Ocean fisheries

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A 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 ocean. This article is an overview of ocean fisheries.

Statistics[edit]

Oceans occupy 71 percent 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 percent of the world catch from the sea comes from the Pacific Ocean.

Ocean metrics
Ocean Area
million km2
 % Volume[1]
million cu km
 % Mean depth
km
Max depth
km
Coastline
km
Fish capture[2]
million tonnes
 %
Pacific Ocean[3] 155.6 46.4 679.6 49.6 4.37 10.924 135,663 84.234 71.0
Atlantic Ocean[4] 76.8 22.9 313.4 22.5 4.08 8.605 111,866 24.045 20.3
Indian Ocean[5] 68.6 20.4 269.3 19.6 3.93 7.258 66,526 10.197 8.6
Southern Ocean[6] 20.3 6.1 91.5 6.7 4.51 7.235 17,968 0.147 0.1
Arctic Ocean[7] 14.1 4.2 17.0 1.2 1.21 4.665 45,389
Totals 335.3 1370.8[8] 4.09 10.924 356,000 118.623

Pacific Ocean[edit]

Pacific Ocean.png

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.[9] The Pacific contains 25,000 islands (over half the islands in the world), most of which are south of the equator.

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.

Atlantic Ocean[edit]

Atlantic Ocean.png

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 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 Falkland Banks. Eel, lobster, and whales have also been taken in great quantities. Because of the threats to the ocean 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.

Indian Ocean[edit]

Indianocean.PNG
  • 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 200 kilometres (120 mi) in width. An exception is found off Australia's western coast, where the shelf width exceeds 1,000 kilometres (620 mi). 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 also 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.

Southern Ocean[edit]

Southern Ocean.png

The Southern Ocean is the fourth-largest ocean, covering 20,327,000 square kilometers. It is typically between 4,000 and 5,000 meters deep with only limited areas of shallow water. The Antarctic continental shelf is narrow and unusually deep, its edge lying at up to 800 meters, compared to a global mean of 133 meters.

The Antarctic Circumpolar Current moves perpetually eastward — chasing and joining itself, and at 21,000 kilometers is the world's longest ocean current, transporting 130 million cubic meters per second — 100 times the flow of all the world's rivers. The Antarctic ice pack fluctuates from an average minimum of 2.6 million square kilometers in March to about 18.8 million square kilometers in September.

Fauna: squid, whales, seals, krill, various fish

Increased solar ultraviolet radiation resulting from the Antarctic ozone hole has reduced marine primary productivity (phytoplankton) by as much as 15% and has started damaging the DNA of some fish[citation needed]. Illegal, unreported, and unregulated fishing, especially the landing of an estimated five to six times more Patagonian toothfish than the regulated fishery, likely affects the sustainability of the stock. Long-line fishing for toothfish causes a high incidence of seabird mortality.

The International Whaling Commission prohibits commercial whaling south of 40 degrees south (south of 60 degrees south between 50 degrees and 130 degrees west). Japan does not recognize this and they carry out an annual whale-hunt which they say is for scientific research. See Southern Ocean Whale Sanctuary. The Convention for the Conservation of Antarctic Seals has limited seal-hunting. The Convention on the Conservation of Antarctic Marine Living Resources regulates fishing in the region.

Arctic Ocean[edit]

Severny ladovy ocean.png

The Arctic Ocean is the smallest of the world's five major oceans and the shallowest.[36] Almost completely surrounded by Eurasia and North America, it is largely covered by sea ice throughout the year. Its temperature and salinity vary seasonally as the ice cover melts and freezes;[37] its salinity is the lowest on average of the five major seas, due to low evaporation, heavy freshwater inflow from rivers and streams, and limited connection and outflow to surrounding oceanic waters with higher salinities. In summer the icepack shrinks about fifty percent.[36]

Endangered marine species include walruses and whales. The area has a fragile ecosystem which is slow to change and slow to recover from disruptions or damage. The Arctic Ocean has relatively little plant life except for phytoplankton. Phytoplankton are a crucial part of the ocean and there are massive amounts of them in the Arctic. Nutrients from rivers and the currents of the Atlantic and Pacific oceans provide food for the Arctic phytoplankton.[38]

See also[edit]

Notes[edit]

  1. ^ The World's Oceans and Seas. Encarta. Retrieved 19 April 2008.
  2. ^ FAO 2005 statistics: Fisheries and Aquaculture. Includes fish, crustaceans, and molluscs, does not include marine mammals or aquatic plants.
  3. ^ CIA Factbook: Pacific ocean.
  4. ^ CIA Factbook: Atlantic ocean.
  5. ^ CIA Factbook: Indian ocean.
  6. ^ CIA Factbook: Southern ocean.
  7. ^ CIA Factbook: Arctic ocean.
  8. ^ Elert, Glenn Volume of Earth's Oceans. The Physics Factbook. Retrieved 19 April 2008.
  9. ^ "Pacific Ocean". Britannica Concise. 2006. Chicago: Encyclopædia Britannica, Inc.
  10. ^ Hopley, David; Smithers, Scott G.; Parnell, Kevin E. (2007). The geomorphology of the Great Barrier Reef : development, diversity, and change. Cambridge : Cambridge University Press. p. 27. ISBN 0-521-85302-8. 
  11. ^ "Tides in Marginal, Semi-Enclosed and Coastal Seas - Part I: Sea Surface Height". ERC-Stennis at Mississippi State University. Retrieved 2007-02-02. 
  12. ^ Bleaching Threatens Caribbean Coral Reefs. CBS News. URL accessed on April 29, 2006.
  13. ^ Alarm sounded for Caribbean coral. BBC News. URL accessed on April 29, 2006.
  14. ^ 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.
  15. ^ LME 12: Caribbean Sea NOAA Fisheries Northeast Fisheries Science Center Narragansett Laboratory. URL last accessed May 14, 2006.
  16. ^ "GULF OF MEXICO". Handbook of Texas Online. Texas State Historical Association. 
  17. ^ Pinet, Paul R. (1996) Invitation to Oceanography, St Paul, MN: West Publishing Co., ISBN (3rd ed.), p.202
  18. ^ Pinet, p. 206
  19. ^ Pinet, pp. 206–7
  20. ^ Pinet, p. 207
  21. ^ 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.
  22. ^ http://www.explorecrete.com/nature/mediterranean.html
  23. ^ http://europa.eu/scadplus/leg/en/lvb/l28084.htm
  24. ^ http://www.monachus-guardian.org/factfiles/medit01.htm
  25. ^ >"Marine Litter: An analytical overview". United Nations Environment Programme. 2005. Retrieved 2008-08-01. 
  26. ^ "] ROYAL SOCIETY OF EDINBURGH INQUIRY INTO THE SCOTTISH FISHING INDUSTRY". Retrieved 2007-12-09. 
  27. ^ Phillip Colla Natural History Photography URL accessed January 21, 2007
  28. ^ Naturalist: On the swatch of no ground: Mashida R Haider goes to the Bay of Bengal and comes back full of the marine life there URL accessed January 21, 2007
  29. ^ CMS: Stenella attenuata, Pantropical spotted dolphin URL accessed January 21, 2007
  30. ^ a b "Hydrographic Survey Results". Food and Agriculture Organization of the United Nations (FAO). 2008. Retrieved 2008-04-06. 
  31. ^ "Red Sea & Gulf of Aden". United Nations Environment Programme. 2005. Retrieved 2008-04-04. 
  32. ^ "US Coalition Presence in Gulf Helps Cut Piracy: Commander". Arab News. 2005-07-03. Retrieved 2008-04-04. 
  33. ^ a b FishBase. Ed. Ranier Froese and Daniel Pauly
  34. ^ Siliotti, A. (2002) fishes of the red sea Verona, Geodia ISBN 88-87177-42-2
  35. ^ NZ National Institute of Water & Atmospheric Research (2003) [www.niwa.cri.nz/__data/assets/pdf_file/0007/29842/fau-2003-06.pdf Fisheries & Aquaculture Update.] No 6. Retrieved 2 May 2008.
  36. ^ a b Michael Pidwirny (2006). "Introduction to the Oceans". www.physicalgeography.net. Retrieved 2006-12-07. 
  37. ^ Some Thoughts on the Freezing and Melting of Sea Ice and Their Effects on the Ocean K. Aagaard and R. A. Woodgate, Polar Science Center, Applied Physics Laboratory University of Washington, January 2001. Retrieved 7 December 2006.
  38. ^ Physical Nutrients and Primary Productivity Professor Terry Whiteledge. National Oceanic and Atmospheric Administration. Retrieved 7 December 2006.

References[edit]