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Species - Grey Seal


Protected under the European Communities Habitat Directive, which looks to create Special Areas of Conservation (SAC) to protect breeding and feeding areas.


Grey Seal (Halichoerus grypus)

The grey seal is a very social mammal. It lives and feeds in big groups along the coastline. The females have a slightly lighter coat than that of the males with it being a light brown or tan coloured coat with a paler chest displaying dark patches or spots. The males have a dark brown/grey coat with lighter blotches or patches. Both sexes look much darker when wet. The seals have almost horse-shaped heads with long noses surrounded by long wire-like whiskers. They have two front flippers which are used to power them through the water and heave their bodies along the ground when they are on land. The flippers each contain five strong, curved claws that are used for feeding. Their tail flipper is a vital feature as it is used to guide them through the water and is a primary reason for their immense agility. Their bodies are a long oblong shape making them very cumbersome on land, but creating a sleek shape for breaking through water. They have a thick layer of blubber and two layers of fur to allow them to retain as much heat as possible and spend a longer time at sea. The males can weigh from 170 to 310 kilograms and reach 2 to 2.5 metres in length. The females tend to be smaller at 1.65 to 2 metres and 103 to 180 kilograms in weight.

They can spend two to three days at sea foraging for food, which can take place several hundreds of kilometres offshore. The seals tend to return to favoured feeding grounds, but being opportunistic feeders they will venture to new regions. They have a varied diet consisting of a wide variety of fish, cephalopods (octopus family) and crustaceans, but have been found to eat seabirds. They usually take short shallower dives consisting of less than 120 metres and lasting around 8 minutes. Despite this they can hold their breath for up to half an hour and dive to depths of 300 metres.

Seals spend most of their time at sea and their primary reason for coming ashore is for breeding. They will stay with their newly born pup for the short period of 2-4 weeks feeding them three to four times a day. During this time the pup will moult their white fluffy coats and produce their waterproof adult coat and develop a layer of blubber. The mother’s milk contains 60 percent fat, which rapidly builds up the size of the pup. During this interim the mother will lose up to a third of her body weight. The first year of the pup’s life has a very high mortality rate averaging from the 30 to 55 percent.

Currently the population of the grey seal is increasing, but it was severely reduced through over harvesting. The seal also faces threats from organised government culls as they believe the seals are competition for the commercial fishing industry. Fishing equipment can also cause physical damage along with the impact of pollutants from run-off and boats. The importance of the species has been noted and is now protected under the European Communities Habitat Directive, which looks to create Special Areas of Conservation (SAC) to protect breeding and feeding areas. The presence of the seals was also used to create the Lundy Marine Nature Reserve (LMNR). The British population is considered to be highly important as they make up 40 percent of the world’s population and is the most closely monitored population of grey seal.  
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