Summary #
Several standardized methods exist for using biological organisms to assess stream health. This page describes the most common biological assessment approaches used in volunteer and professional monitoring programs.
Biological testing can involve any organism that is a part of the waterway, including bird and mammal interaction. The two most common biological testing methods, however, are the biotic index and fish shocking.
The biotic index uses a pollution sensitive index to determine the health of a waterway from the macro invertebrate population. Macro invertebrates are the insects, molluscs, and worms living in the streams and rivers. They are large enough to be seen with the naked eye. Macro invertebrates may also be referred to as benthic, or bottom dwelling, organisms.
Fish shocking is another method of biological assessment. This method allows you to gain a fairly accurate representation of the fish population size and diversity. A similar pollution sensitive index to that of insects can be used on fish.
Sources/Links (as provided in the source text):
Related Pages #
- Developing a Monitoring Plan
- Water Quality — What biological monitoring tells us
- Collection Methods — How to collect biological samples
- Macroinvertebrate Guide — Identifying stream organisms
Source and Last Reviewed #
Source: AMR Clearinghouse (amrclearinghouse.org). Migrated to AML-Connect. Last Reviewed: 2026-03-13.
[Admin note: Some external links in this article may be outdated. Verify before relying on them. Flag dead links for removal or replacement.]
Tags: monitoring, sampling, education
