Harp seals are part of the family Phocidae, known as the “true” or “earless” seals because they lack external ear flaps. They have a robust body, a relatively small, broad, flat head, and a narrow snout that contains eight pairs of teeth in both the upper and lower jaws. Their front flippers have thick, strong claws. On their hindflippers, the inner and outer digits are longer and have small, narrow claws. Phocids are unable to rotate these back flippers underneath them to walk, and instead use their front flippers to pull themselves along on land. Adults are approximately 5-6 feet (1.7 m) long, and weigh around 300 pounds (135 kg). They have light gray fur, with a black face and a horseshoe-shaped black saddle on their back. Their common name refers to this pattern, which looks like a harp.
Harp seals are modest divers by pinniped standards. The average maximum dive is to about 1,200 feet (370 m), with a duration of approximately 16 minutes. They eat a variety of fish and invertebrates, but mainly focus on smaller fish such as capelin, arctic and polar cod, and invertebrates including krill.
Females give birth to pups near the southern limits of their range from late February to mid-March. Pups nurse on high-fat milk for approximately 12 days, during which they gain about 5 pounds (2.2 kg) per day and develop a thick blubber layer. At birth, harp seals are just under 3 feet (1 m) long, and weigh about 25 pounds (11 kg). Called “whitecoats,” newborns have long, wooly, white fur known as “lanugo”, and undergo a complicated series of “molts” before reaching adult coloration. Harp seal pups are abruptly weaned from their mothers when they weigh approximately 80 pounds (36 kg). Adult females leave their pups on the ice where they remain without eating for approximately 6 weeks. Pups can lose up to half of their body weight before they enter the water and begin feeding on their own.
After pups are weaned and left alone, adult harp seals begin mating. Adult females undergo a period of suspended development known as “delayed implantation” during which embryos do not attach to the uterine wall for three months or more. This allows all females to give birth during the limited period of time when pack ice is available.
During breeding in February and March, and when molting in late spring, harp seals aggregate in large numbers of up to several thousand seals on the pack ice. During extensive seasonal migrations, large groups may feed and travel together.
MMPA – Harp seals, like all marine mammals, are protected under the MMPA.
|about 300 pounds (135 kg)|
|about 5-6 feet (1.7 m)|
|light gray fur, with a black face and a horseshoe-shaped black saddle on their back;
newborns have long, wooly, white fur known as “lanugo”
|varied mix of many species of finfish and invertebrates, mainly capelin, cod, and krill|
|During breeding season, harp seals can be found in large numbers of up to several thousand seals on the pack ice.|
Harp seals occur in the pack ice throughout much of the North Atlantic and Arctic Oceans. They can be found from Newfoundland to northern Russia.
The harp seal population is divided into three separate stocks, and each uses a specific breeding site. The first and largest, the Western North Atlantic stock, is located off eastern Canada and is divided into two herds based on breeding location. The Front herd breeds off the coast of Newfoundland and Labrador, and the Gulf herd breeds near the Magdalen Islands in the middle of the Gulf of St. Lawrence. The second stock breeds on the “West Ice” off eastern Greenland, and the third stock breeds on the “East Ice” in the White Sea off the coast of Russia. Breeding occurs between mid-February and April, at varying times for each stock.
Harp seals are highly migratory. Following the breeding season, adults assemble north of their “whelping” sites to undergo an annual molt before continuing to migrate north to Arctic summer feeding grounds. In late September, after feeding all summer, most adults and some immature seals of the Western North Atlantic stock migrate south along the Labrador coast to the entrance to the Gulf of St. Lawrence, generally arriving by early winter. There they split into two groups, one moving into the Gulf and the other remaining off the coast of Newfoundland.
In recent years, the number of sightings and strandings from January to May have increased off the east coast of the United States from Maine to New Jersey. During this time, the Western North Atlantic stock of harp seals is at the most southern point of their migration.
The most recent stock assessment reports with population estimates are available on our website.
- ship strikes
- fishing gear interactions
- power plant entrainment
- oil spills
- loss of sea ice is a potential threat to their habitat
All marine mammals, including harp seals, are protected under the Marine Mammal Protection Act of 1972, as amended.
- Although harp seals live in the Arctic, they are born with no protective fat. As pups, their white coats absorb sunlight, and their fur traps heat, keeping the pups warm.
- Harp seals like variety in their diets–over 65 species of finfish and 70 species of invertebrates have been found in their stomachs!
- Their common name, “harp” seal, refers to the black pattern on their backs pattern, which looks like a harp.