The Arctic, a vast environment of ice and frigid waters, is home to diverse marine life. Among its most recognizable inhabitants are seals, which thrive in this unique polar landscape. These marine mammals are well-suited to the extreme conditions, forming a significant part of the Arctic’s natural heritage.
Key Arctic Seal Species
Several distinct seal species inhabit the Arctic. The ringed seal (Pusa hispida) is the most abundant and widespread, found throughout the circumpolar Arctic Ocean. These are the smallest true seals, measuring around 4 to 5 feet long and weighing between 110 and 150 pounds, identified by light spots on dark gray fur that often form ring-like patterns. They primarily inhabit ice-covered waters, maintaining breathing holes in thick ice.
The bearded seal (Erignathus barbatus) is a larger species, measuring 7 to 8 feet long and weighing between 475 and 750 pounds, named for its prominent white whiskers. These seals prefer shallow, seasonally ice-covered waters and often rest on floating ice. Harp seals (Pagophilus groenlandicus) are known for a distinctive black harp-shaped marking on their backs in adulthood, reaching 5 to 6.5 feet long and weighing 254 to 310 pounds. They are highly migratory, spending most of their lives in the icy waters of the North Atlantic and Arctic Oceans, coming to ice only for breeding and molting.
The hooded seal (Cystophora cristata) is a large, silver-gray seal with dark spots, measuring up to 8.5 feet and weighing up to 776 pounds, notable for the inflatable nasal sac in males. They inhabit the North Atlantic and Arctic Oceans, primarily associated with drifting pack ice. Spotted seals (Phoca largha) are medium-sized, 5 to 6 feet long and 143 to 253 pounds, characterized by irregular dark spots on a lighter background. They are found in seasonally ice-covered subarctic and marginal seas of the North Pacific, extending into the Arctic Ocean.
Adapting to the Frozen World
Arctic seals possess adaptations that allow them to thrive in their cold environment. A thick layer of blubber provides insulation, helping them maintain body temperature in frigid waters. This blubber also serves as an energy reserve during periods of reduced food availability. Their dense fur coats offer additional thermal protection.
Seals are skilled divers, capable of holding their breath for extended periods and slowing their heart rate to conserve oxygen during deep dives. Ringed seals, for instance, can dive to depths of about 295 feet and remain submerged for up to 45 minutes. Many Arctic seals, particularly ringed seals, use their strong claws to create and maintain breathing holes through thick ice, sometimes exceeding 6 feet. This allows them access to water for foraging beneath the ice. Their diet primarily consists of fish, such as Arctic cod and capelin, along with crustaceans and squid, which they hunt using keen eyesight, sensitive whiskers, and sharp hearing.
Seals in the Arctic Ecosystem
Seals play a significant role in the Arctic food web as both predators and prey. They consume various marine organisms, including fish, squid, and crustaceans. In turn, seals are a primary food source for larger Arctic predators.
Polar bears rely heavily on seals, particularly ringed and bearded seals, for their high-fat blubber, which is essential for energy needs. Killer whales also prey on seals, contributing to the balance of the marine ecosystem.
For Indigenous Arctic communities, seals are a culturally and economically important resource. Seal hunting provides a traditional food source, offering nutritious meat and oil. Seals also provide materials for clothing and other essential items, with hunting practices deeply intertwined with cultural traditions. Arctic seal populations face impacts from climate change, particularly the loss of sea ice habitat crucial for breeding, molting, and resting. Pollution accumulating in the food web and increased human activity also influence their well-being.