Common Seal

Scientific name: Phoca vitulina

Common Seal - Phoca vitulina
Common Seal - Phoca vitulina. Photo © Planet Pictures / Getty Images.

The common seal (Phoca vitulina), also known as the harbor seal, is an agile carnivore with a streamlined body and flipper-like limbs that enable them to swim with great skill. Common seals have a thick coat of short hair. Their fur color varies from off white, to gray, to tan or brown. Common seals have a unique pattern of spots across their body and in some individuals this pattern is more distinct than in others.

Their nostrils are V-shaped and can be closed tightly to prevent water from entering their nose when they swim. Common seals do not have an outer ear structure, which helps with streamlining in the water.

Common seals occupy the widest range of all the seal species. They inhabit the coastal areas of the North Atlantic Ocean and the North Pacific Ocean. They can be found throughout the arctic, subarctic, and temperate regions. Their habitat preference includes coastal islands, beaches, and sand bars.

There are between 300,000 and 500,000 common seals living in the wild. Seal hunting once threatened the species but is now illegal in most countries. Some populations of common seals are threatened, even though the species as a whole is not. For example, populations that are declining include those of Greenland, the Baltic Sea, and Japan. Killing by humans still poses a threat in these areas, as does disease.

Some common seals are killed intentionally to protect fish stocks or by commercial hunters. Other common seals are killed as bycatch by fishing activities. Common seals are protected by various countries by legislation such as the Marine Mammal Protection Act of 1972 (in the United States) and the Conservation of Seals Act of 1970 (in the United Kingdom).

Common seals feed on a variety of fish as prey including cod, whitefish, anchoview, and sea bass. They also sometimes eat crustaceans (shrimps, crab) and mollusks. They feed while at sea and sometimes forage long distances or dive to considerable depths to find food. After foraging, they return to resting sites on the coast or on islands where they rest and recover.

There are about 25,000 Pacific harbor seals (Phoca vitulina richarii) that live along the California coast. Members of this population remain close to shore where they feed in the intertidal zone. On the east coast, Western Atlantic harbor seals (Phoca vitulina concolor) are present on the coast and islands of New England. They spend the winter further north along the coast of Canada and migrate south to the New England area to breed. Breeding occurs in May through June.

Size and Weight

About 6.5 feet long and up to 370 pounds. Males are generally larger than females.

Classification

Common seals are classified within the following taxonomic hierarchy:

Animals > Chordates > Vertebrates > Mammals > Pinnipeds > Phocidae > Phoca > Phoca vitulina

Common seals are divided into the following subspecies:

  • Eastern Atlantic harbor seal (Phoca vitulina vitulina) - Eastern Atlantic harbor seals are found along the coastlines of Europe.
  • Insular seal (Phoca vitulina stejnegeri) - Insular seals are found in eastern Asia.
  • Pacific harbor seal (Phoca vitulina richarii) - Pacific harbor seals are found along the coastlines of western North America.
  • Ungava seal (Phoca vitulina mellonae) - Ungava seals are freshwater seals that inhabit eastern Canada.
  • Western Atlantic harbor seal (Phoca vitulina concolor) - Western Atlantic harbor seals are found along the east coast of North America.
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Klappenbach, Laura. "Common Seal." ThoughtCo, Apr. 25, 2016, thoughtco.com/about-the-common-seal-130381. Klappenbach, Laura. (2016, April 25). Common Seal. Retrieved from https://www.thoughtco.com/about-the-common-seal-130381 Klappenbach, Laura. "Common Seal." ThoughtCo. https://www.thoughtco.com/about-the-common-seal-130381 (accessed January 17, 2018).