measurements of lake basin, such as water depth, sediment
depth, relief of bottom, or volume.
community-an aggregate of organisms that form a distinct ecological unit. A
community may be comprised of plant or animal life or a combination. The
spatial scale of a freshwater community may be as vast as the pelagic zone
(open water) phytoplankton of Lake Michigan or as highly localized as the
algae attached to a submerged log. Since plants and animals occur on the same
habitat and have many interrelations, they comprise the biotic community.
initial or existing conditions or flux before treatment or impact.
living on the bottom or at the greatest depths of a body of water.
bioassay-a test procedure that measures the response of living plants, animals,
or tissues to a sample that usually contains a pollutant. For example, algae
may be exposed to a predetermined concentration of atrazine in the lab or
some other controlled environment. The results of the experiment may be
used to estimate the potential response of the organism to stress from
pesticides in the natural environment.
biota -the animals and plants that live in a particular location or region.
concentration -mass per unit volume such as milligrams per liter.
bacteria-a type of bacteria that ferments lactic acid, producing a gas.
Fecal coliform bacteria are found in the intestinal tracts of mammals. The
presence of high numbers of fecal coliform bacteria in a water body can
indicate the recent release of untreated wastewater or the presence of animals
and may indicate the presence of pathogens.
a measure of the conducting power of a solution. Expressed in
micromhos per centimeter at 25 degrees C.
a ratio used to describe the fit between a regression
equation and a set of data.
the correlation coefficient
the fit of the regression equation improves.