Harp seals, known scientifically as Pagophilus groenlandicus, are earless seals found across the cold waters of the North Atlantic and Arctic Oceans. Their scientific name, meaning “ice-lover from Greenland,” reflects their strong connection to icy environments. These marine mammals are highly adapted to their frigid habitats.
Physical Characteristics
Adult harp seals typically measure between 5 and 6 feet (1.7 to 2.0 meters) in length and weigh approximately 260 to 300 pounds (115 to 140 kg). Their bodies are robust with small, flat heads and narrow snouts. The distinguishing feature of mature harp seals is a silver-gray fur coat marked with a black, harp- or wishbone-shaped pattern on their backs, which gives them their common name.
The coloration of harp seals changes throughout their lives. Pups are born with a fluffy white coat, earning them the name “whitecoats,” which helps them absorb sunlight and stay warm. After two to three weeks, this white fur sheds, revealing a silver-to-gray coat with dark spots. The characteristic harp-shaped marking develops as they approach sexual maturity.
Habitat and Migration
Harp seals inhabit the cold waters of the North Atlantic and Arctic Oceans, with three distinct populations in the Barents Sea, East Coast of Greenland, and Northwest Atlantic. They rely on sea ice for various life stages, including giving birth, nursing their young, and molting. While they spend much of their lives in open water, they gather on pack ice in large groups during breeding and molting seasons.
These seals are highly migratory, undertaking extensive seasonal journeys. They spend summers in northern feeding grounds, then migrate southward as winter approaches, following the ice to specific breeding and molting areas. Annual migrations can cover over 3,100 miles roundtrip, demonstrating their ability to navigate vast oceanic distances.
Diet and Predation
Harp seals are foraging predators with a diverse diet, consuming a wide range of fish and invertebrate species. Their prey includes smaller fish such as capelin, Arctic cod, and polar cod, alongside crustaceans like shrimp and prawns. Harp seals are opportunistic feeders, eating what is available.
These seals can dive to depths of 1,300 feet (400 meters) and remain underwater for up to 16 minutes while hunting. Harp seals face several natural predators. Adult seals are preyed upon by killer whales and large sharks, including Greenland sharks. Younger harp seals, especially pups, are vulnerable to polar bears, foxes, and wolves.
Life Cycle and Reproduction
Harp seals gather on ice floes between late February and mid-March to give birth, with females typically having a single pup. Newborn pups, known as “whitecoats,” weigh about 25 pounds (11 kg) and are approximately 3 feet long. Although born without a thick layer of blubber, their white fur helps trap heat.
The nursing period is brief, lasting only about 12 days, during which the mother’s milk, rich in fat, allows the pup to gain significant weight rapidly, sometimes up to 5 pounds per day. Pups can triple their birth weight during this time, developing a protective blubber layer. After weaning, the mother abandons the pup, which remains on the ice for several weeks, relying on its fat reserves and learning to swim and hunt independently. During this vulnerable period, pups may lose up to half their body weight before they begin feeding on their own.
Conservation and Threats
The global population of harp seals is estimated at nearly 7.5 million animals, making them among the most abundant seal species and currently classified as Least Concern. However, they face various threats, particularly those linked to their reliance on sea ice. Climate change poses a significant risk, as diminishing and unstable ice platforms threaten breeding and pup survival. Poor ice conditions can lead to increased pup mortality due to drowning, separation from mothers, or being crushed.
Commercial hunting has historically impacted harp seal populations, and while the scale has reduced in some areas, it continues in Canada, Norway, Russia, and Greenland. Other threats include entanglement in fishing gear, which can cause injury or death, and exposure to chemical contaminants that accumulate in their blubber.