Stream Waders

Why We Do It:

Every spring we assess the macroinvertebrate (e.g., stonefly, mayfly, caddisfly, dragonfly) population in our streams.  Macroinvertebrates are animals big enough to see (macro) and also lack a backbone (invertebrate).

The numbers and species of these insects are an excellent indicator of stream health. Stoneflies and mayflies are among the most pollution sensitive so their presence tells us the stream is healthy.  Worms and snails tolerate pollution so their presence tells us the stream is having problems.

How We Do It:


Volunteers can either attend a one-day training session in March to learn how to collect the insect larva or they can join one of our trained volunteers (a team consists of two people – one trained and one untrained).

Click here to find out more about the training sessions.

Each team is assigned 1-2 streams – sample collection takes about 45 minutes per stream.  The samples are sent to the Maryland Department of Natural Resources where the various insect species are identified.  Data are reported back to us at the end of the year. Contact us to sign up for this exciting program.

Note that the above stream is a lot deeper than those we usually sample.  Most streams are only about 6 inches deep. But they do look like they're having fun!