Biomass estimates of Pacific herring Clupea harengas pallasi, in California from the 1986-87 spawning-ground surveys

Spratt, Jerome D. (1987) Biomass estimates of Pacific herring Clupea harengas pallasi, in California from the 1986-87 spawning-ground surveys. Monterey, CA, California Department of Fish and Game, Marine Resources Region, (Marine Resources Administrative Report, 87-12)

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Abstract

The 1986-87 spawning biomass estimates of Pacific herring, Clupea harengus pallasi, in San Francisco Bay is 57,000 tons. This is the third consecutive year that the San Francisco Bay population has increased, and the population is at its highest level since the 1982-83 season, when 59,000 tons of herring spawned. Spawning-ground surveys in Tomales Bay yielded a spawning biomass estimate of 5800 tons. This is the fourth consecutive year that the Tomales Bay spawning biomass has been below the long-term average of 6700 tons. In San Francisco Bay, over 80% of the herring spawned in December and January. Spawning began later in Tomales Bay where 70% of the herring spawned in February. No spawns were found during March in either bay. Herring spawned throughout Tomales Bay. In San Francisco Bay, major spawning activity was limited to Belvedere, Tiburon, Angel Island, and the San Francisco waterfront. No herring spawns were found in Richardson Bay or the east bay shoreline. Quantitative samples of eelgrass were taken from 16 eelgrass beds in Tomales Bay for the first time since 1976. Densities ranged from 0.5 to 2.7 kg/m2. (32pp.)

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