Facts about the Common Seal

The common seal also, known as the harbor seal, can be found in the Northern Hemisphere in both the Eastern and Western Atlantic and the Pacific Oceans.

The Western Atlantic Harbour Seal (P.v. Concolor) can be found from Greenland and the eastern Canadian Arctic down to New Jersey in the USA while the Eastern Atlantic Harbor Seal (P.v. Vitulina) can be found along the coastlines of Great Britain and Ireland.

It’s estimated that there are up to 6,000,000 common Barbour seals worldwide with about 50,000 common seals living in the waters around the UK. 85% of the UK’s common seals can be found in Scotland but they can also be found on the east coast of England and in South-West Ireland. Though they are called the common seal they are actually not the most common seal in Britain with the grey seal being more populous, numbering approximately 120,000.

The common seal can be recognized by its rounded head which has no visible ears and its V-shaped nostrils. They don’t have a sloping forehead like the grey seal and in the UK are usually a dark grey/ black color with a light spotted pattern though can be brown or tan colored. In some places, including Walton in Essex, the harbor seals have a reddish-orange tint to them which is caused by the iron oxides in the water. The speckled pattern on a harbor seal is unique to each individual and does not change making it useful for identifying individuals.

Adult males are only slightly larger than females measuring up to 1.9 meters in length and weighing up to 170kg with the female measuring 1.7 meters in length and weighing roughly 130kg. The female lives longer than the male, living approximately 30-35 years whilst the male is unlikely to live beyond 20-25 years.

Harbor seals eat a wide variety of fish which includes sand-eel, cod, herring, flatfish, sprat and whiting. They will also eat shrimps, crab, octopus and squid on occasion along with sea-birds. They don’t chew their food, it’s just swallowed whole or for larger fish torn into chunks. They need to consume 3-5kg of food per day and dive to depths of 10-150 meters foraging for food, usually making short dives lasting only 3-7minutes though they can stay below water for up to 30 minutes at one time and can travel up to 31miles in search of feeding grounds.

Harbor seals mate underwater but the seal pups are born on land on rocky shores or inter-tidal sandbanks from June-August. The pups weigh about 10kg at birth and can crawl and swim within just a few hours, though can sometimes be seen riding on their mothers back to save energy. They grow rapidly on their mothers milk which has a high fat content enabling them to double their weight within a month. The mother will nurse her pup for 3-4 weeks before weaning, at this time the young pup remains close to the nursery site for another 2-3 weeks as they learn to catch fish.

The National Seal Sanctuaries in the UK rescue, rehabilitate and release seals from sanctuaries in Gweek, Oban and Hunstanton.