Seals, sea lions, and walruses are all pinnipeds. Some scientists believe that pinnipeds belong to a separate order of mammals, while others believe that pinnipeds belong to the sub-order Pinnipedia within the order Carnivora. Pinnipeds have fur and blubber for thermoregulation, long whiskers, two sets of flippered limbs, reduced or lost ear flaps, and nasal openings at the tip of the snout. Also, all pinnipeds molt their fur once per year. There are three families within the sub-order pinniped: Phocids, Otariids, and Odobenids.
The Phocidae (also referred to as true or earless seals) are characterized by the following: The absence of external ear flaps, short foreflippers with hair and claws on each of the digits, hindflippers that are oriented posteriorly and cannot be rotated forward, beaded vibrissae (whiskers),a short muzzle, short fur, and dark skin.
The Otariids (or eared seals) are comprised of the sea lions and fur seals. All otariids have external ear flaps called pinnae, and in all species of otariids the males are significantly larger than the females. These seals have long fore and hind flippers which lack claws, and they can use their flippers to sit upright and walk on land.
The only living member of the Odobenid family is the walrus. Walruses can be recognized by their huge bodies, sparse hair, and their modified canine teeth, which form the long tusks that are their trademark. Walruses are able to rotate their hind flippers underneath their bodies and walk on them on ice or land. Walruses also do not have fur, and have no external ear flaps.
The Riverhead Foundation for Marine Research and Preservation operates the New York State Marine Mammal and Sea Turtle Stranding Program. The program responds to an average of 200 animals per year, with the majority of the animals being seals. The seals that we see in the Long Island area are all true seals. The five species most commonly seen in Long Island waters are Harbor seals, Harp seals, Gray seals, Ringed seals, and Hooded seals.
Harbor Seal (Phoca vitulina)
Harbor seals are highly social animals known to haul out on sandy or rocky areas. Hauled out seals often exhibit a banana-shaped position that is characteristic of healty seals. Their coats are usually tannish or black on the back, with a their bellies being lighter in color, and scattered dark spots throughout the coat. When first born, harbor seal pups weigh approximately 8-12 kg (18-26 lbs) and are around 70-100 cm (28-40 inches) in length. Pups born early in the season may have a wooly, grayish coat called a lanugo coat, while others born later may shed this coat in the womb. Juveniles grow very quickly, and adult males can grow to be up to 1.9 meters (6 ft 3 inches) in length, and can weigh up to 170 kg (370 lbs). Adult females are slightly smaller, reaching 1.7 meters (5 ft 7 inches) in length, and weighing in at up to 130 kg (290 lbs). These seals can live to be between 25 and 35 years old. Harbor seals range widely in coastal areas of the North Pacific and North Atlantic, and are commonly found in Maine and eastern Canada during the spring and summer. In the wintertime, they have been found to migrate as far south as Long Island. These seals feed primarily on schooling fish such as bunker or herring, and also on squid, octopus, and crustaceans. Their major predators include large sharks, killer whales, northern sea lions, polar bears, and humans, and their worldwide population is estimated to number between 400,000-500,000, with at least four subspecies being recognized. Harbor Seals are usually very wary and shy on land, and are easily frightened into the water when they feel they are threatened.
Harp Seal (Phoca groenlandica, or Pagophilus groenlandicus)
The Harp seal is the most abundant pinniped in the Northern Hemisphere, and it gets its name from the distinctive harp shaped saddle on the backs of the adults. Harp seal pups are born with a yellow coat , which is stained by the amniotic fluid. This coat is bleached white by the sun after approximately 3 days, giving them the nickname "whitecoats". At around four weeks of age, the pups molt and develop a spotted silvery-black coat. Newborn harp seals are typically up to 85 cm (33 inches) in length, and weigh in around 11 kg (24 lbs). Adult females can reach lengths up to 1.8 meters (5 feet, 11 inches) and weigh up to 130 kg (290 lbs), while adult males are slightly larger, reaching 1.9 meters (6 feet, 3 inches) in length, and weights up to 140 kg (310 lbs). These seals can live to be up to 30 years old, and are distributed primarily in the pack ice of the North Atlantic Ocean, from Newfoundland to Northern Russia. Harp seals may travel up to 2,500 km (1,600 miles) during their migrations, moving northward to feed in the spring and summer, but some are found as far south as Virgina. These seals feed mainly on schooling fish such as herring and cod, and crustaceans. Major predators of Harp seals include polar bears, walruses, sharks, and humans. Their total worldwide population is estimated to be between 4 and 6 million, with the largest population in western North Atlantic.
Gray Seal (Halichoerus grypus)
Gray seals can be easily recognized by their horse-shaped snout and long head. Males are usually dark with light markings on their coat, while females are lighter, with dark markings. Pups are born with a long and thick lanugo coat, which they shed around two to four weeks of age for a less speckeld version of the adult pelage. Pups gain approximately 3 pounds per day when they are nursing, because the fat content of their mothers milk increases sharply during lactation from 40% to as high as 60%. Gray Seal pups are usually weaned by 3 weeks of age. Adult females can reach up to 2 meters (6 ft, 7 inches) in length, and weights up to 200 kg (440 lbs). Adult males can be up to three times the size of some females, reaching lengths of 2.6m (8ft, 6inches) and weighing in at up to 350 kg (770 lbs). These seals live to be between 30 and 50, and are found only in the waters of the western North Atlantic. Populations are concentrated in eastern Canada, but extend southward to southern New England and eastern Long Island. Gray seals feed primarily on schooling fish such as herring, mackerel, flounder, cod, and salmon, as well as squid, octopus,crustaceans, and even seabirds. Major predators of this species include sharks, humans, and possibly killer whales. Worldwide population estimates are around 200,000-300,000. Gray seals are gregarious, and are also polygynous, meaning they will mate with more than one individual. Female Gray Seals reach sexual maturity between 3 and 5 years of age, and males reach sexual maturity between the ages of 4 and 8.
Hooded Seal (Cystophora cristata)
The Hooded Seal is named for the inflatable nose and extrudable nasal sac of the adult males, which can be inflated to attract a mate or to ward of potential predators. The color pattern of adult Hooded Seals can be described as a light background with scattered dark splotches, and a dark head. The pups are often referred to as "blue-backs", because they shed their lanugo coat in-utero, and are born with bluish- gray backs and faces, and lighter underbellies. Hooded Seal pups have the shortest lactation period known of any mammal - they are only nursed by their mother for four days. The mothers milk consists of 60% fat, which allows the pups to gain around 16 pounds per 24 hour period while they are nursing. Adult females weigh in around 300 kg (600 lbs) and reach lengths up to 2.4 meters (7 ft, 10 inches), while adult males reach lengths of 3 meters (10 ft) and weights up to 400 kg (880 lbs). The breeding range of these seals is limited to the central and western North Atlantic, where they stay mostly along the edge of pack ice.Adult male Hooded seals are monogamous, but the mating system of the Hooded Seal is polygynous. Breeding season lasts for around 2 to 2.5 weeks, with adults not feeding at all during this time. Juveniles have been known to wander surprisingly far during the non- breeding season. Hooded Seals feed on a variety of schooling fish, as well as squid, shrimp, octopus, and crustaceans. Their major predators include polar bears, sharks, killer whales, and humans. Worldwide population estimates range from 250,000 to 300,000.
Ringed Seals (Phoca hispida)
Ringed Seals are the smallest and most commonly found seals in the Arctic Ocean, with large populations also concentrated in the Hudson Bay, and Baltic and Bering Seas. It is rare to see these seals in Long Island waters, but vagrants have been spotted as far south as Portugal in the Atlantic Ocean. Ringed Seals can be recognized by their small, plump body, and their pelage, which is light on their bellies and dark on their back, with scattered irregular rings throughout. Pups have a white, wooly lanugo coat that they shed around six to eight weeks of age for a pelage that is dark on top and light on the bottom. Only after their first molt do they begin to develop the characteristic irregular ringed pattern. Ringed Seal adults can reach lengths of 1.6 meters (5 ft, 3 inches) and weights up to 110 kg (240 lbs), and live to be about 25 to 30 years old. This species is known for excavating birth lairs under the ice and snow to protect themselves and their young from predators such as polar bears and humans. They are the only species known to do this, as all other pinnipeds give birth on exposed surfaces, beaches, or occasionally in caves. Ringed Seals feed mainly on polar cod, and their worldwide population has never been surveyed, but may surpass 4 million.
All marine mammals are protected under The Marine Mammal Protection Act of 1972. This act gives the federal government jurisdiction over all marine mammals in the United States. This act prohibits any individual from capturing, harassing, hunting, killing, and possessing any marine mammal (dead or alive), except for those persons specifically authorized to do so. Stranding networks around the country work within the legal boundaries established by various federal, state, and regional agencies.
It is very important to remember that seals are wild animals and can be very aggressive. It is also important to realize that all seals will periodically come out of the water and haul out on rocks and beaches - this does not always mean that they are sick or injured. Never attempt to approach or handle a seal. If you are concerned about a seal's behavior or condition, please call our 24 hour Hotline number at (631) 369-9829.
Jefferson, T.A, S. Leatherwood, and M.A. Webber 1993 FAO Species Identification Guide. Marine Mammals of the World. Food and Agriculture Organization of the United Nations and United Nations Environment Program, Rome, Italy.
Lavigne, D.M. and K.M. Kovacs 1988. Harps and Hoods: Ice-breeding seals of the Northwest Atlantic. University of Waterloo Press, Waterloo, Ontario, Canada.
Reeves, R.R., B. Stewart, and S. Leatherwood. 1992 The Sierra Club handbook of Seals and Sirenians. Sierra Club Books, San Francisco, CA.
National Audubon Society. Guide to Marine Mammals of the World. 2002. Chanticleer Press, New York.