Sablefish (Anoplopoma fimbria) are members of the Anoplopomatidae family that includes sablefish and skillfish. They occur only in the North Pacific Ocean, the Bering Sea, and adjacent waters from Hokkaido, Japan to Baja, California, with the greatest abundance in the Gulf of Alaska (Wolotira et al. 1993). Adult sablefish inhabit the deeper water areas of the continental shelf, the slope, and the deep water coastal fjords. Most adults live in depths of 366 m to 914 m [200 to 500 fathoms (fm)] although they have been found in depths of less than 183 m (100 fm) to over 1829 m (1,000 fm) (Allen and Smith 1988).

Sablefish are divided into two populations; a northern population that extends from northern British Columbia to Japan and a southern population that extends from southern British Columbia, southward. The population subdivision was based on differences in size at maturity, growth, and movement (McDevitt 1990, McFarlane and Saunders 1997)

Sablefish are a long-lived species with fish over age 40 commonly found in commercial samples. Maximum reported age in Alaska is 94 years (Kimura e. al. 1998), in Canada is 55 years (McFarlane and Beamish1983,) and in SE inside waters the maximum age is 65 years (from ADG&G survey data, 1988-2001). Because sablefish are difficult to age, these ages are approximate.

Sablefish spawn in pelagic waters near the edge of the continental slope (300-500 m depth) in the spring of the year (McFarlane and Nagata 1988). Eggs develop at depth and larvae develop near surface waters. Sablefish juveniles exhibit rapid growth, and reside in continental shelf waters, often in bays and nearshore waters, moving to the continental shelf beginning around age 2 (Sigler et al. 2001).

In the Gulf of Alaska adult, sablefish may reach an average maximum length and weight of 69 cm and 3.4 kg for males and 83 cm and 6.2 kg for females (Sigler et al. 2001). Fifty percent of females are sexually mature at 69 cm (6.5 years) and fifty percent of males are mature at 57 cm (5 years) (Sigler et al. 2001).

Adult sablefish are opportunistic feeders, preying on fish (including pollock, eulachon, capelin, herring, sandlance, and Pacific cod) squid, euphasids and jellyfish (Yang and Nelson 2000). Yearling sablefish primarily feed on euphasids (Sigler et al. 2001). Juvenile sablefish are eaten by adult coho, and chinook salmon and were the fourth most commonly reported prey species in the Alaska Trollers Association logbook program from 1977 through 1984 (Wing 1985).

Natural mortality for sablefish in the Gulf of Alaska is estimated to range from 0.10 (Sigler et al. 2001, Funk and Bracken 1984, Johnson and Quinn 1988) to 0.22 (Low et al. 1976).

References

Allen, M. J. and G. B. Smith, 1988, Atlas and zoogeography of common fishes in the Bering Sea and north Pacific. NOAA Tech. Rep. NMFS-NWFSC 66.

Funk, Fritz and Barry Bracken 1984. Growth of sablefish in Southeastern Alaska. Alaska Sea Grant Report 83-8. p51-57

Kimura, Daniel K., A. M. Shaw and F. R. Shaw 1998. Stock Structure and movement of tagged sablefish, , Anoplopoma fimbria, in offshore northeast Pacific waters and the effects of El Nino-Southern Oscillation on migration and growth. Fish. Bull. 96:462-481.

Johnson, Scott L. and Terrance J. Quinn II 1988. Catch-age analysis with auxillary information of sablefish in the Gulf of Alaska. Contract report to National Marine Fishery Service, Auke Bay, Alaska. 79 pp. Center for Fisheries and Ocean Sciences, University of Alaska, Juneau, Alaska.

McDevitt, Sandra A. 1990. Growth and analysis of sablefish (Anoplopoma fimbria), from mark recapture data from the northeast Pacific. M.S. Thesis, University of Washington, Seattle.

McFarlane, Gordon A. and R. J. Beamish 1983. Summery of results of the Canadian sablefish tagging program. Alaska Sea Grant Report 83-8. p147-183

McFarlane, Gordon A. and W. D. Nagatta 1988. Overview of sablefish maricultureand its potential for industry. In proceedings of the Fourth Alaska Aquaculture Conference, p. 105-120. Alaska Sea Grant Rep. 88-4.

McFarlane, Gordon A. and Mark W.Saunders 1997. Dispersion of Juvinile sablefish, Anoplopoma fimbria, as indicated by tagging in Canadian waters. NOAA Technical Report NMFS 130. p137-150.

Sigler, Michael F., Chris R. Lunsford, Sandra A. Lowe, and Jeffrey T. Fujioka 2001. 2001 Groundfish stock assessment and fishery evaluation document, Alaska Sablefish Assessment for 2002. NPFMC SAFE Document. sec. 9, pp1-57.

Wing, Bruce L. 1985. Salmon stomach contents from the Alaska troll logbook program 1977-1984. NOAA Technical Memorandum NMFS F/NWC-91

Wolotira, Robert J. et al. 1993. Geographic and bathymetric distributions for many commercially important fishes and shellfishes off the west coast of North America, based on research survey and commercial catch data, 1912-84. NOAA Technical Memorandum NMFS-AFSC; C55.13/2: 6

Yang, M-S and M. W. Nelson 2000. Food habits of the commercially important groundfishes in the Gulf of Alaska in 1990, 1993, and 1996. NOAA Technical Memorandum NMFS-AFSC-112. 174 p.