Relative Abundance and Size Composition of Sablefish ('Anoplopoma fimbria') inthe Coastal Waters of California and Southern Oregon, 1984-1991

摘要

Trap survey results indicate that the relative abundance of sablefish (Anoplopomafimbria) off the coasts of California and southernmost Oregon decreased by 66% in numbers and 64% in kilograms per trap between 1988 and 1991. Catch rates decreased at all nine sites sampled. The largest decreases in catch per unit of effort were in the central part of the survey area; declines of between 70% and 84% were observed at the Point Arena, Half Moon Bay, Carmel Bay, and Morro Bay sites. Smaller declines in catch rate (24% to 57%) were observed at the northern (Cape Sebastian, Point Saint George, and Cape Mendocino) and Southern (Cortes Bank) sites. Small and undersized sablefish made up 83% of the catch, down from 90% in 1988, whereas medium and large sablefish comprised 14% and 3% of the catch, respectively. Highest catch rates (number/trap) occurred at the depths of 225 and 300 fathoms. Mean length increased with depth and generally decreased from north to south within the sampling area.