The Wildlife of the Frozen Continent: Abundant and Fragile
Online entry 03/07/2012 - 18:15
Antarctica is a land of extremes. The continent that surrounds the South Pole is the world’s largest cold desert, and has the lowest temperatures and greatest accumulation of ice of anywhere on the globe. With 98% of its surface covered by ice, it is also the largest fresh water reserve on Earth. In a place such as this, only plants and animals adapted to cold, reduced light, and aridity, can survive: penguins, seals, fish, crustaceans, mosses, lichens, and algae. But the dynamic biodiversity of the frozen continent is facing numerous threats from introduced species, the presence of humans, and global climate change.
2008 was an exciting year. That was the year the British Antarctic Survey published the results of its research in Antarctica, with an inventory of 1,284 species, 1,026 of which are marine, heretofore unknown. Some of these species seem to come from another world, such as ghostly pale octopuses and seven-legged sea stars. The new discoveries represented approximately 0.1% of the Earth’s known and described species to date.
Antarctica’s wildlife does indeed exhibit some bizarre traits! Take the ice fish, which produces a sort of “antifreeze” that enables it to live in the glacial depths of the Southern Ocean, earning it the distinction of being the best cold-adapted animal in world history. Other endemic species live between land and sea, such as Emperor Penguins, the emblematic heroes of the animated feature “Happy Feet” widely known for pirouetting on top of icebergs. But there are others as well: the Crabeater Seal, the Spinous Spider Crab, the Screaming Albatross, the Bearded Penguin, the Fur Seal, three hundred different species of fish, and better known animals such as the Blue Whale, the Orca Whale, and sea stars.
Spinous Spider Crab
Exotic invaders spotted!
Unfortunately, Antarctica’s biodiversity is under threat from an invasion of non-native species. The harshness of the climate is not enough to stave off these conquering hordes. Global warming is now making it easier for exotic species to invade, adapt, and reproduce in large numbers. Non-native spiders, slugs, caterpillars, and weevils are often more resistant than native species, and end up invading their natural habitats, to the detriment of the locals. To make matters worse, a few of these invaders, along with certain funguses, also carry diseases that can prove fatal to endemic flora and fauna.
Caught in the trap of a changing world
Global warming also poses a grave danger to Antarctica’s biodiversity. Some species, such as the King Penguin and the Fur Seal, seem to appreciate the increased warmth (+2.5°C, on average, over the past fifty years). But others, such as the Emperor Penguin and the Southern Elephant Seal, have recently seen their populations decline, and may one day be added to the long list of extinct species. Other of global warming’s negative effects include reduced precipitation and temperatures that are unfavorable to plants and animals at the bottom of the food chain, leading to a decrease in the food supply all the way up.
Global changes such as the acidification of the oceans are also having a negative impact on Antarctica. Triggered by the CO2 build-up, acidification is changing the water’s pH so rapidly that flora and fauna do not have time to adapt. Sea stars, for example, are compromised by this increased acidity, which empties the ocean of the nutrients they need to develop their spiny skin, ossicles of calcium carbonate (CaCO3) and magnesium carbonate (MgCO3).
The impact of humans
Approximately 4,000 scientists live in Antarctica each year. But they are no longer the only ones rushing to the continent. Antarctica has become a high-end adventure vacation destination. Although it is still out of the reach of most budgets, it remains very popular, drawing over 55,000 visitors a year to marvel at the beauty of its landscapes. But these visitors rarely question their own impact on this exceptional environment.
The presence of human beings, however sparse over such a vast land mass, nevertheless exerts significant pressure on the continent’s biodiversity in the form of pollution from heating sources and means of transport, disturbance of animals, and destruction of natural habitat. Scientific studies have shown that, simply by their presence, human beings disrupt the delicate reproductive cycle of Emperor Penguins.
Industrial fishing is also a problem, and is having a major impact not only on marine fauna, but also on birds, which often get caught in the nets and drown.
A ray of hope?
Despite the urgency of the situation, it is very difficult to enact comprehensive measures to protect Antarctica, because the continent is now governed by a treaty signed by 48 different countries. The 1991 Madrid Protocol relating to the environmental protection of Antarctica, does not appear to be adequate. In theory, Antarctica has been declared a “natural reserve devoted to peace and science.” The mining of all minerals has been prohibited on the continent until 2048. However, at the 34th Antarctic Treaty Consultative Meeting held in June of 2011, Russia stated its desire to explore the continent’s mineral and hydrocarbon resources. Let’s hope that Mumble, the hero of “Happy Feet,” and his friends won’t fall prey to such plans in real life!
Baby Fur Seal
Photo credits: British Antarctic Survey