|Document Type:||Contract Report|
|Title:||A study to define the migrational characteristics of Chinook and coho salmon and steelhead trout in the Columbia River estuary: annual report-1977|
|Author/Editor:||Earl M. Dawley, Carl W. Sims, Richard D. Ledgerwood|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||Pacific Northwest Regional Commission. Vancouver, Washington|
The National Marine Fisheries Service, in cooperation with the Pacific Northwest Regional Commission, initiated a 3-year study of the migrational characteristics of juvenile salmon and steelhead trout in the Columbia River estuary in February 1977. The overall objectives of this study are to: (1) monitor the survival of the various stocks of hatchery fish released into the Columbia River, (2) develop a sampling system capable of evaluating hatchery production techniques and procedures, and (3) define the migrational characteristics of juvenile salmonids to and through the estuary.
Research activities in 1977 concentrated on the development of an operational sampling system in the upper Columbia River estuary at Jones Beach, Oregon, along with defining migrational timing, rates of movement, and relative survival of hatchery releases to the estuary. Research in these areas will continue in 1978 and 1979. In addition, new studies will be initiated to determine if the sampling system can provide survival estimates that are statistically related to actual adult returns.
If this is in fact true, the estuary sampling system at Jones Beach can provide a new and unique method of evaluating hatchery production techniques based on juvenile survival to the estuary rather than on the much later adult returns. The system would also be able to provide yearly abundance estimates and forecasts of year-class survival. Planning for 1978 also includes establishment of a second sampling site in the lower estuary. This will provide needed information on migrational timing through the estuary and estuarine residence requirements of migrating juveniles.
This report summarizes the results of research conducted during 1977.