Northwest Fisheries Science Center

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Document Type: Contract Report
Center: NWFSC
Document ID: 7023
Title: Migratory behavior and adult contribution of summer outmigrating subyearling Chinook Salmon in John Day reservoir, 1981-1983
Author/Editor: Albert E. Giorgi, David R. Miller, Benjamin P. Sandford
Publication Year: 1990
Publisher: National Marine Fisheries Service
Contracting Agency: Bonneville Power Administration. Portland, Oregon
Contract Number: DE-AI79-83BP39645
Project Number: 81-1
Date: 1990

During summer 1981–1983, the National Marine Fisheries Service investigated the effects of river flow volumes on the travel time of subyearling chinook salmon migrating through John Day Reservoir.  Analyses were based on mark recovery data from freeze–branded fish released in the McNary Dam tailrace and recaptured at John Day Dam.  In addition to this effort, the distribution of juvenile chinook salmon within the reservoir was observed through purse–seine sampling.  Coded–wire tag data provided a measure of intra– and interannual performance in terms of adult contribution.  The travel time data were largely inconclusive.  This was due to poor mark–recovery capability coupled with the difficulty of isolating flow from other closely related variables.  A large portion of the juveniles tended to range upstream and did not exhibit consistent displacement downstream.  Subyearling chinook salmon migrating through John Day Reservoir early in the summer contributed more adults than those juveniles migrating later in the summer.  This pattern was consistent each year.   

Notes: Author is Sandford, not Sanford