EPA EcoBox Tools by Receptors - Biota
Overview
An ecological risk assessment might evaluate one or more of the following wildlife groups (including endangered and threatened species), depending on the types of receptors that are likely to be present at the site (U.S. EPA Region 8, 2015; U.S. EPA, 1991; 1994; 2008):
- Aquatic receptors: Fish, benthic invertebrates, plankton, aquatic macrophytes
- Semi-aquatic receptors: Amphibians, piscivorous
piscivorousOrganisms that feed on fish. birds, piscivorous mammals, plants - Terrestrial receptors: Insects (e.g., pollinators such as honey bees), small mammals, large mammals, passerine birdspasserine birdsAlso known as "perching birds". In simple terms, and with few exceptions, they can be described as small birds that sing., raptorsraptorsA bird of prey, including eagles, ospreys and hawks., soil organisms (plants, soil invertebrates, soil microbes)
The table below presents types of receptors included within these receptor groups and describes the potential utility in using them as target receptors. For each receptor group, sensitivitysensitivityMore susceptible to the adverse effects of exposure to toxic chemicals, pesticides, and other pollutants. is likely to vary by receptor and type of stressor.
| Receptor Group | Type | Rationale |
|---|---|---|
| Aquatic organisms | Periphyton—microscopic algae that grow on substrate and vegetation | Provides information about primary producers in the aquatic environment; can be useful in assessing cause, extent, and magnitude of stressor problems. |
| Phytoplankton—microscopic plantlike organisms in the water column | Like periphyton, a foundational food resource that can be sensitive indicators of ecological injury resulting from contamination or enrichment of water bodies. | |
| Zooplankton—microscopic animals in the water column | Like periphyton and phytoplankton, a foundational food resource that can be sensitive indicators of ecological injury resulting from contamination or enrichment of water bodies. | |
| Aquatic macrophytes—includes submerged aquatic vegetation, emergent aquatic vegetation, and floating vegetation | May be useful for aquatic toxicity testing (e.g., duckweed); respond to contamination or enrichment of water bodies. | |
|
Benthic macroinvertebrates—invertebrate animals, visible to the naked eye, that live in or near the bottom of the water body |
Freshwater benthic macroinvertebrates include insects, worms, freshwater clams, snails, and crustaceans; marine and estuarine benthic macroinvertebrates include worms, clams, mussels, scallops, oysters, snails, crustaceans, sea anemones, sponges, starfish, sea urchins, sand dollars, and sea cucumbers. Indicate the degree to which sediment contamination can adversely affect biota; the composition and diversity of benthic communities can provide information on structure and functioning of aquatic ecosystems. |
|
| Fish | Useful indicators of community-level effects; relatively easy to identify most juvenile and adult forms; field study methods are relatively simple and inexpensive. | |
| Semi-aquatic and terrestrial animals | Insects | Small size and large numbers can make them convenient for study; large numbers of species often present; occupy a variety of microhabitats and differ in behaviors enabling measures of a range of effects; some lifestages are dependent on water; include species at different trophic levels to help assess potential for biomagnification of chemical stressors; consider honey bees and many other types pollinators that are declining in health due to pesticides. |
| Soil fauna—includes microbes, insects, and other invertebrates | Perform important functions in terrestrial ecosystems such as soil aeration and organic decomposition that help support growth of terrestrial plants. | |
| Amphibians, reptiles | Range over smaller area. | |
| Birds | Can be resource-intensive; can range far off-site. | |
| Mammals | Small mammals range over smaller area; larger animals may range off-site. | |
| Terrestrial plants | Plants | Provide information about primary producers in terrestrial environments; ecological impact to vegetation can affect other terrestrial biota. |
Sources: U.S. EPA Region 8, 2015; U.S. EPA, 1991; 1994; 2008
Within a particular receptor group (as listed above), a risk assessor might choose to evaluate receptors at one or more of the following levels, depending on which types of receptors are likely to be present at the site (U.S. EPA, 1998).
- Individuals of a given species (e.g., piping plover) or populations (i.e., aggregate of individuals of the same species within a specified location in space and time).
- Functional groups of species that share a common resource (e.g., fish-eating vertebrates or piscivores, burrowers).
- Community—i.e., an assemblage of populations of different species within a specified space and time (e.g., soil community, benthic invertebrates).
One way to identify which types of ecological receptors are likely to be present at a site is to perform a site surveysite surveyAn ecological survey provides a snapshot outline view of what a particular area was like at the time of surveying.An ecological survey provides a snapshot outline view of what a particular area was like at the time of surveying.. Another way is to review available information for species known to occur in certain areas and certain habitat locations as provided on U.S. Fish and Wildlife Service websites and state-specific programs as listed on EPA regional websites. In characterizing receptors, risk assessors typically collect information on the species’ feeding habits, life historieslife historiesThe stages of life/development through which a plant or animal progresses over the course of its life, such as larval, juvenile, adult., habitat preferences, and other attributes that affect their exposure or sensitivity to stressors (U.S. EPA, 1991). This information is helpful in determining likelihood of exposure.
Tools
There are a number of information resources, data sources, and modeling tools listed below to help in the evaluation of plant, animal, and other biotic receptors in an ERA. Please note that many resources from private organizations also provide species lists, but are not included in the tool table below. The resources compiled here are generally limited to freely available resources from U.S. state and federal sources.
In addition to the tools shown below, there are many available sources of information and data related to the fate and transport of contaminants in environmental media and the transfer of contaminants from an environmental medium to receptor. See the Chemical module of the Stressors Tool Set for information and tools on fate and transport related to chemical stressors.
See the Food Chains and Webs module of the Exposure Pathways (Media) Tool Set for information, data sources, and modeling tools available to help in the evaluation of food chain and food web contaminant transfers in an ERA.