Steps in Developing a Bioassessment and Biocriteria Program

Final Ecological Classification and Expectations

The preliminary ecosystem classification is tested with the biological data to determine whether it consistently reflects the biological communities. If necessary, the classification is revised. Seasonal and spatial variability in biological data are accommodated by using measures of central tendency and variability, and by indexing the sampling period to one or two seasons (index period sampling). Successful classification will result in less variation within a class, leading to more refined characterization of the reference condition and, therefore, to criteria with better resolution for detecting impairment.

EPA encourages refinement of designated aquatic life uses to protect the biological integrity identified by the final ecological classifications. Furthermore states and tribes can stratify their aquatic life uses within each ecological class to reflect the management objectives for the waterbody and set appropriate protection and restoration goals. Development of a such a tiered designated aquatic life use system should occur concurrently with biological criteria development so that the aquatic life uses will be adequately protected by the criteria.

Review case studies on: Setting Ecologically-Based Water Quality Goals