ABSTRACT
Aquatic invertebrates can be good indicators of water quality and can provide documentation of ecological effects of changing water quality. Bottom-dwelling (benthic) invertebrates have been used extensively to assess biological conditions in streams. Benthic macroinvertebrates can also be used in assessing lake biology, but their use for this purpose has not been common in the United States. More commonly, in this country, biological conditions in the epilimnion of thermally stratified lakes are evaluated using zooplankton. Both stream macroinvertebrate and lake zooplankton data can provide useful information to reveal some of the ecological effects that result from atmospheric deposition of acid precursors, nutrients, or toxic substances and consequent alterations of surface water chemistry.
