Even fluffy white baby seals will ultimately grow up to a dark brown-better to blend in with the dark Arctic ocean waters instead of blinding white ice floes. Species of Arctic fox and Arctic hare, for example, are snowy white in winter but molt and grow a brownish or greyish fur coat during the summer months. Many Arctic animals even change their coloration seasonally. This coloring helps camouflage them in heavy snow and ice. Like the polar bear, many other animals of the Arctic are white: beluga whales, snowy owls, juvenile harp seals. The polar bear, the iconic apex predator of the Arctic, is equally able to hunt on land and around ice floes. Secondary consumers include Arctic foxes, and raptors such as owls and eagles. One of the most familiar Arctic herbivores is the caribou, often known as the reindeer in Europe and Asia. Primary consumers across the region range from tiny lemmings to enormous muskoxen. Insects and insect larvae provide a crucial diet for birds, such as wrens and sandpipers, and freshwater fish. Insects such as mosquitoes and moths are common, especially as icemelt creates ponds during spring and summer. These autotrophs have the ability to survive despite being covered in snow and ice for much of the year. Although some forests lie near the Arctic Circle, plant life is mostly limited to grasses, sedges, and tundra vegetation such as mosses and lichens. The Arctic includes the peaks of the Brooks mountain range in western North America, the enormous Greenland ice sheet, the isolated islands of the Svalbard archipelago, the fjords of northern Scandinavia, and the grassland plateaus and rich river valleys of northern Siberia. Terrestrial EcosystemsThe varied landscapes of the Arctic provide for a variety of ecosystems. Organic nutrients are thus recycled into the marine ecosystem of the Arctic.

Scavengers (including some sharks and crabs) and decomposers such as marine worms and algae break down dead and decaying materials. Tertiary consumers, animals that prey mostly on other carnivores, include toothed whales and dolphins (such as orcas and narwhals) and pinnipeds such as seals, sea lions, and walruses. Secondary consumers include fish, seabirds (such as gulls and puffins), and a wide variety of baleen whales, including giant blue whales and bowhead whales. Primary consumers such as jellies and shrimp consume plankton, the basis of the Arctic marine food web. The cold, circulating water is rich in nutrients, as well as the microscopic organisms (such as phytoplankton and algae) that need them to grow. River mouths, calving glaciers, and constantly moving ocean currents contribute to a vibrant marine ecosystem in the Arctic.

It is also the least salty, due to low evaporation and huge influxes of freshwater from rivers and glaciers. Life in the Arctic Marine EcosystemThe Arctic ocean basin is the shallowest of the five ocean basins on Earth. By the June solstice, the Arctic experiences 24-hour sunshine. The sun rises again during the March equinox, and increases the light and heat reaching the Arctic. Following sunset on the September equinox, the Earth’s tilted axis and its revolution around the sun reduce the light and heat reaching the Arctic until no sunlight penetrates the darkness at all. During the Northern Hemisphere’s winter months, the Arctic is one of the coldest and darkest places on Earth. The Arctic experiences the extremes of solar radiation. Due to thermohaline circulation, the Arctic’s thick, reflective sea ice moderates ocean temperatures around the world.

The dark surface of the liquid ocean, however, absorbs about 90% of solar radiation. This albedo means about 80% of sunlight that strikes sea ice is reflected back to space. Sea ice has a very bright surface, or albedo. Sea ice helps deter mine Earth’s climate. Often, sea ice is covered with a thick blanket of snow. Some parts of the ocean’s surface remain frozen all or most of the year. Most of the Arctic, however, is the liquid saltwater of the Arctic ocean basin.

In fact, the glaciers and icebergs in the Arctic make up about 20% of Earth’s supply of freshwater. Some frozen features, such as glaciers and icebergs, are frozen freshwater. The Arctic is almost enti rely covered by water, much of it frozen. Within this circle are the Arctic ocean basin and the northern parts of Scandinavia, Russia, Canada, Greenland, and the U.S. Most scientists define the Arctic as the area within the Arctic Circle, a line of latitude about 66.5° north of the Equator. The Arctic is the northernmost region of Earth.

Artic circle