It is precisely the severity of the Arctic climate that gave rise to its unique ecosystems and remarkable biodiversity. While the Arctic is known for such species as Arctic foxes, snowy owls, walruses, and polar bears, it is also home to more than twenty-one thousand lesser-known species of mammals, birds, fish, invertebrates, plants, fungi, endoparasites, and microbes that are equally as adapted to the extreme climatic conditions of the North, including subfreezing temperatures, short growing seasons, permafrost, sea ice, and extremes in solar radiation. For local human populations, this beautiful biodiversity constitutes far more than just a simple source of food: it also provides the backdrop for cultural and spiritual identities.
One of the Arctic’s most iconic animals is the polar bear (Ursus maritimus), a large mammal weighing up to 720 kilograms with black skin that absorbs heat from the sun and thick fur, ivory in colour, that helps it blend into the snow and insulates it from the cold. The small, omnivorous Arctic fox (Vulpes lagopus) is a land mammal that often burrows in the snow and has silvery-white fur that also makes for great camouflage, helping the animal evade its predators. Reindeer (called Cariboo in Canada) are largely found in the Norwegian archipelago of Svalbard, as well as certain parts of the Russian and Canadian Arctic, and constitute a vital source of food and clothing for many indigenous peoples. The walrus can be found in Svalbard, Greenland, the Canadian Arctic, the Bering Sea, and the East Siberian Sea. This tusked and whiskered animal, naturally brown in colour but sometimes appearing white after diving or pink in heat due to changes in blood supply, weighs anywhere from 800 to 1,700 kilograms in adulthood. Other endemic Arctic mammals include musk oxen, the Arctic hare, and the Arctic ground squirrel, amongst others.
The Arctic’s warm-blooded endemic animals have adapted, both physiologically and behaviourally, to remain alive in severe temperatures that fall as low as -50 degrees Celsius. Reindeer, for instance, eat lichens buried under snow. Instead of hibernating like their cousins the brown bears, polar bears take advantage of the winter months to hunt and accumulate enough fat reserves to be able to go several months without eating in summer, when it is more difficult to hunt. Animals that cannot adapt to the Arctic environment in winter, such as most of the region’s birds, are migratory.
Migratory birds winter as far away as the southern United States and even the sub-Antarctic, which lies just above Antarctica, taking advantage of longer and warmer days and intense growing seasons wherever they are. The Arctic has no reptiles, but is home to one amphibian, the wood frog, that spends most of the year outside of its July-August breeding season buried in the mud (found at the bottom of ponds and small lakes) which does not freeze. The Arctic also has several species of freshwater fish, such as speckled trout, Arctic grayling, and Arctic char, as well as a wide range of invertebrates, such as crustaceans (branchiopods and copepods), spiders, and insects (scourges, mosquitoes, and blackflies), amongst others.
Both polar bears and walruses rely on sea ice for survival, but they are not the only ones. The sea ice “edge” – the transition area between the open ocean and sea ice – is a diverse biological community comprised of bacteria, algae, shrimp, seals, and many other organisms, all of which are adapted to their specific living conditions.
The Arctic is also home to a wide range of photosynthesising endemic flora, which can be divided into three general groups: vascular plants (including Arctic poppy, saltmarsh grass, goosegrass, Arctic whitlow-grass), bryophytes (including mosses and liverworts), and algae (including microalgae and macroalgae); the former two comprise terrestrial vegetation and the latter is more abundant in water. Many local plants from all three categories play an important role in the lives of indigenous peoples. The Arctic has approximately 2,218 vascular plants, around 5 percent of which (106 species) are endemic. The region has no endemic woody species. Over the past 250 years, no predominantly Arctic-based vascular plant has been known to go extinct for anthropogenic reasons and no plant is currently considered seriously invasive. The Arctic has approximately 900 species of bryophytes, at least 4,000 species of algae (this is a conservative estimate), and tens of thousands of species of plankton (with at least 10,000 species of phytoplankton in the Canadian Arctic alone).