Macroinvertebrates: Important Information From Insects Living In A Stream, River or Lake
Stonefly
I'm an entomologist.  That's right I study bugs-especially aquatic ones that the fish eat.  But the bugs or benthic macroinvertebrates tell us a story for biomonitoring and bioassessment. Unfortunately, a story that too many EPA and DEPs don't like: what's really happening to our streams.  The macroinvertebrates are the best indicators of stream pollution and environmental degradation.  The EPA Rapid Bioassessment Protocols which are used (sometimes) are more than a bit outdated.  Each state has their own derived version of these protocols but you'd never know it from their use.  DEPs don't like benchmarking and establishing baselines for their waters.  And for good reason, it would show just how bad much of their work is with the issuance of NPDES. Instead many departments lean towards chemical data (which is fleeting to say the least) which can easily be rigged or done improperly.
mayfly
The decline in both quality and quantity of macroinvertebrate communities is a major sign of total stream and river degradation in America. Aquatic scientists label or define waters by certain indicator species from macroinvertebrate communities.  These are usually quantified in some form to give an environmental index or "rating."  By benchmarking and establishing baselines for streams,  rivers, and lakes using these indicators a complete progression can be seen on the health of the water