Fish response to discharge events from a power plant cooling reservoir in a river affected by acid mine drainage and thermal influences.

摘要

In the summer, a discharge from a power plant cooling reservoir (Mount Storm Lake) located on the Stony River can result in large increases in discharge and temperature. Further, the Stony River is affected by mining-impacted tributaries, which degrade water quality. To study the impact of reservoir discharges upon fish populations we evaluated community composition and smallmouth bass (Micropterus dolomieu) movement along a temperature gradient and relative to the mining-impacted tributaries. The fish community did not differ with discharge events, but community structure varied with mining-impacted inputs. Smallmouth bass avoided areas associated with mining-influenced inputs. Thermal increases associated with reservoir discharges have minimal effects on fish movement and the current community composition. Fish movement and community composition are influenced by the presence of mining-influenced tributaries. Although effective treatment of acid mine drainage reduces the negative influence on fish communities, these inputs are still likely degrading miles of streams.