The harp seal is a medium-sized, grayish earless seal possessing a black harp-shaped or saddle-shaped marking on its back. Because of the marking, it is also called a saddleback seal. The harp seal is both the best-known and among the most abundant of all seal species. Its scientific name is Pagophilus, or Phoca, groenlandica.
Harp seals are found on or near ice floes from the Kara Sea of Russia west to the Gulf of St. Lawrence in Canada. Worldwide, the total population of harp seals is estimated at nearly 7.5 million animals, which are separated into three distinct populations. The largest population (approximately 5 million animals in the early 21st century) inhabits the northwestern Atlantic and breeds both near the coast of Newfoundland and within the Gulf of St. Lawrence. The second largest population occurs in the vicinity of the Barents Sea, numbers between 1.5 million and 2 million animals, and breeds on the ice-covered White Sea in northwest Russia. The smallest population (approximately 300,000 animals) inhabits the area between Norway’s Jan Mayen island and the eastern coast of Greenland, and its mating grounds are mainly located near Jan Mayen island. Each population is considered by some authorities to be a separate subspecies.
The common names for harp seals vary by age and coloration. At birth, pups are known as “whitecoats” because of their pure white hair. This stage lasts approximately two weeks. The subsequent growth of dark hair under their white fur produces a grayish coloration, and they are called “graycoats.” Once the white coat is completely shed, the seals become gray with dark spots and are often referred to as “beaters” because of the sound made by their tails as they learn to swim. At 13–14 months of age the seals molt again, and their spotted pelt remains. At this stage they are called “bedlamers.” The transition from bedlamer to adult coloration arrives with the onset of sexual maturity, which usually occurs at four or five years of age.
Average-sized adults of both sexes measure 6 feet (1.8 meters) in length. Male harp seals typically weigh 300 pounds (135 kilograms), females weigh 265 pounds (120 kilograms), and the largest adults may reach 400 pounds (180 kilograms). The face of an adult harp seal is completely black, while the gray coloration of its body is accented by a black harp-shaped marking on its back. Adults typically hold this coloration between five years of age and the end of their lives. The maximum life span for the harp seal is 35 years.
Harp seals are not strong divers compared with other seal species. Their maximum dive depth is 1,200 feet (370 meters), and they may stay underwater for only 16 minutes before resurfacing. Although they consume a wide variety of prey, their diet is centered on small fish such as capelin (a species of smelt) and cod. They also eat numerous invertebrates. Contrary to popular belief, harp seals rarely consume the commercially important Atlantic cod. Polar bears, killer whales, and large sharks are the natural predators of harp seals.
Harp seals spend most of their lives in the water, though some have been known to ride bits of drifting sea ice for short distances during migration. All harp seals must come up on land or ice to give birth, rear their young, and molt. From late February to March, seals relocate to the southern limit of their range to breed and give birth.
Pups are born on pack ice. Each female gives birth to only one pup; twins are extremely rare. Pups weigh 24 pounds (11 kilograms) at birth, but they lack the thick layer of blubber (fat) present in adults. Instead, they are insulated by their thick fur and obtain energy from their mothers’ milk, which is rich in fat. During their 12-day nursing period, pups gain about 4.4 pounds (2 kilograms) per day of blubber, which allows them to attain a weight of approximately 79 pounds (36 kilograms) at weaning. Weaning is abrupt as females stop nursing their young in order to mate with males. During this time, since the pups do not feed for up to six weeks, they may lose more than 50 percent of their body mass. Eventually, hunger motivates the pups to enter the water and start feeding on their own.
Harp seals have been hunted commercially for more than two centuries. The commercial sealing industry began with the harvest of adult harp seals in Newfoundland and Labrador during the middle of the 18th century. Recoverable seal parts include meat (for Asian pet food and meat markets), skins (for waterproof coats and boots), fur (for coats), genitals (for aphrodisiacs), and blubber (which is used to produce seal oil).
Between the 1950s and ’70s, hunting pressure caused the world harp-seal population to decline to about 1.5 million animals. About this time, the killing of whitecoats began to generate worldwide public outrage, and in 1983 the European Union (EU) instituted a ban on seal products. These factors brought about a collapse in the market. In response, during the 1980s and early ’90s the Canadian government set an annual “total allowable catch” quota, which allowed the harp-seal population to recover. Since this recovery, the quotas have been increased. The annual seal harvest remains an object of highly publicized controversy, attracting much international media coverage.