An ocean fishery is an area with an associated fish or aquatic population which is harvested for its commercial value. Fisheries can be wild or farmed. Most of the world's wild fisheries are in the oceans.
Overview Oceans occupy 71% of the Earth's surface. They are divided into five major oceans, which in decreasing order of size are: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean and Arctic Ocean. Over 70% of the world catch from the sea comes from the Pacific Ocean.
Ocean metrics Ocean Areamillion km2 % VolumeThe World's Oceans and Seas. Encarta. Retrieved 19 April 2008.million cu km % Mean depthkm Max depthkm Coastlinekm Fish captureFAO 2005 statistics: Fisheries and Aquaculture. Includes fish, crustaceansand molluscs, does not include marine mammals or aquatic plants.million tonnes % Pacific OceanCIA Factbook: Pacific ocean. 155.6 46.4 679.6 49.6 4.37 10.924 135,663 84.234 71.0 Atlantic OceanCIA Factbook: Atlantic ocean. 76.8 22.9 313.4 22.5 4.08 8.605 111,866 24.045 20.3 Indian OceanCIA Factbook: Indian ocean. 68.6 20.4 269.3 19.6 3.93 7.258 66,526 10.197 8.6 Southern OceanCIA Factbook: Southern ocean. 20.3 6.1 91.5 6.7 4.51 7.235 17,968 0.147 0.1 Arctic OceanCIA Factbook: Arctic ocean. 14.1 4.2 17.0 1.2 1.21 4.665 45,389 Totals 335.3 1370.8Elert, Glenn Volume of Earth's Oceans. The Physics Factbook. Retrieved 19 April 2008. 4.09 10.924 356,000 118.623
Pacific Ocean
The Pacific Ocean is the largest of the world's oceans, extending from the Arctic in the north to Antarctica in the south. Covering 169.2 million square kilometers, it is larger than all of the Earth's land area combined."Pacific Ocean". Britannica Concise. 2006. Chicago: Encyclopædia Britannica, Inc. The Pacific's greatest asset is its fish. The shoreline waters of the continents and the more temperate islands yield herring, salmon, sardines, snapper, swordfish and tuna, as well as shellfish. Many seas within the Pacific Ocean are abundant in fisheries resources.
Seas The Celebes Sea has warm clear waters and harbors about 580 of the world's 793 species of reef-building corals, which are among the most biodiverse coral reefs in the world and home to an impressive array of marine life, including whales and dolphins, sea turtles, manta rays, eagle rays, barracuda, marlin, tuna and other reef and pelagic species. The sea also yields other aquatic products like sea tang. The Coral Sea is an ecologically important source of coral.
The Sea of Japan has almost no tides due to its nearly complete enclosure. It has an area of 978,000 square kilometre, a mean depth of 1,753 meters and a maximum depth of 3,742 meters. The areas in the north and the southeast of this sea are rich fishing grounds. The importance of the fishery in the sea is well illustrated by the dispute between South Korea and Japan over Liancourt Rocks.
The South China Sea is the repository of large sediment volumes delivered by the Mekong River, Red River and Pearl River. Within the sea, there are over 200 identified islands and reefs, including a 100 km wide seamount with a depth of 20 m and an area of 8,866 km2. According to studies made by the Department of Environment and Natural Resources, Philippines, this body of water holds one third of the all world's marine biodiversity, thereby making it a very important area for the ecosystem.
Atlantic Ocean
The Atlantic Ocean is the second-largest ocean covering 106.4 million square kilometres with a coastline of 111,000 kilometres. It occupies about one-fifth of the Earth's surface. The ocean has some of the world's richest fishing resources, especially in the waters covering the continental shelves. The major species of fish caught are cod, haddock, hake, herring and mackerel. The most productive areas include the Grand Banks of Newfoundland, the shelf area off Nova Scotia, Georges Bank off Cape Cod, the Bahama Banks, the waters around Iceland, the Irish Sea, the Dogger Bank of the North Sea and the Burdwood Bank of the Falkland Islands. Eel, lobster and whales have also been taken in great quantities. Because of the threats to the marine environment presented by oil spills, marine debris and the incineration of toxic wastes at sea, various international treaties exist to reduce some forms of pollution in the Atlantic ocean.Biomass distributions for high tropic-level fishes in the North Atlantic, 1900 - 2000
Seas Caribbean Sea
The Caribbean Sea is home to about 29% of the world's coral reefs. Currently, unusually warm Caribbean waters are endangering the Caribbean coral reefs. Coral reefs support some of the most diverse habitats in the world, but are fragile ecosystems. When tropical waters exceed 85°F for an extended period of time, microscopic plants called zooxanthellae die off. These plant provide food for the coral and give them their color. The resultant bleaching of the coral reefs kills them and ruins the ecosystem. Up to 42% of the coral colonies have gone completely white, while 95% have undergone at least some bleaching.Bleaching Threatens Caribbean Coral Reefs. CBS News. URL accessed on April 29, 2006. The habitats supported by the reefs are critical to such tourist activities such as fishing and diving and provide an annual economic value to Caribbean nations of $3.1-$4.6 billion. Continued destruction of the reefs could severely damage the region's economy.Alarm sounded for Caribbean coral. BBC News. URL accessed on April 29, 2006. A Protocol of the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region came in effect in 1986 to protect the various endangered marine life of the Caribbean through forbidding human activities that would advance the continued destruction of such marine life in various areas. Currently this protocol has been ratified by 15 countries.Protocol Concerning Specially Protected Areas and Wildlife to the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (SPAW) NOAA Fisheries:Office of Protected Resources. URL accessed on April 30, 2006.The area also generates a large fishing industry for the surrounding countries, accounting for half a million metric tons of fish a year.LME 12: Caribbean Sea NOAA Fisheries Northeast Fisheries Science Center Narragansett Laboratory. URL last accessed May 14, 2006.
The Gulf of Mexico is an important fisheries resource with major catches of red snapper, amberjack, tilefish, swordfish and various grouper, as well as shrimp and crabs. Oysters are also harvested on a large scale from many of the bays and sounds.
Mediterranean Sea
The Mediterranean Sea has an average depth of 1,500 metres (4,920 ft) and the deepest recorded point is 5,267 meters (about 3.27 miles). The coastline extends for . Invasive species originating from the Red Sea have been introduced into the sea by the construction of the Suez Canal and have had a serious impacts on the sea's ecology, endangering many local and endemic Mediterranean species. About 300 species native to the Red Sea have been identified in the Mediterranean Sea. In recent years, the Egyptian government's announcement of its intentions to deepen and widen the canal have raised concerns from marine biologists, fearing that such an act will only worsen the invasion of Red Sea species into the Mediterranean, facilitating the crossing of the canal for yet additional species.Galil, B.S. and Zenetos, A. (2002). A sea change: exotics in the eastern Mediterranean Sea, in: Leppäkoski, E. et al. (2002). Invasive aquatic species of Europe: distribution, impacts and management. pp. 325-336.
Pollution in this region has been extremely high in recent years. The United Nations Environment Programme has estimated that 650 million tons of sewage, 129,000 tons of mineral oil, 60,000 tons of mercury, 3,800 tons of lead and 36,000 tons of phosphates are dumped into the Mediterranean each year. The Barcelona Convention aims to 'reduce pollution in the Mediterranean Sea and protect and improve the marine environment in the area, thereby contributing to its sustainable development.' Many marine species have been almost wiped out because of the sea's pollution. The Mediterranean monk seal is considered to be among the world's most endangered marine mammals. The Mediterranean is also plagued by marine debris. A 1994 study of the seabed using trawl nets around the coasts of Spain, France and Italy reported a particularly high mean concentration of debris; an average of 1,935 items per square kilometre. Plastic debris accounted for 76%, of which 94% was plastic bags.
North Sea
The North Sea is a mjor sea in Northern Europe, where a large part of the European drainage basin empties into it including water from the Baltic Sea. Fishing in the North Sea is concentrated in the southern part of the coastal waters with the main method of fishing being trawling. Annual catches grew each year until the 1980s, when a high point of more than 3 million metric tons (3.3 million S/T) was reached. Since then, the numbers have fallen back to around 2.3 million tons (2.5 million S/T) annually with considerable differences between years. Besides the fish caught, it is estimated that 150,000 metric tons (165,000 S/T) of unmarketable by-catch are caught and around 85,000 metric tons (94,000 S/T) of dead and injured invertebrates.
The Norwegian Sea is the source of much of the North Atlantic Deep Water. The region remains ice-free due to the warm and saline Norwegian Atlantic Current. It provides rich fishing grounds, with catches mostly consisting of cod, herrings, sardines and anchovies. Shifts and fluctuations in these currents are closely monitored as they are thought to be indicators for an ongoing climate change.
Indian Ocean
The Indian Ocean is the third largest ocean, covering 73,556,000 square kilometres, or about twenty percent of the water on the Earth's surface. Small islands dot the continental rims. The ocean's continental shelves are narrow, averaging in width. An exception is found off Australia's western coast, where the shelf width exceeds . The average depth of the ocean is 3,890 metres (12,760 feet). The remaining 14% is layered with terrigenous sediments. Glacial outwash dominates the extreme southern latitudes.
The warmth of the Indian Ocean keeps phytoplankton production low, except along the northern fringes and in a few scattered spots elsewhere; life in the ocean is thus limited. Fishing is confined to subsistence levels. Its fish are of great and growing importance to the bordering countries for domestic consumption and export. Fishing fleets from Russia, Japan, South Korea and Taiwan exploit the Indian Ocean mainly for shrimp and tuna. Endangered marine species include the dugong, seals, turtles and whales. Oil and ship pollution threatens the Arabian Sea, Persian Gulf and Red Sea.
Seas Arabian Sea The Arabian Sea is a region of the Indian Ocean bounded on the east by India, on the north by Pakistan and Iran, on the west by Arabian Peninsula, on the south, approximately, by a line between Cape Guardafui, the north-east point of Somalia, Socotra and Kanyakumari (Cape Comorin) in India. The maximum width of the Arabian Sea is approximately , and its maximum depth is .