Status of the Pacific mackerel resource and fishery 1994 and 1995

Barnes, J. Thomas and Hanan, Doyle A. (1995) Status of the Pacific mackerel resource and fishery 1994 and 1995. La Jolla, CA, California Department of Fish and Game Marine Resources Divison, (Marine Resources Division Administrative Report, 95-4)

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The California fishery for Pacific mackerel, Scomber japonicus, has declined precipitously since 1990, and statewide landings during 1994 totaled only 11,070 short tons. The principal cause of the low catches has been low biomass and poor availability on the traditional fishing grounds in southern California waters. Several sources of information are available on the status of the Pacific mackerel stock. Landing statistics were available since 1978 for both the U.S. and Mexican fisheries, and both fisheries show similar declines during recent years. Other fishery-independent data from aerial observations and plankton surveys (mackerel larvae samples) also show declines in abundance compared to the early 1980's. We used a tuned virtual population analysis (VPA) model called ADEPT to estimate Pacific mackerel abundance. The model finds the best statistical fit between fishery-based age-structured biomass estimates and other data from the aerial observations and the plankton surveys. A model-derived biomass estimate for July 1, 1994 was 71,000 tons. Based on the estimated number of fish in each year class at the end of 1994, and using certain assumptions concerning expected fishing mortality during the first half of 1995, we project that the Pacific mackerel biomass will be 56,000 tons at the beginning of the 1995/96 fishing season, on July 1, 1995. The Fish and Game Code specifies that when the biomass is between 20,000 and 150,000 tons, the season's quota shall be 30 percent of the biomass in excess of 20,000 tons. Using that formula and our projection for July 1, 1995, the commercial fishery quota for the 1995/96 fishing season is 10,800 tons. (21pp.)

Item Type: Monograph or Serial Issue
Title: Status of the Pacific mackerel resource and fishery 1994 and 1995
Personal Creator/Author:
Barnes, J. Thomas
Hanan, Doyle A.
Series Name: Marine Resources Division Administrative Report
Number: 95-4
Date: 1995
Publisher: California Department of Fish and Game Marine Resources Divison
Place of Publication: La Jolla, CA
Issuing Agency: California Department of Fish and Game
Uncontrolled Keywords: Pacific mackerel; Scomber japonicus; fisheries
Subjects: Management
Item ID: 382
Depositing User: Joan Parker
Date Deposited: 23 Oct 2007 12:27
Last Modified: 29 Sep 2011 22:08

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