Harbor Seal

Harbor Seal



COMMON NAME: harbor seal
KINGDOM: Animalia
PHYLUM: Chordata
CLASS: Mammalia
ORDER: Pinnipedia
FAMILY: Phocidae
GENUS SPECIES: Phoca vitulina


DESCRIPTION: Harbor seals have a rounded head with a fairly blunt snout and, like other true seals, lack external ear pinnae. They exhibit a wide range of color variations, from silver with black spots, to black with gray or white rings, to almost pure white.
MALE Adult males are slightly larger than adult females
SIZE: At birth, harbor seal pups are about 756-100 mm (29.5-39.4 in.) in length
MALE Up to about 2.0 m (6.6 ft.)
FEMALE Up to 1.7 m (5.6 ft.)
WEIGHT: Newborn harbor seal pups weigh from 8-12 kg (8-26 lbs.)
MALE Males weigh as much as 170 kg (375 lb.)
FEMALE Females weigh up to 150 kg (331 lb.)
DIET: Squid, crustaceans, mollusks, and fishes
GESTATION: Gestational period 9-11 months; with 1.5-3 months delayed implantation
ESTRAL PERIOD At the end of lactation
NURSING DURATION 4-6 weeks (wean)
MALE 3-7 years
FEMALE 2-7 years
LIFE SPAN: 25-30 years
RANGE: Temperate, Arctic and subarctic waters throughout the Northern Hemisphere. One subspecies, Phoca vitulina mellonae, is a landlocked group of harbor seals living in freshwater Seal Lake in Quebec, Canada.
HABITAT: Cobble or sandy beaches, rocky reefs, tidal mudflats and sandbars along the coast or in bays or estuaries
POPULATION: GLOBAL 400,000-500,000
  LOCAL The most abundant subspecies is P.v. richardsi - an estimated 200,000 individuals inhabit the eastern North Pacific from the Pribilof Islands to Baja California, Mexico
STATUS: IUCN Not listed
CITES Not listed
USFWS Not listed


1. Harbor seals belong to the scientific order Pinnipedia, which includes seals, sea lions, and walruses. Seals differ from sea lions in a number of ways, including having shorter, stouter flippers, and no visible earflaps.
2. Unlike most other pinnipeds, harbor seals are generally solitary and rarely interact with one another. An exception to this is the strong mother-pup bond maintained until the pup is weaned. When hauled out, adults maintain a meter or more (several feet) between them. Harbor seals are not highly communicative, but if threatened a seal may respond by snorting, growling, lunging, scratching, or other aggressive gestures.
3. Harbor seals swim with alternate back-and-forth movements of their hind flippers. Harbor seals can remain submerged for up to 28 minutes and dive to depths of 90 m (295 ft.); however, they routinely forage in shallower waters.
4. Harbor seals along the Pacific coast usually give birth between February and July. The well-developed pup may measure up to 100 cm (39 in.) and 12 kg (26 lb.). A pup nurses for four to six weeks. Its mother's milk, containing as much as 45% milk fat, enables the pup to more than double its weight by the time it's weaned.
5. For more information about harbor seals, explore the HARBOR SEAL INFO BOOK.


As for other marine mammals, the U.S. Marine Mammal Protection Act of 1972 protects harbor seals in U.S. waters.


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Jefferson, T.J. Leatherwood, S. and M.A. Webber. FAO Species Identification Guide. Marine Mammals of the World. Rome. FAO, 1993.

Reeves, R.R., Stewart, B.S. and S. Stephen. The Sierra Club Handbook of Seals and Sirenians. San Francisco: Sierra Club Books, 1992.

Nowak, Ronald M. (ed.). Walker's Mammals of the World. Vol. II. Baltimore: Johns Hopkins University Press, 1991.

Parker, S. (ed.). Grizmek's Encyclopedia of Mammals. Vol. IV. New York: McGraw-Hill Publishing Co., 1990.

Reeves, R. R., Stewart, B.S., Clapman, P.J., and J.A. Powell (Peter Folkens illustrator). National Audubon Society: Guide to Marine Mammals of the World. New York: Random House, 2002.

Riedman, M. The Pinnipeds: Seals, Sea Lions and Walruses. Berkeley and Los Angeles. University of California Press. 1990.