North America Benthological Society

Izaak Walton League of America Save Our Streams

Know Your Macros by Michael Clapp - slideshow about macroinvertebrates and how to identify them

Name That Bug - benthic macroinvertebrate identification page with color photos

Macroinvertebrate ID Key - by New York DEC

Benthic Macroinvertebrates in Our Waters - EPA

Aquatic Insects of American Trout Streams - excellent macroinvertebrate photos

The Fisher Monk (guide to identifying mayflies for fly fishermen)

Mayfly Identification - by Dr. Corey Leonhard

An Introduction to Benthic Macroinvertebrates - by Kentucky Water Watch Program