|Scientific Name:||Pagophilus groenlandicus|
|Species Authority:||(Erxleben, 1777)|
Phoca groenlandica Erxleben, 1777
Phoca groenlandica Erxleben, 1777
|Taxonomic Notes:||Pagophilus groenlandicus has shifted genera frequently in the last two decades. Most recently it was commonly referred to as Phoca groenlandica. Rice (1998) recognizes two subspecies, groenlandicus and oceanicus. The former breeds in the western North Atlantic off North America and off Jan Mayen in the Greenland Sea, and the latter breeds in the White Sea. Lavigne (2002) refers to three distinct populations centred on the breeding localities, based on morphological, genetic and behavioural differences. Heptner et al. (1996) provides evidence for two distinct groups, but includes the Jan Mayen breeding group in the White Sea subspecies based on no discernable morphological or protein polymorphism differences. Analysis of DNA sequence variation and also comparisons of fingerprint band-sharing coefficients, revealed that the breeding groups in the Northwest Atlantic (Gulf of St Lawrence and the Front off Labrador and Newfoundland) were one group and the animals that breed in the White Sea and those in the Greenland Sea off Jan Mayen were another group (Meisfjord and Sundt 1996, Perry et al. 2000). Given the lack of genetic differentiation between the two "recognized" subspecies, they are not differentiated below.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Kovacs, K. (IUCN SSC Pinniped Specialist Group)|
|Reviewer(s):||Kovacs, K. & Lowry, L. (Pinniped Red List Authority)|
Due to its large population size, and increasing trends, the Harp Seal should continue to be classified as Least Concern. However, climate change poses a serious threat to this species and Harp Seals should be reassessed within a decade.
IUCN Evaluation of the Harp Seal, Pagophilus gronlandicus
Prepared by the Pinniped Specialist Group
A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1 CR > 90%; EN > 70%; VU > 50%
Al. Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality
(d) actual or potential levels of exploitation
(e) effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
Harp Seal females attain sexual maturity at 4-6 years of age and have a maximum longevity of 30-35 years. Thus, the average age of reproducing individuals should be at least 10 years.
A2, A3 & A4 CR > 80%; EN > 50%; VU > 30%
A2. Population reduction observed, estimated, inferred, or suspected in the past where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
All known stocks of Harp Seals are increasing in number.
A3. Population reduction projected or suspected to be met in the future (up to a maximum of 100 years) based on (b) to (e) under A1.
Climate change impacts are almost certainly going to be negative for Harp Seals in the future.
A4. An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
Rates of population reductions over the next 100 years are difficult to predict. Impacts of climate change will depend on the relative rates of ice declines across the range of Harp Seals and the degree to which they are flexible about shifting breeding locations – which is currently unknown.
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1. Extent of occurrence (EOO): CR < 100 km²; EN < 5,000 km²; VU < 20,000 km²
The EOO of Harp Seals is > 20,000 km².
B2. Area of occupancy (AOO): CR < 10 km²; EN < 500 km²; VU < 2,000 km²
The AOO of Harp Seals is > 2,000 km².
AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN < 5; VU < 10
(b) Continuing decline in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals.
(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals.
C. Small population size and decline
Number of mature individuals: CR < 250; EN < 2,500; VU < 10,000
The current abundance of Harp Seals is approximately 8 million, with pup production of approximately 1.4 million.
AND either C1 or C2:
C1. An estimated continuing decline of at least: CR = 25% in 3 years or 1 generation; EN = 20% in 5 years or 2 generations; VU = 10% in 10 years or 3 generations (up to a max. of 100 years in future)
C2. A continuing decline AND (a) and/or (b):
(a i) Number of mature individuals in each subpopulation: CR < 50; EN < 250; VU < 1,000
(a ii) % individuals in one subpopulation: CR = 90–100%; EN = 95–100%; VU = 100%
(b) Extreme fluctuations in the number of mature individuals.
D. Very small or restricted population
Number of mature individuals: CR < 50; EN < 250; VU < 1,000 AND/OR restricted area of occupancy typically: AOO < 20 km² or number of locations < 5
The total population of Harp Seals is approximately 8 million.
E. Quantitative analysis
Indicating the probability of extinction in the wild to be: Indicating the probability of extinction in the wild to be: CR > 50% in 10 years or 3 generations (100 years max.); EN > 20% in 20 years or 5 generations (100 years max.); VU > 10% in 100 years
Harp Seals are almost certainly going to be negatively impacted by climate change. But, they are currently abundant and increasing.
Listing recommendation — Because of their current high population size and increasing trends, the Harp Seal should be listed as Least Concern. However, they should be assessed again within the next decade, because of the risk of climate change induced habitat degradation.
|Range Description:||Harp seals are widespread in the North Atlantic and the adjacent Arctic Ocean and shelf seas. Their range extends from northern Hudson Bay and the Foxe Basin, Baffin Island, and the Davis Strait, Gulf of St Lawrence and Newfoundland in the western North Atlantic, east to somewhat south of Greenland, continuing east to Iceland and from there to Northern Norway, the White Sea and the Barents and Kara Seas. The northern limit in the eastern North Atlantic is at least to Franz Joseph Land and Svalbard and may continue to between 82-85 degrees north depending on ice conditions (Lavigne and Kovacs 1988, Rice 1998, Lavigne 2002).
The southern limit of the distribution off North America shifts southeast in some years, such as occurred in the early 1990s (Lacoste and Stenson 2000), leading to increased occurrences of harp seals south of their usual limits, reaching the Gulf of Maine and Sable Island where large numbers have been record since the mid-1990s (Harris et al. 2002, Lucas and Daoust 2002). Harp seals often occur as vagrants outside this range, south to Virginia in the United States (Scheffer 1958, Rice 1998). Similarly in Europe, harp seals reach the United Kingdom (Ronald and Healy 1981), the Faroe Islands, Denmark, Germany, France, and even Spain (Bree 1997, Bloch et al. 2000).
Prehistorically, harps seals bred in the Baltic Sea. Genetic drift, interspecific completion and over-hunting by humans are all factors likely to have contributed to their extinction in this region (Stora and Ericson 2004).
Native:Canada; Greenland; Iceland; Norway; Russian Federation; Svalbard and Jan Mayen; United States
Vagrant:Denmark; Faroe Islands; Finland; France; Germany; Spain; United Kingdom
|FAO Marine Fishing Areas:||
Arctic Sea; Atlantic – eastern central; Atlantic – northeast; Atlantic – northwest; Atlantic – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The harp seal is the most abundant pinniped species in the Northern Hemisphere. Globally this species numbers close to 8 million animals. Pup production at all breeding sites combined is at least 1.4 million pups per year currently (Stenson et al. 2003, Potelov et al. 2003, Haug et al. 2006). The Northwest Atlantic stock of harp seal is estimated to number 5.9 million animals (DFO 2005). This latest estimate for Canadian waters is significantly higher than the previous estimate produced in 2000, when the Gulf and Front herds combined were estimated to number 5.5 million. This is a marked recovery from an estimated low of around 1.8 million in the early 1970s (Sergeant 1976). Catch levels have been increased repeatedly for this population during the last decade and likely now exceed potential biological removal levels by 1.5 – 5.9 times. Given this level of removal the population is likely to now be in decline (Johnston et al. 2000). The breeding group in the West Ice near Jan Mayen was estimated at 296,000 in 1994; this population increased to approximately 348 000 by 2003. The White Sea breeding group was estimated to be 1.8 million animals when last surveyed in 2000 (Potelov et al. 2003).|
|Habitat and Ecology:||
Harp seals are medium-sized, monomorphic phocids. Adult males and females are approximately 1.8 m long and weight about 130 kg. Age at sexual maturity has varied quite dramatically over the last century, in part as a consequence of population size which has been largely determined by harvest levels and food availability. Females reach sexual maturity between 4-8 years of age (Frie et al. 2003). Males probably do not participate in breeding before they are somewhat older, though they reach sexual maturity around the same time as females.
Birthing takes place in vast herds, which are quite highly synchronized. Birthing occurs from late February to April, with some variation across the range in the precise timing (Lavigne and Kovacs 1988). Pups are born on the open free-floating pack ice and nursed for 12 days, during which time they gain weight at about 2.2. kg per day (Kovacs and Lavigne 1985, Kovacs 1987, Kovacs et al. 1991, Lydersen and Kovacs 1996). To minimize energy expenditure, most pups are sedentary for the first month; some so immobile that they melt into the ice beneath them, forming ice “cradles” (Kovacs 1987). Pups are referred to as “whitecoats” because they are born with an insulating coat of white lanugo. Lactating females spend up to 85% of their time in the water, depending on the weather (Lydersen and Kovacs 1993). Towards the end of lactation, females come into estrus and mate (Lavigne and Kovacs 1988). Weaned pups remain on the ice for up to 6 weeks, losing up to 50% of their weight before entering the water to feed. During this post-weaning fast they complete moulting of the lanugo. After this coat is shed the black and silver-gray pelage is exposed and the juveniles are known as “beaters” until they are about a year old.
Gestation lasts about 11.5 months, including a 3-4 month period of delayed implantation (Stewart et al. 1989). The maximum life span of a harp seal is approximately 30 years; most animals that reach sexual maturity live to over 20 years. Both males and females are sexually active until the ends of their lives, showing no reproductive senescence (Ronald and Healey 1981).
Harp seals (1+ years of age) undergo a moult in the post-breeding months, from early April to early May (Lavigne and Kovacs 1988). Harp seals are highly migratory and after breeding, Canadian seals follow the pack ice up the coast of Labrador, with small numbers going into Hudson Bay, around Baffin Island, and the rest travelling up both sides of the Davis Strait. The Jan Mayen and White Sea groups migrate northward and mix in the Barents Sea (ref). The Jan Mayen group reaches the High Arctic, up to 85ºN. The Canadian seals have a round-trip migration that is over 5,000 km long (Lavigne and Kovacs 1988). The Northwest Atlantic group begins the return trip to their breeding grounds in late autumn.
Harp seals consume a wide range of prey that varies along the migration route. Throughout their range, the harp seal diet includes 67 species of fish and 70 species of invertebrates (Lavigne 2002). The pups and juveniles take a lot of invertebrate prey, especially euphausiids (Thyanoessa spp.) and amphipods (Parathemisto spp.) (Haug et al. 2000, Nilssen et al. 2001). Adults in Greenland eat pelagic crustaceans, and fish such as capelin (Mallotus villosus), sandeel (Ammodytes sp.), polar cod (Boreogadus saida) and Arctic cod (Arctogadus glacialis). Commercial species such as Atlantic cod (Gaddus morhua) appear to be of minor importance in the diet (Kapel 2000). In the Barents Sea, harp seals eat amphipods, prawns, and small fish including polar cod, sculpin (Cottidae), snail fish (Liparidae), capelin (Nilssen 1995); but show a clear preference for large polar cod (Wathne et al. 2000). The seals off Newfoundland eat capelin and Arctic cod, and off Labrador they eat Arctic cod and Atlantic herring (Clupea herringus). In the Gulf of St. Lawrence, the seals have been known to consume capelin, herring, Atlantic cod, Arctic cod and redfish (Sebastes) (Lawson et al. 1995). Harp seals feed heavily in winter and summer and less in spring and autumn. They are a highly social species that travels and forages in groups, yet maintain a stratification of diet according to age class and depth of the feeding dives.
Harp seals are relatively shallow divers. Jan Mayen animals stay close to the edge of the pack ice during the spring moult, usually dive to less than 100 m, but by July, satellite-tagged seals in the Barents Sea dove to 400 m. Overall, the deepest dives occur during the day in winter (Folkow et al. 2004).
Harp seals have been harvested for thousands of years by native peoples of the Atlantic Arctic, including coastal Northern Europeans (Lavigne and Kovacs 1988). Basque whalers began taking harp seals in the 1500s. By the mid-1600s, French settlers developed land-based netting techniques on the St. Lawrence River in the 1700s. French-Canadians exported 500 tons of oil per year by the mid-1700s, based on an estimated take of 6,000 seals per year. In Newfoundland, English settlers hunted harp seals on a larger scale that accounted for an estimated average take of 7,000-12,800 seals per year for most of the 1700s. By the 1800s, schooner-based sealing developed and the number of seals harvested rose dramatically; from 1803-1816 the average annual take was 117,000. The peak of sealing in the Northwest Atlantic occurred between 1818 and 1862, when 500,000 seals were harvested in many years, with maxima between 640 000-740 000 in individual years. During that time, it is estimated that 18.3 million harp seals, mostly whitecoats, were killed for oil. The records show somewhat lower figures for the Northeast Atlantic. At Jan Mayen, the catch began falling in the late 1850s; the drop in catch is likely attributable to over-harvesting. From 1860 to 1900, an estimated 12.8 million seals were harvested from the West Ice.
During the 20th century harp seals became more valued for their pelts than their oil. In 1917 143,000 seals were taken. The catch dropped for a time, then escalated in the 1950s, when it averaged 312,000 seals per year. In 1960, Canada became concerned about the large numbers of adults being killed, so it placed limits on the length of the hunting season. During the 1960s, an average of 284,000 seals were taken per year in the Northwest Atlantic stock. In the mid 1960s adult females became protected on the breeding grounds, and Norway was excluded from sealing in Canadian waters. In 1971 a quota management program was established; from 1970 to 1987 quotas varied from 127,000 per year to 245,000 per year, but the actual harvest was often much lower than the quota (Lavigne and Kovacs 1988).
In 1983, the European Economic Community imposed an import ban on all whitecoat products and the average annual harvest in Canadian waters fell to 52,000 seals from 1983-1995. By 1987, Canada banned the killing of whitecoats and the focus of the hunt switched to beaters (post-weaning to 13 months of age) (DFO 2006a). From 1999-2003, the estimated annual mortality of harp seals in the Northwest Atlantic was 453,962, broken down into an average of 232,915 taken in the commercial harvest by Canada, 83,000 taken from 1999-2002 in Greenland and approximately 5,000 taken in the Canadian High Arctic, plus a by-catch of close to 20,000 in the Newfoundland lumpfish fishery, with an average annual struck and loss rate of 119,430 from all harvests (Waring et al. 2005).
The Canadian harvest has recently increased with the combined three-year 2003-2005 quota (“Total Allowable Catch”) set at 975,000 (DFO 2005a). Given the age structure of the current hunt, this quota is not sustainable (see Johnston et al. 2000). In addition to Canada’s commercial harvest, some harp seals are still taken in subsistence hunts in Labrador, Newfoundland, northern Quebec and in Nunavut. Aboriginal peoples and non-Aboriginal coastal residents who reside north of latitude 53 degrees can hunt seals for subsistence purposes without a permit (DFO 2006b).
In the Northeast Atlantic, Norway established a commercial hunt in 1846, which peaked in the 1870s-1880s when annual catches ranged between 50,000-120,000 animals. In the 20th century, annual harvests increased to an average above 100,000 per year, with the maximum in the 1920s and 1930s, when the catches were 200,000-300,000 seals per year. In 1989, Norway banned the killing of whitecoats (N-RFC 2006). For 2005, the harvest of the West Ice stock was approximately 20,000. In the White Sea, Russia hunters took 14,277 harp seals in 2005 (DFO 2005). The numbers of harp seals struck-and-lost in the both the current commercial hunts (which is focused largely on 1+ animals) and in subsistent hunting is high, and most harvest estimates do not account for this additional mortality (Lavigne 1999). The struck and loss rate for harp seals in Greenland could be as high as 50% (Sjare and Stenson 2002).
Another threat to harp seals is over-harvesting of their prey, including capelin and herring. Several harp seal “invasions” have taken place in recent decades along the north coast of Norway. By-catch mortality in nets during these events was estimated to be as high as 100,000 animals in 1987 and 21,474 in 1988 (Haug et al. 1991). These reasons for these emigrations out of their normal range within the Barents and Greenland Seas seems to have been a collapse of the herring and capelin stocks due to a combination of over-fishing and shifting oceanographic conditions (low temperatures and salinity, and extensive ice cover) (Haug et al. 1991, Woodley and Lavigne 1991).
A small tourist industry that visits the whelping patches in the Gulf of St Lawrence is not thought to pose any risk to the seals under its current rotational mode of operation (Kovacs and Innes 1990).
Global climate warming is currently already causing major reductions in the extent and seasonal duration of sea ice cover in the Northern Hemisphere, creating a threat to many species of ice-associated marine mammals (Tynan and DeMaster 1997, Learmonth et al. 2006, Kovacs and Lydersen 2008, Laidre et al. 2008). Pinnipeds, such as the harp seal that are dependant on sea ice for pupping, moulting and resting are likely to be heavily impacted by such changes in the future (Johnston et al. 2005, Friedlaender et al. 2007).
Oil spills in the Northwest Atlantic off the east coast of Canada remain a threat to seals. There is a concern about the impacts of tanker traffic, particularly in places like Lancaster Sound in the eastern Canadian Arctic, which is an important harp seal summering area (Reijinders et al. 1993). The discharge from a ruptured tank on the shore of New Brunswick, Canada in March–April 1969 led to 10,000 to 15,000 seals being heavily coated with oil. The high number of dead seal pups washing ashore after this event was evidence of the lethal effects of the oil (St Aubin, 1990). Oil development in the Barents Sea is on-going and poses a future threat to harp seals in the White Sea and West Ice stocks.
Harp seals have been found to carry significant loads of contaminants including metals, DDT and PCBs (Ronald et al. 1984a,b). Organochlorines are still present in their blood, despite DDT levels (and PCBs to a lesser extent) declining from the early 1970s to the 1980s (Addison et al. 1984) and further in the 1990s.
Phocine distemper virus (PDV) was first found in harp seals from the West Ice off Jan Mayen in 1987 and 1989. It is widespread in harp seals, but only shows up in terms of antibodies; it is not known if there are significant health effects or mortality from PDV infection in this species (Daoust et al. 1993, Duignan et al. 1997). Harp seals might have been the carriers responsible for the harbour seals PDV epidemic in Europe in 1988 (Markussen and Have 1992). PDV also appeared in the Gulf of St Lawrence in 1991, but not in epidemic proportions (Daoust et al. 1993).
Natural predators of harp seals include polar bears, killer whales, and Greenland shark (Lavigne and Kovacs 1988). In Svalbard, 13% of polar bears prey is comprised of harp seals (Derocher et al. 2002).
|Conservation Actions:||Canada has in place sealing regulations pursuant to the 1993 Marine Mammal Regulations that require annual quotas, referred to as “Total Allowable Catches,” hunting licenses, and official observers of the commercial hunt (DFO 2005). In the northeast Atlantic, quotas for sealing are based on recommendations made by the International Council for Exploration of the Sea (ICES) and the Northwest Atlantic Fisheries Organisation (NAFO). Russia is responsible for managing seals in the southeast part of the Barents Sea, while Norway is responsible for managing stocks in the Greenland Sea by Jan Mayen (NMFCA 2006, N-RFC 2006).|
Addison, R. F., Brodie, P. F. and Zinck, M. E. 1984. DDT has declined more than PCBs in eastern canadian seals during the 1970s. Environmental Science and Technology 18: 935-937.
Bloch, D., Mikkelsen, B. and Ofstad, L. H. 2000. Marine mammals in Faroese waters with special attention to the south-south-eastern sector of the region. Available at: www.foib.fo/foibportal/desktopdefault.aspx?tabid=113.
Daoust, P. Y., Haines, D. M., Thorsen, J., Duignan, P. J. and Geraci, J. R. 1993. Phocine distemper in a harp seal (Phoca groenlandica) from the Gulf of St. Lawrence, Canada. Journal of Wildlife Diseases 29: 1114-117.
Department of Fisheries and Oceans Canada. 2005. Atlantic Seal Hunt 2003 Management Plan. Available at: http://www.dfo-mpo.gc.ca/seal-phoque/reports-rapports/mgtplan-plangest2003/mgtplan-plangest2003_e.htm..
Department of Fisheries and Oceans Canada. 2006. Frequently Asked Questions About Canada's Seal Hunt. Available at: http://www.dfo-mpo.gc.ca/seal-phoque/faq_e.htm..
Department of Fisheries and Oceans Canada. 2006. The Canadian Seal Hunt - A Timeline. Available at: http://www.dfo-mpo.gc.ca/seal-phoque/reports-rapports/facts-faits/facts-faits_tl_e.htm..
Derocher, A. E., Andersen, M. and Wiig, Ø. 2002. Diet composition of polar bears in Svalbard and the western Barents Sea. Polar Biology 25: 448-452.
Duignan, P. J., Nielsen, O., House, C., Kovacs, K. M., Duffy, N., Early, G., Sadove, S., St. Aubin, D. J., Rima, B. K. and Geraci, J. R. 1997. Epizootiology of morbillivirus infection in harp, hooded, and ringed seals from the Canadian Arctic and western Atlantic. Journal of Wildlife Diseases 33: 7-19.
Folkow, L. P., Nordoy, E. S. and Blix, A. S. 2004. Distribution and diving behaviour of harp seals (Pagophilus groenlandicus) from the Greenland Sea stock. Polar Biology 27: 281-298.
Friedlaender, A. S., Johnston, D. W., Fink, S. L. and Lavigne, D. M. 2007. Variation in ice cover on the east coast of Canada, February-March, 1969-2006: implications for harp and hooded seals. IFAW Technical Report 2007-1.
Harris, D. E., Lelli, B. and Jakush, G. 2002. Harp seal records from the southern Gulf of Maine: 1997-2001. Northeastern Naturalist 9: 331-340.
Haug, T., Kroyer, 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 48: 363-371.
Haug, T., Nilssen, K. T. and Lindblom, L. 2000. First independent feeding of harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups in the Greenland Sea. In: G. A. Vikingsson and F. O. Kapel. (eds), Minke whales, harp and hooded seals: major predators in the North Atlantic ecosystem, pp. 40-49. NAMMCO Scientific Publication.
Haug, T., Stenson,G. B., Cockeron, P. J. and Nilssen, K. T. 2006. Estimation of harp seal (Pagophilus groenaldicus) pup production in the North Atlantic completed; results from surveys in the Greenland Sea in 2002. ICES Journal of Marine Science 63: 95-104.
Heptner, V. G., Chapskii, K. K., Arsen’ev, V. A. and Sokolov, V. E. 1996. Mammals of the Soviet Union. Smithsonian Institution Libraries and National Science Foundation.
Johnston, D. W., Friedlaender, A. S., Torres, L. G. and Lavigne, D. M. 2005. Variation in sea ice cover on the east coast of Canada from1969 to 2002: climate variability and implications for harp and hooded seals. Climate Research 29: 209-222.
Johnston, D. W., Meisenheimer, P. and Lavigne, D. M. 2000. An evaluation of management objectives for Canada’s commercial harp seal hunt, 1996-1998. Conservation Biology 14: 729-737.
Kapel, F. O. 2000. Feeding habits of harp and hooded seals in Greenland waters. NAMMCO Scientific Publications 2: 50-64.
Kovacs, K. M. 1987. Maternal behaviour and early behavioral ontogeny of harp seals, Phoca groenlandica. Animal Behaviour 35: 844-855.
Kovacs, K. M. and Innes, S. I. 1990. The impact of tourism on harp seals (Phoca groenlandica) in the Gulf of St. Lawrence, Canada. Applied Animal Behaviour Science 26: 15-26.
Kovacs, K. M. and Lavigne, D. M. 1985. Neonatal growth and organ allometry of Northwest Atlantic harp seals (Phoca groenlandica). Canadian Journal of Zoology 63: 2793-2799.
Kovacs, K. M. and Lydersen, C. 2008. Climate change impacts on seals and whales in the North Atlantic Arctic and adjacent shelf seas. Science Progress 91(2): 117-150.
Kovacs, K. M., Lavigne, D. M. and Innes, S. I. 1991. Mass transfer efficiency between harp seal Phoca groenlandica mothers and their pups during lactation. Journal of Zoology (London) 223: 213-221.
Lacoste, K. N. and Stenson, G. B. 2000. Winter distribution of harp seals (Phoca groenlandica) off eastern Newfoundland and southern Labrador. Polar Biolgy 23: 805-811.
Laidre, K.L., Stirling, I., Lowry, L.F., Wiig, Ø., Heide-Jørgensen, M.P. and Ferguson, S.H. 2008. Quantifying the sensitivity of Arctic marine mammals to climate-induced habitat change. Ecological Applications 18: S97-S125.
Lavigne, D. M. 1999. Estimating total kill of northwest Atlantic harp seals, 1994-1998. Marine Mammal Science 15: 871-879.
Lavigne, D. M. 2002. Harp seal Pagophilus groenlandicus. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 560-562. Academic Press, San Diego, California, USA.
Lavigne, D. M. and Kovacs, K. M. 1988. Harps and hoods: ice-breeding seals of the northwest Atlantic. University of Waterloo Press, Ontario, Canada.
Lawson, J. W., Stenson, G. B. and McKinnon, D. G. 1995. Diet of harp seals (Phoca groenlandica) in nearshore waters of the northwest Atlantic during 1990-1993. Canadian Journal of Zoology 73: 1805-1818.
Learmonth, J. A., Macleod, C. D., Santos, M. B., Pierce, G. J., Crick, H. Q. P. and Robinson, R. A. 2006. Potential effects of climate change on marine mammals. Oceanography and Marine Biology: An Annual Review 44: 431-464.
Lucas, Z. and Daoust, P.-Y. 2002. Large increases of harp seals (Phoca groenlandica) and hooded seals (Cystophora cristata) on Sable Island, Nova Scotia, since 1995. Polar Biology 25: 562-568.
Lydersen, C. and Kovacs, K. M. 1993. Diving behaviour of lactating harp seal, Phoca groenlandica, females from the Gulf of St Lawrence, Canada. Animal Behavior 46: 1213-1221.
Lydersen, C. and Kovacs, K. M. 1996. Energetics of lactation in harp seals (Phoca groenlandica) from the Gulf of Saint Lawrence. Journal of Comparative Physiology 166: 295-304.
Meisfjord, J. and Sundt, R. C. 1996. Genetic variation between populations of the harp seal, Phoca groenlandica. Journal of Marine Science 53: 89-95.
Nilssen, K. T., Haug, T. and Lindblom, C. 2001. Diet of weaned pups and seasonal variations in body condition of juvenile Barents Sea harp seals Phoca groenlandica. Marine Mammal Science 17(4): 926-936.
Norwegian Ministry of Fisheries and Coastal Affairs. 2006. Sealing in the southeast part of the Barents Sea and in the Greenland Sea by Jan Mayen. Available at: http://www.fisheries.no/marine_stocks/mammals/seals/Marine_stocks_mammals_seals.htm.
N-RFC. 2005. Report of the working group on seals. The 34th Session of the Joint Norwegian – Russian Fisheries Commission. Kaliningrad, Russia.
Perry, E. A., Stenson, G. B., Bartlett, S. E., Davidson, W. S. and Carr, S. M. 2000. DNA sequence analysis identifies genetically distinguishable populations of harp seals (Phoca groenlandicus) in the northwest and northeast Atlantic. Marine Biology 137: 53-58.
Potelov, V. A., Golikov, A. P. and Bondarev, V. A. 2003. Estimated pup production of harp seals Pagophilus groenlandicus in the White Sea, Russia in 2000. ICES Journal of Marine Science 60: 1012-1017.
Reijnders, P., Brasseur, S., van der Toorn, J., van der Wolf, P., Boyd, I., Harwood, J., Lavigne, D. and Lowry, L. 1993. Seals, fur seals, sea lions, and walrus. Status survey and conservation action plan. IUCN Seal Specialist Group.
Rice, D.W. 1998. Marine Mammals of the World. Systematics and Distribution. Society for Marine Mammalogy, Lawrence, Kansas.
Ronald, K. and Healy, P. J. 1981. Harp seal Phoca groenlandica Erxleben, 1777. In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Volume 2: Seals, pp. 55-87. Academic Press.
Ronald, K., Frank, R. J., Dougan, J. L., Frank, R. and Braun, H. E. 1984. Pollutants in harp seals (Phoca groenlandica). II. Heavy metals and selenium. Science of the Total Environment 38: 153-166.
Ronald, K., Frank, R. J., Dougan, J. L., Frank, R. and Braun, H. E. 1984. Pollutants in harp seals (Phoca groenlandica). I. Organochlorines. Science of the Total Environment 38: 133-152.
Scheffer, V.B. 1958. Seals, sea lions and walruses: A review of the Pinnipedia. Stanford University Press, Stanford, USA.
Sergeant, D. E. 1976. History and present status of populations of harp and hooded seals. Biological Conservation 10: 95-118.
Sjare, B. and Stenson, G. B. 2002. Estimating struck and lost rates for harp seals (Pagophilus groenlandicus) in the Northwest Atlantic. Marine Mammal Science 18(3): 710-720.
St. Aubin, D. J. 1990. Physiologic and toxic effects on pinnipeds. In: J. R. Geraci and D. J. St. Aubin (eds), Sea mammals and oil: confronting the risks, pp. 103-127. Academic Press, New York, USA.
Stenson, G. B., Rivest, L. P., Hammill, M. O., Gosselin, J. F. and Sjare, B. 2003. Estimating pup production of harp seals, Pagophilus groenlandicus, in the Northwest Atlantic. Marine Mammal Science 19(1): 141-160.
Stewart, R. E. A., Stewart, B. E., Lavigne, D. M. and Miller, G. W. 1989. Fetal growth of Northwest Atlantic harp seals, Phoca groenlandica. Canadian Journal of Zoology 67: 2147-2157.
Stora, J. and Ericson, P. G. 2004. A prehistoric breeding population of harp seals (Phoca groenlandica) in the Baltic Sea. Marin Mammal Science 20: 115-133.
Tynan, C. T. and DeMaster, D. P. 1997. Observations and predictions of Arctic climate change potential effects of marine mammals. Arctic 50: 308-322.
Van Bree, P. J. H. 1997. On extralimital records of Arctic seals (Mammalia, Pinnipedia) on the west European continental coast in the past and at present - a summary. Beaufortia 47: 153-156.
Waring, G. T., Josephson, E., Fairfield, C. P. and Maze-Foley, K. 2005. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments – 2005. NOAA Technical Memorandum. NOAA.
Wathne, J. A., Haug, T. and Lydersen, C. 2000. Prey preference and niche overlap of ringed seals Phoca hispida and harp seals P. groenlandica. Marine Ecology Progress Series 94: 233-239.
Woodley, T. H. and Lavigne, D. M. 1991. Incidental capture of pinnipeds in commercial fishing gear. International Marine Mammal Association Technical Report 91-01: 35 pp.
|Citation:||Kovacs, K. (IUCN SSC Pinniped Specialist Group) 2008. Pagophilus groenlandicus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 23 May 2015.|