Research on a System for Bypassing Juvenile Salmon & Trout Around Low-Head Dams
adult, Army Corps of Engineers, bypass, Columbia River, diversion, fish ladder, intake, juvenile, mortality, predation, salmon, screens, steelhead, traveling screen, trout, turbines
Journal or Book Title
Commercial Fisheries Review
Young Pacific salmon (genus Oncorhynchus) and steelhead trout (Salmo gairdneri) from the upper Snake and Columbia Rivers must now pass through 6 to 9 low-head dams (such as Bonneville) on their journey to the sea. Although these dams are equipped with fish ladders to aid them when they return as adults, only recently have facilities for safe guarding them as juveniles begun to receive attention. Juvenile fish are subject to mortality from turbines and from predators immediately downstream from the dams. BCF and the U.S. Army Corps of Engineers are now modifying existing facilities to protect juvenile fish. The method provides for diverting most of the fish that enter turbine intakes into a bypass. This report explains the nature of the modification, how it may protect fish, and the type of research needed to prove the adequacy of the system.