Most species in Antarctica seem to be the descendants of species that lived there millions of years ago. As such, they must have survived multiple
glacial cycles. The species survived the periods of extremely cold climate in
isolated warmer areas, such as those with
geothermal heat or areas that remained ice-free throughout the colder climate.
Animals s with juveniles Invertebrate life of Antarctica includes species of microscopic
mites such as
Alaskozetes antarcticus,
lice,
fleas (
Glaciopsyllus antarcticus),
nematodes,
tardigrades,
rotifers,
krill and
springtails. The flightless
midge Belgica antarctica, the largest purely terrestrial animal in Antarctica, reaches in size.
Antarctic krill, which congregates in large
schools, is the
keystone species of the
ecosystem of the Southern Ocean, being an important food organism for whales, seals,
leopard seals, fur seals,
squid,
icefish, and many bird species, such as penguins and
albatrosses. Some species of marine animals exist and rely, directly or indirectly, on
phytoplankton. Antarctic sea life includes
penguins,
blue whales,
orcas,
colossal squids and
fur seals. Leopard seals are
apex predators in the Antarctic ecosystem and migrate across the Southern Ocean in search of food. There are approximately 40 bird species that breed on or close to Antarctica, including species of
petrels,
penguins,
cormorants, and
gulls. Various other bird species visit the ocean around Antarctica, including some that normally reside in the Arctic. The
emperor penguin is the only penguin that breeds during the winter in Antarctica; it and the
Adélie penguin breed farther south than any other penguin. A
Census of Marine Life by some 500 researchers during the
International Polar Year was released in 2010. The research found that more than 235 marine organisms live in both polar regions, having bridged the gap of . Large animals such as some
cetaceans and birds make the round trip annually. Smaller forms of life, such as
sea cucumbers and
free-swimming snails, are also found in both polar oceans. Factors that may aid in their distribution include temperature differences between the deep ocean at the poles and the equator of no more than and the major current systems or marine conveyor belts which are able to transport eggs and
larva. In January 2025, the detachment of the massive iceberg A-84 (comparable in size to the city of
Chicago) from the
George VI Ice Shelf provided a rare opportunity to explore the seafloor beneath floating ice shelves using
robotic submersibles. Researchers uncovered ecosystems unexpectedly rich in
large corals,
ancient sponges,
icefish, giant
sea spiders, and even
octopuses at depths of up to . These ecosystems may harbor novel species that have remained concealed for centuries, sustained by nutrient-bearing ocean currents.
Fungi '') growing on the
Yalour Islands,
Wilhelm Archipelago About 1,150 species of
fungi have been recorded in the Antarctic region, of which about 750 are non-
lichen-forming. Some of the species, having evolved under extreme conditions, have
colonised structural cavities within porous rocks and have contributed to shaping the rock formations of the McMurdo Dry Valleys and surrounding mountain ridges. The same features can be observed in algae and
cyanobacteria, suggesting that they are
adaptations to the conditions prevailing in Antarctica. This has led to speculation that
life on Mars might have been similar to Antarctic fungi, such as
Cryomyces antarcticus and
Cryomyces minteri. Some of the species of fungi, which are apparently endemic to Antarctica, live in bird dung, and have evolved so they can grow inside extremely cold dung, but can also pass through the intestines of warm-blooded animals.
Plants '' at
Collins Glacier, Antarctica. This species is one of only two flowering plants native to Antarctica, the other one being Antarctic pearlwort (Colobanthus quitensis). Throughout its history, Antarctica has seen a wide variety of plant life. In the
Cretaceous, it was dominated by a fern-
conifer ecosystem, which changed into a temperate
rainforest by the end of that period. During the colder
Neogene (17–2.5 Ma), a
tundra ecosystem replaced the rainforests. The climate of present-day Antarctica does not allow extensive vegetation to form. A combination of freezing temperatures, poor
soil quality, and a lack of moisture and sunlight inhibit plant growth, causing low
species diversity and limited distribution. The
flora largely consists of
bryophytes (25 species of
liverworts and 100 species of
mosses). There are 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).
Other organisms Of the 700 species of algae in Antarctica, around half are marine
phytoplankton. Multicoloured
snow algae are especially abundant in the coastal regions during the summer. Even
sea ice can harbour unique ecological communities, as it expels all salt from the water when it freezes, which accumulates into pockets of
brine that also harbour dormant microorganisms. When the ice begins to melt, brine pockets expand and can combine to form brine channels, and the
algae inside the pockets can reawaken and thrive until the next freeze. Bacteria have also been found as deep as under the ice. It is thought to be likely that there exists a native bacterial community within the subterranean water body of
Lake Vostok. The existence of life there is thought to strengthen the argument for the possibility of life on
Jupiter's moon
Europa, which may have water beneath its water-ice crust. There exists a community of
extremophile bacteria in the highly
alkaline waters of
Lake Untersee. The prevalence of highly resilient creatures in such inhospitable areas could further bolster the argument for
extraterrestrial life in cold,
methane-rich environments.
Conservation and environmental protection on
King George Island, photographed in 1992 The
first international agreement to protect Antarctica's biodiversity was adopted in 1964. The
overfishing of
krill (an animal that 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, an international treaty that came into force in 1980, regulates fisheries, aiming to preserve ecological relationships. In analogy to the 1980 treaty on
sustainable fishing, countries led by New Zealand and the United States negotiated a treaty on mining. This
Convention on the Regulation of Antarctic Mineral Resource Activities was adopted in 1988. After a strong campaign from environmental organisations, first Australia and then France decided not to ratify the treaty. Instead, countries adopted the
Protocol on Environmental Protection to the Antarctic Treaty (the Madrid Protocol), which entered into force in 1998. The Madrid Protocol bans all mining, designating the continent as a "natural reserve devoted to peace and science". The pressure group
Greenpeace established
a base on Ross Island from 1987 to 1992 as part of its attempt to establish the continent as a
World Park. The
Southern Ocean Whale Sanctuary was established in 1994 by the
International Whaling Commission. It covers and completely surrounds the Antarctic continent. All
commercial whaling is banned in the zone, though Japan has continued to hunt whales in the area, ostensibly for research purposes. Despite these protections, the biodiversity in Antarctica is still at risk from human activities.
Specially protected areas cover less than 2% of the area and provide better protection for
animals with popular appeal than for less visible animals. Ecosystems are impacted by local and global threats, notably
pollution, the
invasion of non-native species, and the various
effects of climate change. == History of exploration ==