USGS Scientist Standing in a Metal Contaminated Stream
U.S. Geological Survey (USGS) scientist pauses during field work in a stream impacted by acidic runoff and metal contamination. Iron precipitates are visible on the stream's rocks. The mesh pyramid is an insect emergence trap. A riparian zone rich in terrestrial insects can provide an alternate food source for fish in metal-impacted watersheds. USGS scientists have found that fish diets can switch from aquatic to terrestrial insects in streams effected by metal contamination.