As It Happens

How many oceans can you name? National Geographic just added a new one

There’s a good chance you learned about four oceans in school: Arctic, Atlantic, Indian and Pacific. But National Geographic says there’s a fifth.

The media and education NGO is officially recognizing the waters around Antarctica as a 5th ocean

National Geographic now recognizes these icy waters surrounding Antarctica as a fifth ocean called the Southern Ocean. (Getty Images)

There's a good chance you learned about four oceans in school: Arctic, Atlantic, Indian and Pacific. But National Geographic says there's a fifth.

The National Geographic Society has announced it will officially recognize the area around Antarctica as the Southern Ocean, due to its unique ecological features and marine life. 

"It's because of a building consensus that recognizes the unique ecological region of the ocean that is the Southern Ocean," National Geographic Society geographer Alex Tait told As It Happens host Carol Off.

"We've never added an ocean in over 100 years of map-making that we've done in National Geographic, so this is a rare occurrence."

The non-profit media and education organization says it will now include the Southern Ocean on maps in all its publications and materials. 

What makes an ocean an ocean?

When you get right down to it, Tait says, the whole idea of separate oceans is a misnomer. 

"There is, of course, just one world ocean. It's all interconnected. But there are regions of the ocean," he said.

While those regions are typically divided by land areas, he says the Southern Ocean is set off by physical conditions. 

A circumpolar current that goes around Antarctica separates the water there from the connecting Pacific and Atlantic oceans, and there are key differences in temperature and salinity. To put it simply, the Southern Ocean is colder and less salty than the Pacific and Atlantic oceans.

What's more, Tait says, it's home to a unique set of marine mammals, birds, fish, micro-organisms and fauna. 

National Geographic now recognizes five world oceans. Most of the waters that surround Antarctica out to 60 degrees south latitude, excluding the Drake Passage and Scotia Sea, constitute the newly acknowledged Southern Ocean. (Matthew W. Chwastyk and Greg Ugiansky/National Geographic )

National Geographic is not alone in this stance. The U.S. National Oceanic and Atmospheric Administration (NOAA) has recognized the Southern Ocean since 1999.

The International Hydrographic Organization (IHO), which tracks and charts the world's seas and oceans, discussed the possibility of adding a fifth ocean in 2000, but member countries could not agree on a set of proposed boundaries, according to the NOAA

For its part, National Geographic says the Southern Ocean encompasses most of the waters surrounding Antarctica out to 60 degrees south latitude, excluding the Drake Passage and Scotia Sea.

CBC has reached out to Environment and Climate Change Canada to find out Canada's position on the number of world oceans.

What are the practical implications?

The National Geographic Society is perhaps best known for publishing the National Geographic magazine, TV shows and website. But it also produces educational materials about science and the environment for classrooms. 

Now all of those media outlets and school materials will recognize a fifth ocean.

Adelie penguins leap off a floating icebergs near Paulet Island on the Antarctic Peninsula. (Getty Images)

The idea, Tait says, is to educate people about this area of the world and its importance in terms of conservation and climate change.

"Its role in the system of ocean currents that circulates warmer waters and cooler waters around the globe is very important," Tait said. 

"This area plays a big role in how those waters move around the Earth, which, of course, has a big effect on climate. And as climate changes, some of those ocean currents are predicted to change as well."

While several countries vie for sovereignty over Antarctica's waters, it doesn't really belong to anyone, but is rather "a world resource," Tait said.

That means the international community has to work together to protect it. Already, it is home to the largest marine protected area in the world, established in the Ross Sea off West Antarctica in 2016.   

National Geographic says the industrial fishing of species like krill and Patagonian toothfish in the Southern Ocean poses a risk to an area that is critical for the global ecosystem. That's why conservationists have long been pushing to establish more protected areas in the region. 

"It is a matter of working with many different governments around the world on the Antarctic region, because it is a shared region," he said. "It actually encourages co-operation in many ways."

Written by Sheena Goodyear. Interview produced by Niza Lyapa Nondo. 

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