Pacific herring, Clupea harengus pallasi, studies in San Francisco and Tomales Bays, April 1989 to March 1990

Oda, Kenneth T. and Wendell, Frederick (1990) Pacific herring, Clupea harengus pallasi, studies in San Francisco and Tomales Bays, April 1989 to March 1990. Menlo Park, CA, California Department of Fish and Game, Marine Resources Division, (Marine Resources Administrative Report, 90-14)

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Abstract

Herring schools were surveyed hydroacoustically in San Francisco Bay from early November 1989 through mid March 1990. Seven large schools (>1000 tons) and two smaller ones were detected. The total acoustic biomass estimate based on visual integration was 58,100 tons. Merging with the independent spawn escapement estimate yielded a "best" estimate of 64,500 tons. Sixty-three samples, containing 10,239 herring, were collected. Patterns evident in prior seasons continue. Larger, older fish continue to dominate early season schools. Males continue to be numerically superior during the first half of the season. Mean size and weight at age suggest conditions following the 1988-89 season were not favorable for growth. Contrary to forecasts, the 1988 year class recruitment strength was high; second only to the 1982 year class. Although still being validated, forecasts suggest the 1989 year class will be strong and the 1990 year class will be extremely weak. (64pp.)

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