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Glossary of Bioassessment Terms
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United States
Environmental Protection
Agency |
Office of Water
Office of Wetlands, Oceans
and Watersheds (4502-F) |
EPA843-F-98-001j
July 1998 |
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Wetland Bioassessment Fact Sheet 10
- Ambient Monitoring: Monitoring within natural systems (e.g.,
lakes, rivers, estuaries, wetlands) to determine existing conditions.
- Assemblage: An association of interacting populations of organisms
in a given waterbody. Examples of assemblages used for biological assessments
include : algae, amphibians, birds, fish, herps (reptiles and amphibians),
macroinvertebrates (insects, crayfish, clams, snails, etc.), and vascular
plants.
- Attribute: A measurable component of a biological system. (Karr,
J.R., and E.W. Chu. 1997. Biological Monitoring and Assessment: Using
Multimetric Indexes Effectively. EPA 235-R97-001. University of
Washington, Seattle)
- Biological Assessment (bioassessment): Using biomonitoring
data of samples of living organisms to evaluate the condition or health
of a place (e.g., a stream, wetland, or woodlot).
- Biological Criteria (biocriteria): Numerical values or narrative
expressions that describe the condition of aquatic, biological assemblages
of reference sites of a given aquatic life use designation.
- Biological Integrity: "...the ability of an aquatic ecosystem
to support and maintain a balanced, adaptive community of organisms
having a species composition, diversity, and functional organization
comparable to that of natural habitats within a region." (Karr, J. R.
and D. R. Dudley. 1981. Ecological perspective on water quality goals.
Environmental Management 5:55-68)
- Biological Monitoring (biomonitoring): Sampling the biota of
a place (e.g., a stream, a woodlot, or a wetland)
- Biota: The plants and animals living in a habitat.
- Composition (structure): The composition of the taxanomic grouping
such as fish, algae, or macroinvertebrates relating primarily to the
kinds and number of organisms in the group.
- Community: All the groups of organisms living together in the
same area, usually interacting or depending on each other for existence.
- Criteria (singular = criterion): Statements of the conditions
presumed to support or protect the designated use or uses of a waterbody.
Criteria may be narrative or numeric.
- Designated Use: Classification designated in water quality
standards for each waterbody or segment that defines the optimal purpose
for that waterbody. Examples - drinking water use and aquatic life use.
- Diatom: Microscopic algae with cell walls made of silicon and
of two separating halves.
- Diversity: A combination of the number of taxa (see taxa richness)
and the relative abundance of those taxa. A variety of diversity indexes
have been developed to calculate diversity.
- Ecological Assessment: A detailed and comprehensive evaluation
of the status of a water resource system designed to detect degradation
and if possible, to identify causes of that degradation.
- Ecological Integrity: The condition of an unimpaired ecosystem
as measured by combined chemical, physical (including physical habitat),
and biological attributes.
- Ecoregion: Regions defined by similarity of climate, landform,
soil, potential natural vegetation, hydrology, and other ecologically
relevant variables.
- Functions: The roles that wetlands serve, which are of value
to society or environment.
- Functional Groups: A means of dividing organisms into groups,
often based on their method of feeding (e.g., shredder, scraper, filterer,
predator), type of food (e.g., fruit, seeds, nectar, insects), or habits
(e.g., burrower, climber, clinger).
- Habitat: The sum of the physical, chemical, and biological
environment occupied by individuals of a particular species, population,
or community.
- Herpetiles: Reptiles and amphibians.
- Hydrogeomorphic (HGM) Classification: A wetland classification
system based on the position of a wetland in the landscape (geomorphic
setting), dominant sources of water, and the flow and fluctuation of
water once in the wetland. Hydrogeomorphic classes include riverine,
depressional, slope, mineral soil flats, organic soil flats, estuarine
fringe, and lacustrine fringe.
- Hydrogeomorphic (HGM) Approach: A functional assessment method
which compares a wetland's condition to similar wetland types (as defined
by HGM classification) that are relatively unaltered. HGM functions
normally fall into one of three major categories: (1) hydrologic (e.g.,
storage of surface water), (2) biogeochemical (e.g., removal of elements
and compounds), and (3) habitat (e.g., maintenance of plant and animal
communities).
- Hydrology: The science of dealing with the properties, distribution,
and circulation of water both on the surface and under the earth.
- Impact: A change in the chemical, physical (including habitat),
or biological quality or condition of a waterbody caused by external
forces.
- Impairment: A detrimental effect on the biological integrity
of a waterbody caused by an impact that prevents attainment of the designated
use.
- Index (plural = indices or indexes): An integrative expression
of site condition across multiple metrics. An index of biological integrity
is often composed of at least 7 metric. (Karr, J.R., and E.W. Chu. 1997.
Biological Monitoring and Assessment: Using Multimetric Indexes Effectively.
EPA 235-R97-001. University of Washington, Seattle)
- Index of Biological Integrity: An integrative expression of
the biological condition that is composed of multiple metrics. Similar
to the Dow Jones Industrial index used for expressing the condition
of the economy.
- Macroinvertebrates: Animals without backbones that can be seen
with the naked eye (caught with a 1 mm2
mesh net). Includes insects, crayfish, snails, mussels, clams, fairy
shrimp, etc.
- Metric: An attribute with empirical change in value along a
gradient of human influence. (Karr, J.R., and E.W. Chu. 1997. Biological
Monitoring and Assessment: Using Multimetric Indexes Effectively.
EPA 235-R97-001. University of Washington, Seattle)
- Pollution: The Clean Water Act (�502.19) defines pollution
as "the [hu]man-made or [hu]man-induced alteration of chemical, physical,
biological, and radiological integrity of water."
- Reference Condition: Set of selected measurements or conditions
of minimally impaired waterbodies characteristic of a waterbody type
in a region.
- Reference Site: A minimally impaired site that is representative
of the expected ecological conditions and integrity of other sites of
the same type and region.
- Taxa (singular = taxon): A grouping of organisms given a formal
taxonomic name such as species, genus, family, etc.
- Taxa Richness: The number of distinct species or taxa that
are found in an assemblage, community, or sample.
- Water Quality Standard: A legally established state regulation
consisting of three parts: (1) designated uses, (2) criteria, and (3)
antidegradation policy (See Fact Sheet 7).
- Wetland: Those areas that are inundated or saturated by surface
or groundwater at a frequency and duration sufficient to support, and
that under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions. Wetlands generally
include swamps, marshes, bogs, an similar areas. (Cowardin et al.
1979. Classification of Wetlands and Deepwater Habitats of the United
States. U.S. Department of the Interior. Fish and Wildlife Service.
FWS/OBS-79/31)
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