The Atlantic Cod is a well-known benthopelagic fish belonging to the family Gadidae widely consumed by humans. Several cod stocks collapsed in the 1990s (declined by >95% of maximum historical biomass) and have failed to recover even with the cessation of fishing. This absence of the apex predator has led to a trophic cascade in many areas. Many other cod stocks remain at risk. The "Atlantic cod" is labelled VU (vulnerable) on the IUCN Red List of Threatened Species. Adult Atlantic Cod form spawning aggregations from late winter to spring. Females release their eggs in batches, and males compete to fertilize them. Fertilized eggs drift with ocean currents and develop into larvae. Age of maturation varies between cod stocks, from ages two to four in the west Atlantic, but as late as eight years in the northeast Arctic. Atlantic Cod can live for 13 years or more.
The Atlantic Cod is soft-rayed, has three dorsal fins on its back and two anal fins behind its whitish-coloured belly, and generally has an elongated hair-like projection called a barbel on its chin. It is generally grey or green but may be brown or reddish, depending upon the habitat into which its colour will generally blend. The scales are small and smooth. The mouth is large with a projecting upper jaw and the gill openings are wide. The lateral line of the cod is pale, and the tail is slightly concave, almost square. Generally Atlantic Cod average 2 to 3 kg in weight and about 60 to 70 cm in length. Is similar to the Pacific Cod.
There are several gear types that are used in the Alaskan and Canadian fishery, each with their own habitat effects. Hook and line, or jigging are deemed the least damaging of the gear types used, while traps, pots, and bottom longline all have varying degrees of bycatch levels and/or habitat effects. The gear used for trawling includes many different types of bottom trawls, most typically having a headrope to footrope vertical distance rise of 2 to 5 fathoms. The offshore fishery is also prosecuted by non-pelagic bottom trawls. Pots used in a directed cod fishery are modified crab pots, which are constructed with a steel bar frame and covered with tarred nylon mesh netting. Pot sizes range from 6 to 8 foot(2-3m) diameter square, with the average vessel using 6 by 6 foot(2x2m) pots. Each pot has two or three tunnel openings on opposite sides, with plastic finger funnels to retain the fish. The tunnel eye cannot be greater than 9 inches(23cm) in any one dimension. An escape panel of untreated cotton must be sewn into the mesh.
In the western Atlantic Ocean, Atlantic Cod has a distribution north of Cape Hatteras, North Carolina, and around both coasts of Greenland and the Labrador Sea; in the eastern Atlantic, it is found from the Bay of Biscay north to the Arctic Ocean, including the Baltic Sea, the North Sea, Sea of the Hebrides, areas around Iceland and the Barents Sea.