What Is The Southern Ocean?

South of 60 Degrees South Latitude, the Southern Ocean surrounds Antarctica. James Cook first sailed these cold waters in the 1770s.

5. Description

The Southern Ocean is found way "down under" in and around the Antarctic region. It is the fourth biggest ocean in the world. It has the strongest visible circumpolar current, and one that flows through the Indian, Pacific, and Atlantic Oceans alike. This process is the result of the really thick, frigid, and salty waters that are below the icebergs and sea ice in the Antarctic region. These currents create an upwelling effect that encourages phytoplankton to thrive, and in turn these feed the krill and copepods that whales and other large marine mammals ultimately feed upon. For much of the year, depending on the location, the Southern Ocean's temperatures fluctuate from -2 to 10 Degrees Celsius. The winter months see freezing of much of the ocean, as water temperatures go down to below 0 Degrees Celsius.

4. Historical Role

The existence of a southern continent was already a belief held as far back as to be discussed among the Ancient Greeks. This was later partially validated by the Spanish explorer Castilla, who saw snow-capped mountains off in the southern region in 1603. Thereafter, Dutch explorer Abel Tasman found that Australia was separated from the Antarctic landmass by a great body of water. Later on, Roche, Halley, and Cook each encountered the frigid waters of the Southern Ocean in their respective explorations of the Southern Hemisphere. Most notably of these, James Cook sailed through its frigid waters in winter until he was stopped by icebergs. James Weddell also ventured farther into the Southern Ocean in his search for sealing grounds.

3. Modern Significance

The Southern Ocean's exploration has produced a belief that it could be a tremendous source of gas and oil fields. There could be huge deposits of gold there as well, in addition to such 'placer' minerals as manganese nodules and iron hydroxides. There is also fresh water to be extracted from the huge icebergs in the Antarctic Region. The Southern Ocean is also a sanctuary to seals, whales, and other sea mammals that live and thrive within its frigid waters. The water and natural processes that go on in the region combine to create climatic, biological, and geochemical cycles on such a large scale that these affect the entirety of our planet.

2. Habitat

The water-columned marine ecosystems in the region support phytoplankton and zooplankton en masse, and these in turn feed a host of fish, birds, and larger sea mammals. The landmasses of ice atop the Southern Ocean are also home to many species of seals and penguins. Its rocky mainlands, notably Antarctica and outlying islands, are also sanctuaries for over 100 million birds in the springtime each year. The ocean's Pelagic Zone is the hunting ground of orcas, blue whales, giant squids, fur seals, and several species of penguins. The Benthic zone is home to snails, giant squids, mudworms, sea cucumbers, and about 155,000 other kinds of marine animals. Some of these Benthic marine animals exhibit deep-sea gigantism and bio-luminescence. In addition, the middle water column of the Southern Ocean acts as a sea transport system that supports the egg and larval stages of many native marine animals.

1. Threats and Disputes

Climate change has also affected the Southern Ocean, much of which has been plagued with the effects of not only greenhouse gas accumulations in the atmosphere, but increased exposure to ultraviolet radiation as well as the atmospheric ozone layer was thinned and depleted. Research has confirmed that this effect has even cause genetic damage to the very DNA of some native fish species. Although there are several international fishing agreements that are enforced in the Southern Ocean, several countries violate these agreements, and further threaten the marine habitats by doing so. Long-line fishing in the area has increased sea bird mortality rate, and overfishing is another concern in the area, which has specifically affected the population of the tooth-fish in a harmful manner. Unfortunately, such unregulated fishing of the Patagonia tooth-fish is an issue that remains unresolved. Commercial whaling ships have continued killing whales in the area as well, despite the strict prohibitions set forth by the International Whaling Commission in these Southern Ocean waters.

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