Forest streams and brooks are valued and used by humans, but they are also aquatic ecosystems that support communities of animals and plants. The unique characteristics of aquatic environments – both natural conditions and those caused by human activities – determine the kinds of organisms living in them. Aquatic organisms, such as macroinvertebrates that exist in the larval form of certain insects, some adult insects, and members of other invertebrate groups live in these habitats and can be sensitive or tolerant of pollution. Since these invertebrates require certain environmental conditions to ensure their survival surveying a stream to detect their presence tells us about the health of aquatic ecosystems.

Credit: New York State Department of Environment and Conservation

To learn about the surveying methods used to monitor the physical conditions of our streams and the collection and identification methods we use to survey macroinvertebrates, watch our video on Macroinvertebrates inside!