Harp Seal, Pagophilus groenlandicus
The harp seal (Pagophilus groenlandicus), also known as the saddleback seal, is a true seal in the Phocidae family. It is native to northern areas of the Atlantic Ocean and to some areas of the Arctic Ocean. Its scientific name means “ice-lover from Greenland,” and it was previously classified within Phoca genus, although studies have shown that it is unique enough to be in a distinct genus. It holds two recognized subspecies, P. groenlandicus groenlandicus and P. groenlandicus oceanicus.
The harp seal can reach an average body length between five and six feet, with a weight between three hundred and four hundred pounds. Its fur is typically greyish silver in color, with black fur occurring on the face. It bears a black harp-shaped marking on its back, from which it derives its common name. Pups are born with yellow fur, which turns white after three days, and then gets darker after twelve days.
The harp seal uses its thick blubber to keep warmth in, instead of using a high metabolic rate to maintain a stable temperature. This blubber also provides a source of nutrients when food is not abundant or when the seal is fasting. When swimming, the blubber allows the seal to move with ease. Its flippers are used to move heat where it is needed most, and it will pull its front flippers into its bod y to stay warm on the ice. Its large, black eyes are equipped to give it an enhanced ability to see. Its pupils allow it to reduce the glare caused by bright ice, and give it some color distinction. The harp seal’s sense of smell is not as enhanced as its sight, but it uses this sense to locate its pup on the ice and may use it to detect predators.
The harp seal is sociable, forming large groups that separate into smaller hierarchal groups. These groups are reported to be especially noisy. There are three populations of harp seals that migrate frequently, spending little time on the ice. The western North Atlantic population can be found off the coast of eastern Canada. This is the largest population and is separated into two, smaller populations that are designated by their breeding locations. One group, the Front herd, breeds of the coasts of Labrador and Newfoundland, while the other group, the Gulf herd, breeds in the Gulf of St. Lawrence, near the Magdalen Islands. The second population breeds of the coast of eastern Greenland and the third breeds off the coast of Russia, in the White Sea. The harp seal does not only migrate to breeding areas, but will also move into summer feeding grounds to molt. The largest population can move as far as 2,500 miles away from the breeding grounds.
During courtship and breeding, males and females will make up to nineteen different vocalizations. After breeding, pregnancy is delayed for up to three months, to ensure that pups are born when pack ice is abundant. Pups are typically born in late February, weighing about twenty-four pounds. The mother takes sole care of the pup, nursing it for twelve days. The mother can lose up to seven pounds a day nursing just one pup, but the pup can gain up to 4.9 pounds a day. At the time of weaning, at just twelve days of age, the pup will have a darker fur than when it was born and weigh up to eighty pounds. Mothers will literally abandon their pups on the ice, beginning courtship and breeding shortly after in the water.
Initially, the weaned pup will cry for its mother, but will shortly after learn to remain still in order to conserve heat. The weight that the pups gained while nursing becomes vital to its survival for the next seven to eight weeks, because they do not move, and are unable to hunt food or find shelter on their own. Thirty percent of pups will perish in their first year because of this immobility, and all pups are easy prey for polar bears.
Throughout the next year or so, the pups will molt several times and may be spotted in appearance. After a few years, most harp seals gain their silver adult fur, but some females will remain spotted. The average lifespan of this species is about twenty years.
The harp seal is commercially hunted in every area of its range, specifically in Canada, Russia, Greenland, and Norway. The hunting season in Canada occurs in November 15 to May 15, but most hunting typically occurs in the Gulf of St. Lawrence in late March. Peak hunting occurs in Newfoundland in the first two weeks of April, and this is known as the Canadian seal hunt. Hunters are not allowed to kill baby seals, known as whitecoats, in this area. The Inuit communities in the seal’s range hunt the species mainly for food, but will occasionally hunt them commercially.
The three-year hunting quota of harp seals, initiated by the Department of Fisheries and Oceans, was increased in 2003 to 975,000, with a maximum of 350,000 individuals allowed in any given two year period. First Nations hunters can kill ten thousand seals during this period. In Greenland, seventy thousand to ninety thousand individuals are hunted. In 1987, a large number of harp seals migrated to the Shetland Islands. It was thought that this occurred due to a lack of food caused by humans. Near the end of February of that year, nearly 24,000 seas were reported dead from becoming caught in fishing nets, and 300,000 had moved into Oslo fjords, appearing to be emaciated and searching for food. Despite the large numbers of deaths caused by humans, the population numbers of the harp seal are high enough for it to appear on the IUCN Red List with a conservation status of “Least Concern.”
Image Caption: Harp Seal. Credit: Matthieu Godbout/Wikipedia (CC BY-SA 3.0)