The Arctic is a polar region at Earth’s northernmost part, encompassing the Arctic Ocean, adjacent seas, and parts of Alaska, Canada, Finland, Greenland, Iceland, Norway, Russia, and Sweden. Its climate features extreme cold, long periods of winter darkness, continuous summer daylight, and extensive ice cover. Despite these conditions, the Arctic supports diverse life adapted to its unique environment.
Iconic Arctic Mammals
The Arctic is home to several large mammal species adapted to extreme cold. Polar bears, for instance, possess thick blubber and dense fur, including hollow guard hairs, providing insulation. These apex predators primarily hunt seals, often waiting by breathing holes in the ice. Arctic foxes also adapt by growing a dense winter coat that changes color from brown to white, offering camouflage against the snow.
Caribou, also known as reindeer, undertake seasonal migrations across the tundra in search of food. Their broad hooves help them navigate deep snow and soft ground, also aiding in digging for lichens and mosses. Muskoxen, another large herbivore, are distinguished by their shaggy coats and form defensive circles when threatened, protecting calves from predators like Arctic wolves.
Marine mammals thrive in Arctic waters. Ringed seals and bearded seals, for example, have a thick blubber layer for insulation and buoyancy, spending much of their lives in or near the ice. Walruses use their long tusks to haul themselves onto ice floes and to forage for clams and other benthic invertebrates on the seafloor.
Several whale species inhabit the Arctic Ocean, including bowhead whales, which possess the thickest blubber of any animal, allowing them to withstand icy waters. Beluga whales, known for their white coloration and flexible necks, navigate through ice-choked waters using echolocation. Narwhals, often called the “unicorns of the sea,” are notable for the long, spiraled tusk that protrudes from the male’s head, which is actually an elongated canine tooth.
Avian and Aquatic Life
The Arctic hosts diverse bird species, many migratory, arriving in spring for abundant food and continuous daylight for breeding. Arctic terns are known for their long migrations, flying from the Arctic to the Antarctic and back each year, experiencing two summers. Puffins, with their colorful beaks, nest in large colonies on coastal cliffs, feeding on small fish.
Various gull species and snowy owls are also common. Snowy owls are one of the few bird species that remain in the Arctic year-round, adapted to hunt lemmings and other small prey even in winter. Many Arctic birds rely on the marine ecosystem for sustenance, feeding on fish and invertebrates.
Arctic waters are rich with life, forming the base of the food web for larger predators. Arctic char, a cold-water fish, is a significant food source for both marine mammals and humans, thriving in freshwater and saltwater environments. Cod species, such as Arctic cod, are also prevalent, playing an important role in transferring energy from lower trophic levels to seals, whales, and seabirds.
Marine invertebrates are an important part of the Arctic marine ecosystem. Krill, small crustaceans, form large swarms and are a primary food source for many filter-feeding whales and other marine life. Copepods, another type of tiny crustacean, are also abundant and represent a significant link in the food chain, converting phytoplankton into food for larger organisms. Various jellyfish, sea stars, and other crustaceans also inhabit these cold waters, contributing to the biodiversity of the Arctic.
The Tundra’s Hidden World
Beyond prominent mammals and marine life, the Arctic tundra supports an important array of plants and smaller terrestrial invertebrates. The vegetation is characterized by low-growing forms, an adaptation to strong winds, permafrost, and short growing seasons. Mosses and lichens are dominant, often forming extensive mats across the landscape, providing insulation for the permafrost below and food for herbivores.
Dwarf shrubs, such as Arctic willow and dwarf birch, grow close to the ground, insulated by snow in winter and absorbing heat from the soil in summer. Sedges, grasses, and various wildflowers like Arctic poppy bloom rapidly during the brief summer, completing their life cycles before freezing temperatures return. These plants are important primary producers, converting sunlight into energy that supports the terrestrial food web.
Terrestrial insects, despite the cold, are diverse and play important ecological roles. Mosquitoes and midges emerge in large numbers during the summer, forming a significant food source for migratory birds. Arctic bumblebees are important pollinators for tundra plants, helping to ensure the reproduction of flowering species. Spiders also inhabit the tundra, preying on other insects.
Smaller invertebrates, often microscopic, contribute significantly to the tundra ecosystem. Nematodes, or roundworms, are abundant in the soil, participating in nutrient cycling. Springtails, tiny, wingless insects, help decompose organic matter, returning nutrients to the soil. These organisms, though often overlooked, are integral to the Arctic’s web of life, supporting everything from plant growth to the diets of larger animals.