EARLY-LIFE HISTORY OF SABLEFISH, ANOPLOPOMA-FIMBRIA, OFF WASHINGTON, OREGON, AND CALIFORNIA, WITH APPLICATION TO BIOMASS ESTIMATION

In January-February 1987 we conducted a cruise over the central Califo rnia continental slope to sample the eggs and larvae of sablefish (Ano plopoma fimbria). Sablefish eggs were taken in 35% of the bongo and MO CNESS nets towed through the entire water column. Discrete depth rows showed that eggs were distributed between 200 and 800 m and were most concentrated between 240 and 480 m. On surveys off Oregon in February- April 1989 (slope region) and in January 1990 (slope region and offsho re to ca. 170 n. mi.) we employed oblique bongo tows to sample the ent ire water column to a maximum depth of 1500 m. The inshore limit of eg gs was at about 500 m bottom depth, and they were found seaward to abo ut 150 n. mi. Eggs at the most seaward positive stations were four or five days old, suggesting that they were produced by an offshore segme nt of the sablefish population and did not represent eggs advected fro m the continental slope. Estimation of sablefish biomass by the egg pr oduction method is possible since we now have a quantitative method fo r sampling the pelagic eggs and simultaneously recording temperature t hroughout the tow. For the method to be successfully employed in the n ortheast Pacific, the sampling pattern would have to extend at least 2 00 n. mi. offshore, and the survey vessel would have to be capable of operating in the heavy seas encountered during the sablefish spawning season (January-March).