees begin seeking out a dry hollow space. Then, they return to their sisters and begin to dance out the details of these locations. One by one their sister bees travel to these proposed locations and check them out. When they each return, they vote on the best location by taking up the dance of the scout bee who chose the best spot. The decision about where to go is an important one. They have no resources with them except what they carry in their stomachs, and they need to find a safe, dry place to build their new home. Communication about new sites is vital to finding the best location. The dancing deliberation continues until the bees reach consensus about the best place for their new home. Finally, they leave their outpost and head for their new home.
To entice our swarm, my friend and I bungee strapped an old hive box about 10 feet up in an old chestnut tree to see if they’d like it, and they did! The next day the honey bees had chosen this box to build their new home within and were already building a foundation of wax to rear their young upon.
If we look to the swarm, we can see a road map for collaboration through consensus building. In the process, every bee retains their autonomy in this consensus building. There is no charismatic leader. The queen is a passive onlooker in the worker bee’s collective process. Consensus building amongst honey bees is an intricate democracy. The consensus is built by sharing power, information and trust.
According to honey bee researcher Tom Seeley, “These bees achieve their collective wisdom by organizing themselves in such a way that even though each individual has limited information and knowledge, the group as a whole makes first-rate collective decision.”
But we are not bees; we are not yet as agile as they are in a group. Plus some of us think we can’t even dance! There is deep complexity to our humanity, and our shared vs. autonomous experiences. There needs to be room for our autonomy along with opportunities for collective process. So how do we build successful collaboration in our lives? Even if you have two left feet, you can begin the “dance” of learning how to collaborate.
Bees take time to build communication that is iterative, equitable, interdependent and accountable. They eliminate charismatic leaders and to mimic this concept we have to minimize hierarchy.
We have to practice consciously sharing power so we can begin to have honest dialogue while holding ourselves accountable to our purpose. Just like our team of QT bee day organizers, we can begin to practice sharing trust. With practice, our human groups can become agile like honey bees. We can build intimacy in our collaboration that truly takes everyone into consideration and makes room for new ideas. Authentic human consensus building can help us recognize we’re part of a larger whole.
We, as humans, with autonomy, can move from this model of “collectivism” and towards accountability. We can build intimacy in our collaboration that is accountable so that when we need to be accountable to each other we can be. When we need to address harm, we can, so we can discover if/how to move through it. That requires holding space for grief, trauma, apology and reparations. I think accountable communication in groups, organizations and communities happens when we start small and build clear mechanisms for communication and accountability. Then we can aim to be accessible and build trust across differences, but this can only happen with radical honesty and iterative practice in high trust groups.
A high trust group can be very coherent and effective after establishing agreement about state, direction and norms. If you want to be agile and adaptive in a complex and rapidly changing environment, you must move as much decision-making power as possible into a consensus model that is small enough to be governed by authentic dialogue.
In small groups we can assess and respond to the pressures outside our group effectively and quickly address dysfunction and respond accordingly. In small groups we can abort a project if conditions are unhealthy or not generative. We can know when to fold. We can know when to set and hold boundaries for the health of our community. In small groups we can build efficient systems, we can grow with each individual, clear about the roles they need to play for cooperative success. This creates space for us to focus on thriving when conditions are optimal and sustaining them when under pressure.
Then decision making can become iterative. There is trust built when we aim for accountable and nonhierarchical systems, and this trust helps us build our capacity to be interdependent.
Honey bees teach us to:
1. Build solid but malleable foundations
2. Embrace Change
3. Make Equitable Decisions through Consensus
Bees are a whole world, and they open you up to these other worlds — blossoming trees, spiders, ants, predators, opossums and bears, and how all of these things interact with each other. If we look to the ecological world all around us, to our allies in the plant, animal and insect world, we can draw inspiration for how to shape change. We can build our muscles for understanding natural rhythms and lessons once again. We can take lessons from inside the hive to begin the process of building new resilient worlds together beyond the hive. We can build collective care through shared networks. Networks that build power with each other. To me, this is true collaboration, power with each other rather than power over one another, or over another species.
When you can see systemically, in patterns, in iterations, in fractals, you realize how flawed our social systems and structures are because they are both limited AND disconnected. The more you realize that, the easier it becomes to decouple from degenerative practice and align ourselves with ecologically responsive, adaptive and generative process.
When we need hope, we can look at the small-scale changes already underway. Small-scale beekeepers are already building collaborative relationship with honey bees, raising bees who are adaptive and resilient. Small is where we begin to build trust with one another. We can take trust building and change making in steps, in movements, in seasons. We can practice together. We allow for mistakes and shift behavior, thought and action. We can dismantle, rebuild and rewire. We can create new pathways to change. And take back our humanity, our intimacy and our shared understanding.
For an example of how to implement collaborative practices into your work, visit this resource.
For an instructional guide to using these principles in your community, visit this recorded webinar here.
_
1See research by Eva Crane on the world history of beekeeping
2 Sam or the History of Mystery”
Media Attributions
1. See research by Eva Crane on the world history of beekeeping ↵
2. null ↵ | textbooks/bio/Ecology/Radicalize_the_Hive_(Roell)/01%3A_A_Radicalize_the_Hive_Manifesto/1.01%3A_A_Radicalize_the_Hive_Manifesto.txt |
Thumbnail: www.pexels.com/photo/man-holding-honey-comb-3213004/
02: Interviews From the Field
I’m a small-scale beekeeper. At my farm, we are supporting aspiring beekeepers and teaching skills like swarm catching and how to raise queens. Last fall, my friends and I hosted the first Queer and Trans bee field day. Together, we gathered 18 “newbees,” or aspiring queer and trans beekeepers, to foster an affirming space to share skills and resources. We gathered to build a deeper relationship with honey bees and practice interdependence with one another.
When I need hope in my work, I often look to mentors and peers in the field of small-scale beekeeping. Small-scale beekeepers are shaping small-scale changes to the beekeeping industry.
They are already working in small ways to adapt, find ways to support bees and radicalize the beekeeping industry. It takes incredible commitment and careful work to build change at this small scale, especially when you’re facing down behemoths like “industrial agriculture.” But beekeepers are hoping to build a new culture of beekeeping by working with the adaptive capacity of honey bees that they observe in the wild. All of the stories shared here were selected based on community-centered and natural beekeeping models, with some overlap of the two.
Small-scale beekeepers, whether in their own practices or embedded in community practice, are modeling collaboration. They are building relationship with honey bees and raising bees who are adaptive and resilient. Small-scale beekeepers are also working on honey bee education and leveraging community collaboration to support pollinators in rural, urban and suburban landscapes. These radical ways of “beeing” are important to uplift in an industry where the onus is focused on production and expansion rather than education and community building. The stories of these community-centered beekeepers are important to uplift, which is why I share them with you here.
Many of these stories come from places and faces underrepresented in the beekeeping community — the stories here center communities of people of the global majority, woman or femme led projects and Indigenous voice. Why? Because these are the faces shaping honey beekeeping in the 21st century and the voices shaping change in how we work with honey bees and the natural world.
All of these practices — whether small scale producers or community-centered beekeepers — are all happening at a small scale. Why? Because small is where we begin to build with one another. We can practice together, allow for mistakes and shift behavior. We can dismantle, rebuild and rewire. As we do this, we can create new pathways to change and take back our humanity, our intimacy and our shared understanding.
2.02: My experience at WSU
Washington State University (WSU) runs a well respected honey bee lab. It is set in Pullman, Washington a few hours outside of Spokane, Washington in the heart of wheat production country.
At WSU researchers Sue Cobey, Erin O’Rourke, Dr. Steve Sheppard and Dr. Brandon Hopkins lead a honey bee lab where they research and develop strategies in:
1. Cryogenic freezing and preservation of genetic material
2. Instrumental insemination of queen bees
3. Brood assays to determine hygienic behavior
WSU collaborates with commercial beekeepers providing pollination services across the United States. WSU researchers work to produce and evaluate genetically diverse Carniolan queens, which they refer to as “New World Carniolans.” They also work with beekeepers across the world to collect and preserve genetic material from Europe, the Middle East and North Africa in an effort to increase the genetic diversity of queens in the United States. Due to a law established in the mid-1920s, beekeepers cannot bring new queens into the United States without authorization and clearance from the State Department.
WSU researchers collect drone semen and cryogenically preserve this genetic material to bring into the US. Here WSU artificially inseminates queens, creating “breeder queens” who are host to specific genetic traits brought in through the cryogenic preservation practice. Through this highly technical and scientific method, they are working to increase the genetic diversity and resilience of honey bees in North America.
In Summer 2019 I had the pleasure of attending their “Queen Rearing Symposium” to learn about the lab, the researchers and their work in the field. Here I was able to interview Melanie Kirby as she worked on her own honey bee queen mating research for her master’s degree, and see her work in action through the wider lens of the lab and the landscape of Eastern Washington state.
Learn more about WSU in this short video below.
A YouTube element has been excluded from this version of the text. You can view it online here: http://openbooks.library.umass.edu/radicalizethehive/?p=257 | textbooks/bio/Ecology/Radicalize_the_Hive_(Roell)/02%3A_Interviews_From_the_Field/2.01%3A_Interviews_From_the_Field.txt |
Figure 2.2.1 Melanie Kirby, Zia Queen Bees (left) and Angela Roell (right)
This summer I had the privilege of traveling to Pullman, Washington to interview Melanie Kirby of Washington State University (WSU) and Zia Queen Bees. Melanie is completing her Master of Science in WSU’s Apiculture department while running her own queen breeding operation in Washington (WA) and New Mexico (NM). Melanie generously shared her beekeeping journey with me.
Melanie fell into beekeeping by happy accident while on assignment in Paraguay as a Peace Corps volunteer. During her time in Paraguay, Melanie facilitated women’s groups, exploring tropical apiculture.
Melanie shares, “I was trying to help the women diversify their farming so that then they could have additional streams of income. We’d go out and catch these wild swarms from cocoa palms, and then transfer them into hives. There was a lot of citrus and sugarcane as well as different trees that were flowering so we’d get a good subtropical mix honey out of it there. It was really fascinating to see some of the women take to it.”
After the Peace Corps, Melanie travelled to Hawaii to study queen breeding at Kona Queen on the Big Island of Hawaii. Kona Queen is the largest queen producing honey bee operation in the world, producing over 245,000 queens a year. At Kona Queen, Melanie got a lot of practice with grafting — [a method that mimics the bees natural system of swarming to raise several queens at once in a synthesized environment]. It was here that Melanie realized, “Oh wow, this is a skill that’s needed and I can travel the world with it.”
Melanie continued her journey of working and learning in commercial beekeeping operations in both Hawaii and the continental United States before returning to her home state of NM to begin her own operation, “New Mexico is…a really unique state. It has everything from desert to tundra. It’s what we call a tri-cultural landscape. You have the Native Americans – the Pueblo Indians, the Apache, Picuris Indians as well as the Spanish and Europeans. Over time there has been a blending of these cultures who are also fighting to keep their distinct identities and learn how to coexist in a very diverse yet adverse landscape.”
Melanie shares with me that the Indigenous people of NM have always occupied their ancestral lands and they have developed Indigenous technology learned through trial and error on these lands.
“That is how these cultures have survived for thousands of years. Taos Pueblo is a community with these ancestral buildings which are over a thousand years old and somebody’s always lived in them. Always. Growing up where there’s these communities that have survived successfully for thousands and thousands of years, and the seeds that they saved for strains of chili, and the three sisters, corn, beans and squash – these crops that they were able to maintain and these seeds that they saved and then they’d pass them onto the next generation. It really made me recognize, ‘Well, that’s kind of similar to bees and these ecotypes.’”
There are 28 recognized subspecies of honey bees. They can all interbreed because they’re of the same species but the subspecies adapt to different bioregions and ecosystems based on environmental need.
Figure 2.2.2 Melanie Kirby, Zia Queen Bees
In NM Melanie made the connection between bees and seeds, “Oh, the bees are seeds too and their stories, their historical capacities that have allowed them to do what they’re doing now have been formed over millennia. The genetic story that every organism carries with them can be passed onto the next generation. It’s like living proof of the past but also it’s already the future within itself. Just ready to evolve or adapt.”
Melanie’s work and research now centers on honey bee breeding selection in the United States, where honey bees are not endemic. Melanie researches strains of honey bees who can deal with various environmental stressors while still surviving and thriving. She trials bees in different areas and propagates them to share with other beekeepers. She also seeks out beekeepers who are doing similar types of “honey bee seed saving” to swap queen bees – the genetic “seeds” of a honey bee hive. Though Melanie already found bees marvelous, magnificent creatures breeding and swapping queens has made her realize how special each hive and its genetic makeup can be.
“I’m so glad they found me…I think a lot of the gratitude I have towards them is that they have really opened my eyes to just how interconnected we all are with not only each other but with our food, with our food system, with our land, with our soil, with our weather. They are a part of basically everything in some way, shape, or form through relationship. I can’t ever stop thinking about how interconnected they are and that is their allure.” | textbooks/bio/Ecology/Radicalize_the_Hive_(Roell)/02%3A_Interviews_From_the_Field/2.03%3A_Melanie_Kirby.txt |
Figure 2.3.1 Antonio Rafael, SW Beetroit.
Antonio Rafael is an artist-farmer-beekeeper-educator-environmentalist who co-founded SW Beetroit, a collaborative of beekeepers in the Detroit area whose mission is to improve the ecology of the neighborhood through green spaces and tree planting. One of three people running the show and one of two of Puerto Rican descent, Antonio graduated college in 2012 during a period where 50% of Michigan’s Black population was put into “emergency management” following the 2008 U.S. financial crisis.*
Antonio’s critical consciousness, radicalization, and draw to beekeeping emerged as Detroit was going through this economic downturn. Along with a group of friends, Antonio started a Chicago Indigenous hip hop and art collective (Raiz Up) to organize civil disobedience to protest the emergency management. He says, at a time when 1 in 3 Detroiters were losing their homes, he “turned to agriculture, farming, beekeeping, as a way to heal myself.”
The SW Beetroit collective is more than about selling honey. They aim to expose the community at large to beekeeping and reconnection to the land. Their programming has garnered interest from young people and Black and brown communities in particular.
In addition to the Black and Latinx communities served, “A lot of my Yemeni neighbors love it,” says Antonio. “They like to buy the honey. A lot of people don’t trust in store honey so they appreciate that aspect of it.”
SW Beetroit works with and mentors young people. Antonio says, “It’s fun to watch them develop as young people” in addition to seeing their knowledge grow about the bees. He sees them gain “a certain competency…and confidence…from working with something that a lot of people [are] scared of.”
In Detroit’s landscape where food insecurity and health issues disproportionately affect Black and brown communities, engaging in beekeeping has proven healing for Antonio and the community at large.
“There’s nothing like you getting your hands in that dark soil and just like cultivating life,” says Antonio. “I think bees and honey – it’s just something that’s so good and so healing for communities that are so marginalized and so underserved and so traumatized.” In producing their own honey, they bypass the larger capitalist systems at work and also provide an opportunity to connect with nature and the “rhythms of the seasons.”
Antonio does a lot of work with Native American communities related to environmental justice and sees a deep need for Black and Indigenous communities “to be establishing as much sovereignty as they possibly can,” particularly for those located in the city where there’s a tendency to be more disconnected from nature.
One advantage to beekeeping in an urban setting like Detroit is there are so many abandoned houses and properties, says Antonio. There’s a lot more foraging that happens because people don’t cut their lawns. “We aren’t subjected to fungicides and pesticides like rural bees are.” Of course, there are negatives too – with so many residents buying potted plants from places like Home Depot, the chance of engaging with neonicotinoids might be a little higher.
Another advantage to SW Beetroit’s operation is that they favor natural methods of treating mites over pesticide use. Antonio uses King Stropharia white cap mushrooms to help break down woodchips to increase soil organic matter to make use of the clay that’s on the land. He’s noticed that the bees will flock to the mycelium (mushroom network) throughout the year. Research by Washington State University and Cornell University is ongoing about metarhizium fungi that helps to attack varroa mites, but rather than wait around to be “sold” finalized products, Antonio and crew rely on their own systems to deal with mites.
Figure 2.3.2 Antonio Rafael, SW Beetroit (far right, in red)
Antonio says, “We’re harvesting mushrooms with the intention to create extracts that we will be putting in our feed next year. And working with Native communities to do that as opposed to white, power institutions and businesses.” Yet another way SW Beetroit has found to remove themselves from the dominant structure and money systems with which Black and brown communities generally have less access to and a poorer quality relationship to. Antonio says, “Once we get it down [how to best use mycelium for treating mites], we wanna be spreading that knowledge.”
SW Beetroit is a smallish operation: 30 hives. But they are small and mighty. For Antonio, “It’s really about the culture. If the thousands of beekeepers or even just a couple hundreds of those folks were just treating their bees a little more holistically, it would be less of a threat to our bees, so we feel like it’s our duty to share some of the knowledge and share some of these interesting techniques we are trying to develop.”
*Emergency management is essentially a financial emergency that’s imposed by the governor that allows the governor to put in place bankruptcy lawyers that take the place of government). | textbooks/bio/Ecology/Radicalize_the_Hive_(Roell)/02%3A_Interviews_From_the_Field/2.04%3A_Antonio_Rafael-_Beekeeping_to_Reconnect_to_the_Land_and_Indigeneity.txt |
Figure 2.4.1 Brian Peterson-Roest, Bees in the D (second from left, first row)
Brian Peterson-Roest of Bees in the D came into beekeeping as a hobbyist. A fifth grade teacher at Musson Elementary School in Rochester Hills, Michigan, Brian’s “call” to beekeeping literally came via a call. In 2008, he was asked as a public school teacher to participate in a free two-week crash course in beekeeping (taught through Oakland University) on Beaver Island on Lake Michigan. An award-winning math and science teacher, it was this opportunity and experience to learn with other teachers that “started my love for beekeeping,” he says.
Now Brian works at Bees in the D, a non-profit organization that works with Detroit and Southeast Michigan residents, schools and organizations on honey bee colony preservation and education.
Brian fell into beekeeping at a time of personal hardship in his life, and 10 years later, with the bee population being threatened by CCD, Brian feels it is his “obligation to now be a voice for them. And to help them in their hard time.”
With Bees in the D and a regional beekeepers club, Brian provides workshops, courses, and networking with other beekeepers. He also works with a company called Hive Tracks, which developed a software to compile data and reports for clients on the 160+ hives they’ve placed in 50 locations. The data is used to look at mite counts and the health of the beehives.
Through various modes of education, Brian enjoys working with urban youth and communities and helping dispel some stereotypes about bees in the process. He’s seen youth go from a place of not wanting to go near bees at all to a “point that I eventually get them in the suits,” says Brian. “I eventually get them near the hives and before you know it they are just thinking it’s the coolest thing.”
Brian has also found a need to educate building engineers and other adults in communities who often confuse nesting wasps with bees and assume an aggressive nature without distinguishing between the two.
With more knowledge and curiosity about bees spreading, beekeeping is “almost becoming trendy,” says Brian, which he doesn’t have a problem with as long as people do their homework. “I just don’t want people to misunderstand that you can’t just buy a hive, put bees in it and just expect it to just take care of itself. There is a lot that goes along with it.”
Figure 2.4.2 Brian Peterson-Roest, Bees in the D.
Brian recommends people interested in getting into beekeeping do a year of research to start. During that year, join a bee club, be part of a bee community and maybe find a mentor if you can. A lot of learning goes into the process but even with that, his own personal style is “minimalist.”
“I’m not going to go in the hives more than I have to because I want the bees to be able to do what they do,” says Brian.
Brian likes the direction that bee education is leading in with more and more people realizing the importance of bees – not just honey bees but also our native pollinators as well.
When he first started out in the business, he saw many beekeepers beekeeping in secret. “The hives were out of sight, out of mind.” There were many misconceptions. But now he feels “like beekeepers are kind of coming out of the dark because now people are starting to realize how important it is.” | textbooks/bio/Ecology/Radicalize_the_Hive_(Roell)/02%3A_Interviews_From_the_Field/2.05%3A_Brian_Peterson-Roest-_Bringing_Beekeeping_into_the_Light.txt |
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