The Ohio River Ecological Research Program (ORERP): History and Accomplishments.

The article focuses on the Ohio River Ecological Research Program (ORERP), a 50-year collaborative monitoring effort initiated by multiple power plants along the Ohio River to assess potential impacts of thermal discharges and cooling water intake structures on fish communities. The ORERP conducted extensive fish community sampling, impingement studies, and larval fish entrainment assessments, finding that thermal avoidance by fish near discharge areas is temporary and reversible, with no long-term community disruptions detected. Impingement was episodic and dominated by young clupeids and Freshwater Drum, while entrainment studies revealed large annual variability influenced by species' spawning behaviors. The program's comprehensive data have supported regulatory decisions, resource management, and serve as a model for public-private collaboration in managing large aquatic ecosystems.