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National Geographic, has officially declared the presence of a fifth ocean, the Southern Ocean. It is the body of water encircling Antarctica, unlike any other. Ever since National Geographic began making maps in 1915, it has recognized four oceans: the Atlantic, Pacific, Indian, and Arctic Oceans. But Starting from June 8, World Oceans Day, it will recognize the Southern Ocean as the world’s fifth ocean.
The debate Between Geographers was, whether the waters around Antarctica had enough unique characteristics to deserve their own name, or whether they were simply cold, southern extensions of the Pacific, Atlantic, and Indian Oceans.
“The Southern Ocean has long been recognized by scientists, but because there was never agreement internationally, we never officially recognized it”
– National Geographic Society Geographer, Alex Tait
“It’s sort of geographic nerdiness in some ways,” Tait says. He and the National Geographic Society’s map policy committee had been considering the change for years, watching as scientists and the press increasingly used the term the Southern Ocean.
The change, he adds, aligns with the Society’s initiative to conserve the world’s oceans, focusing public awareness onto a region in particular need of a conservation spotlight.
“We’ve always labeled it, but we labeled it slightly differently [than other oceans],…This change was taking the last step and saying we want to recognize it because of its ecological separation.”
– Alex Tait
It is the waters that surround Antarctica out to 60 degrees south latitude, excluding the Drake Passage and the Scotia Sea.
Usually, the other oceans are defined by the continents that fence them in, While the Southern Ocean is defined by a current called the Antarctic Circumpolar Current (ACC).
Scientists estimate that the ACC was created roughly around 34 million years ago when Antarctica separated from South America. Thus allowing the unimpeded flow of water around the bottom of the Earth.
The ACC flows from west to east around Antarctica, in a broad fluctuating band roughly centered around a latitude of 60 degrees south—the line that is now defined as the northern boundary of the Southern Ocean. Its waters are colder and slightly less salty than ocean waters to the north.
Extending from the surface to the ocean floor, the ACC transports more water than any other ocean current. It pulls in waters from the Atlantic, Pacific, and Indian Oceans, helping drive a global circulation system known as the conveyor belt, which transports heat around the planet. Cold, dense water sinks to the ocean floor off Antarctica that helps store carbon in the deep ocean. In both those ways, the Southern Ocean has a crucial impact on Earth’s climate.
The Southern Ocean ecologically is distinct thanks to the ACC. Thousands of species live there and nowhere else.
According to the notes of National Geographic Explorer in Residence, Enric Sala – The Fifth ocean “encompasses unique and fragile marine ecosystems that are home to wonderful marine life such as whales, penguins, and seals,”
The Southern Ocean even has ecological effects elsewhere as well. For example – Humpback whales feed on krill off Antarctica and migrate far north to winter in very different ecosystems off South and Central America. Some seabirds migrate in and out too.
The National Geographic Society hopes to promote its conservation By drawing attention to the Southern Ocean. As climate change is altering it. The Ocean water moving through the ACC is warming. For decades the impacts of industrial fishing on species like krill and Patagonian toothfish have been a concern in the Southern Ocean. In 1982, catch limits were imposed in the region. The largest marine protected area (MPA) in the world was established in the Ross Sea off West Antarctica in 2016. A number of organizations are working to set aside more MPAs to protect the Southern Ocean’s most critical feeding grounds, for example off the Antarctic Peninsula.