Gray seals are large, with males larger than females. Males can reach lengths up to 10 feet and weights up to 880 pounds, while females grow to about 7.5 feet and 550 pounds. They range in coloration from a dark brown to dark gray coat in males and a lighter grayish-tan in females. Both males and females may have spots or patches. The older males have a more “roman-nosed” appearance than females.
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Carnivora
- Family: Phocidae
- Genus: Halichoerus
- Species: grypus
Migration and Reproduction:
Female gray seals are sexually mature at 3-5 years and males at 4-6 years. Gray seals may mate on land or in the water, but they come ashore to give birth. Males will often try to mate with more than one female.
The gestation period is about 11 months, after which the female gives birth to a pup with a white coat that is about 3 feet long and weighs about 40 pounds. The female nurses for about 2 ½ weeks and then the pup is left to fend for itself. At first it lives off of its blubber, but then starts feeding at sea when it is about 3-6 weeks old.
Gray seals live in cold water in the Atlantic Ocean and Baltic Sea. In the western Atlantic, the population is distributed from the Labrador Sea in northern Canada down to the Gulf of Maine. In the eastern Atlantic, the gray seal is concentrated around the United Kingdom and Ireland but is also present around Iceland, the Faroe Islands, and Norway. There is a third stock in the Baltic Sea.
The gray seal is listed as of “least concern” on the IUCN Red List because of its large, increasing population.
Fishermen have called for culling of gray seals because they are thought to damage fish stocks by eating too many fish and because they host a parasite called cod worm. However, there are no large-scale hunts of gray seals, although small-scale hunts have occurred in recent years in Canada, Iceland and Norway.
Other threats to the seals include entanglement, pollution, and threats from fisheries conflicts (e.g., seals shot to prevent damage to fishing gear).
- Cawardine, M. Whales, Dolphins and Porpoises. Dorling Kindersley. London. 1995.
- Halichoerus grypus, Gray Seal - MarineBio.org. Retrieved February 19, 2009.
- Smith, J. 2008. "Halichoerus grypus" (On-line), Animal Diversity Web. Accessed February 19, 2009.
- Thomspon, D. & Harkonen, T. 2008. “Halichoerus grypus”. (Online), 2008 IUCN Red List of Threatened Species. Accessed February 19, 2009.