Northwest Fisheries Science Center

Display All Information

Document Type: Contract Report
Center: NWFSC
Document ID: 6749
Title: Effects of flow on the migratory behavior and survival of juvenile fall and summer Chinook salmon in John Day Reservoir 1984
Author/Editor: David R. Miller, Carl W. Sims
Publication Year: 1984
Publisher: National Marine Fisheries Service
Contracting Agency: Bonneville Power Administration. Portland, Oregon
Contract Number: DE-A179-83BP36945
Pages: 51
Date: 06/01/1984

The National Marine Fisheries Service in cooperation with the Bonneville Power Administration is conducting a 6–year study of the effects of instream river flow on the passage time, survival, and migrational behavior of juvenile fall and summer (0–age) chinook salmon in John Day Reservoir.  In 1983, the final year of juvenile sampling in the reservoir, research activities continued to refine flow/travel time relationships and distributional behavior of 0–age chinook salmon.  Fifteen groups (72,559 fish) of marked 0–age chinook salmon were wire–tagged, branded, and released into the tailrace at McNary Dam, and 32 groups (22,206 fish) were branded and released into the reservoir at various other sites.  Sampling at John Day Dam, utilizing the airlift pump system in the B and C slots of Turbine Intake Unit 3, captured 82,698 subyearling chinook salmon including 640 mark recoveries.  Additional marks (458) were recovered from purse–seine samples taken at various sites throughout the reservoir.  Weekly mean fork lengths of 0–age chinook salmon captured at McNary and John Day Dams and in the reservoir by purse seine ranged from 103 mm in mid–June to 166 mm in mid–December.  Fish captured at the John Day Dam monitoring facility and by purse seine throughout the reservoir were in excellent condition.  Preliminary analysis of stomach samples taken in 1982 and 1983 from purse–seine catches indicates active feeding is taking place in the reservoir.