Downstream Movement of Fall Chinook Salmon Juveniles in the Lower Snake River Reservoirs during Winter and Early Spring
| Autor: | Tobias J. Kock, Frank L. Mullins, R. Kirk Steinhorst, William P. Connor, Kenneth F. Tiffan |
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| Rok vydání: | 2012 |
| Předmět: |
geography
Chinook wind geography.geographical_feature_category biology Aquatic Science biology.organism_classification Fishery Condition factor Downstream (manufacturing) Spring (hydrology) Oncorhynchus Environmental science Juvenile Spatial variability Annual variation Ecology Evolution Behavior and Systematics |
| Zdroj: | Transactions of the American Fisheries Society. 141:285-293 |
| ISSN: | 1548-8659 0002-8487 |
| Popis: | We conducted a 3-year radiotelemetry study in the lower Snake River to (1) determine whether juvenile fall Chinook salmon Oncorhynchus tshawytscha pass dams during winter, when bypass systems and structures designed to prevent mortality are not operated; (2) determine whether downstream movement rate varies annually, seasonally, and from reservoir to reservoir; and (3) identify some of the factors that contribute to annual, seasonal, and spatial variation in downstream movement rate. Fall Chinook salmon juveniles moved downstream up to 169 km and at a sufficiently fast rate (7.5 km/d) such that large percentages (up to 93%) of the fish passed one or more dams during the winter. Mean downstream movement rate varied annually (9.2–11.3 km/d), increased from winter (7.5 km/d) to spring (16.4 km/d), and increased (from 6.9 to 16.8 km/d) as fish moved downstream from reservoir to reservoir. Fish condition factor at tagging explained some of the annual variation in downstream movement rate, whereas wate... |
| Databáze: | OpenAIRE |
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