The Western glacier stonefly generates more attention than you might expect for a tiny bug that only lives in a few streams in Glacier National Park. Joe Giersch, an aquatic entomologist at the USGS and others have spent their careers hunting in untracked parts of Glacier for the tiny stonefly that lives in cold waters from glacial melt.
Stoneflies in waterways are generally good indicators of stream health. They are sensitive to habitat changes from temperature to pollution and often are the first species to disappear when a change occurs.
The glacier stonefly will likely disappear with the melting glaciers and is being considered for ESA listing by 2016. The species is a model for the entire ecosystem that is expected to change without the glaciers; it just happens to be first.
For more info:
Predicting Effects of Climate Change on Aquatic Ecosystems in the Crown of the Continent Ecosystem