Marine Wildlife Encyclopedia
Atlantic Cod Gadus morhua
The Atlantic cod is a powerful, heavily built fish with a large head, an overhanging upper jaw, and a single long chin barbel. It has small, elongated scales. The coloration varies from reddish, especially in young fish, to a mottled brown with a conspicuous white lateral line. The Atlantic cod is a shoal-forming fish, living in water over the continental shelf, and usually feeding at 100–250 ft (30–80 m) above areas of flat mud or sand. Adults migrate to established breeding grounds to spawn, usually in the early spring, with each female releasing several million eggs into the water. Atlantic cod can live for 60 years and mature fish can reach a weight of over 200 lb (90 kg), but modern fishing techniques mean that most cod today are caught long before they reach this age and weight. The average weight is now 24 lb (11 kg) and specimens over 33 lb (15 kg) are rare. Atlantic cod is still one of the world’s most commercially important species, however.
Overfishing of Atlantic Cod
Stocks of Atlantic cod were once thought to be inexhaustible, but numbers of this once-abundant fish have declined drastically over most of its range. Cod exist as a number of discrete populations, or stocks, that spawn in specific areas in water about 660 ft (200 m) deep. Important stocks include those in the North Sea, northeast Arctic Ocean, Labrador Sea, and the Grand Banks. The latter stock collapsed due to overfishing some years ago and has still not fully recovered.