|Food from the Sea
Oceans cover nearly 75% of the earth's surface. However, because ocean water is salty, most animals and plants living on land cannot drink it.
Ocean fishing accounts for 80% of the world fish catch. The other 20% comes from inland fishing (5%) and aquaculture (15%). 95% of all ocean catches occurs in coastal waters. 1/4 to 1/3 of the world's ocean fish catch is used to feed animals.
Oceans have always been an important and reliable source of food. Considering the ocean's vast size in comparison to land, it is easy to assume that we could never deplete it resources. Recently, overuse of the ocean by man has led to the decline in population of some commercially caught fish. Overfishing, is a real problem that does not have an easy solution.
Symptoms of overfishing include: accelerated growth rates (because of decreased competition within the species), earlier sexual maturity, and gaps in generations. Older fish get caught first, and younger fish react by maturing faster. As these symptoms increase the number of fish caught remains the same, because the younger fish are reproducing at an earlier age. The number of fish caught remains the same until the population does not have any fish old enough to reproduce. When this finally happens, the population level drops dramatically.
What is the real danger in overfishing?
Over the past 10 years a number of fish stocks have collapsed. These include the Peruvian anchovy, Alaskan pollack, North Sea cod, South African anchovy, Alaska king crab, and California sardine.
Canada has eliminated cod fishing off Newfoundland because of overfishing. This area used to be one of the world's richest sources of cod. Overfishing drove cod populations so low, that further fishing would have driven the species to near extinction.
It is estimated that 90% of the world's fisheries are overfished.