Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean
Autor: | Aswea D. Porter, Melinda C. Jacobs-Scott, Paul M. Winchell, Erin L. Rechisky, David Welch |
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Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
Washington
Chinook wind Population Dynamics Population Fisheries Pacific ocean Oregon Rivers Salmon Spring (hydrology) Tributary Telemetry Juvenile Animals Letters education Hydropower geography education.field_of_study Pacific Ocean Multidisciplinary geography.geographical_feature_category business.industry Estuary Biological Sciences Survival Analysis Fishery Oceanography Animal Migration business Geology |
Popis: | Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River’s largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. |
Databáze: | OpenAIRE |
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