ABSTRACT
Biomonitoring is the process of inventorying aquatic organisms in a selected region of an aquatic system. The types of organisms can range from benthic macroinvertebrates to algae to fish. All organisms have a tolerance level for pollutants. Tolerance levels vary from organism to organism. Thus, it is possible to determine at a point in time, qualitatively, the level of water quality impairment based on what fauna are present and their abundances. It is also possible to monitor changes in water quality by repeated sampling of the same areas over an extended period of time. As mentioned, benthic macroinvertebrates are excellent indicators for several reasons: (1) They are ubiquitous. (2) They are relatively sedentary and long-lived (larval and nymph forms). (3) Some species of benthic macroinvertebrates are sensitive to pollution, and
some are tolerant. (4) Benthic macroinvertebrates are easy to collect and identify.
