Northwest Fisheries Science Center

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Document Type: Contract Report
Center: NWFSC
Document ID: 6743
Title: An assessment of freeze–brand and PIT–tag recovery data for juvenile salmonids at McNary Dam, 1988
Author/Editor: Clinton Scott McCutcheon, Albert E. Giorgi
Publication Year: 1990
Publisher: National Marine Fisheries Service
Contracting Agency: Bonneville Power Administration. Portland, Oregon
Contract Number: DE-AI79-87BP34269
Project Number: 97-130
Pages: 31
Date: 02/01/1990

This study evaluated mark recovery data from PIT–tagged and freeze–branded river–run yearling and subyearling chinook salmon (Oncorhynchus tshawytscha), sockeye salmon (O. nerka), and steelhead (O. mykiss) at McNary Dam in 1988.  Double–marked (PIT–tagged and freeze–branded) juvenile salmonids were released within the McNary Dam collection system upstream from the PIT–tag detectors and brand–sampling system.  Results indicate that brands were recovered in smaller proportions than PIT tags, and the variability of brand data was considerable.  Most of the error associated with brands was attributable to human error inherent in brand detection and interpretation.