Marine Mammals of the Arctic
- Grades: 3–5, 6–8
Arctic waters contain many fascinating forms of marine life. Marine mammals that live in these waters include walrus, several varieties of seals, as well as many whales.
Bearded seals are one of the largest seals in Arctic waters, averaging 2.5 meters in length and 270 kg in weight. They have a coat of stiff gray hairs and a dark brown head. As the name suggests, the bearded seal has a noticeable set of whiskers. Bearded seals spend most of their time in shallow water where they feed on crustacea, mollusks and bottom-feeding fish. Hooded seals are another of the largest seals. Males average between 2 and 3 meters in length and weigh up to 450 kg. Hooded seals are also known as bladdernose seals. Males have an inflatable pouch, which usually hangs limp and wrinkled over the nose. For a mating display the pouch may be blown up to twice the size of a soccer ball. Hooded seals also have an inflatable membrane which can be thrust out one nostril like a bright red balloon.
Ringed seals are the most common northern seal. They are found throughout Arctic and subarctic waters. They are the smallest of the seal family and average 68 kg in weight and are less than 1.5 m in length. Adults are white to creamy-yellow underneath, and brown to bluish-black on top with irregular cream-colored rings with dark centers. The young are called "whitecoats" because their fur is soft and pure white for about one month after birth. Ringed seals feed primarily upon crustaceans and polar cod. They themselves are the main food of polar bears, which stalk the basking seals on the ice in summer, or catch them when they surface at breathing holes in winter. Another seal whose newborn pups are called "whitecoats" is the Harp seal. Harp seals are migratory, following the melting ice northward in late May and spend the summer in Arctic waters.
Another interesting Arctic mammal is the walrus. The distinguishing characteristic of these mammals is their tusks. Both males and females can have tusks, which can grow to one meter in length. The tusks are used as weapons against bears, other walrus, as indicators of superiority in males, and for maneuvering young pups about. Contrary to popular belief, walrus do not use their tusks to plow the ocean bottom for food. Their food consists of mollusks and invertebrates.
The largest animal which has ever lived is the blue whale. It may reach a length of 30 meters and weigh in excess of 100 tons. Blue whales are found in both Atlantic and Pacific oceans, and they migrate into Arctic and Antarctic waters in the summer. The blue whale has up to 400 black baleen plates suspended from its upper jaw, which are used to filter small planktonic crustaceans, or "krill," from the sea, which is their main food. Bowhead whales also have baleen plates to filter krill out of the sea water. Bowheads are the only species of baleen whale to inhabit polar waters year round. They have very large heads compared to their body size, therefore, they are not restricted to ice-free areas as they can use their large heads and bodies to push through half-a-meter or more of solid ice.
Other whale species found in Arctic waters include the sperm whale, the narwhal, and the beluga. The sperm whale is the largest of all toothed whales. Sperm whales are migratory, but only bulls travel to Arctic waters. Their main food is squid. The narwhal is sometimes called the unicorn of the sea because of the long spiral tusk which projects through the upper lip of the male. Narwhal are found throughout the eastern Arctic, migrating with the ice in spring and fall. Belugas, or white whales, resemble a tuskless narwhal, and they live primarily in the Arctic waters.
For many years there has been a strong relationship between the peoples of the Arctic and the marine mammals of this region. When being harvested, all parts of the animals are used; their hides, oil, fat, and meat. In Canada and Alaska, there are regulations which set annual limits regarding the hunting of various species. In most cases, local communities working with federal regulators establish these numbers. Native peoples are very involved in this process, sitting on many of the regulatory boards which establish the limits. Some species, such as the blue whale and bowhead whale, are now listed as endangered species, and can no longer be hunted.
The main resource used for today's marine mammals section was the bookArctic Animals, which is put out by the Department of Renewable Resources, Government of the Northwest Territories, Yellowknife. It has great information and sketches of many of the animals of the Canadian Arctic region. The text is by Jonquil Graves and Ed Hall and the illustrations are by Germaine Arnaktauyok. It can be obtained through Artisan Press Limited located in Yellowknife. For more information you can contact them at 403-920-2794.