What is a Stonefly?
Stoneflies are insects who live in streams and rivers throughout the temperate zone on most continents. The scientific name of the order is Plecoptera and means folded wing. The earliest stonefly fossils have been found in 260 million year old Permian rocks. Stoneflies are more common in mountainous areas with clean water. In our area, mining has caused the disappearance of stoneflies (and the other aquatic insects) from all the orange-red streams you see contaminated with acid mine drainage. However, researchers working in the Arkansas River near the Superfund site by Leadville Colorado have found that a few species of stoneflies are quite tolerant of heavy metals. In fact, stoneflies are good indicators of water quality since they disappear immediately after exposure to some kinds of pollution. Most are among the first taxa to disappear in rivers with low oxygen such as in sewage contaminated rivers. Most of the upper Gunnison Basin is good habitat in excellent condition. Since fish
