Abstract

The Highseas Salmon program of Fisheries and Oceans Canada conducted a survey of Pacific salmon in the Gulf of Alaska during August 15-26, 2002. The objectives of the surveys 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, an important prey for Pacific salmon at sea. Fish, oceanographic, and zooplankton sampling was conducted at stations spanning the area from Estevan Point on the west coast of Vancouver Island in southern British Columbia (49.3°N) to Forrester Island off Southeast Alaska (54.8°N).

A total of 7263 Pacific salmon were caught on the survey. Of these, 3615 were juvenile pink salmon (O. gorbuscha), 2840 were juvenile chum salmon (O. keta), 49 were juvenile sockeye salmon (O. nerka) and 325 were juvenile coho salmon (O. kisutch) in their first summer in the ocean and 43 were chinook salmon (O. tshawytscha) under 350 mm in fork length.

Juvenile pink, chum, and sockeye were caught on the shelf throughout the range of the survey. Juvenile pink and chum were relatively abundant, while only a few juvenile sockeye were caught. Almost all juvenile coho (age X.0) and all size classes of chinook were caught in two regions: in the south on the shelf off the west coast of Vancouver Island, and further north on the shelf along the Forrester Island transect and in Dixon Entrance.

Juvenile pink, chum, and coho increased significantly in fork length from the west coast of Vancouver Island to Southeast Alaska.

Five CWT chinook were recovered, including three from the northern regions of Dixon Entrance and Southeast Alaska. All were rapidly migrating, age 1.0 chinook that had been released into the Columbia River in Washington and Oregon in the spring of 2002.

Six CWT coho were recovered: five off the west coast of Vancouver Island and one inside Southeast Alaska. All were age 1.0 juvenile coho that had been released from Washington and Oregon hatcheries in the spring of 2002.