Last modified: Thursday September 24th, 1999

Other phocid seals

Harp seal

 Phoca groenlandica (Erxleben, 1777)

Nomenclature

This species was originally by Fabricius in 1776, but the species was described by Erxleben in 1777. Gray (1850) changed the name to Pagophilus groenlandicus, but the species is now again included in the genus Phoca by most. However, according to Rice (1998) the inclusion of a large number of species in the genus Phoca is not admissible, which means the Pagophilus groenlandicus would be the valid name for this species. Common names that are also used to describe the harp seal are Greenland seal and saddleback.

Appearance

Harp seals are 1.7m long and weigh 130 kg. Pups measure 90-105 cm and weigh 6-10 kg at birth. Males are silvery grey with a black head and a horseshoe-shaped band across the back and the flanks. Females have a lighter head and also the "harp" is lighter and can be fragmented. Pups have a silky white fur at birth and moult after 1 week. After moult they are silvery grey with irregular dark and black spots.

The harp seal goes through a number of stages during its early development (Lavigne and Kovacs, 1988):

Stage Age (days)   Short description
Newborn 0   small, skinny, uncoordinated movements
Yellowcoat 1   dried up, yellowish
Thin whitecoat 4   white, growing, more coordinated movements
Fat whitecoat 7   end of weaning: half of body weight (30+kg) is stored fat
Greycoat 12   spotted, juvenile pelage can be seen underneath white fur
Ragged-jacket 21   moulting. white pelage is shed
Beater 25+   black-spotted juvenile pelage. The name refers to the poorly developed swimming skills. They "beat" the water.

Distribution

There are 3 different stocks: in the White Sea, at Jan Mayen and on Newfoundland (2 substocks: Labrador and Gulf of St. Lawrence).

Feeding

Young harp seals feed mainly on euphasiids. Adults eat capelin, polar cod, herring, cod and shrimp. They eat 1-5% of their body weight of fish per day. The Northwest Atlantic harp seal population consumes and estimated 500,000 tonnes of capelin and 20,000 tonnes of herring per year. The total consumption for this population can be as high as 2,000,000 tonnes per year (Ronald et al, 1982).

Population dynamics and life history

Females become mature at 5 years, males at 6-8 years. The age of maturity might be density dependent. The pregnancy rate is over 90%. Gestation lasts 11 months, including a 4 month delay of implantation (Ronald et al (1982) mention a delay of implantation of 11 weeks, followed by a gestation of 7 months). Lactation lasts 8-12 days. In this period the pup grows at a rate of about 2 kg/day. (Lavigne and Kovacs, 1988). First year mortality is 20-30%. Longevity is about 30 years. The natural mortality for adult is 8-10%.

Trophic relations

The harp seal competes with fin whales and minke whales for capelin. Polar bears, killer whales and sharks are the main predators of this species. There appear to be some interactions with hooded seals, although there is probably no competition for food. Kovacs et al (1997) reported the birth of a harp X hooded seal hybrid in the Gulf of St. Lawrence.

Interactions

There is competition for capelin and herring with commercial fisheries. The harp seals have been implicated in the decline of the Northern Cod stock. However, an internation working group concluded that this is unlikely (Canadian Centre for Fisheries Innovation, 1997).

Population size

Lavigne (1979) gives the following estimates for the different stocks: This gives a total population of 1.3-2.3 million. Lavigne et al (1982) arrive at a Newfoundland population in 1975 of 630,000-790,000. Ronald et al (1982) find the following abundances: Total population: less than 1.7 million.

Exploitation

This species is exploited under regulations of the International Commission for Northwest Atlantic Fisheries (ICNAF).In the White Sea pups can be harvested between 23. March and 30. April. Quota are 27,000 for Soviet natives and 14,000 for Norwegian vessels. At Jan Mayen, Norway can catch 15,000 pups between 23. March and 5. May. In Newfoundland the quota for 1976 were: 52333 for Canadian vessels, 44667 for Norwegian vessels and 30,000 for Canadian land-based hunters. Not included in the quota are catches by Japanese vessels, which amount to about 7,000 per year.

Catch statistics for the Northwest Atlantic (Lavigne, 1999)
Year Canada
reported		 Canada
estimated		 Greenland
reported		 Greenland
estimated
1994 52,916 63,571-93,509 57,905 115,810
1995 64,794 75,813-105,441 63,202 126,404
1996 242,262 274,968-342,405 50,626-67,886 101,252-135,772
1997 264,204 296,187-370,394 50,626-67,886 101,252-135,772
1998 282,070 315,918-397,719 50,626-67,886 101,252-135,772

Threats to the population

The main threats are over-exploitation of the seal stocks and over-exploitation of the capelin and herring stocks.

References

Bonner, W.N. (1982)
Seals and Man. A study of interactions. University of Washington Press, Seattle, 170pp.
Bowen, W.D. (1985)
Harp seal feeding and interactions with commercial fisheries in the Northwest Atlantic.
in: Beddington, J.R., Beverton, R.J.H. and Lavigne, D.M. (eds.): Marine Mammals and Fisheries, pp. 135-152,
George Allen & Unwin (Publishers) Ltd, London
Canadian Centre for Fisheries Innovation (1997)
Report of the Workshop on harp seal-fishery interactions in the Northwest Atlantic: Towards research & management actions. 43pp.
Canadian Centre for Fisheries Innovation and Memorial University of Newfoundland. (can be downloaded from the International Marine Mammal Association Web site)
King, J.E. (1983)
Seals of the world, 2nd edition.
British Museum (Natural History), London and Oxford University Press, Oxford, 240pp.
Kovacs, K.M., Lydersen, Chr., Hammill, M.O., White, B.N., Wilson, P.J. and Malik, S. (1997)
A harp seal X hooded seal hybrid.
Mar. Mamm. Sci. 13(3): 460-468
Lavigne, D. (1979)
Harp Seal.
in: Mammals in the Seas, volume II: pinniped species summaries and report on sirenians.
FAO Fisheries Series No. 5, Vol II, pp. 76-80
Lavigne, D.M. (1999)
Estimating total kill of Northwest Atlantic harp seals, 1994-1998
Mar. Mamm. Sci. 15(3): 871-878
Lavigne, D.M., Innes, S., Kalpakis, K., Ronald, K. (1982)
An aerial census of Western Atlantic harp seals (Pagophilus groenlandicus) using ultraviolet photography.
in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters.
FAO Fisheries Series, No. 5, vol. IV, pp. 295-302
Lavigne, D.L. and Kovac, K.M. (1988)
Harps and hoods.
University of Waterloo Press, 174pp.
Popov, L.A. (1982)
Status of the main ice-living seals inhabiting inland waters and coastal marine areas of the USSR.
in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters.
FAO Fisheries Series, No. 5, vol. IV, pp. 361-381
Rice, D.W. (1998)
Marine mammals of the world - Systematics and distribution
Society of Marine Mammalogy Special Publication Number 4, 231 pp.
Ronald, K., Healey, P.J. (1981)
Harp Seal, Phoca groenlandica Erxleben, 1777.
in: Ridgway, S.H. and Harrison, R.J. (eds.): Handbook of Marine Mammals, vol. 2: Seals, pp. 55-87,
Academic Press Inc., Ltd, London
Ronald, K., Healey, P.J., Fisher, H.D. (1982)
The harp seal, Pagophilus groenlandicus.
in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters.
FAO Fisheries Series, No. 5, vol. IV, pp. 267-293

About the pictures

These pictures were taken at the National Aquarium in Baltimore, in November 1997. This seal was on display there, after being rehabilitated. It was not released because it has eye problems.

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Ribbon seal

 Phoca fasciata (Zimmerman, 1783)

Nomenclature

In 1783, Zimmerman described this seal and named it Phoca fasciata. In 1873 Gill put this seal in a separate genus and named it Histriophoca fasciata. Burns and Fay included it again in the genus Phoca in 1970, but according to Rice (1998) this is not admissible. This seal is also called the banded seal.

Appearance

This seal measures on average 155-165 cm (maximum 190 cm (Popov, 1982)) and weighs 70-80 kg (maximum 100 kg (Popov, 1982)). At birth, pups are 80-90 cm long and weigh 9-10 kg. Males are dark chocolate brown with white to yellowish bands around the neck, flippers and hind part. Females have a similar colouration, but less distinct. Pups are born with a white lanugo, which after the moult is replaced by coat with a blue-grey dorsal and siver-grey ventral.

Distribution

This seal lives near the pack ice, in the Sea of Okhotsk and in the Bering Sea.

Feeding

The ribbon seal feeds primarily on bottom invertebrates, fishes like pollack, eelpoutand arctic cod as well as cephalopods.

Population dynamics and life history

Females are mature when they are 2-4 years old and males when they are 3-5 years (Popov (1982) gives 4-5 and 5-6 years respectively). The pregnancy rate is 85%. Gestation lasts 10-11 months. The longevity is anywhere between 22 and 26 years. First year mortality is 44% and the mortality rate for older age classes is on average 11.2%.

Trophic relations

There may be competition with other pinniped species, but there are no data on that. Possible predators include the killer whale and the polar bear.

Interactions

None known.

Population size

Stirling (1979) estimates the Bering Sea population at 100,000 and the Okhotsk Sea population at 140,000. Popov (1982) arrives at estimates of 60,000 for the Bering Sea and 133,000 for the Okhotsk Sea. The population may be declining.

Exploitation

In the Alaska only subsistence hunting occurs. 100-250 animals are taken there per year. In the USSR a permit system is in effect, which allows the harvest of 3,000 ribbon seals in the Bering Sea and of 3,500 seals in the Sea of Okhotsk. In the past this species has been over-exploited.

Threats to the population

The main threat lies in over-exploitation. This species has been over-exploited in the past and may very well still be over-exploited.

References

Burns, J.J. (1981)
Ribbon Seal Phoca fasciata Zimmermann, 1783. in: Ridgway, S.H. and Harrison, R.J. (eds.): Handbook of Marine Mammals, vol. 2: Seals, pp. 89-109, Academic Press Inc., Ltd, London
King, J.E. (1983)
Seals of the world, 2nd edition. British Museum (Natural History), London and Oxford University Press, Oxford, 240pp.
Popov, L.A. (1982)
Status of the main ice-living seals inhabiting inland waters and coastal marine areas of the USSR. in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters. FAO Fisheries Series, No. 5, vol. IV, pp. 361-381
Rice, D.W. (1998)
Marine mammals of the world - Systematics and distribution
Society of Marine Mammalogy Special Publication Number 4, 231 pp.
Stirling, I. (1979)
Ribbon Seal. in: Mammals in the Seas, volume II: pinniped species summaries and report on sirenians. FAO Fisheries Series No. 5, Vol II, pp. 81-82

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Hooded seal

 Cystophora cristata (Erxleben, 1777)

Appearance

The males of this species are 2.5m long and weigh about 300 kg. Females measure 2.2m and weigh about 160 kg. Pups are 100-120 cm long and weigh 10-15, maybe even over 20 kg (Popov, 1982). The hooded seals are grey, with black irregular patches. The males have an inflatable crest, which is an enlargement of the nasal cavity. To inflate it, they close the nostrils. (This is not necessary for the proboscis of elephant seals). Hooded seal pups shed the light grey lanugo before birth. At birth they appear blue-grey on the back and silver-grey on the sides and underneath (Lavigne and Kovacs, 1988).

Distribution

Hooded seals are migratory animals. They can be found throughout the Northern Atlantic. There are a few distinct breeding sites: the West Ice (Jan Mayen region), the Davis Strait at 64°N, the Front (Newfoundland) and the Gulf of St. Lawrence. Moulting takes place on 2 locations: in Denmark Strait (Greenland) and off Greenland at 72-74°N.

Feeding

Adult hooded seals feed on squid, redfish and Greenland halibut. Pups feed mainly on capelin, polar cod and amphipods.

Population dynamics and life history

Female are meture at the age of 3. The onset of maturity in males is unknown. The pregnancy rate is 95%. Gestation lasts 11.7 months, including a delay of implantation of more than 4 months. Lactation lasts about 4 days. The pups grow about 5 kg/day during lactation. Natural mortality is estimated at 7-15% for adults. The maximum longevity is probably about 35 years (Lavigne and Kovacs, 1988).

Trophic relations

Although they live in the same area as the harp seal, Phoca groenlandica, there is probably no competition between harp seals and hooded seals, because they forage in different areas and on different species. There appear to be some interactions, though. Kovacs et al (1997) reported the birth of a harp X hooded seal hybrid in the Gulf of St. Lawrence. Predators of the hooded seal are sharks and polar bears.

Interactions

No interactions with fisheries have been recorded.

Population size

For some areas photo surveys have been carried out. In the Davis Strait 42,000 animals were counted.In the Front area, 77,000 females were counted and from that a pup production of 38,000 was estimated. On the West Ice 225,000 seals were counted. On the molting site in Denmark Strait 230,000 seals were counted. Popov (1982) estimates the total hooded seal population at 500,000-600,000.

Exploitation

There is a quota system for the harvest of this species. 30% of the total kill consists of adult seals, of which 60-70% are females. The 1974-1982 yearly harvest rates were: 30,000 for Jan Mayen and 15,000 for Newfoundland. For 1984-1988 a yearly quota of 2,340 was set for Newfoundland. Actual catches were lower.

Threats to the population

There is a serious risk of over-exploitation, especially on Jan Mayen. Especially the rather large portion of adult females in the total harvest poses a serious threat to the population.

References

King, J.E. (1983)
Seals of the world, 2nd edition. British Museum (Natural History), London and Oxford University Press, Oxford, 240pp.
Kovacs, K.M., Lydersen, Chr., Hammill, M.O., White, B.N., Wilson, P.J. and Malik, S. (1997)
A harp seal X hooded seal hybrid. Mar. Mamm. Sci. 13(3): 460-468
Lavigne, D.L. and Kovac, K.M. (1988)
Harps and hoods.University of Waterloo Press, 174pp.
Popov, L.A. (1982)
Status of the main ice-living seals inhabiting inland waters and coastal marine areas of the USSR. in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters. FAO Fisheries Series, No. 5, vol. IV, pp. 361-381
Reeves, R.R., Ling, J.K. (1981)
Hooded Seal Cystophora cristata, Erxleben, 1777. in: Ridgway, S.H. and Harrison, R.J. (eds.): Handbook of Marine Mammals, vol. 2: Seals, pp. 171-194, Academic Press Inc., Ltd, London
Sergeant, D.E. (1979)
Hooded Seal. in: Mammals in the Seas, volume II: pinniped species summaries and report on sirenians. FAO Fisheries Series No. 5, Vol II, pp. 86-89

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Bearded seal

 Erignathus barbatus (Erxleben, 1777)

Nomenclature

There are 2 subspecies commonly recognized, each with its own geographical range: E.b. barbatus (Erxleben, 1777) and E.b. nauticus (Pallas, 1811).

Appearance

The bearded seal is 225-270cm long and weighs 275-340 kg. Pups are 87-120 cm long and weigh 25-43 kg. Bearded seals are grey, with occasionally a brown face and neck. They have moustachial whiskers, which curl in tight spirals. Their flippers are rather square. Pups are dark with white patches on the back and on the flippers. Bearded seals have 4 mammary glands.

Distribution

The bearded seal lives circumpolar with a northern limit at 80-85°N. They do not migrate. E.b. barbatus is found from the Laptev sea westwards to the Hudson bay. It can be found as far south as the Gulf of St. Lawrence. E.b. nauticus ranges from the Laptev Sea eastwards to the Barents sea and the Canadian Arctic, upto Baffin Island. It can be found as far south as the Sea of Okhotsk or even Hokkaido.

Feeding

The bearded seal feeds mainly only bottom invertebrates, such as crustaceans, mollusks, whelks and polychaets, but also takes sculpin, flounder and polar cod.

Population dynamics and life history

Females reach maturity at ages 5-6; males at 6-7 years. The pregnancy rate in Alaska is 85% and in the USSR 75% (Popov, 1982). Gestation lasts 10-11 months including a delay of implantation of 2-3 months. Lactation lasts 12-18 days. Mortality rates are unknown. Only for the Okhotsk Sea the first year mortality is known: 22% (Popov, 1982)

Trophic relations

There is no known competition. The main predator is the polar bear. Occasionally killer whales will take bearded seals.

Interactions

There is no interaction with fisheries. There is a potential for disturbance from oil explorations.

Population size

Complete data on abundance are not available. The Northern Pacific population (Laptev Sea, Chukchi Sea, Bering Sea, Okhotsk Sea and Japan) has been estimated to consist of 300,000 to 450,000 animals. Popov (1982) gives an estimate for the Okhotsk Sea of 180,000-200,000 and for the Bering Sea of 250,000, which would mean that the Pacific population is over 450,000 animals. There are no estimates for the Atlantic population.

Exploitation

There have been quota set for the Okhotsk Sea (5,000) and the Bering Sea (3,000). These quota are for land-based hunters. Ship-based sealing is prohibited. The annual kill in Norway is 2,000-3,000 seals. There are no records for Canadian sealing. There is a considerable loss during the hunt, because bearded seals sink when dead. In Alaska natives can hunt bearded seals without permits. They may take as much as 6,000 seals. There is no harvest allowed in the Barents Sea and the White Sea.

Threats to the population

There is a potential for over-exploitation in certain areas.

References

Burns, J.J. (1981)
Bearded Seal Erignathus barbatus, Erxleben, 1777. in: Ridgway, S.H. and Harrison, R.J. (eds.): Handbook of Marine Mammals, vol. 2: Seals, pp. 145-170, Academic Press Inc., Ltd, London
King, J.E. (1983)
Seals of the world, 2nd edition. British Museum (Natural History), London and Oxford University Press, Oxford, 240pp.
Popov, L.A. (1982)
Status of the main ice-living seals inhabiting inland waters and coastal marine areas of the USSR. in: Mammals in the Seas, Volume IV: small cetaceans, seals, sirenians and otters. FAO Fisheries Series, No. 5, vol. IV, pp. 361-381
Stirling, I., Archibald, R. (1979)
Bearded Seal. in: Mammals in the Seas, volume II: pinniped species summaries and report on sirenians. FAO Fisheries Series No. 5, Vol II, pp. 83-85

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