Abstract

The Highseas Salmon program of Fisheries and Oceans Canada conducted a survey of Pacific salmon in the Gulf of Alaska during June 27 to July 6, 2000. 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. Oceanographic, fish and zooplankton sampling was conducted at stations spanning the area from Cape Alava at the northern tip of the Olympia Peninsula in Washington State (49°N) to Forrester Island off Southeast Alaska (55°N).

A total of 2887 Pacific salmon were caught on the survey. Of these, 2425 were juvenile pink (O. gorbuscha), chum (O. keta), coho salmon (O. kisutch), and sockeye (O. nerka) salmon in their first summer in the ocean and 94 were chinook salmon (O. tshawytscha) under 350mm in fork length.

Juvenile pink, chum, sockeye, coho, and chinook under 350mm in fork length were caught on the continental shelf within the 1000 m isobath along the entire coastal length of the survey from Washington State to Southeast Alaska.

Juvenile pink, chum, and sockeye were significantly larger in size in the northern regions that included Dixon Entrance and Southeast Alaska, than in the southern regions that included the west coast of Vancouver Island and Queen Charlotte Sound. Juvenile coho were not significantly different in size between the north and south. Juvenile chinook in their first summer at sea, that averaged 200 mm fork length, were caught primarily off the west coast of Vancouver Island.