Harp Seal

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Harp Seal
Conservation status
Least concern [1]
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Phocidae Genus: Phoca Species: P. groenlandica
Binomial name
Phoca groenlandica Erxleben, 1777

Contents 1 Features 2 Population 2.1 The Northwest population 2.2 White sea and west ice populations 3 Hunting 4 External links 5 Notes and references

[edit] Features

Harp seals resemble harbor seals in body and head form, but are larger: adult Harp Seals grow to 1.7 m long and can weigh over 130 kg. Polar Bears, sharks, Orcas, and in some areas Walruses are natural predators of Harp Seals. They are often given different names according to their age :

• “Whitecoats” : Birth
• “Ragged Jackets” : 2-4 weeks
• “Beaters” : 4 weeks to 1 year
• “Bedlamers” : 1 to 4 years
• “Spotted Harp” : 4 to 7 years
• “Dark Harp” : mature/adult

[edit] Population

Harp Seal separates into three populations according to their breeding locations: the White Sea, the West Ice and Northwest Atlantic. Seals breeding in the Northwest Atlantic near Newfoundland, Canada represent the largest population and are genetically different from seals breeding in the two other places, which have not been proven genetically different from each other. All three populations are hunted commercially, mainly by Canada, Norway, Russia and Greenland

[edit] The Northwest population

The Northwest population historically was greater than 30 million, but the population declined by 50–66% between 1950 and 1970 due to commercial hunting in Canada, and by 1970, was in serious trouble. Since 1970 it has nearly tripled in size to 5.2 million according to a peer-reviewed survey in 1999. 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. After the Canadian cod collapse many French fishermen and politicians blamed Harp Seals for the destruction and hindering the recovery of the North-West Atlantic Cod population. Although cod is a major contribution to Harp Seals diets, most of the cod is Arctic Cod and not the commercial Atlantic. The ratio is about 36:10 although the total tonnage of cod is around 200,000 tonnes. Although the effect of harp seals on the recovery of the cod stocks is disputed, it is widely accepted that harp seals did not cause the collapse. The issue with most regarding the cod stocks is that if the hunting were to stop, the population would grow and therefore cause total prey consumption to increase. Even with heavy hunting, from 1990 to 1999 there was a 800,000-tonne (32%) increase. If the hunt were to stop, the belief is that the population would skyrocket and within a few years more than likely double the consumption rate. The Harp Seal is at the top of its food chain and has few natural predators to keep its population at bay. For more information, review Northwest Atlantic Harp Seals Stock Status Report 2000 from the Canadian Government.

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 50% 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.

As mother Harp Seals wean their young, mature males (6–7 years old) roam around breeding with the females promiscuously. Courtship begins on the ice; however 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.

[edit] 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). The Harp Seal is migrating searching for food over large areas in the Barents Sea, the Norwegian Sea, the Greenland Sea and the Denmark Strait. Age of maturation is 4–8 years, normal life length more than 30 years. An adult animal is about 1.9 m long with a weight around 200 kg.

The population size was in 2000 estimated to more than 300,000 animals in the White Sea and 361,000 animals 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).

[edit] Hunting

Main article: seal hunting

In Canada, the season for the commercial hunt of harp seal 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.

In 2003, the three-year harp seal 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 will be killed. An additional 10,000 animals are allocated for hunting by Aboriginal peoples.

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.

While the Inuit hunt seals for food, tools, energy, clothes, and art, the commercial hunters only hunt for hides, often leaving the body intact. The only part the Inuit do not use is the bladder, which they float to sea as part of custom.

[edit] External links

• 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
• Harp Seal Factsheet. International Marine Mammal Association. http://www.imma.org/harpseal.html

[edit] Notes and references