implications for the management of inland aquatic resources at the ecosystem and landscape scales. NEPA has resulted in a more holistic and long-range view of past, present, and future management actions on natural resources in an ecosystem context and has called for a greater and more thorough knowledge of resource states under different management treatments.
The Endangered Species Act of 1973 (ESA; P.L. 93-205) protects all species (except pests) of plants and animals in danger of extinction. Twelve percent of all animal species live in inland waters, and many species are restricted to limited geographic ranges. As freshwater habitats have been destroyed, altered, or polluted, biodiversity and ecosystem integrity have declined. The listing of federally recognized threatened or endangered freshwater species is an important means of tracking total biological integrity (Covich, 1993). The Endangered Species Act has served to emphasize the importance of identifying and preserving the diversity of inland aquatic organisms and their habitats, and of assessing long-term trends in their conditions.
Several recent developments stemming from these legislative acts have brought the biological aspects of water quality to the forefront: (1) the initiation of several large federal monitoring and assessment programs that emphasize the measurement of water quality in biological rather than solely chemical or physical terms; (2) legal mandates to institute biological criteria into state water quality standards in the next few years; and (3) comprehensive assessment of the status of resources throughout the Columbia River Basin and how to manage these resources. These directives and comprehensive programs at the state and national levels will severely overload existing resource management personnel, a situation that is unlikely to be alleviated at the current rate of qualified graduates entering the work force.
Specific federal programs of monitoring and assessment have been instituted by the Environmental Protection Agency (EPA) and the U.S. Geological Survey (USGS). Presumably, the newly instituted National Biological Service (NBS) also will emphasize biological assessments through wetland surveys, inventories of biological resources, and the like, unless these responsibilities are abrogated by the new Congress.
At the moment, the premier U.S. federal program involving bioassessment is the National Water Quality Assessment (NAWQA) Program of the USGS (Gurtz, 1994). This program is designed to integrate chemical, physical, and biological data to assess the status of, and trends in, national water quality. It consists of 60 study units (major river basins and large aquifers) located throughout the country (Gurtz, 1994) that represent