The Antarctic is a continent larger than Europe, measuring 5.4 million square miles (14 million sq km). Temperatures rarely rise above freezing and most of the land is covered in ice. Glaciers flow from the interior into the oceans, creating enormous, ice-shelves, half a mile thick.
Life flourishes despite these severe conditions, and the terrain serves as a living laboratory for teams of scientists from around the world. The lichens growing on the rocks of the cold, dry valleys of Victoria Land, for example, give vital clues to life in severe conditions, such as those millions of years ago on Mars, and studies of the relationship between populations of natural predators and their prey in the seas surrounding the continent inform the management of fisheries worldwide.
Argentina, Australia, Chile, France, New Zealand, Norway, and the UK have all laid claim to parts of the Antarctic, although their sovereignty is not recognized by most other nations. The 1959 Antarctic Treaty promotes scientific co-operation and prohibits military activity, such as weapons testing, and waste dumping. Participating countries designate Specially Protected Areas (see map), to which access is restricted in order to leave important wildlife features undisturbed. Until the mid-1980s, scientific bases created high levels of local contamination (waste products, oil and rubbish). More recently, the scientific community has realized the importance of maintaining the Antarctic in its pristine state, as far as possible. Unfortunately, this has coincided with an increase in tourism in the area. More than 30,000 tourists visited the continent in 2007–08 – four times as many as 10 years previously. This increases the risk of the introduction of invasive species of plants and animals, and of a cruise ship grounding in the treacherous waters and causing an oil spill.
A further, and potentially even more damaging, threat to the region is posed by climate change. Temperatures on the Antarctic Peninsula have risen by around 2.5°C since the 1950s, leading in recent years to the dramatic disintegration of several ice shelves. The effect of this change on the flora and fauna is already being recorded, with the loss of sea-ice around the peninsula decimating the population of Adélie penguins, which use it to reach their feeding grounds. As their numbers dwindle, they are being replaced by gentoo penguins, which thrive in open waters. Warming ocean temperatures could also herald the arrival of a range of predatory species, such as king crabs, that could destroy the delicate ecosystem.
Krill – small crustaceans that provide food for fish, seabirds and mammals – feed on algae that form under sea-ice, and so are affected by its diminishing area. A more immediate threat, however, comes from commercial fishing, which began in the 1970s. Fears of over-exploitation led, in 1981, to the Convention on the Conservation of Antarctic Marine Living Resources, which regulates the annual krill catch but, despite this, krill stocks in 2003 were estimated at just one-fifth of their level in the 1970s, and the annual catch has continued to rise: from 109,000 tons in 2006–07 to over 684,000 tons the following season. It is feared that falling global fish-stocks and improved technology for catching krill could increase demand to several million tons a year, which would have serious implications for the survival of whales, seals, penguins and other birds.
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