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- Published: 13 Sep 2009
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- Author: malmiw
The Atlantic cod, Gadus morhua, is a well-known demersal food fish belonging to the family Gadidae. It is also commercially known as cod, codling or haberdine.
In the western Atlantic Ocean cod has a distribution north of Cape Hatteras, North Carolina, and round both coasts of Greenland; in the eastern Atlantic it is found from the Bay of Biscay north to the Arctic Ocean, including the Baltic Sea, the North Sea, areas around Iceland and the Barents Sea.
It can grow to 2 meters in length and weigh up to . It can live for 25 years and sexual maturity is generally attained between ages 2 to 4, but can be as late as 8 years in the northeast Arctic. Colouring is brown to green with spots on the dorsal side, shading to silver ventrally. A lateral line is clearly visible. Its habitat ranges from the shoreline down to the continental shelf.
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.
Technologies that contributed to the collapse of Atlantic Cod include engine power vessels and frozen food compartments aboard ships. Engine power vessels had larger nets, larger engines, and better navigation. The capacity to catch fish became limitless. In addition, sonar technology gave an edge to catching and detecting fish. Sonar was originally developed during WWII to locate enemy submarines, but was later applied to locating schools of fish. These new technologies, as well as bottom-trawlers that destroyed entire ecosystems, contributed to the collapse of Atlantic Cod. They were vastly different from old techniques used, such as hand lines and long lines.
The fishery has yet to recover, and may not recover at all because of a possibly stable change in the food chain. Atlantic cod was a top-tier predator, along with haddock, flounder and hake, feeding upon smaller prey such as herring, capelin, shrimp and snow crab. With the large predatory fish removed, their prey has had a population explosion and have become the top predators, affecting the survival rates of cod eggs and fry.
Females release their eggs in batches, and males compete to fertilise them.
Category:Commercial fish Category:Gadidae Category:Fish of Europe Category:Fish of the North Sea Category:Fish of the Baltic Sea Category:Fauna of Greenland Category:Fish of the Atlantic Ocean
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