Macroinvertebrate Monitoring

Volunteer collecting macroinvertebrates in Gravelly Brook, Ipswich.

Through this program, IRWA volunteers collect data on “benthic macroinvertebrates” – a biological term that means an organism without a backbone (invertebrate), that can be seen with the naked eye (macro), and lives on the river bed rather than in the water column (benthic). Benthic macroinvertebrates include insects such as larval damselflies, dragonflies, and midges, as well as crustaceans, mollusks, etc. that live in the streambeds of fresh water rivers like the Ipswich.




The presence of different types of benthic macroinvertebrates are good indicator of water quality.

Macroinvertebrates, or “macros” for short, are an important part of the ecology of the Ipswich River. They can also be used as an indicator of water quality based on their preferences and tolerances. For example, certain macros such as mayfly larvae can only thrive in waters with relatively high dissolved oxygen. Therefore, the presence of mayfly larvae in a river segment is an indicator of high dissolved oxygen. However, if that river segment only contained macros that can tolerate low dissolved oxygen (such as damselfly larvae) we could conclude that the dissolved oxygen levels are too low to support a diverse range of macros.




Sampling, sorting and identifying macroinvertebrates is a fun activity for volunteers. To find out how to get involved in this program and for information of when these events take place, contact the Program Coordinator Ryan O’Donnell at

Macroinvertebrate Sampling Sites

Information for Volunteers: