Macroinvertebrates are animals without a backbone that can be seen with the naked eye. These bottom-dwelling animals include crustaceans and worms but most are aquatic insects. Beetles, caddisflies, stoneflies, mayflies, hellgrammites, dragonflies, true flies, and some moths are among the groups of insects represented in streams. Macroinvertebrates are an important link in the food web between the producers (leaves, algae) and higher consumers such as fish.
Macroinvertebrate Identification Resources
- Macroinvertebrates.org, an explorable resource for stream insect identification
- Freshwater Macroinvertebrates of New York
Visit Stroud™ Water Research Center’s Leaf Pack Network® website to learn about a simple experiment that uses tree leaves and aquatic insects to determine the health of your local stream.
The following books are recommended resources. Check your local library; they are also available for purchase from online booksellers.
McCafferty, W. P. 1981. Aquatic entomology: The fishermen’s guide and ecologists’ illustrated guide to insects and their relatives. Jones and Bartlett Publishing Company, Boston, Massachusetts.
Voshell, J. Reese. 2002. A guide to common freshwater invertebrates of North America. The McDonald & Woodward Publishing Company, Blacksburg, Virginia.
Stream Sampling Information
Protocols and Fact Sheets
- Didymo Fact Sheet
- EPA Volunteer Stream Monitoring: A Methods Manual
- EPA Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers
Stream Sampling License and Permit Information
Citizens from outside Pennsylvania should consult with the appropriate state agency for permit requirements.
Pennsylvania law requires anyone 16 years of age or older collecting aquatic organisms for any reason to have a valid fishing license and follow current Pennsylvania Fish & Boat Commission regulations.
High school and undergraduate college students are exempt from the license requirement if their teacher/educator applies for and is issued an Educational Aquatic Field Study Permit. For more information, visit the Pennsylvania Fish & Boat commission website.