Gray Seals belong to the Mammalian Order
Pinnipedia, in the family Phocidae. Other members of Phocidae
include elephant seals, harbor seals, and monk seals. Phocids are
referred to as true seals. They are distinguished from other
pinnipeds by their inability to support their body using their hind
limbs. The Gray Seal's scientific name, Halichoerus grypus,
means "hook-nosed sea pig".
Gray seals are generally 8-10 feet in
length, with males weighing about 770lbs and females weighing about
440lbs. They range in color from gray to almost black. Their
stomachs are paler in color, an aquatic adaptation called
countershading. Males are usually dark with lighter splotches,
females are light with dark splotches.
Gray seals can be found in the northern
Atlantic waters along the coast of Canada, Greenland, and northern
Europe. Gray seals feed on bottom-dwelling fish, squid and octopus.
The gray seals gather in groups to
feed. They can dive to depths of 475ft, remaining submerged for 20
minutes at a time. This is achieved by a combination of
adaptations. Gray seals have large amounts of hemoglobin in their
blood, storing large amounts of oxygen. Their heart rate also slows
down, slowing the amount of oxygen used by the body. A thick layer
of blubber enables gray seals to survive in frigid waters.
Like most other seals they do not make
long migrations. The breeding season varies depending on location.
During the 4 to 6 week breeding season, males and females will not
hunt or eat. The males do not defend territories, but instead
maintain harems of females. They maneuver better on land than other
members of its family and may crawl far inland to give birth.
Newborn pups weight 30lbs. The seal pup gains three pounds each day
until it is weaned. At 4-5 weeks the pup sheds its white coat and
enters the water, beginning its life at sea. Males may live up to
30 years, with females reaching 40 years of age.
Seals have been hunted for thousands of
years for food and blubber. Recently, pups have been killed for
their white fur, which is used in the fashion industry. Fortunately
for the gray seal, the efforts of conservationists have halted the
slaughter of seal pups. Gray seals are also unpopular with
fishermen. Some fishermen claim they destroy fishing gear, consume
great quantities of fish, and host codworms. Codworm larvae reduce
the commercial value of fish. However, scientists claim gray seals
do not seriously reduce the number of fish. Once rare, the gray
seal is now more common due to protective laws. Some locations have
seen quite an increase in gray seal numbers. Water pollution,
fishing gear, and physical waste still threaten the gray seal.