The North Atlantic Cod (Gadus morhua) is on of 59 species of the family Gadidae. Since the discovery of the New World, the North Atlantic Cod has been the dominant commercial fishery species of the Northwest Atlantic.
This particular species of Cod have three fins on their back, and two fins on the underside near the tale. The North Atlantic Cod is a bottom dwelling fish that inhabits cold waters. They are capable of living up to 22 years. Most adult Cod range from 2-3 feet in length and 5-25 pounds. But cod up to 6 feet and 212 pounds have been recorded. They are capable of living up to 22 years. The Cod is a major food fish, 2nd only to the herring. The North Atlantic Cod migrate in response to seasonal change in water temperature. Cod also migrate to search for food. Mature cod eat small fish, squid, and shellfish. Small cod usually feed on worms and small shrimp.
Like most fish, the North Atlantic Cod have special times and places to lay eggs. The female cod normally lay their eggs between January and March. Some of the most important spawning grounds are found in offshore banks off of the coast of New England, along the coasts of Greenland and Iceland, Hamilton Bank and the Grand Bank of Newfoundland. Other traditional spots include George s Bank, Labrador, Gulf of St. Lawrence, and South Grand Bank. An adult female cod lays between 4 to 6 million eggs at a single spawning. These eggs are released into the water to become fertilized. They develop and grow without the help of parents. All but a handful of these million eggs will end up as food for other fish. Normally a deep-water fish but they come into shallower water to spawn.
The water temperature plays an important part in the North Atlantic Cod s reproductive process. The cod, like most species of fish, have their own favorite temperature range for spawning. Eggs at 32 aF will hatch in approximately 40 days and eggs at 41 aF. If the temperature is not to their liking they will not spawn at all. These eggs are very sensitive to heat and cold; and if the temperature changes just a few degrees, it could kill them. Cod Eggs hatch as they float in the ocean.
Cod Eggs hatch as they float in the ocean. Of the million eggs laid, only a small portion will survive. The surviving eggs float for ten to twenty days until they hatch.
The Atlantic Cod fishery was one of the primary reasons for the development of the Northern Atlantic. The cod was very valuable to fisherman for many reasons. Cod is a very lean fish with approximately 0.3% fat. When dried, it becomes almost 80% protein and preserves well. In the early days of cod trade there was no refrigeration and therefore preservation was very important. Dried Cod also tasted better than other types of fish. At that time, the Catholic Church dictated that meat could not be eaten on Fridays and other holy days, their dried cod provided a cheap alternative. The Cod is a very useful fish: we get glue from the Cod s skin, it s a source of high grade protein, it s an important source of Vitamin A and Vitamin D, it s a source of Cod Liver Oil. As the second major food fish, we get many types of foods with cod: Cod Fish cakes, Fish Fillets, Cod Antipasto, Cod Chowder, smoked cod and many, many more.
Here in the United States, the demand for cod increased sharply after the introduction of precooked food. Since the early 1990 s Atlantic Cod declined greatly because of over-fishing and mismanagement of cod stocks. Restrictions placed on fishing by the Canadian and U.S. in the 1990 s to help the Northern Cod recover. With this severe over-fishing most cod are being caught before they mature. Therefore they will not be able to produce.
Over-fishing is not the only major concern for the North Atlantic Cod. It use to be that there was an average of 1 billion pounds of cod harvested annually but as of 1992 only 625,000 million pounds have been recorded. There has been a lot of debate about the exact cause of the collapse of the northern cod stocks. While many researchers agree that over-fishing has played a large role in the collapse, a number of scientists believe that changes in the environment in the Northern Atlantic ay have impacted survival rates either directly or indirectly. Other scientists disagree with the environmental theories and believe that the collapse was entirely due to over-fishing.
There has been a trend towards cooler towards cooler temperatures in the 80 s and 90 s, there has also been a shift in the cod populations toward the south. Some scientists have related these changes to the temperature conditions. This could be a direct result of the colder temperatures or may be an indirect response to other factors such as prey abundance that may be influenced by temperature. This is where potential spawning becomes quite evident. With the cod migrating south, the survival of their eggs decrease significantly. Other scientists have suggested that the southerly shift of cod populations is due to the fact that the northern areas have been fished out.
In closing, the numbers of the Atlantic Cod have fallen to historically low levels throughout the Atlantic. Over-fishing has been the most important factor, however it may have been aided by environmental changes. Since the fishing regulations by the U.S. and Canadian governments were imposed in the early 1990 s the North Atlantic Cod stocks have remained at very low levels with little or no sign of improvement. Whatever the cause may be, good environmental conditions will be necessary for the stocks to rebuild. Also, with no older cod to show young cod the migration roots, they may never be able to reestablish their populations in traditional areas.