A unique habitat

Antarctica has been a source of fascination since it was discovered. Adventurers set off to explore the icy continent, seal hunters ventured into this unknown world seeking valuable furs. In 1911, the Norwegian Roald Amundsen and the Briton Robert Falcon Scott raced to the South Pole, a race which cost Scott and his team their lives. To this day, the South Pole has not lost its fascination. Every year, more and more tourists travel to this dream destination on cruise ships. And these days scientists spend the winter in the research stations around Antarctica and it does not even strike us as unusual. Many people consider Antarctica to be our planet’s last remaining wilderness. It stretches across the continent of Antarctica and the Southern Ocean. The continent of Antarctica alone has a coastline which is 32,000 kilometres long. A broad band of polar ice forms around it in winter more or less doubling the continent’s size. In summer, this polar ice melts. Thus the ice limit shifts throughout the year reaching into the ocean and then drawing back.

A continent of superlatives

The huge area around the South Pole is a region of extremes and records. The Antarctic ice cap is the Earth’s largest connected ice mass with a depth ranging from zero to almost 5000 metres. What is more, with 2500 metres Antarctica is the world’s highest continent in terms of average elevation. Antarctica is the driest, windiest and coldest place on Earth. The lowest ever temperature reading was recorded in July 1983 on Russia’s Vostok station when the thermometer read minus 89.2 degrees Celsius. The very low temperatures in Antarctica are basically due to the low level of solar radiation. In the southern winter (when it is summer in the northern hemisphere), the South Pole is tipped away from the sun, meaning it is dark around the clock. In the southern summer, the high reflection levels of the snow (albedo) mean that the region barely warms up.

Pronounced regional differences

In the coastal areas of the western Antarctic, an oceanic climate prevails, while the climate in the central eastern Antarctic is mainly continental. Generally speaking, the temperature drops from the coast to inland areas because the coasts do not cool down as dramatically due to the maritime influence. The average winter temperature at the coast is minus 20 to minus 30 degrees Celsius. Inland, winter temperatures are considerably lower at minus 60 to minus 70 degrees Celsius. Only some areas of the Antarctic Peninsula regularly reach temperatures above freezing point in summer. It is here that the impact of the rising temperatures associated with climate change is clearest.

A habitat for experts

All in all, conditions in Antarctica make survival a challenge: thick ice cover, little light, dry very salty soils and extremely short vegetation periods. Some species have been able adapt to this environment. Most of the vegetation is non-flowering species such as lichens and mosses, as well as algae and fungi and more than a thousand species have been identified. There are however two kinds of flowering plants: the Antarctic hair grass and the Antarctic pearlwort, the latter belonging to the carnation family. The two are to be found mainly on the Antarctic Peninsula, an area with a mainly oceanic climate.

Krill as a food source for animals

The number of higher animals in the Antarctic is relatively low given the extreme living conditions. Many live exclusively in the narrow ice-free coastal areas, all are dependent on the sea for food. Presumably the most important link in the food chain of the Southern Ocean is the Antarctic krill, a shrimp-like crustacean between four and six centimetres long. It feeds mainly on diatoms and zooplankton. The krill is the primary food source for squids, bone fish, penguins and seabirds, seals and whales. Furthermore, some 200 fish species live under the ice in coastal areas. They include 96 species of Antarctic fish and icefish, a group particularly well adapted to the extremely low temperatures which in part even have frost protection proteins in their blood.

Mascot in tails

Penguins are presumably Antarctica’s most well-known animals. These flightless divers are only found in the southern hemisphere. But only five of the total of eighteen known penguin species actually live in Antarctica breeding exclusively on the continent, the ice around it or the neighbouring islands. The best known of all is the emperor penguin, the world’s largest diving bird and the only species living permanently in Antarctica.

The other four penguin species of Antarctica and the subantarctic islands are the chinstrap penguin, the gentoo penguin, the macaroni penguin and the adélie penguin. As well as penguins, more than 20 other species of seabird are to be found including the albatross, the procellariidae, the skua and terns.

Large numbers of larger mammals

Then there are the larger mammals — the seals and whales which populate Antarctica, the surrounding islands or the Southern Ocean often in large numbers. The global population of the Antarctic crabeater seal alone is estimated at up to twelve million. This number is above all due to the huge numbers of Antarctic krills.

Of the 80 whale species worldwide, 14 live in Antarctica and are to be found there regularly in the Antarctic summer, they include six baleen whales: the blue whale (our largest mammal), the fin whale (second-largest mammal), sei whale, humpback whale as well as the Antarctic and the common minke whale. There are also six species of toothed whale including the killer whale, the sperm whale and the bottlenose whale.