Walruses are large, distinctive marine mammals recognized by their prominent tusks and bristly whiskers. These creatures are well-adapted to the cold, icy environments of the Arctic, where they spend most of their lives. Understanding their distribution provides insight into the delicate ecosystems they inhabit.
Where Walruses Live Globally
Walruses have a circumpolar distribution throughout the Arctic regions of the Northern Hemisphere. Their range extends across the Arctic Ocean and into subarctic seas. These animals inhabit shallow waters over continental shelves, typically no more than 80 meters (approximately 262 feet) deep. This preference for shallower depths is linked to their feeding habits, as their prey often resides on the seafloor. Walruses spend a significant portion of their lives in the water, but also utilize ice floes or land for resting.
Distinct Habitats of Walrus Populations
The walrus species (Odobenus rosmarus) is divided into two recognized subspecies: the Pacific walrus (Odobenus rosmarus divergens) and the Atlantic walrus (Odobenus rosmarus rosmarus). A third population, the Laptev walrus, is sometimes considered a distinct subspecies, though its classification is debated and it is often considered part of the Pacific walrus group. These populations are geographically separated, with limited interbreeding.
The Pacific Walrus
The Pacific walrus inhabits the Bering and Chukchi Seas, extending into the Arctic Ocean along the northern coast of eastern Siberia and Alaska. During winter, they are found in the central and southern Bering Sea, migrating northward into the Chukchi Sea for the summer months. Adult females and their young typically follow the receding sea ice, while many adult males remain in the Bering Sea, utilizing coastal haul-out sites when ice melts. Smaller groups of males also summer in areas like the Gulf of Anadyr and Bristol Bay off the southern coast of Alaska.
The Atlantic Walrus
The Atlantic walrus has a more fragmented distribution compared to its Pacific counterpart, found in Arctic waters that are seasonally ice-covered. Their range includes the eastern Canadian Arctic, Greenland, Svalbard, and the western Russian Arctic, specifically areas like the Barents, Pechora, and Kara Seas. Within this broad range, there are several distinct stocks, with the largest populations occurring in Arctic Canada and West Greenland. Historically, their range extended further south to Nova Scotia, but populations in southeastern Canada were eliminated by the mid-19th century.
The Laptev Walrus
The Laptev walrus is localized to the central and western regions of the Laptev Sea, extending from the eastern Kara Sea to the westernmost parts of the East Siberian Sea. This population is unique as it remains in the same area year-round, unlike the migratory patterns observed in other walrus groups. Its taxonomic status is debated, with recent studies suggesting it is the westernmost population of Pacific walruses rather than a separate subspecies. The estimated population for the Laptev walrus is between 5,000 and 10,000 individuals.
Environmental Factors Guiding Walrus Locations
Walrus distribution is influenced by environmental factors that support their lifestyle and feeding habits. Sea ice is a platform for resting, breeding, and giving birth; they prefer snow-covered moving pack ice or ice floes. The constant movement of sea ice allows walruses to access new foraging areas, reducing the energetic costs of feeding and preventing localized depletion of their prey.
Walruses feed on benthic organisms, such as bivalves and mollusks, found on the seafloor. This dietary preference means they are found in shallow continental shelf waters, less than 80 meters deep, where these food sources are abundant. Their sensitive whiskers help them locate food buried in the sediment.
When sea ice is not available, walruses utilize accessible land or ice haul-out sites for resting and social interaction. These sites are important for their survival, providing a place to rest between foraging trips. The presence of suitable haul-out locations directly impacts where walruses can be found, especially as sea ice conditions change.