31 OCTOBER. NORTH PACIFIC: FISHERY

During the past three years I have analyzed historical NMC Marine and COADS sea surface temperature data in the North Pacific Ocean in order to provide a preseason forecast of Bristol Bay sockeye salmon run timing (early, average, or late return) to the University of Washington and to the salmon industry. I have noted that SST below the Aleutian Islands, which corresponds to a portion of the region occupied by Bristol Bay sockeye, has been exceptionally warm compared to the historical range in the database (1965-present). Given that the warm SST started at least by winter 1995-1996 and continued into winter 1996-1997, it seems that this warming event in the western North Pacific may not be directly linked to the 1997 El Nino event; I also observed unusually warm temperatures in the Gulf of Alaska during spring 1997 but not during winter 1996-1997. The message by Vivian Mendenhall (Oct. 24), USFWS, seems to support this idea. As many have read, the Bristol Bay sockeye run (18.8 million) was only half of the projected run of approximately 34 million fish. Salmon runs to other areas of southwestern Alaska were generally below expectations (Chignik and Kodiak). In 1997, my run timing forecast (12.6% of run by 25 June) was close to the observed value (9.2%), but it erred more than in the previous two years for which I have released a timing forecast. A reportedly high incidence of sockeye salmon having skin parasites (not yet identified) was observed near Kodiak Island; premature coloration was observed in some sockeye captured along capes from Kodiak to the South Peninsula area where sockeye salmon are typically bright. Mendenhall suggested that ocean temperatures near Alaska may increase even more in the coming year. The tremendous increase in Alaskan salmon production that began in the late 1970s was correlated with an increase in SST during winter. The potential effects of a subsequent increase in SST on salmon run size and timing will be very interesting to follow in the coming year. --Greg Ruggerone GRuggerone@aol.com

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