Spratt, Jerome D.
Biomass estimate of Pacific herring Clupea harengus pallasi, in California from the 1983-84 spawning-ground surveys.
California Department of Fish and Game, Marine Resources Region,
(Marine Resources Administrative Report, 84-2)
The spawning biomass of Pacific herring, Clupea
harengus pallasi, in San Francisco Bay and Tomales Bay
was estimated to be 40 000 tons and 1300 tons, respectively
during the 1983-84 season.
The San Francisco biomass estimate declined for the second consecutive year and is now 60% below the peak year of 1981-82, when 100 000 tons of herring spawned. In Tomales Bay the population estimate declined 88% from one of the higher estimates the year before, to the lowest estimate recorded.
These declines in biomass were not totally unexpected,
due to the continued high ocean temperatures off
California during 1983. One of the major contributors
to the decline was the poor growth rate exhibited by
individual herring during 1983. There is also a strong possibility that part of the decline this season was due to a northerly shift in the distribution of California's herring stocks.
The ocean temperatures off California returned to
normal in 1984, and both San Francisco Bay and Tomales
Bay populations are expected to respond in a positive
manner during the year.
Monograph or Serial issue
||Biomass estimate of Pacific herring Clupea harengus pallasi, in California from the 1983-84 spawning-ground surveys
|Spratt, Jerome D.|
||Marine Resources Administrative Report
||California Department of Fish and Game, Marine Resources Region
|Place of Publication:
||California Department of Fish and Game
||Pacific herring; Clupea harengus pallasi
||04 Oct 2007 15:33
||29 Sep 2011 22:14
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