Atlantic Grey Seal
(Halichoerus grypus)
Male up to 3.0M, female up to 2.0M and newborn up to 0.9M in length.
Lifespan of female = 35 to 45 years
Lifespan of male = 20 to 25 years.
These seals have a large robust body, short thick flippers with long slender claws
and large heads. Males develop robust neck & chest with prominent skin folds and
wrinkles and tend to be uniformly dark brown-grey with light blotches, whilst females
& juveniles are lighter with dark brown blotches. Females reach sexual maturity at
5-6 years and give birth to a single pup
between September and December each year. About 17 are estimated to be born along
the C.M.H C.each year. Gestation lasts for 8 months with a delayed implantation
period of 3-4 months thus the pups are born a year after conception around the same
time as the breeding season and are suckled on a rich fatty milk (about 3 ltrs a
day). They can triple their body weight in just 2 to 3 weeks after which they shed
there milky white fur coat and are off to fend for themselves. There are estimated
to be over 4,700 Atlantic Grey seals in the west coast Wales area. Approximately
92,000 are estimated to live in the UK. On the cruise, they can be seen hauled out
on the rocks along the coast whilst resting and basking in the sun but they do spend
80% of their time submerged in the water. They can stay submerged for up to 8 mins
on these dives as they take in large amounts of oxygen and store it in blood and
muscle tissue. They stop water entering their lungs by closing the nostrils as a
reflex action when diving and by closing the airway to the lungs with the tongue
and the soft palatte. They feed mainly near the sea floor on a wide variety of fish
such as whiting, bass, salmon, sewin, sandeel, the odd squid and some crustacea.
