Many of us volunteering in stream monitoring are familiar with "macroinvertebrates", but most people don't know why these animals are indicators of stream health.
According to the EPA, "macroinvertebrates are small organisms without a backbone that are visible to the naked eye and large enough to be easily collected." They typically live in water for some, if not all, stages of their life. Think crayfish, mayflies, aquatic worms, or beetles.
Macroinvertebrates are helpful in water monitoring as they have "differing sensitives to chemical pollution and physical disturbances" (EPA). In short, knowing how many and what kind of macroinvertebrates are living in a body of water can help tell us how healthy or unhealthy the habitat is for them. If you find multiple stonefly larvae during your spring biotic index (look for two tails!), your stream is likely healthy.
That's why WAV has developed a Biotic Index poster to help our volunteers and students of all ages identify and count macroinvertebrates!
