Pacific Cod Research
Pacific cod (Gadus macrocephalus), also known as
grey cod, are moderately fast growing and relatively short-lived fish,
with a maximum age of approximately 18 years.Females reach 50% maturity at 4.4 years in the Gulf of Alaska and 4.9 years in the eastern Bering Sea (Stark, 2007). Total body length at 50% maturity was significantly smaller (503 mm) in the Gulf of Alaska than in the eastern Bering Sea (580 mm). Similarly, Pacific cod females grow significantly faster in the Bering Sea than in the Gulf of Alaska. Males reach a smaller maximum length in the Gulf of Alaska than females; in contrast, Bering Sea males reach a similar maximum length as females. Pacific cod are highly fecund and can produce up to 5.7 million ova each year.
Cod are demersal and
concentrate on the shelf edge and upper slope
(100-250 m) in the winter and move to
shallower waters (<100 m) in the summer. Cod prey on clams, worms, crabs, shrimp,
and juvenile fish. In turn, they are eaten by halibut and marine
mammals. Pacific cod are taken with trawl, longline, pot,
and jig gear. Cod begin to recruit to trawl fisheries at age 3, but are
not fully recruited to all gear types until about age 7.
Pacific cod are managed under two Fishery Management Plans: one for the Bering
Sea/Aleutian Islands region and the other for the Gulf of Alaska region.
The Fishery Management Plans control the fishery through permits and
limited entry, catch quotas, gear restrictions, closed waters, seasons, bycatch limits and rates, and other measures.
During 2006, pollock made up 71.4% of the average groundfish catch off Alaska. The pollock catch for 2006 was 1.56 million metric tons (t), down approximately 0.4% from 2005.
The next major species, Pacific cod, accounted for 239,427 t or 10.9% of the total 2006 groundfish catch. The Pacific cod catch was down about 5.4% from a year earlier.
The 2006 catch of flatfish, which includes yellowfin sole, rock sole, and arrowtooth flounder was 231,343 t, up about 10.1% from 2005.
Other important species are sablefish (0.7%), rockfish (1.9%), and Atka mackerel (2.9%).
- CONNERS, M. E., and P. MUNRO.
2008. Effects of commercial fishing on local abundance of Pacific cod (Gadus macrocephalus) in the Bering Sea. Fish. Bull., U.S. 106:281-292. (.pdf, 948KB) Online.
- STONER, A. W., B. J. LAUREL, and T. P. HURST.
2008. Using a baited camera to assess relative abundance of juvenile Pacific cod: Field and laboratory trials. J. Exp. Mar. Biol. Ecol. 354:202-211.
- LAUREL, B. J., A. W. STONER, C. H. RYER, T. P. HURST, and A. A. ABOOKIRE.
2007. Comparative habitat associations in juvenile Pacific cod and other gadids using seines, baited cameras and laboratory techniques. J. Exp. Mar. Biol. Ecol. 351:42-55.
- NICHOL, D.
2007. Archival tagging of Atka mackerel, Pacific cod, and flatfish in the Aleutians, Gulf of Alaska, and eastern Bering Sea, p. 41-42. In P. Sheridan, J. W. Ferguson, and S. L. Dowling (editors), Report of the National Marine Fisheries Service Workshop on Advancing Electronic Tag Technologies and Their Use in Stock Assessments. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-F/SPO-82.
- NICHOL, D. G., T. HONKALEHTO, and G. G. THOMPSON.
2007. Proximity of Pacific cod to the sea floor: Using archival tags to estimate fish availability to research bottom trawls. Fish. Res. 86:129-135.
- STARK, J. W.
2007. Geographic and seasonal variations in maturation and growth of female Pacific cod
(Gadus macrocephalus) in the Gulf of Alaska and Bering Sea. Fish. Bull., U.S. 105:396-407. (.pdf, 948KB). Online.
- Reproductive Potential of Pacific Cod in Alaska
By: OLAV A. ORMSETH, BRENDA NORCROSS
Conference: American Fisheries Society, 138th Annual Meeting, Ottawa, ON, Aug 2008
(2008 poster, .pdf, 564KB) Online.
- Juvenile Pacific Cod Habitat Studies Around Kodiak Island, AK
By: BRIAN KNOTH
Conference: ComFish Alaska 29th Annual Trade Show and Policy Summit, Kodiak, AK, Mar 2008
(2008 poster, .pdf, 4.87MB) Online.
- Additional publications, posters, and reports.
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