evaluation of the biological conditions of a waterbody that uses biological surveys of the resident plants, animals, and other living organisms that depend upon the aquatic resource.

An evaluation of the biological condition of a waterbody that uses biological surveys and other direct measurements of resident biota in surface waters. Most often evaluated is the fish population, the bottom dwelling insects and other invertebrates, and plants or attached algae. Data collected from bioassessments can be used to determine whether the biological health of the waterbody is what would be expected if pollution and other water quality stressors were not causing an effect. Bioassessment data are the foundation for developing biocriteria.

A generic name for monitoring meth...