Definitions

harp seal

harp seal

harp seal, crested earless, or true, seal, Phoca groenlandica, found in the N Atlantic around Greenland and the White Sea. In the spring, harp seals migrate southward to assemble in large groups to breed near the Newfoundland and Norwegian coasts. The young, born on ice floes, are covered with a fluffy white coat from birth to weaning (about 12 to 18 days) and are hunted for their fur, meat, and skin. The clubbing to death of baby seals aroused much protest in the 1970s, and trade in their white furs has declined after Europe banned imports in the mid-1980s. A decade later, however, concerns over the seals' affect on the cod fisheries led to increased quotas and the return of large commercial operations to the annual hunt, but killing of white-coated baby seals is banned. The fur gradually darkens to gray as the young seals mature. The old males are marked with a brown crest on each side, suggesting the outline of a harp. Harp seals, sometimes seen as far S as Maine, are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Carnivora.

See F. Bruemmer, The Life of the Harp Seal (1977).

Migratory earless seal (Pagophilus groenlandicus, sometimes Phoca groenlandica) of the North Atlantic and Arctic oceans. The adult male is light grayish or yellowish, with brown or black on the head and a similarly coloured U-shaped marking on the back and sides. The female is less clearly marked. Adults are about 6 ft (1.8 m) long and typically weigh between 265 and 300 lbs (120 and 135 kg). Harp seals feed on fish and crustaceans and spend much of the year at sea. They breed near Newfoundland, Can., and in the Greenland and White seas. Until two weeks old, the pups bear a fluffy white coat highly valued by the fur trade; public indignation over hunting methods (including clubbing) has led to increased regulation and supervision of sealing activities in the Newfoundland area.

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The Harp Seal (Phoca groenlandica; syn. Pagophilus groenlandicus) is a species of earless seal native to the northernmost Atlantic Ocean and adjacent parts of the Arctic Ocean.

Features

It is somewhat larger than the Common Seal, growing to 5.5 ft (1.67 m) long and with a weight of 115–180 kg (253-400 lb), males are distinctly larger than females. Adult males are creamy white overall, with a dark chocolate brown head and a broad dark chocolate brown U-shaped pattern on their back, running across the shoulders and down each flank to near the base of the tail; the pattern is often slightly asymmetrical and irregular, with dark brown spots extending onto the white parts. Adult females have a similar but less distinct pattern, with the brown being paler and greyer. Immatures up to two to three years old are pale grey, variably spotted with darker grey. The flippers are white or pale grey, with five stout claws on each fore flipper. The tail is short, 10–15 cm long. The fur on adults is 2 cm long, dense, stiff and velvety; the skin is roughly the same colour as the fur, whitish-grey under the white fur, and dark brown under the brown fur. The vibrissae are numerous on the muzzle, the longest about 12 cm long. The newborn pups are all white except for a black nose and eyes, which helps them blend in with the snow. Puberty is reached at 5–7 years, and the maximum lifespan is more than 30 years.

Structurally, it resembles the Common Seal closely, and it is now usually included in the same genus Phoca, rather than separated into its own genus Pagophilus as was often done in older texts.

Population

Harp Seals separate into three populations according to their breeding locations; the White Sea, the West Ice between Jan Mayen and Greenland, and the Northwest Atlantic near Newfoundland, Canada. Seals breeding in the Northwest Atlantic represent the largest population and are genetically different from seals breeding in the two other areas, which have not been proven genetically different from each other. They are however visually indistinguishable, and a degree of mixing between the populations occurs.

The Northwest population

There are no reliable estimates of the size of Northwest Atlantic population when commercial hunting began in the early 1800s. Several simulation models estimated virginal populations to be in the 3 to 4 million range. It is considered that the population recovered to about 3 million at the end of World War II, but subsequently declined by 50–66% between 1950 and 1970 due to commercial hunting in Canada. Quotas and other conservation measures since then have enabled the population to nearly triple in size to 5.2 million according to a peer-reviewed survey in 1999.

White Sea and West Ice populations

Mature females usually give birth to one pup in March/April each year. The pups are born within well defined areas in the drift ice in the White Sea or in the area between Jan Mayen and East Greenland (the West Ice population). Harp Seals migrate in search for food over large areas in the Barents Sea, the Norwegian Sea, the Greenland Sea and the Denmark Strait.

The population size in 2000 was estimated to be more than 300,000 in the White Sea and 361,000 in the West Ice.

The annual prey consumption was in 2000 estimated to about 3.5 million tonnes in the White Sea area (Nilssen et al 2000).

Breeding

Each year, mature females (5-6 years old) give birth to a single pup, typically in late February. Pups weigh approximately 10 kg and are 80–85 cm long. Immediately after giving birth, the mother smells her offspring, and from that point on will only ever feed her own pup, whose scent she remembers. Harp Seal milk contains up to 48% fat, so pups gain over 2 kg per day when nursing, which lasts roughly 12 days. During this time the mother does not eat, and will lose up to 3 kg per day of body weight. Weaning is abrupt; the mother simply leaves and never comes back. The stranded pup will cry at first, and then become very sedentary to conserve body fat.

Pups are unable to swim or find food until they are about 25 days old, leaving them very vulnerable to Polar Bears and humans during this time. Due in part to the period of helplessness as infants, and to the long time it takes them to become proficient swimmers, as many as 30% of pups fail to survive their first year. Also, although it is not legal to catch seals using nets, thousands of seals are inadvertently killed in commercial fishing nets every year.

When the mother weans its pup, mature males (6–7 years old) roam around breeding with the females promiscuously. While courtship begins on the ice, the actual mating takes place in the water. Harp Seals have delayed implantation, meaning the fertilized egg becomes an embryo, but does not implant in the uterus right away. The embryo will float around for about three and a half months before implanting and beginning to grow. This allows all the females to give birth within a very small time window each year, when the ice pack is available for giving birth and raising their young.

Migration and vagrancy

Harp Seals are strongly migratory. The northwest population regularly moves up to 4,000 km northeast outside of the breeding season; one tagged individual of this population was recovered at sea off the north Norwegian coast, 4,640 km east-north-east of its tagging location. Their navigational accuracy is very high, with good eyesight being an important factor.

They are occasionally found as a vagrant south of its normal range. In Great Britain, a total of 31 were recorded between 1800 and 1988, with one subsequently, on Lindisfarne in Northumberland in September 1995.

One recorded in the Shetland Islands in 1987 was linked to a mass movement of Harp Seals into Norwegian waters; by mid-February 1987, 24,000 were reported drowned in fishermen's nets and perhaps 300,000 (about 10% of the world population) had invaded fjords as far south as Oslo. The animals were in an emaciated condition and this was believed to be the result of food shortages, likely due to over-fishing by humans.

Diet

Harp Seals eat a wide variety of fish and other sea creatures, and their diet seems to vary during different stages of life. Since reporting of the stomach contents of killed seals began in 1941, at least 67 species of fish and 70 species of invertebrates have been found to be part of the Harp Seal's diet.

Predators

Natural predators include Polar Bear, Orca, sharks, and in some areas Walruses, and humans.

Seal hunting

All three populations are hunted commercially, mainly by Canada, Norway, Russia and Greenland. In hunting terminology, Harp Seals are often given different names according to their age:

In Canada, the season for the commercial hunt is from November 15 to May 15. The majority of sealing, however, occurs in late March in The Gulf of St. Lawrence, and during the first or second week of April off Newfoundland, in an area known as "The Front". This peak spring period is generally what is referred to as the "Canadian Seal Hunt". In 2006, the St. Lawrence seal hunt officially started on March 25. This date was initially uncertain, due to thin ice conditions caused by the year's milder temperatures. Inuit people living in the region hunt them mainly for sport and to a lesser extent, commercial reasons.

In 2003, the three-year quota granted by the Department of Fisheries and Oceans was increased to a maximum of 975,000 animals, with a maximum of 350,000 animals in any two consecutive years. In 2006, 325,000 Harp Seals, as well as 10,000 Hooded Seals and 10,400 Grey Seals were killed. An additional 10,000 animals are allocated for hunting by natives.

The Canadian seal hunt is monitored by the Canadian Government. However, although approximately 70% of Canadian seals killed are killed on "The Front", the vast majority of private monitors focus on the St. Lawrence hunt, due to its more convenient location.

The 2006 St. Lawrence leg of the hunt was officially closed on April 3, 2006. Sealers had exceeded the quota by 1,000 animals by the time the hunt was closed.

External links

  • Save the Seals: http://www.seashepherd.org
  • Harp Seal on pinniped.org: http://www.pinnipeds.org/species/harp.htm
  • Harp Seal http://www.marinebio.org/species
  • The Harp Seal on Underwater World. Canada Fish and Aquatic Life. http://www.dfo-mpo.ge.ca/zone/underwater
  • Harp Seal Factsheet. Young Peoples Trust for the Environment. http://www.yptenc.org.uk
  • Characteristics of Seals Alaska Fisheries Science Center. http://www.afsc.NOAA.gov
  • Seals. Provincetown Center for Coastal Studies. http://www.coastalstudies.org
  • FAQ Seals. Memorial University of Newfoundland Ocean Sciences Center. http://www.osc.mun.ca/seals
  • Harp Seal. Center for Distance Learning and Innovation. http://www.stemnet.nf.ca

Notes and references

The Northwest population:

The White Sea and West Ice populations:

  • Hamre, J.(1994). Biodiversity and exploitation of the main fish stocks in the Norwegian- Barents Sea ecosystem. Biodiversity and Conservation 3:473-492
  • Haug, T., Kroeyer, A.B., Nilssen, K.T., Ugland, K.I. and Aspholm, P.E., (1991). Harp seal (Phoca groenlandica ) invasions in Norwegian coastal waters: Age composition and feeding habits. ICES journal of marine science. Vol. 48, no. 3:363-371
  • ICES 2001. Report of the Joint ICES/NAFO Working Group on Harp and Hooded Seals, ICES Headquarters, 2-6 October 2000. ICES CM, 2001, ACFM:8, 40 pp.
  • Nilssen, K.T., Pedersen, O.-P., Folkow, L.P., & Haug. T. 2000. Food consumption estimates of Barents Sea harp seals. NAMMCO Sci. Publ. 2:9-28.

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