Abstract

The Highseas Salmon program of Fisheries and Oceans Canada conducted a survey of Pacific salmon in the Gulf of Alaska during October 8-27, 2003. 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 Barkley Sound on the west coast of Vancouver Island in British Columbia (48.86° N) to Sumner Strait in Southeast Alaska (56.46° N).

A total of 3381 Pacific salmon were caught on the survey. Of these, 1652 were juvenile pink salmon (O. gorbuscha), 498 were juvenile chum salmon (O. keta), 165 were juvenile sockeye salmon (O. nerka) and 531 were juvenile coho salmon (O. kisutch) in their first fall in the ocean and 880 were chinook salmon (O. tshawytscha) under 350 mm in fork length.

Juvenile pink, chum, sockeye, and coho were caught on the shelf throughout the survey area from the west coast of Vancouver Island to Southeast Alaska, and along the inside passages on the central coast of British Columbia and Southeast Alaska.

Juvenile chinook from 100 to 199 mm in fork length were caught primarily inside the inlets and close to the beach along the shelf off the west coast of Vancouver Island. The distributions of chinook over 200 mm in fork length were more wide-spread over the area of the survey. These larger chinook were caught both inside the inlets and close to the beach along the shelf off the west coast of Vancouver Island, and along the inside passages on the central coast of British Columbia and Southeast Alaska.

Juvenile pink, chum, sockeye, and coho were significantly greater in size from Vancouver Island to Southeast Alaska.

Seven age 0.0, CWT chinook that had been released from west coast Vancouver Island hatcheries in the spring of 2003, were recaptured not far from the release sites in the inlets on the west coast of Vancouver Island. These ocean-type, age 0.0 chinook averaged 168 mm and ranged from 138 to 185 mm in fork length.