Survival Estimates for Migrant Yearling Chinook Salmon and Steelhead Tagged with Passive Integrated Transponders in the Lower Snake and Lower Columbia Rivers, 1993–1998

Autor: John G. Williams, Eric E. Hockersmith, John R. Skalski, Steven G. Smith, William D. Muir
Rok vydání: 2001
Předmět:
Zdroj: North American Journal of Fisheries Management. 21:269-282
ISSN: 1548-8675
0275-5947
DOI: 10.1577/1548-8675(2001)021<0269:sefmyc>2.0.co;2
Popis: Precise, up-to-date survival estimates for salmonids that migrate through reservoirs, hydroelectric dams, and free-flowing sections of the Snake and Columbia rivers are essential to develop effective strategies for recovering depressed stocks. To provide this information, survival was estimated for yearling chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss with passive integrated transponder (PIT) tags that migrated through Snake River dams and reservoirs from 1993 through 1998. A multiple-recapture model for single release groups was used to estimate survival from detections of PIT-tagged fish at dams. The stretch of river over which survival was estimated varied between years, depending on the release site, the number of dams with the capability to detect and rerelease PIT-tagged fish back to the river, the total number of fish marked, and the efficiency of detecting PIT-tagged fish at each dam. Precision of survival estimates varied with the number of fish PIT-tagged and released...
Databáze: OpenAIRE
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