THE NORTHERN ANCHOVY SPAWNING BIOMASS FOR THE 1982-83 CALIFORNIA FISHING SEASON

Abstract

The 1982 equivalent larval census estimate of the spawning biomass of the northern anchovy (Engradis mordax) central subpopulation is 1,866,000 MT (2,060,000 short tons). This estimate is based on data gathered by an egg production survey conducted from January 18 to March 9. 1982. The abundance of larvae is projected from the daily production of eggs and the subsequent mortality of eggs and larvae. This equivalent larval census estimate will be the basis of the anchovy fishery optimum yield (OY) for 1982-83. The egg production method estimate of anchovy spawning biomass is 378,000 MT (417.000 short tons). This is based on a production of 12.30 x 10l2 eggsiday and a population (males and females) fecundity of 3.253 X IO7 eggs/day/MT. The standard error of the egg production method estimate is 97.200 MT, for a coefficient of variation of 25.7%. In 1982 the central subpopulation of northern anchovy was geographically distributed in the inshore portion of the Southern California Bight, from the Santa Barbara Channel Islands to northem Baja California. A smaller group was detected between Monterey and San Francisco Bays. RESUMEN