Antarctic

 / ©: SYLVIA RUBLI
Cap Renard, Antarctic Peninsula
© SYLVIA RUBLI
WWF’s vision is for the seas, islands and coasts of Antarctica and the Southern Ocean to be valued, understood, wisely used and protected.
WWF believes that with adequate protection, we can create a future where much of this remarkable region is still in a pristine state.

Our vision of the future is one where healthy and productive waters underpin the great Antarctic web of life - waters that are home to recovering populations of great whales, albatrosses, seals and penguins that characterise the southern regions.

To achieve this, nations must cooperate with a common purpose to manage the sustainable fisheries, shipping, and tourism that can co-exist with plentiful wildlife and a healthy sea.

The threat to the Antarctic and Southern Ocean

There is a perception that the Antarctic and Southern Ocean are largely pristine and the threat from human activities has been removed, however this is not true!

Today, the world’s last great wilderness and its wildlife are under threat as never before. In addition to very dramatic climatic warming which already appears to be having an impact on penguin populations, there is huge demand for Southern Ocean resources – with harvesting of fish stocks and krill, replacing sealing and whaling.

The Antarctic and Southern Ocean are now more accessible than ever before. Antarctic tourism, research, and demand for fish are increasing both the risk of a major shipping disaster as well as the pressure on the resources.

Non-native species, likely to have been brought over by humans, have already decimated breeding habitats on a number of sub-Antarctic islands.

WWF’s global conservation network is uniquely placed to protect the world’s last great wilderness - forging new partnerships and delivering innovative and practical solutions.

Antarctica

The world’s fifth largest continent, Antarctica, covers around 14 million square kilometres and winter sea ice doubles the area.

A continent of extremes, it is often described as a 'crystal desert' - it's also the world’s largest desert.

It is the windiest place on the earth with average wind speeds at Cape Denison reaching hurricane force roughly every three days.

The lowest temperatures ever of -89.2oC or -128.6oF were recorded near Russia’s Vostok station in 1983. 75% of the world’s freshwater is ice and 90% of that ice is in Antarctica - the dome of the polar ice sheet is 4,800 meters thick at the deepest point.

The average elevation of Antarctic is 2,160 meters - the second highest continent. There are no trees, yet more than 100 million birds nest and breed in Antarctica.

The Southern Ocean

The Southern Ocean represents around 10% of the world's ocean surface and covers an area of almost 35 million square kilometres.

It includes some of the most productive marine regions on the planet. The Southern Ocean includes a number of distinct regions each with its own physical, chemical and ecological characteristics, underwater features include deep ocean basins, large mid-ocean ridges, plateaus, and seamounts.

Forming part of the Southern Ocean are a number of seas which fringe the continent of Antarctica, frequently named after the great explorers - Ross, Weddel, Amundsen. 

The Southern Ocean can be divided into three zones:

  • The Permanently Open Ocean Zone (POOZ) which is nutrient-rich but has relatively low levels of primary productivity.
  • The Seasonal Ice Zone (SIZ) which lies south of the POOZ and is covered in ice in winter but open water in the summer months. It is the most productive zone, with baleen whales, crabeater seals, penguins and other seabirds exploiting the krill stocks.
  • The Coastal and Continental Shelf Zone (CCSZ) is the most southerly region, covered in pack ice except at the time of its maximum retreat. Wildlife here is less abundant than in the SIZ.

Southern Ocean wildlife

Despite the extreme conditions, the many species of marine mammals, seabirds, together with unusual fish, krill and seabed communities, make up an extremely diverse and highly productive environment.

The Southern Ocean is renowned for its populations of great whales, seals and seabirds.

It was the large populations of whales and seals that attracted the first "wave" of Antarctic hunters - the whalers and sealers. The world’s largest whale sanctuary (although so-called "scientific" whaling goes on) is home to a large number of different whales - minke, sei, fin, humpback, blue and southern right whales are found in the polar waters. Most baleen whales migrate to warmer waters to breed.

Of the toothed whales, orca, sperm whale, Arnoux's beaked whale, and southern bottlenose whale are present. More than a third of the world’s seal and southern fur seal species are found in sub-Antarctic or Antarctic waters, including crabeater, Weddell, Ross, leopard and southern elephant seals and a number of fur seal species.

100 million seabirds spend the greatest part of their lives at sea, only coming to ashore to breed and nest in Antarctica or on the many isolated and remote sub-Antarctic islands. The best known are the many species of albatrosses and penguins. Also important are fulmars, diving petrels, storm petrels, sheathbills, cormorants, skuas, terns and gulls.

Around 120 species of fish are found south of the Polar Front - a major natural barrier to the movement of fish species. Antarctic fish are well adapted to living in the cold, inhospitable Southern Ocean. They tend to be slow growing, have long life spans, take a few years to become sexually mature and reproduction is slow.

These characteristics make many fish particularly vulnerable to overfishing. Marbled rock cod, mackerel icefish and Patagonian toothfish have all suffered from overexploitation. Today, toothfish, icefish, and krill form the primary target stocks.

Squid are considered to be one of the most important components of the Southern Ocean food web, yet relatively little is known about them. They form a major part of the diet of many seabirds, particularly albatrosses and also of seals and toothed whales. Yet the species found in the stomachs of whales are not the same as the species caught in nets. Squid can eat up to 30% of their body weight each day, with lantern fish and deepwater fish their major prey.

The Ross Sea in the Southern Ocean was the site of the recent capture in February 2007 of the largest recorded specimen of the colossal squid, the world's largest living invertebrate. There have only been five recorded sightings of the colossal squid, believed to be a major prey item for Antarctic sperm whales and Pacific sleeper sharks. Other animals which feed on the juveniles or young adult colossal squid include beaked whales, pilot whales, southern elephant seal and Patagonian toothfish.

Krill is commonly regarded as the central component of the Southern Ocean food web. Not only do they provide food for a range of fish, seabirds, seals and the baleen whales, they are also a target species for commercial fisheries. Yet, little is known about the abundance and distribution of krill, except that it can vary significantly from year to year. Rich seabed communities of filter feeders and mobile scavengers including anemones, soft corals, molluscs, sea urchins, starfish, various worms, crustaceans and fish are present in the coastal and continental shelf areas of Antarctica. Around 700 species of algae have been recorded from Antarctic waters of which 35% are endemic.

The importance of the Antarctic and Southern Ocean

As well as being important for its wildlife, the Antarctic and Southern Ocean is important to the rest of the world in other ways.

The polar regions act as "heat sinks" that influence the whole world's climate and they are warming faster than other areas of the world.

Short and small temperature changes are connected to fast changes in the north by the changing Atlantic currents. The Antarctic Circumpolar Current – the world's largest current - carries around 135 million cubic meters of water per second from west to east around the Antarctic continent. This is about 135 times the flow of all the world's rivers combined and it connects each of the world's major ocean basins which permits a truly global ocean circulation pattern.
 / ©:  © Wim van Passel / WWF-Canon
© © Wim van Passel / WWF-Canon
 / ©: Cassandra Phillips / WWF-Canon
© Cassandra Phillips / WWF-Canon
 / ©: © Wim van Passel / WWF-Canon
© © Wim van Passel / WWF-Canon
 / ©: Brian J. Skerry / National Geographic Stock / WWF
Southern right whales (Eubalaena australis) underwater off the Auckland Islands, New Zealand (sub Antarctic islands).
© Brian J. Skerry / National Geographic Stock / WWF