Sablefish (Anoplopoma fimbria) have a wide distribution along the Pacific coast, extending from Baja California to Alaska, the Bering Sea and through to the eastern coast of Japan. A unique feature of these fish is the wide variation in temperature and depth that sablefish experience throughout their life cycle, extending from depths 200m as adults to the surface as larvae and juveniles. While the landed weight of sablefish in the commercial fishery is relatively small, the exceptionally high value of this species ranks it 3rd in economic value to walleye pollock and Pacific cod. As such, sablefish are highly managed throughout the Pacific, and understanding the biology of this species is essential for proper management. The aim of this project is to characterize the reproductive life history of two populations of sablefish in coastal Washington and California.

Fish will be collected from the same geographical location on a monthly basis for one year. The reproductive status will be determined from gonadal histology and plasma sex steroid levels, and age will be determined from otoliths. It is expected that data on size, age, rate of gonadal development, seasonal timing of spawning, fecundity, frequency of reproduction, and potential shifts in distribution of sexes will be obtained. This study applies directly to the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act, because the data will be used to improve stock assessments and estimates of spawning biomass in this commercially important species. This project is a cooperation with the commercial fishing industry and scientists at the Northwest Fisheries Science Center (NWFSC) and Southwest Fisheries Science Center (SWFSC). Size, sex, gonad stage, fecundity.