Biomass estimates of Pacific herring, Clupea pallasi, in California from the 1989-90 spawning-ground surveys

Spratt, Jerome D. (1990) Biomass estimates of Pacific herring, Clupea pallasi, in California from the 1989-90 spawning-ground surveys. Monterey, CA, California Department of Fish and Game, Marine Resources Division, (Marine Resources Administrative Report, 90-13)

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Abstract

The 1989-90 spawning biomass estimate of Pacific herring, Clupea pallasi, from spawning-ground surveys in San Francisco Bay was 71,000 tons, a 5,000 ton increase over the 1988-89 biomass estimate of 66,000 tons. The San Francisco Bay herring biomass has been on an upward cycle since 1984, and results from spawning-ground surveys indicated that the population was at its highest level in eight years. In Tomales Bay the 1989-90 herring spawning biomass estimate was 345 tons. This was the third consecutive poor season. Herring have nearly abandoned Tomales Bay, and reduced freshwater in flows due to the current drought condition in California were the probable cause for the change in spawning behavior. An additional 445 tons were found in Bodega Bay by hydroacoustic surveys. The total herring biomass estimate for Tomales-Bodega area was 790 tons. January was the month of peak spawning activity in San Francisco Bay, with 30,000 tons of herring spawning during the month. In Tomales there was only one spawning run; it occurred on January 31, 1990. In San Francisco Bay, 67% of all spawning occurred along the San Francisco waterfront, and only 6% of all spawning activity was in the northern part of the bay. No spawning was found near Tiburon, Belvedere, Richmond, Berkeley, Candlestick Point, Sierra Point, Oyster Point, or Coyote Point. A total of 3.5 million m2 of eelgrass, Zoster marina, was measured in Tomales Bay this season, a decline of about 10% over the past two seasons. Eelgrass density kg/m2 did not change significantly this season. (34pp.)

Item Type: Monograph or Serial Issue
Title: Biomass estimates of Pacific herring, Clupea pallasi, in California from the 1989-90 spawning-ground surveys
Personal Creator/Author:
CreatorsEmail
Spratt, Jerome D.
Series Name: Marine Resources Administrative Report
Number: 90-13
Date: 1990
Publisher: California Department of Fish and Game, Marine Resources Division
Place of Publication: Monterey, CA
Latitude: 38.1696
Longitude: -122.91
Issuing Agency: California Department of Fish and Game
Uncontrolled Keywords: Pacific herring, Clupea pallasi, California, Tomales Bay, San Francisco Bay, California
Subjects: Ecology
Fisheries
Biology
Item ID: 97
Depositing User: Joan Parker
Date Deposited: 12 Aug 2007 14:13
Last Modified: 29 Sep 2011 22:36
URI: http://aquaticcommons.org/id/eprint/97

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