Harp seals (Pagophilus groenlandicus) are marine mammals recognized for their distinct appearance and association with the Arctic environment. These animals spend much of their lives in the frigid waters of the North Atlantic and Arctic Oceans. Their scientific name, Pagophilus groenlandicus, translates to “ice-lover from Greenland,” reflecting their reliance on ice for various life stages.
Identifying Harp Seals
Harp seals undergo changes in physical appearance as they mature. Adults measure between 1.7 and 2.0 meters in length and weigh around 115 to 140 kilograms, with males being slightly larger than females. Their streamlined bodies and specialized flippers are adapted for efficient movement through water, though they also use their short front flippers to maneuver on ice.
Newborn harp seals, known as “yellowcoats,” have a yellowish-white fur that transforms into a fluffy, pure white coat within a few days, becoming “whitecoats.” As they grow, this white fur is shed, replaced by a silver-gray coat with irregular dark spots, at which point they are called “beaters.” Adult harp seals develop a silvery-gray fur with a prominent black, harp-shaped mark spanning their back, which is more distinct in males who also develop a black head.
Their Arctic Home and Habits
Harp seals inhabit the North Atlantic and Arctic Oceans, favoring areas with extensive ice floes and open water. There are three primary populations: one in the Northwest Atlantic, another off East Greenland, and a third in the White Sea/Barents Sea region. These seals are carnivorous, consuming a diverse diet of fish and invertebrates. Their preferred prey includes small fish such as capelin, herring, and cod, as well as crustaceans like krill and shrimp.
Harp seals are highly migratory, traveling thousands of kilometers annually between their breeding, molting, and feeding grounds. These journeys can cover distances up to 3,100 miles roundtrip. They are gregarious, gathering in large groups, sometimes numbering in the thousands, particularly during breeding and molting seasons. While more vocal underwater, they use various sounds, including clicks, trills, and growls, to communicate within their colonies.
The Journey of Life
The life cycle of harp seals is closely tied to stable ice. Breeding occurs between mid-February and April, with females reaching sexual maturity around four to seven years of age, and males between seven and eight years. Females give birth to a single pup on the pack ice from late February through mid-March. These newborn pups are without a thick layer of blubber for warmth.
Newborn pups weigh approximately 10 to 12 kilograms and measure 80 to 85 centimeters in length. The mother provides fatty milk, up to 40% fat, enabling pups to gain weight rapidly, over 2.2 kilograms per day. This nursing period lasts about 10 to 12 days, during which pups can gain 30 to 45 kilograms, developing a protective blubber layer. After weaning, pups shed their white fur, revealing a silver-gray coat.
Adults also undergo an annual molting process in April and May. Pups are left to fend for themselves on the ice after weaning, learning to forage for food around four weeks of age. Harp seals can live for 30 to 35 years in their natural habitat.
Protecting Harp Seals
Harp seals are classified as “Least Concern” by the IUCN Red List, indicating a relatively stable population. Despite this status, they face environmental challenges. Climate change poses a threat, as their reliance on sea ice for breeding, nursing, and molting makes them vulnerable to diminishing ice habitats. Reduced ice coverage can lead to increased pup mortality.
Threats include commercial hunting, which, though regulated, has impacted populations. Entanglement in fishing gear and the effects of overfishing on their prey sources also present concerns. Chemical contaminants in the ocean, which can accumulate in their blubber, add to environmental pressures. International agreements and ongoing monitoring efforts aim to manage populations and address these challenges, with protections in place such as the Marine Mammal Protection Act in the United States.