Upstream Passage Monitoring: Difficulties in Estimating Survival for Adult Chinook Salmon in the Columbia and Snake Rivers
- 1 August 2000
- journal article
- Published by Oxford University Press (OUP) in Fisheries
- Vol. 25 (8) , 24-34
- https://doi.org/10.1577/1548-8446(2000)025<0024:upmdie>2.0.co;2
Abstract
We reviewed current methods used to estimate survival of adult chinook salmon (Oncorhynchus tshawytscha) as they migrate upstream past hydroelectric projects in the Columbia and Snake rivers, evaluated known and unaccounted-for loss factors, and assessed how adult survival estimates could be improved. Dam counts and associated passage conversion rates do not always provide accurate estimates of adult survival between hydroelectric projects. Expansion techniques for reconstructing run size and harvest rates also contribute to variability in estimates of run size and potential loss between hydroelectric projects. Use of passage conversion rates to estimate in-river survival of adult spring chinook salmon had less uncertainty than for estimates of other runs. Fixed-run cutoff dates for migration timing result in a high uncertainty for monitoring relative numbers of summer chinook salmon. We also found it difficult to reconstruct run size to spawning areas or to estimate interdam survival for fall ch...This publication has 0 references indexed in Scilit: