For centuries, most of us have been taught that there are four oceans on Earth: the Atlantic, Pacific, Indian, and Arctic Oceans. Now though, National Geographic has recognized a fifth ocean: the Southern Ocean surrounding Antarctica. Many scientists have long recognized the Southern Ocean as its own ocean and the US Board on Geographic Names has referred to the region as the Southern Ocean for more than two decades. In February, the US National Oceanic and Atmospheric Administration recognized it "as the body of water extending from the coast of Antarctica to the line of latitude at 60 degrees South." Still, others argue that it's just an extension of the Pacific, Atlantic, and Indian Oceans. (Of course, the real truth is that there's only ONE global ocean that covers 71 percent of the Earth's surface.) From National Geographic:
For now, by fencing in the frigid southern waters, the ACC helps keep Antarctica cold and the Southern Ocean ecologically distinct. Thousands of species live there and nowhere else.
The Southern Ocean "encompasses unique and fragile marine ecosystems that are home to wonderful marine life such as whales, penguins, and seals," notes National Geographic Explorer in Residence Enric Sala.
What's more, the Southern Ocean has ecological effects elsewhere as well. Humpback whales, for example, 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.
By drawing attention to the Southern Ocean, the National Geographic Society hopes to promote its conservation.
image: "A general delineation of the Antarctic Convergence, sometimes used by scientists as the demarcation of the Southern Ocean" by Apcbg (CC BY-SA 3.0)