Effects of Power Peaking Operations on Juvenile Salmon and Steelhead Trout Migrations - Progress 1977

Abstract

Abstract : Research activities in 1977 continued to define the effects of dams, power peaking, and flow regulation on juvenile salmon and steelhead migrations in the Snake and Columbia Rivers. Juvenile salmonid migrations were sampled in the Salmon, Snake, and Columbia Rivers(Figure 1), Fish were marked and released at various sites to provide information on survival, migrational timing, and rates of downstream movement, A scanning sonar system was used to define movement and behavioral characteristics of juveniles at dams, Diel movement patterns at dams, residualism, and predator fish population were also investigated. River flows in the Columbia River Basin during 1977 were the lowest on record. The fishery agencies and water management entities implemented an action plan to protect downstream migrants. This plan, called Operation Fish-flow 1977, provided water for augmenting river flows and spilling at Columbia River dams during periods of peak juvenile migration. This research program was charged with monitoring fish migrations at McNary, John Day, The Dalles, and Bonneville Dams to insure the optimum use of allotted water along with measuring the benefits of this special spill and flow augmentation.