Appendix A
Glossary of Terms
a posteriori classification: a classification made based
upon the results of experimentation.
a priori classification: a classification made prior to
experimentation.
alkali lakes: also referred to as "soda lakes;" characterized
by high pH (³=pH 10) and a high concentration of salts.
antidegradation statement: statement that protects existing
designated uses and prevents high-quality waterbodies from deteriorating
below the water quality necessary to maintain existing or anticipated
designated beneficial uses.
aquatic assemblage: an association of interacting populations
of organisms in a given waterbody, for example, fish assemblage or a benthic
macroinvertebrate assemblage.
aquatic community: an association of interacting assemblages
in a given waterbody, the biotic component of an ecosystem.
aquatic life use: a beneficial use designation in which
the waterbody provides suitable habitat for survival and reproduction
of desirable fish, shellfish, and other aquatic organisms.
assemblage structure: the make-up or composition of the
taxonomic grouping such as fish, algae, or macroinvertebrates relating
primarily to the kinds and number of organisms in the group.
beneficial uses: desirable uses that water quality should
support. Examples are drinking water supply, primary contact recreation
(such as swimming), and aquatic life support.
Best Management Practice (BMP): an engineered structure
or management activity, or combination of these, that eliminates or reduces
an adverse environmental effect of a pollutant.
biological assessment: an evaluation of the biological
condition of a waterbody that uses biological surveys and other direct
measurements of resident biota in surface waters.
biological criteria: numeric values or narrative expressions
that describe the reference biological condition of aquatic communities
inhabiting waters that have been given a designated aquatic life use.
biological indicators: plant or animal species or communities
with a narrow range of ecological tolerance that may be selected for emphasis
and monitored because their presence and relative abundance serve as a
barometer of ecological conditions within a management unit.
biological integrity: the condition of the aquatic community
inhabiting unimpaired waterbodies of a specified habitat as measured by
an evaluation of multiple attributes of the aquatic biota. Three critical
components of biological integrity are that the biota is (1) the product
of the evolutionary process for that locality, or site, (2) inclusive
of a broad range of biological and ecological characteristics such as
taxonomic richness and composition, trophic structure, and (3) is found
in the study biogeographic region.
biological monitoring: the use of a biological entity
as a detector and its response as a measure to determine environmental
conditions. Toxicity tests and biological surveys are common biological
monitoring methods.
biological survey (biosurvey): the process of collecting,
processing, and analyzing representative portions of a resident aquatic
assemblage to determine the assemblage structure and function.
biota: plants, animals and other living resources of a
region.
bisection scoring: used when metric value distribution
is based upon data from unimpaired reference sites. The 25th percentile
becomes the minimum value for the highest score: the difference between
the 25th percentile and 0 is divided into two equal parts.
canonical correlation analysis (CC): a linear multivariate
ordination procedure using linear canonical equations with multiple dependent
and independent variables.
canonical correspondence analysis: a non-linear multivariate
ordination procedure.
Carlson's Trophic State Index (TSI): a numerical index
for estimating lake trophic state on a scale of 0 to 100 with each increase
of 10 in the index representing a doubling of algal biomass.
coefficient of variation: standard deviation (from the
mean) expressed as a percentage of the mean.
community component: any portion of a biological community.
The community component may pertain to the taxonomic group (fish, invertebrates,
algae), the taxonomic category (phylum, order, family, genus, species,
stock), the feeding strategy (herbivore, omnivore, predator), or the organizational
level (individual, population, assemblage) of a biological entity within
the aquatic community.
designated use classifications: classification of a waterbody
or segment based on the purposes (beneficial uses) for which the waterbody
may be used as specified in water quality standards.
diatoms: any of a number of related microscopic algae,
one-celled or in colonies, whose walls consist of two parts or valves
and contain silica.
discriminant analysis: a type of multivariate analysis
used to distinguish between two groups.
ecological or environmental indicators: measurable features
of an ecosystem that singularly or in combination with other features
provide managerially useful evidence of water resource or ecosystem quality,
or reliable evidence of trends in quality. Indicators can be biological,
physical, or chemical measurements, and can sometimes have elements of
more than one discipline: for instance, concentrations of chemicals in
fish tissue.
ecological integrity: the condition of the biotic (aquatic
community) and abiotic components (water chemistry and habitat) of unimpaired
waterbodies as measured by assemblage structure and function, water chemistry,
and habitat measures.
ecological properties: biotic and habitat attributes of
a waterbody.
ecoregions: a relatively homogeneous area defined by similarity
of climate, landform, soil, potential natural vegetation, hydrology, or
other ecologically relevant variable.
epifauna: benthic animals living on the sediment or among
rocks and other structures.
epilimnion: the upper waters (above the metalimnion) of
a thermally stratified lake.
expert consensus: a method used to establish reference
condition when no candidate sites are available based on the collective
experience and expertise of regional biologists.
flowage lakes: areas of a river system which are sufficiently
deep, slow moving and wide to have lacustrine characteristics. Unlike
reservoirs, they typically have wide inflow and outflow regions.
forebay zone: same as the lacustrine zone of a reservoir.
frustule: the hard shell of a diatom.
gradient analyses: a suite of statistical techniques including
principal component analysis, canonical correlation's analysis, and canonical
correspondence analysis used to examine the relationships between biotic
and environmental factors.
habitat: a place where the physical and biological elements
of ecosystems provide a suitable environment including the food, cover,
and space resources needed for plant and animal livelihood.
hypoxic: waters that have a very low oxygen level.
infauna: animals that live within the sediments, often
in holes they have dug.
inflow zone: area where a river enters a reservoir.
interquartile coefficient: the ratio of the interquartile
range of a metric to its scope for detection.
lacustrine zone: area of a reservoir which is most lake-like:
current velocities are much slower than for riverine or transitional zones.
Little sediment deposition normally occurs since most sediment load has
been deposited in the riverine or transitional zones; may thermally stratify;
primary productivity predominates.
lake: a body of fresh or salt water of considerable size,
whose open-water and deep-bottom zones (no light penetration to bottom)
are large compared to the shallow-water (shoreline) zone, which has light
penetration to its bottom.
limnology: the study of the functional relationships and
productivity of freshwater biotic communities as they are affected by
the dynamics of physical, chemical and biotic environmental parameters.
littoral zone: the area of a lake near the shore from the
region of the highest seasonal water level to the deepest point at which
attached submerged macrophytes occur.
log linear models: statistical modeling techniques for
dealing with categorical data.
marl lakes: lakes in which solid calcium carbonate precipitates
during periods of high photosynthesis forming a characteristic marl bench
in the euphotic zone.
metalimnion: the stratum of steep thermal gradient that
separates the epilimnion from the hypolimnion in a thermally stratified
lake.
morphoedaphic index (MEI): the ratio of dissolved solids
(measured as total dissolved solids, alkalinity, or conductivity) to mean
lake depth; MEI has been used to predict the total fish production, phytoplankton
standing crop, and total phosphorus concentration of lakes not subject
to cultural eutrophication.
multiple metric or multimetric approaches: analysis techniques
using several measurable characteristics of a biological assemblage.
multiple use: when a water body has more than one beneficial
use designation.
multivariate community analysis: statistical methods (e.g.,
ordination or discriminant analysis) for analyzing physical and biological
community data using multiple variables.
ombrotrophic bog: an acidic wetland which receives all
of its nutrients from atmospheric deposition.
ordination analysis: a set of techniques in which sampling
units are arranged in relation to one or more coordinate axes such that
their relative positions to the axes and to each other provide maximum
information about their ecological similarities.
oxycline depth: depth at which dissolved oxygen levels
fall below a threshold value.
paleolimnology: the study of the environmental history
of inland waters, based primarily on analysis of biological, chemical,
and physical characteristics of sediment cores.
pelagic zone: the area of open water beyond the littoral
zone.
predictive models: statistical models that can be used
to predict biological response based on ecological (habitat) variables.
Principal Components Analysis (PCA): a linear multivariate
ordination technique that determines a reduced set of coordinate axes.
principal axes: new variables created by ordination analysis
that account for variation in the data.
profundal zone: the sediments beyond the littoriprofundal
zone.
reference site: a site on a waterbody which represents
the best attainable physical habitat, water chemistry, and biological
parameters for specific environmental conditions.
reference condition: The chemical, physical, or biological
quality or condition exhibited at either a single site or an aggregation
of sites that represent the least impared or reasonably attainable condition
at the least impared reference sites.
regression: any of a number of statistical techniques
in which the relationship of one (or more) variable(s) is (are) estimated
as a function of another variable or variables.
reservoir: a lake created for human use often as the result
of impoundment of a river system; classified as lake type 73 by Hutchinson
(1957).
risk assessment: a scientific process that includes hazard
identification, receptor characterization and endpoint selection, stress-response
assessment, and risk characterization.
riverine zone: the relatively narrow and well-mixed area
of a reservoir immediately down-stream of the river inflow where current
velocities decrease and significant sediment transport still occurs.
robust: insensitive to assumption violations, i.e., holds
even when the probability model is incorrect.
scope for detection: the range from 0 to the lower quartile
for metrics that have high values under unimpaired conditions (e.g., EPT
index) or that range from the upper quartile to 100 for metrics that have
low values under unimpaired conditions (e.g., percent Chironomidae).
spatial variability: variation in a biological parameter
due to different ecological conditions among sites.
temporal variability: variation in a biological parameter
due to temporal fluctuations in ecological condition such as changing
water chemistry or sunlight, e.g., diurnal and seasonal variations.
Total Maximum Daily Load (TMDL): The total allowable pollutant
load to a receiving water such that any additional loading will produce
a violation of water-quality standards.
transitional zone: area of a reservoir between the riverine
and lacustrine zones; current velocities are intermediate, significant
sedimentation occurs, light penetration increases and primary productivity
increases.
trisection scoring: used when metric value distribution
is based upon data from reference and impaired sites (population distribution).
The range of values from the 95th percentile to 0 is divided into thirds
with the top third receiving the highest score, the middle third receiving
the intermediate score, and the bottom third receiving the lowest score.
trophic state index: any numerical index for estimating
trophic state of a lake.
unimodal response: a response in which a species has [a
single] peak abundance at [an] optimal value [or range] of an environmental
variable and its abundance is lower at higher or lower values of [that]
environmental variable.
univariate tests: statistical tests for comparing two
or more groups; techniques include t-test, analysis of variance, sign
test, Wilcoxon rank test, and the Mann-Whitney U-test.
water quality standards: provisions of state or federal
law which consist of a designated use or uses for the waters of the United
States, water quality criteria for such waters based upon such uses. Water
quality standards are to protect public health or welfare, enhance the
quality of the water and serve the purposes of the Clean Water Act (40
CFR 131.3) (USEPA 1983) a law or regulation that consists of the beneficial
designated use or uses of a waterbody, the numerical and narrative water-quality
criteria that are necessary to protect the use or uses of that particular
waterbody, and an antidegradation statement (ITFM 1994).
Home ~ Preface ~ Chapter 1 ~ Chapter 2
Chapter 3 ~ Chapter 4 ~ Chapter 5 ~ Chapter 6
Chapter 7 ~ Chapter 8 ~ Chapter 9 ~ Chapter 10
Appendix A ~ Appendix B ~ Appendix C ~ Appendix D
Appendix E ~ Appendix F ~ Appendix G
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