NATURAL HISTORY

BEARDED SEAL } Erignathus barbatus
FAMILY: Phocidae

DESCRIPTION: The bearded seal gets its name from its thick, elegantly curled, and very abundant whiskers. It is the largest Arctic pinniped after the walrus, averaging 7.2 feet in length and 484 to 572 pounds in weight. The bearded seal ranges in color from silver gray to dark brown and has a distinctively robust body, square-shaped fore-flippers and two pairs of mammary glands for nursing pups.

HABITAT: Bearded seals are found in Arctic and subarctic seas in shallow water where their bottom-living prey are most abundant. They prefer drifting pack ice where the ice is in constant motion and avoid continuous, thick, landfast ice and unbroken, heavy, drifting ice where there are few breathing holes.

RANGE: The bearded seal occurs in a patchy circumpolar distribution around the perimeter of the Arctic Ocean and the subarctic seas, with a northern limit of 85°N in the Arctic Ocean and southern limits of 45°N in the Okhotsk Sea and 55°N in Hudson Bay.

MIGRATION: Among Pacific bearded seals, seals of the Bering-Chukchi Sea population move between the Bering Sea in the winter and the Chukchi Sea in the summer to follow the pack ice year-round, while those in the Okhotsk Sea appear to be resident throughout the year. Among Atlantic bearded seals, populations in the Barents, Kara, and White seas appear to follow the sea-ice year-round. In summer, some populations move significant distances, while others make more local movements.

BREEDING: Females bear a single pup in March through May, and nurse the pup on the ice for about three weeks. Most females breed again within two weeks of weaning their pup. Males produce elaborate underwater songs to attract females and maintain underwater territories. Gestation lasts until the next spring, when another pup is born.

LIFE CYCLE: Female bearded seals reach reproductive maturity at ages three to six, slightly before males. Both sexes are thought to live about 20 to 25 years, although the oldest reported seal was 31 years old.

FEEDING: Bearded seals feed on the bottom of shallow waters on a variety of small ocean prey — primarily crabs, shrimp, clams, and snails — using their whiskers as feelers to find food in the soft bottom sediments.

THREATS: The primary threat to the bearded seal is global warming, which melts the sea ice it depends on for giving birth, nursing pups, resting, and molting, and which depletes its prey through ocean acidification. Global warming exacerbates other threats to the bearded seal, including oil and gas development, shipping activities, fishery bycatch mortality, oil spills, ocean noise pollution, hunting, ocean contamination, and human disturbance.

POPULATION TREND: Population trends for bearded seals are generally unknown because there are few repeated or reliable abundance estimates. Populations in the Bering and Okhotsk seas experienced significant declines in the 1950s and 1960s due to overexploitation by commercial sealing. Population surveys in the 1970s and 1980s do not indicate that bearded seal populations rebounded after commercial sealing in these regions was limited in 1970.

Photo of bearded seal courtesy Flickr/foilistpeter