Abstract

The Highseas Salmon program of Fisheries and Oceans Canada conducted a survey of Pacific salmon in the Gulf of Alaska from June 18-July 5, 2008 on the CFV Viking Storm. The objectives of the survey were to (1) evaluate the distribution and ecology of juvenile Pacific salmon (Oncorhynchus spp.) during their first year in the ocean, (2) describe the ambient oceanographic conditions, and (3) quantify the biomass of zooplankton. Fish, oceanographic, and zooplankton sampling was conducted at stations off the west coast of Vancouver Island, in Queen Charlotte Sound, Hecate Strait, Dixon Entrance, and off the west coast of the Queen Charlotte Islands. Some additional oceanographic and zooplankton sampling was also conducted in the Strait of Georgia.

A total of 18292 juvenile Pacific salmon, that were in their first summer (age X.0) in the ocean, were caught on this survey. Of these, 63 were juvenile pink salmon (O. gorbuscha), 9670 were juvenile chum salmon (O. keta), 7100 were juvenile sockeye salmon (O. nerka) ,17 were juvenile steelhead (O. mykiss ), 607 were juvenile coho salmon (O. kisutch), and 835 were juvenile chinook salmon (O. tshawytscha) under 300 mm in fork length. Juvenile pink were caught occasionally throughout Queen Charlotte Sound, Hecate Strait and Dixon Entrance. Juvenile chum were caught primarily on the west coast of Vancouver Island both on the shelf, and in Barklay Sound and Quatsino Sound. Juvenile steelhead were caught primarily on the shelf off the west coast of Vancouver Island. Juvenile sockeye , coho, and chinook salmon were caught all along the south to north range of the survey, including the west coast of the Queen Charlotte Islands.

The survey recovered 173 CWT juvenile chinook from the Columbia-Snake River, 22 CWT juvenile coho from coastal Oregon and Washington, 2 CWT juvenile sockeye from Cultus Lake on the Fraser River drainage system, and 2 CWT juvenile sockeye from Redfish Lake on the Snake River basin in Idaho. The CWT recovery patterns support previous studies by the Highseas Salmon program that demonstrated that a significant proportion juvenile chinook, coho and sockeye undertake a rapid northward migration along the continental shelf in their first year at sea.