Antarctica - Biodiversity

Animals 

Few terrestrial vertebrates live in Antarctica, and those that do are limited to the sub-Antarctic islands. Invertebrate life includes microscopic mites like the Alaskozetes antarcticus, lice, nematodes, tardigrades, rotifers, krill and springtails. The flightless midge Belgica antarctica, up to 6 mm (1/4 in) in size, is the largest purely terrestrial animal in Antarctica. The snow petrel is one of only three birds that breed exclusively in Antarctica. 

Some species of marine animals exist and rely, directly or indirectly, on the phytoplankton. Antarctic sea life includes penguins, blue whales, orcas, colossal squids and fur seals. The emperor penguin is the only penguin that breeds during the winter in Antarctica, while the Adelie penguin breeds farther south than any other penguin. The southern rockhopper penguin has distinctive feathers around the eyes, giving the appearance of elaborate eyelashes. King penguins, chinstrap penguins, and gentoo penguins also breed in the Antarctic.

The Antarctic fur seal was very heavily hunted in the 18th and 19th centuries for its pelt by sealers from the United States and the United Kingdom. The Weddell seal, a "true seal", is named after Sir James Weddell, commander of British sealing expeditions in the Weddell Sea. Antarctic krill, which congregate in large schools, is the keystone species of the ecosystem of the Southern Ocean, and is an important food organism for whales, seals, leopard seals, fur seals, squid, icefish, penguins, albatrosses and many other birds.

A census of sea life carried out during the International Polar Year and which involved some 500 researchers was released in 2010. The research is part of the global Census of Marine Life (CoML) and ahs disclosed some remarkable findings. More than 235 marine organisms live in both polar regions, having bridged the gap of 12,000 km (7,456 mi). Large animals such as some cetaceans and birds make the round trip annually. More surprising are small forms of life such as sea cucumbers, and free-swimming snails found in both polar oceans. Various factors may aid in their distribution - fairly uniform temperatures of the deep ocean at the poles and the equator which differ by no more than 5 ºC, and the major current systems or marine conveyor belt which transport eggs and larval stages.

Fungi 

About 1,150 species of fungi have been recorded from Antarctica, of which about 750 are non-lichen-forming and 400 are lichen-forming. Some of these species are cryptoendoliths as a result of evolution under extreme conditions, and have significantly contributed to shaping the impressive rock formations of the McMurdo Dry Valleys and surrounding mountain ridges. The apparently simple morphology, scarcely differentiated structures, metabolic systems and enzymes still active at very low temperatures, and reduced life cycles shown by such fungi make them particularly suited to harsh environments such as the McMurdo Dry Valleys. In particular, their thick-walled and strongly melanized cells make them resistant to UV light. Those features can also be observed in algae and cyanobacteria, suggesting that these are adaptations to the conditions prevailing in Antarctica. This has led to speculation that, if life ever occurred on Mars, it might have looked similar to Antarctic fungi such as Cryomyces antarcticus, and Cryomyces minteri. Some of these fungi are also apparently endemic to Antarctica. Endemic Antarctic fungi also include certain dung-inhabiting species which have had to evolve in response to the double challenge of extreme cold while growing on dung, and the need to survive passage through the gut of warm-blooded animals. 

Plants

About 298 million years ago Permian forests started to cover the continent, and there were tundras as late as 15 million years ago, but the climate of present-day Antarctica does not allow extensive vegetation to form. A combination of freezing temperatures, poor soil quality, lack of moisture, and lack of sunlight inhabit plant growth. As a result, the diversity of plant life is very low and limited in distribution. The flora of the continent largely consists of bryophytes. There are about 100 species of mosses and 25 species of liverworts, but only three species of flowering plants, all of which are found in the Antarctic peninsula: Deschampsia antarctica (Antarctic hair grass), Colobanthus quitensis (Antarctic pearlwort) and the non-native Poa annua (annual bluegrass). Growth is restricted to a few weeks in the summer.

Other organisms 

Seven hundred species of algae exist, most of which are phytoplankton. Multicolored snow algae and diatoms are especially abundant in the coastal regions during the summer. Bacteria have been found living in the cold and dark as deep as 800 m (0.50 mi; 2,600 ft) under the ice.

Conservation 

The Protocol on Environmental Protection to the Antarctic Treaty (also known as the Environmental Protocol or Madrid Protocol) came into force in 1998, and is the main instrument concerned with conservation and management of biodiversity in Antarctica. The Antarctic Treaty Consultative Act (1978) in the U.S. brought several restrictions to U.S. activity on Antarctica. The introduction of alien plants or animals can bring a criminal penalty, as can the extraction of any indigenous species. The overfishing of krill, which plays a large role in the Antarctic ecosystem, led officials to enact regulations on fishing. The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), a treaty that came into force in 1980, requires that regulations managing all Southern Ocean fisheries consider potential effects on the entire Antarctic ecosystem. Despite these new acts, unregulated and illegal fishing, particularly of Patagonian toothfish (marketed as Chilean Sea Bass in the U.S.), remains a serious problem. The illegal fishing of toothfish has been increasing, with estimates of 32,000 tonnes (35,300 short tons) in 2000.