Atlantic Cod(Gadus Morhua)
... When the Atlantic cod migrate, they usually travel anywhere from 200 metres to 800 kilometres from their spawning area. Most of them migrate during winter. This is because they need to find comfortable temperatures so they can live. A common area for Atlantic cod to migrate is to the Labrador Current. Depending on where the cod are situated, they may choose a different area to migrate such as the entrance to the Belle Isle Strait or Southeastern Newfoundland. In order for the Atlantic cod to reproduce, they must reach a certain age. For the female, that age is most commonly six, although it may sexually mature earlier or later (somewhere between five or eight). The size of the female at this time is approximately 45 to 60 centimetres long. A male Atlantic cod usually matures earlier than the female and is slightly smaller in length. The ideal temperature for reproduction is 2.5°C to 4°C at depths of 200 to 600 metres. A good place for reproduction is along the outer areas of the continental shelf somewhere between the months of March to June. When the perfect conditions for reproduction are met, the cod begin laying their eggs. Depending on the size of the cod, anywhere between 2 million to 11 million eggs can be laid. Each egg is 1 to 2 millimetres in diameter. Once the eggs are laid, they float to the surface of the water and until they hatch, they are prey for other fish. Statistics show that only one out of every million eggs that the female lays successfully mature. Atlantic cod eggs have a very high mortality rate. For food, young cod depend on the yolk sac that is attached to them for the first one to two weeks. After that, they make their way to the bottom of the ocean floor to feed on living creatures such as copepods, amphipods and small crustaceans in the plankton. As the Atlantic cod begin to mature more, they start feeding on shrimp, euphausiids and fish and shellfish larvae. Once the cod fully matures, they begin to feed on capelin, herring, sand launce, flounders, crabs, shrimp and other species of fish and shellfish. The Atlantic cod is a species at risk of becoming extinct due to over fishing, global warming and the mortality rate of young larvae. In the early 1500’s, not long after North America was discovered, the Portuguese, French and Spanish began fishing in the Newfoundland waters. In the late 1600’s, then English has joined in cod fishing and people were catching as much as 100 000 metric tons each year. By the time the 1700’s came around, people were taking in as much as 200 000 tons of codfish each year. Once the 1800’s rolled in, up to 400 000 tons of codfish were being caught annually. Even by the 1950’s to the 1960’s 900 000 to 2 000 000 tons of cod were being caught yearly. It wasn’t until recently (early 1970’s) that the Atlantic cod population had dropped severely to under 500 000 tons each year. Because of t...