About the Species
Harp seals live throughout the cold waters of the North Atlantic and Arctic Oceans. These seals are named after the black patch on their back, which looks like a harp.
Harp seals gather in large groups of up to several thousand to molt and breed. Although they live in cold water, harp seal pups are born without any protective fat. Newborns quickly develop a thick layer of blubber while nursing.
Harp seals, like all marine mammals, are protected under the Marine Mammal Protection Act. NOAA Fisheries is committed to conserving and protecting harp seals. Our scientists and partners use a variety of innovative techniques to study, learn more about, and protect this species.
To manage harp seals in U.S. waters, we have grouped them in to western North Atlantic stock. Based on the most recent survey, our scientists estimate that there are about 7 million seals in this stock.
- Throughout Its Range
Harp seals are part of the true seal family. All true seals have short flippers, which they use to move in a caterpillar-like motion on land. They do not have external ear flaps.
Harp seals are about 5 to 6 feet long, weigh about 260 to 300 pounds, and have a robust body with a small, flat head. They have a narrow snout and eight pairs of teeth in both the upper and lower jaws. Their front flippers have thick, strong claws, while their back flippers have smaller, narrower claws.
Adult harp seals have light gray fur with a black mask on their face and a curved black patch on their back. This black patch looks like a harp and is the source of the species’ common name. Some animals have dark spots randomly scattered over their entire body. Adults molt, or shed, their fur every spring.
Harp seal pups have long, wooly, white fur known as lanugo that lasts until about 3 to 4 weeks old. This white fur helps absorb sunlight and trap heat to keep the pups warm. Pups molt several times during their development.
Behavior and Diet
Harp seals gather on pack ice in large groups during breeding and molting seasons. These groups can contain up to several thousand seals. Harp seals also feed and travel in large groups during seasonal migrations. They often travel away from the pack ice during the summer and follow the ice north to feed in the Arctic. Annual migrations can be more than 3,100 miles roundtrip.
Harp seals can dive up to 1,300 feet below the surface and remain underwater for about 16 minutes. They eat many different types of fish and invertebrates. Some seals have been found with more than 65 species of fish and 70 species of invertebrates in their stomachs. Their most common type of prey is smaller fish such as capelin, Arctic cod, and polar cod.
Lifespan & Reproduction
The maximum lifespan of a harp seal is approximately 30 years. Females give birth from late February through mid-March. They will only give birth during the short period of time when pack ice is available, as the ice provides a place to nurse their pups.
At birth, newborn harp seals weigh about 25 pounds and are about 3 feet long. They nurse on high-fat milk for about 12 days. During this time, they gain about 5 pounds per day and develop a thick blubber layer. Harp seals wean when they reach around 80 pounds.
After weaning, adult females leave their pups on the pack ice. The pups stay on the ice without eating for about 6 weeks. They can lose up to half of their body weight before they enter the water and start feeding on their own.
Commercial hunters have captured harp seals in Canada for meat and oil since the 1600s. The Canada Department of Fisheries and Oceans sets an annual total allowable catch for commercial, aboriginal, and personal use hunting.
Inadvertent vessel strikes can injure or kill harp seals. Harp seals are vulnerable to vessel collisions throughout their range, but the risk is much higher in some coastal areas with heavy ship traffic.
Harp seals can become entangled in fishing gear and other types of marine debris, either swimming off with the gear attached or becoming anchored. They can become entangled in many different gear types, including gillnets, trawls, purse seines, or weirs. Once entangled, seals may drown if they cannot reach the surface to breathe, or they may drag and swim with attached gear for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.
Contaminants enter ocean waters from many sources, including oil and gas development, wastewater discharges, urban runoff, and other industrial processes. Once in the environment, these substances move up the food chain and accumulate in predators near the top, such as harp seals. Because of their blubber stores, harp seals accumulate these contaminants in their bodies, threatening their immune and reproductive systems.
Oil Spills and Energy Exploration
Offshore oil and gas exploration and development also have the potential to impact harp seals. The most significant risk posed by these activities is the accidental or illegal discharge of oil or other toxic substances due to their immediate and potentially long-term effects. If exposed to oil, a harp seal’s fur can no longer repel water. This makes it difficult for the seal to swim, float, and keep warm. Inhaling or swallowing oil can damage a seal’s respiratory, digestive, reproductive, and central nervous systems. Oil can also irritate or burn the seal’s skin.
Harp seals rely on the availability of suitable sea ice as a haul-out platform for giving birth, nursing pups, and molting. As such, harp seals are sensitive to changes in the environment that affect the timing and extent of sea ice formation and breakup.
Harp seals, like all marine mammals, are protected under the Marine Mammal Protection Act.
NOAA Fisheries is committed to the protection of harp seals. Targeted management actions taken to secure protections for these seals include:
Reducing Vessel Strikes
Collisions between harp seals and vessels can injure or kill seals. The most effective way to reduce vessel disturbance is for vessels to stay away to keep seals and vessels apart. In New England, we have issued “Share the Shore” seal watching guidelines to reduce the disturbance of harp seals.
Implementing Oil Spill Response Plans in the Event of a Spill
Harp seals are at risk of harm in the event of an oil spill. To minimize the effect of a potential spill on harp seals, NOAA developed the Marine Mammal Oil Spill Response Guidelines.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes identify strandings due to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.
Educating the Public
NOAA Fisheries aims to increase public awareness and support for harp seal conservation through education, outreach, and public participation. We share information with the public about the status of harp seals, as well as our research and efforts to promote their recovery.
All marine mammals, including harp seals, are protected in the United States under the MMPA.
NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of harp seals. The results of this research are used to inform management decisions for this species.
Determining the size of harp seal populations helps resource managers determine the success of conservation measures. Our scientists collect population information and present the data in annual stock assessment reports.
Monitoring Population Abundance and Distribution
Scientists observe harp seals to record their numbers and distribution. By comparing numbers collected over multiple years, scientists can look for trends—i.e., whether the population is increasing, decreasing, or remaining stable during a given period.