Seal Species | Sea Life, Islands and Oceania

TRUE SEAL SPECIES

Family Phocidae (True seals, earless seals): Common name (Scientific name), Subspecies, numbers Harbor seal (Phoca vitulina): Subspecies: East Atlantic harbor seal (P. v. vitulina), 62,500; West Atlantic harbor seal (P. v. concolor) 60,000; Freshwater seal (P. v. mellonae), endangered, 50; North Pacific harbor seal (P. v. richardii), 190,000; Kuril Island seal (P. v. stejnegeri), 315,000
Spotted seal (Phoca largha), 320,000, found in Bering Sea and surrounding areas
Ringed seal (Pusa hispida), 1,500,000: Subspecies: P. h. hispida, 1,450,000; Baltic seal (P. h. botnica), 11,500; Ladoga seal (P. h. ladogensis), 3,000–4,500; Okhosk ringed seal (P. h. ochotensis), 60,000; Saimaa ringed seal (P. h. saimensis), endangered, 135–190.

Caspian seal (Pusa caspica), endangered, 68,000
Baikal seal (Pusa sibirica), 54,000
Ribbon seal (Histriophoca fasciata), 183,000
Harp seal (Pagophilus groenlandicus), 4,500,000

From Animal Spot animalspot.net

Gray seal (Halichoerus grypus), 316,000: Subspecies: H. g. grypus, 250,000; H. g. macrorhynchus, 66,000;
Hooded seal (Cystophora cristata), , 340,000
Bearded seal (Erignathus barbatus), 200,000
Weddell seal (Leptonychotes weddellii), 300,000
Leopard seal (Hydrurga leptonyx), 18,000
Crabeater seal (Lobodon carcinophaga), 4,000,000
Ross seal (Ommatophoca rossii), 40,000
Southern elephant seal (Mirounga leonina), 325,000
Northern elephant seal (Mirounga angustirostris), 110,000
Mediterranean monk seal (Monachus monachus), Endangered, 350–450
Hawaiian monk seal (Neomonachus schauinslandi), endangered, 632.

Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se; Encyclopedia of Life eol.org; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures

Warm Sea Seals

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Hawaiian monk seal
Mediterranean monk seal (Monachus monachus), Endangered, 350–450
Hawaiian monk seal (Neomonachus schauinslandi), endangered, 632.

The Mediterranean monk seal is severely endangered and among the rarest of pinnipeds. Less than 1,000 of them survive in small populations in the Canary Islands, Madeira Islands and Morocco and along the European and African coast. Adult may be 2.8 meters in length and weigh 300 kilograms.

The Hawaiian monk sea is found in the northwestern Hawaiian islands. It was hunted nearly to extinct in the 1800s. The remnant population remained virtually undisturbed until fighting broke out on Midway Island in World War II.

The Caribbean monk seal is now extinct. First described by Columbus and last seen off of Jamaica in 1952, it inhabited the Antilles, the Bahamas and the Florida Keys.

Antarctic Seals

While only six of the 35 species of seal live in Antarctica, these six make up the vast majority of all seals on earth. The six species are Antarctic fur seals, leopard seals, Ross seals, southern elephant seals, crabeater seals and Weddell seals. Because of their thick layer of blubber and fur, Antarctica seals are extremely well-adapted to the freezing conditions and actually often find the conditions too hot, having to take dips into the water to cool down. [Source: Antarctica Guide]

Wendell seals probably live further south than any other mammal and can dive really deep. They spend a great deal of time under ice, breathing through holes they make with specially developed canine teeth, They can dive to a depth of around 600 meters and stay down for about an hour.The lungs of Wendell seals collapse at a depth of around 100 feet and stay collapsed when the seal dives further and reinflate when the animal ascends.

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Weddell seal
Weddell seal (Leptonychotes weddellii), 300,000
Crabeater seal (Lobodon carcinophaga), 4,000,000
Ross seal (Ommatophoca rossii), 40,000
Leopard seal (Hydrurga leptonyx), 18,000

The Ross seal is a medium-size seal that rarely exceed 2.5 meters in length. It is a solitary animal and probably the least studied of all pinnipeds. When approached by humans it produces unusual clicking and gurgling noises.

The crabeater seal is found throughout the Antarctic. Despite its name its prime food source is krill, which it filters from the water like baleen whales. They are the most abundant seal in the world. Their population is thought to exceed 15 million.

Leopard seals are apex predators at the top of the Antarctic food chain. Their only known natural predators are killer whales, however leopard seals are rarely eaten. Leopard seals themselves are notorious predators who feed on penguins, fish, squid, krill and other seals, mostly crabeater seal and fur seal pups. They are the only seals that to regularly hunt warm-blooded prey and kill other mammals and seals. Despite their reputation as fearsome predators, leopard seals feed primarily on krill, using their lobodont teeth to filter these small crustaceans from the water. They also eat fish and squid. [Source:Paul Nicklen, Kim. Heacox, National Geographic, November 2006]

Arctic Seals

Ringed seals inhabit the circumpolar pack-ice waters north to North Pole. Adults average 1.25 meters in length. Pups are in sow caves or tunnels These seal are hunted by Inuit for fur, meat and blubber. Ringed seals can live in completely ice-covered waters, using stout claws to dig and maintain breathing holes. They excavate snow caves on sea ice to provide insulated shelters for themselves and their pups. Young ringed seal pups cannot survive in water. They are susceptible to temperature stresses until they grow a blubber layer and shed their lanugo, the white, wooly coat they're born with.

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Ribbon seal
Ringed seal (Pusa hispida), 1,500,000: Subspecies: P. h. hispida, 1,450,000; Baltic seal (P. h. botnica), 11,500; Ladoga seal (P. h. ladogensis), 3,000–4,500; Okhosk ringed seal (P. h. ochotensis), 60,000; Saimaa ringed seal (P. h. saimensis), endangered, 135–190.
Ribbon seal (Histriophoca fasciata), 183,000
Harp seal (Pagophilus groenlandicus), 4,500,000

Ribbon seals are among the most striking and easily recognizable seals in the world. The ribbon seal gets its name from the distinctive adult coat pattern of light-colored bands or “ribbons” on a dark background.Ribbon seals inhabit the North Pacific Ocean and adjacent southern parts of the Arctic Ocean. In U.S. waters, they are found off the coast of Alaska in the Bering Sea and in the Chukchi and western Beaufort Seas.

Ribbon seals are considered relatively solitary, spending most of their time in the open ocean and forming loose aggregations on pack ice during spring to give birth, nurse pups, and molt. They are born white and attain their distinctive black and white ribbon patterns after several molts. They are particularly adept on ice. There are thought to be around 250,000 of them in the Bering and Okhotsk Seas.

Northern Seals

Harbor seal (Phoca vitulina): Subspecies: East Atlantic harbor seal (P. v. vitulina), 62,500; West Atlantic harbor seal (P. v. concolor) 60,000; Freshwater seal (P. v. mellonae), endangered, 50; North Pacific harbor seal (P. v. richardii), 190,000; Kuril Island seal (P. v. stejnegeri), 315,000
Spotted seal (Phoca largha), 320,000, found in Bering Sea and surrounding areas
Gray seal (Halichoerus grypus), 316,000: Subspecies: H. g. grypus, 250,000; H. g. macrorhynchus, 66,000;
Bearded seal (Erignathus barbatus), 200,000.

Larga seals are found from northern Alaska to Korea. Also known as spotted seals or largha seals, they are similar to harbor seal but are smaller, reaching lengths of 1.7 meters. There are thought to be about 400,000 of them in the Bering and Okhotsk Seas. Larga seal pups are covered with cream-colored fur when they are born. The fur serves as camouflage the snow, protecting them from potential predators. Their adult spots begin developing about a month after birth, around the same time they stop being breast fed and enter a period of post-weaning fasting when their weight drops from around 40 kilograms to around 30 kilograms. During that time they get their nutrition from fat stored in their bodies.

Bearded seals are the largest northern seal. They can reach 2.5 meters in length and weigh 340 kilograms. Usually solitary they were hunted by the sealing industry. Inuit still hunt them for meat, leather and oil. A critter cam was hooked up to one in 1997 by National Geographic researchers.

Bearded seals give birth and rear pups on drifting pack ice over shallow waters where prey is abundant. They're very similar to walrus in behavior. They're bottom feeders. They eat crabs and shelled organisms on the floor, so they need ice over shallow water, over the (continental) shelf. If the ice retreats too far off the shelf, they're denied access to their food source." When females give birth, they need ice to last long enough in the spring and early summer to successfully reproduce and then molt, or shed and grown back their fur.

Harbor Seals

Harbor seals are found throughout the temperate, Arctic and subarctic coastal waters of the Northern Hemisphere. They primarily feed on fish and spend most of their time in the same area and are known for raiding fishermen’s nets.

Harbor seals are one of the most common marine mammals along the U.S. West and East Coasts. They are commonly seen resting on rocks and beaches along the coast and on floating ice in glacial fjords with their head and rear flippers elevated in a “banana-like” position. [Source: NOAA]

Harbor seals weigh up to 130 kilograms (285 pounds) and measure up to 1.8 meters (6 feet) in length. Males are slightly larger than females, and seals in Alaska and the Pacific Ocean are generally larger than those found in the Atlantic Ocean. Harbor seals have short, dog-like snouts. The color of each seal’s fur varies but there are two basic patterns: light tan, silver, or blue-gray with dark speckling or spots, and a dark background with light rings. Harbor seals molt (shed hair) in the mid to late summer for 1-2 months, spending more time out of the water.

Harbor seals haul out (rest) on rocks, reefs, beaches, and drifting glacial ice when they are not traveling and/or foraging at sea. They haul out to regulate their body temperature, molt, interact with other seals, give birth, and nurse their pups. These seals also haul out in groups to avoid predators and spend less time being watchful for predators than those that haul out alone. Harbor seal pelvic bones are fused, preventing them from moving their hind flippers under their pelvis to walk on land like sea lions. Instead, they move by undulating in a caterpillar-like motion. This behavior does not mean they are injured.

Harbor seal pups can swim at birth. They can also dive for up to 2 minutes when they are only 2 to 3 days old and by the end of their first month of life embark on journeys of over 100 miles from their natal area. Mother harbor seals sometimes raise their pups in nurseries—groups of mothers and their young—that help protect the seals from predators.

The harbor seal’s diet consists mainly of fish, shellfish, and crustaceans. Harbor seals complete both shallow and deep dives while hunting, depending on the availability of prey. They can sleep underwater and come up for air once every 30 minutes.

Where They Live

Gray Seals

Gray seals are found in coastal waters throughout the North Atlantic Ocean. They are The gray seal are common in Canada and northwestern Europe, with the largest concentration in the British isles. Reaching a length of 2.3 meters (7.5 feet), they are sometimes called "horseheads" because of their long snout. Adult males in particular have large, horse-like heads and large, curved noses. Gray seals gather in large groups during the mating/pupping and molting seasons. Outside of this, they often share their habitat with harbor seals. [Source: NOAA]

Gray 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. Adult female gray seals are about 7.5 feet long and weigh about 550 pounds, while adult males can reach 10 feet long and weigh about 880 pounds. Females have silver-gray or brown fur which may or may not have scattered dark spots, while males have dark gray or brown fur which may or may not have silver-gray spots. Males also have longer noses than females. The male nose is so distinctive that the gray seal’s scientific name, Halichoerus grypus, means "hooked-nosed pig of the sea." Gray seal pups have white fur known as lanugo. This white fur helps absorb sunlight and trap heat to keep the pups warm. The lanugo is also related to their evolutionary history with other ice-breeding seals. Gray seals breed on ice or sandy beaches in parts of Canada (Gulf of St. Lawrence, Sable Island, Nova Scotia) and on sandy or rocky beaches or islands in the U.S., and in parts of the Baltic Sea. Pups shed their lanugo when they are about 3 weeks old.

Gray seals gather in large groups during the mating/pupping and molting seasons. During the rest of the year, they can be found alone, in small groups or at large aggregations either on land or at sea. Gray seals can dive to 1,560 feet for as long as one hour. On average they can eat four to six percent of their body weight in food each day, but do not eat during the mating/pupping or molting seasons. Their excellent vision and hearing makes them effective hunters. They often hunt in groups, which makes it easier for them to catch their prey. They eat fish (mostly sand eels,hake, whiting, cod, haddock, pollock, and flatfish), crustaceans, squid, octopuses, and sometimes even seabirds. Their diet varies by age class, sex, season, and geographic region.

Harp Seals

Harp seals are named for the black, harp-shaped pattern on their backs. For a while they were assaulted are harvested in Greenland and Newfoundland. The Newfoundland hunt drew some notoriety for the clubbing of baby seals. The hunt was suspended.

Harp seals live throughout the cold waters of the North Atlantic and Arctic Oceans. Three populations in the Barents Sea, East Coast of Greenland, and Northwest Atlantic Ocean are recognized based on geographic distribution as well as morphological, genetic, and behavioral differences. 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. [Source: NOAA]

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 1.5 to 1.9 meters (5 to 6 feet) long, weigh 118 to 136 kilograms (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.

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(more than 130 species) 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.

Hooded Seals

Hooded seal (Cystophora cristata) can dive very deep and hunt fish in deep waters of the North Atlantic and Arctic. Males have highly elastic black bladders on their nose and on top of their head. Both are interconnected and used in breeding displays. Males also possess a red nasal bladder, the source of their nickname bladdernose. There are around 340,000 of them.

Hooded seals inflate their nasal bladders like elephant seals. They can close both nostrils and exhale, inflating black skin bladder, or they can close one nostril and exhale, blowing out the blood red sack. On a hooded seal male, BBC television naturalist David Attenborough wrote: “He lies lazily besides a female, he lazily blows air from one nostril to the other. If another male approaches, however, he inflates both at the same time so they come together and form a large black hood twice the size of a football. As the intruder gets closer, the resident shuts one nostril and blows down the other, inflating a nasal membrane into a gigantic scarlet balloon, he then shakes it violently from side to side so that it makes a pinging noise. This usually is enough to dissuade any intruder from persisting.”

Male hooded seals are about 2.6 meters (8.5 feet) long and weigh about 192 to 352 kilograms (423 to 776 pounds), while females are about two meters (6.5 feet) long and weigh about 145 to 300 kilograms (320 to 660 pounds). Both male and female adults have silver-gray fur with darker patches of different sizes and shapes across their bodies. Hooded seal pups have blue-gray fur on their backs and whitish bellies. This beautiful pelt earned them the nickname “blue-backs” and once made them a target for hunting. Pups shed their blue-gray coat when they are 14 months old.

The stretchy cavity, or hood, on the hooded seal nose has two sections, or lobes. Adult males can inflate and extend this hood so that it stretches across the length of their face. Sexually mature males have a unique partition in their nose that, when inflated, looks like a pinkish-red balloon. They use this to attract females' attention during mating season and to show aggression toward other males.

Hooded seals are not social. They migrate and remain alone for most of the year except during mating season. They are more aggressive and territorial than other seal species. Hooded seals begin their annual migration cycle once they reach sexual maturity. They gather at their breeding grounds for two to three weeks in the spring. After pups are born, adults stay in the breeding grounds to molt. Once they have molted, they begin their migration period for the rest of the year.

On average, hooded seals dive 100 to 595 meters (325 to 1,950 feet below the surface for about 13 to 15 minutes in search of food, but they are also known to dive more than 3,280 feet for up to 1 hour. They eat squid, starfish, and mussels. They also eat several types of fish, including Greenland halibut, redfish, Atlantic and Arctic cod, capelin, and herring. Newly weaned pups feed on pelagic crustaceans

Image Sources: Wikimedia Commons, NOAA, boxed species descriptions from Orleans Conservation Trust

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated June 2023