Arctic

Description

The stunning, icy landscapes and charismatic wildlife of the Arctic region have captured the imaginations of humans for centuries. The word ‘Arctic’ comes from the Greek word for bear, ‘arctos’, and it is named after the Great Bear (Ursa Major) and Little Bear (Ursa Minor) constellations that appear in the Arctic sky all year round. ⁽¹⁾.

The Arctic is not a country or continent, but rather a region at the extreme north of the planet. Roughly, it includes the Arctic Ocean (the world’s smallest ocean) and the surrounding seas, as well as the world’s...

Arctic fact file

• Description
• Range
• Biodiversity
• Threats
• Conservation
• Find out more
• Glossary
• References

Description

The stunning, icy landscapes and charismatic wildlife of the Arctic region have captured the imaginations of humans for centuries. The word ‘Arctic’ comes from the Greek word for bear, ‘arctos’, and it is named after the Great Bear (Ursa Major) and Little Bear (Ursa Minor) constellations that appear in the Arctic sky all year round. ⁽¹⁾.

The Arctic is not a country or continent, but rather a region at the extreme north of the planet. Roughly, it includes the Arctic Ocean (the world’s smallest ocean) and the surrounding seas, as well as the world’s largest island, Greenland, and the northern extremities of several countries including Russia, Alaska and Canada ^{(2) (3)}. The most northerly point of the planet, the North Pole, is located on the continually shifting sea ice of the Arctic Ocean ⁽²⁾.

Much of the Arctic Ocean remains covered in floating sea ice throughout the year ⁽⁴⁾. However, in spite of the Arctic’s icy reputation, permanent land ice only covers a small area outside of Greenland. The climate of the Arctic is highly variable, both with season and location ⁽⁴⁾. During the winter months, the sun does not rise above the horizon in the northern reaches of the Arctic, causing temperatures in some areas to plummet to -60 degrees Celsius ^{(1) (5)}. In contrast, average July temperatures over snow-free land can be much warmer, sometimes reaching up to 20 degrees Celsius ⁽⁴⁾. The level of precipitation over the Arctic is also highly variable, with some areas receiving as little as 200 millimetres and others well over 1,000 millimetres ⁽⁴⁾.

Environmental conditions vary dramatically across the Arctic region and, as a result, the Arctic is sometimes divided into the High Arctic and the Low Arctic ⁽⁴⁾. The typical habitat of the Arctic region is tundra, which is characterised by treeless, grassy plains ⁽⁵⁾. The High Arctic is generally distinguished by having more severe environmental conditions and an extreme form of Arctic tundra known as polar desert. Polar deserts are typified by having low levels of moisture and therefore scant vegetation cover ⁽⁴⁾. In the Low Arctic, vegetation cover can be between 80 and 100 percent, with sedges and grasses forming a major component of the tundra, as well as shrubs and some low growing tree species ⁽⁴⁾.

A characteristic feature of the Arctic tundra is permafrost, or permanently frozen ground ⁽¹⁾. The permafrost strongly shapes both the Arctic landscape and the vegetation that can grow there ⁽¹⁾. While the permafrost may remain frozen year round in some areas of the High Arctic, in the Low Arctic it has an active top layer that thaws each summer ⁽⁴⁾. The frozen ground below this active layer acts as an impermeable barrier, leading to the ground becoming waterlogged and forming numerous shallow lakes ⁽⁴⁾.

Range

The boundary of the Arctic region is not well defined ⁽¹⁾. However, in general the Arctic region is said to include the Arctic Ocean and surrounding seas, Greenland, Svalbard, parts of Iceland and also the northern coasts and off-lying islands of Canada, Alaska and Russia ⁽³⁾. Parts of Scandinavia are also often included ⁽³⁾.

Biodiversity

Plants

The sun does not rise at all in the northern reaches of the Arctic from mid-November to late January, contrasting with the almost constant sunlight received in the summer months ⁽⁵⁾. This dramatic variation in light levels means that the growing season for plants in the Arctic is highly variable, ranging from as little as 60 days, up to 200 days ⁽⁶⁾.

Despite the extreme conditions, many parts of this remarkable region support an array of plant life ⁽⁵⁾. In late winter and spring, ice algae blooms along the edge of the retreating sea ice, forming an important part of the Arctic marine ecosystem ⁽¹⁾.

There are around 3,000 species of flowering plant found in the Arctic, including 96 rare, endemic species ⁽¹⁾. Cottongrass grows in distinctive clumps, along with wildflowers such as moss campion (Silene acaulis), Arctic avens (Dryas integrifolia) and the rare Arctic poppy (Papaver laestadianum) ^{(1) (5)}. The Arctic willow (Salix arctica) is one of the taller plants of the tundra, growing up to a couple of metres in height ⁽⁵⁾.

The diversity of mosses is high in the Arctic, with the 1,100 species of moss found in the region comprising 11 percent of the global number of known species ⁽¹⁾.

Mammals

Around 130 species of mammal inhabit the Arctic region, including the aptly named Arctic fox (Vulpes lagopus) and Arctic hare (Lepus arcticus), which are both superbly adapted for life at sub-zero temperatures, with their dense fur providing excellent insulation ^{(7) (8)}. Herds of muskox (Ovibos moschatus) and reindeer (Rangifer tarandus) also roam the Arctic landscape. Undoubtedly, one of the most iconic mammals of the Arctic region is the polar bear (Ursus maritimus). At up to 2.6 metres long, this magnificent species is the world’s largest land carnivore ⁽⁹⁾.

The Arctic is also home to a number of marine-dwelling mammal species, including the main prey of the polar bear, the ringed seal (Pusa hispida) ⁽¹⁰⁾. The walrus (Odobenus rosmarus) with its enormous tusks, the mysterious narwhal (Monodon monoceros) and the snow-white beluga whale (Delphinapterus leucas) also inhabit the waters of the Arctic ⁽³⁾. Each of these species is equipped with a thick layer of fat to insulate them against the cold Arctic waters ⁽³⁾.

Birds

There are an estimated 280 species of bird that occur in the Arctic region ⁽¹⁾. Some of these breed exclusively in the Arctic, including the brent goose (Branta bernicla), the ivory gull (Pagophila eburnea) and 17 of the 24 species of sandpiper ^{(1) (11)}. Of the 206 shorebird species known worldwide, 69 of these occur in the Arctic, with many species undertaking long migrations to reach the region ⁽¹⁾.

There are also predatory species of bird that inhabit the Arctic, including the snowy owl (Bubo scandiaca), which breeds and hunts on the Arctic tundra ⁽¹²⁾.

In spite of popular misconception, there are no species of penguin found in the Arctic, with these charismatic birds only occurring in the southern hemisphere ⁽¹³⁾.

Reptiles and amphibians

Due to the harsh conditions of the Arctic, reptiles and amphibians are generally poorly represented ⁽¹⁾. Just four species of lizard occur in the Arctic region, with the viviparous lizard (Lacerta vivipara) being the most northerly occurring reptile species ^{(1) (14)}.

Amphibians of the Arctic region include the Siberian salamander (Salamandrella keyserlingii), the Endangered Semirechensk salamander (Ranodon sibiricus) and the wood frog (Rana sylvatica) ^{(1) (15)}.

Fish and invertebrates

There is no shortage of invertebrates in the Arctic, with an estimated 3,000 species of insect found in the region. By far the most common group of terrestrial invertebrates found there are in the Order Diptera, or flies ⁽¹⁶⁾. Many of the terrestrial species emerge only in the brief Arctic summer, remaining dormant for the rest of the year ⁽¹⁶⁾. The larvae of the Gynaephora groenlandica moth can take up to 14 years to mature, surviving the winter in a frozen state ⁽¹⁶⁾. Other invertebrates, such as mosquitoes, can complete their development in a single season ⁽¹⁶⁾.

In the Arctic Ocean, zooplankton, such as copepods, form an important part of the marine community ⁽³⁾. A number of species of krill also occur in the Arctic, and these provide a plentiful and important food source for fish, seabirds and whales ⁽³⁾.

In total, there are around 450 species of fish that live in the Arctic ⁽¹⁾. The most northerly ranging of these is the Arctic charr (Salvelinus alpinus), which occurs in both the marine and freshwater systems of the Arctic ⁽¹⁷⁾. The Arctic cod (Boreogadus saida) forms vast shoals, and is specially adapted for a life in the icy waters by having proteins in its blood that act as antifreeze ^{(1) (18)}.

Threats

Climate change is currently the greatest threat to the Arctic region ⁽¹⁾. Changes in global temperatures are likely to have a range of complex impacts on the Arctic region, with some areas predicted to warm and others to cool ⁽¹⁾. The effect this will have on many of the unique Arctic ecosystems is largely unknown, though the Arctic sea ice has been shown to have decreased by 14 percent since the 1970s ⁽¹⁹⁾. This has already reduced the available habitat for species such as the polar bear, which relies on the presence of the Arctic sea ice to hunt ⁽¹⁹⁾.

Overexploitation by humans is another threat faced by numerous species that inhabit the Arctic ⁽¹⁾. In the past, traditional methods meant that hunting in the region was largely sustainable ⁽¹⁾. However, the advent of commercial methods has caused dramatic population decreases in many fish, whale and bird species ^{(1) (19)}. Bycatch is also a serious problem, threatening several fish and seabird species in particular ^{(1) (19)}.

The Arctic region is vulnerable to pollution from a number of sources ⁽¹⁾. The development of the oil and gas industries may result in the spillage of chemicals and oil into Arctic waters, while the high number of nuclear reactors in the region has potential to create future radioactive contamination ⁽¹⁹⁾. The movement of ocean currents mean that the Arctic seas are also a ‘sink’ for long-range pollutants such as insecticides and heavy metals, including mercury ⁽¹⁹⁾.

The construction of roads, use of off-road vehicles, hydropower development and introduction of alien invasive species are all also currently threatening the native species of the Arctic region ⁽¹⁾. Many of these activities destroy and fragment habitat, resulting in species having small, isolated populations that are at greater risk of catastrophic events, either natural or man-made ⁽¹⁾.

Conservation

The Conservation of Arctic Flora & Fauna (CAFF) is the working group tasked with addressing the issue of conservation in the Arctic, and communicating the findings to the governments and residents of the Arctic nations ⁽²⁰⁾. Conservation strategies implemented by CAFF have already shown success, improving the conservation status of seabirds such as the guillemot (Uria aalge) ⁽¹⁾. CAFF have also created the Circumpolar Protected Areas Network (CPAN), which aims to promote the development of a protected network area in the Arctic region ⁽²⁰⁾. Currently, there are 405 protected areas in the Arctic which cover a total of around 2.5 million square kilometres ⁽¹⁾.

Another major conservation aim is to regulate fishing, hunting and gathering in the Arctic region, both at the commercial and subsistence level. By involving local people in the planning of wildlife management it is hoped that sustainable methods that conserve both livelihoods and biodiversity can be developed ⁽¹⁾.

Future priorities for conservation in the Arctic region include the establishment of PSSAs (Particularly Sensitive Sea Areas) in order to protect vulnerable marine areas from shipping activities ⁽¹⁹⁾. It is also hoped that any future development in the Arctic region will use the ‘Conservation First’ principle to conserve vulnerable ecosystems ⁽¹⁹⁾.

The future of the Arctic region is very much reliant upon international conservation efforts. Many problems, such as pollution, climate change and the persecution of migratory species, originate in countries far beyond the borders of the Arctic region. Gaps in the knowledge of Arctic ecosystems also need to be filled in order to understand how to best conserve this unique eco-region ⁽¹⁾.

Find out more

Find out more about the Arctic region:

• Conservation of Arctic Flora and Fauna (CAFF) www.caff.is
• WWF - Arctic: wwf.panda.org/arctic/
• UNEP - Arctic region:
  www.unep.org/regionalseas/programmes/independent/arctic/instruments/r_profile_pame.pdf
• Arctic Seas Biodiversity project: arcticbiodiversity.org/
• Arctic Ocean Biodiversity: www.arcodiv.org/
• Arctic Council: www.arctic-council.org/

Glossary

Algae

simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.

Bycatch

in the fishing industry, the part of the catch made up of non-target species.

Carnivore

an organism that feeds on flesh. The term can also be used to refer to a mammal in the order Carnivora.

Copepod

a large and diverse group of minute marine and freshwater crustaceans. They usually have an elongated body and a forked tail.

Endemic

a species or taxonomic group that is only found in one particular country or geographic area.

Invertebrates

animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Larva

immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.

Order

a category used in taxonomy, which is below ‘class’ and above ‘family’. All members of an order have characteristics in common.

Tundra

treeless, grassy plains characteristic of Arctic and sub-Arctic regions. They are very cold and have little rainfall.

Zooplankton

tiny aquatic animals that drift with currents or swim weakly in water.

References

1. CAFF (2001) Arctic Flora and Fauna: Status and Conservation. Arctic Council, Conservation of Arctic Flora and Fauna Working Group (CAFF).
   http://arcticportal.org/uploads/eX/e6/eXe6XNMebXN263nFyvx_Rg/AFF-Status-and-Trends.pdf
2. Baker, S. (2010) Climate Change in the Arctic. Marshall Cavendish Benchmark, New York.
3. Blix, A.S. (2005) Arctic Animals and their Adaptations to Life on the Edge. Tapir Academic Press, Trondheim.
4. Serreze, M.C. and Barry, R.G. (2005) The Arctic Climate System. Cambridge University Press, Cambridge.
5. Winner, C. (2003) Life in the Tundra. Lerner Publications Company, Minneapolis.
6. Hultén, E. (1968) Flora of Alaska and Neighbouring Territories: A Manual of the Vascular Plants. Stanford University Press, Stanford.
7. Angerbjörn, A., Hersteinsson, P. and Tannerfeldt, M. (2004) Arctic fox Alopex lagopus (Linnaeus, 1758). In: Sillero-Zubiri, C., Hoffmann, M. and Macdonald, D.W. (Eds) Canids: Foxes, Wolves, Jackals and Dogs - 2004 Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland and Cambridge, UK.
8. Feldhamer, G.A., Thompson, B.C. and Chapman, J.A. (2003) Wild Mammals of North America: Biology, Management and Conservation. The Johns Hopkins University Press, Baltimore.
9. International Association for Bear Research and Management - Polar bear (October, 2011).
   http://www.bearbiology.com/index.php?id=40
10. Nowak, R.M. (2003) Walker’s Marine Mammals of the World. The Johns Hopkins Press, Baltimore.
11. Vuaghan, R. (2010) In Search of Arctic Birds. T & AD Poyser Ltd., London.
12. Parmelee, D.F. (1992) Snowy owl (Bubo scandiaca). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca.
    http://bna.birds.cornell.edu/bna/species/010
13. WWF - Penguins (October, 2011).
    http://www.worldwildlife.org/species/finder/penguins/penguins.html
14. Beebee, T. and Griffiths, R. (2000) The New Naturalist: Amphibians and Reptiles - A Natural History of the British Herpetofauna. HarperCollins Publishers, London.
15. IUCN Red List (October, 2011).
    http://www.iucnredlist.org/
16. Wharton, D.A. (2004) Life at the Limits: Organisms in Extreme Environments. Cambridge University Press, Cambridge.
17. Schultz, K. (2004) Ken Schultz Field Guide to Freshwater Fish. John Wiley & Sons Inc., Hoboken.
18. Sakshaug, E., Johnsen, G. and Kovacs, K. (2009) Ecosystem Barents Sea. Tapir Academic Press, Trondheim.
19. WWF - Arctic (October, 2011).
    http://www.panda.org/arctic
20. Conservation of Arctic Flora & Fauna (CAFF) (October, 2011).
    http://www.caff.is/