|Scientific Name:||Pusa hispida (Schreber, 1775)|
|Infra-specific Taxa Assessed:|
Phoca hispida Schreber, 1775
|Taxonomic Notes:||The Ringed Seal has been moved back and forth between the genus name Pusa and Phoca in recent decades, largely a result of difficulty in reconciling the molecular and morphological relationships of the Grey Seal, Halichoerus grypus, to those two genera (Rice 1998). The very limited genetic differences between these taxa (Fulton and Strobeck 2010) argue for inclusion of all of them in a single genus, Phoca, (Nyakatura and Bininda-Emonds 2012) but widespread reluctance to rename the Grey Seal has led to common, though not universal, use of Pusa as a full genus despite the typical placement of Halichoerus in its midst on recent molecular phylogenetic trees (e.g., Committee on Taxonomy 2014). In contrast to the nomenclature for the genus, use of the species name hispida for the Ringed Seals inhabiting the Arctic Ocean and adjoining seas has been broadly accepted (Rice 1998).
There are currently five recognized subspecies of Ringed Seal (Rice 1998, Committee on Taxonomy 2014), the Arctic Ringed Seal (P. h. hispida), the Okhotsk Ringed Seal (P. h. ochotensis), the Baltic Ringed Seal (P. h. botnica), the Ladoga Seal (P. h. ladogensis), and the Saimaa Seal (P. h. saimensis). Each of the subspecies has been individually assessed by the IUCN Pinniped Specialist Group. This assessments combines those results to determine the status of Ringed Seals at the species level.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Contributor(s):||Kovacs, K.M. & Härkönen , T.|
|Facilitator/Compiler(s):||Ahonen, H., Pollock, C.M., Battistoni, A. & Chiozza, F.|
As a species, Ringed Seals are widely distributed in ice-covered waters of the northern hemisphere, and they may presently number about three million animals. Some of the subspecies, however, have restricted distributions and exist in much smaller numbers. With climatic warming, all subspecies will be negatively impacted by continuing decreases of ice habitats critical for their reproduction. Nevertheless, at this time Ringed Seals as a species do not meet any IUCN criteria for a threatened listing, and are listed as Least Concern. Subspecies Pusa hispida ladogensis, the Ladoga Seal, is assessed separately as Vulnerable and subspecies P. h. saimensis, the Saimaa Seal, is assessed as Endangered.
|Previously published Red List assessments:|
|Range Description:||Ringed Seals have a circumpolar distribution throughout the Arctic Basin including records of individuals near the North Pole (Rice 1998). Ringed Seals also range widely into adjacent seas being found in the Bering Sea, Chukchi Sea, Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay, Hudson Strait, Davis Strait, and Greenland, Barents, White, Kara, Laptev, and East Siberian Seas, and they occasionally range into some lake and river systems in Northern Canada (Heide-Jørgensen and Lydersen 1998). Separate subspecies occur in the Baltic Sea, Lake Ladoga in the Russian Federation, Lake Saimaa in Finland, and the Sea of Okhotsk (Frost and Lowry 1981, Reeves 1998). Extralimital records for Ringed Seals extend far south on both sides of the Atlantic, to New Jersey USA in the west and Portugal in the east. In the Pacific, vagrants have been recorded south to the Zhejiang in China and southern California USA (Rice 1998).|
Native:Canada; Estonia; Finland; Greenland; Japan; Latvia; Norway; Russian Federation; Svalbard and Jan Mayen; Sweden; United States
Vagrant:China; Denmark; Faroe Islands; France; Germany; Iceland; Lithuania; Poland; Portugal; United Kingdom
|FAO Marine Fishing Areas:|
Arctic Sea; Atlantic – northeast; Atlantic – northwest; Pacific – northeast; Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Available data on Ringed Seal abundance were compiled and reviewed in the 2016 IUCN Red List assessments for the five recognized subspecies. Estimates of the number of mature individuals, and population trend, for each of those subspecies were as follows:|
Nevertheless, the figures presented above indicate the number of mature individuals is more than 1.5 million, and the total population size is likely more than 3 million.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Ringed Seals are in many respects the “classic” ice-seal. Throughout most of their range they use sea ice exclusively as their breeding, molting, and resting (haul-out) habitat, rarely if ever moving onto land (Frost and Lowry 1981, Reeves 1998). Their ability to create and maintain breathing holes in ice using the well-developed claws on their fore-flippers allows them to thrive in areas where even other ice-associated seals cannot reside. Although Ringed Seals are quite small they deal with the thermal challenges posed by the arctic winter by having a very thick blubber layer, and by building lairs (small caves) in the snow on top of sea ice during the winter. The lairs are particularly important for neonatal survival (Lydersen and Smith 1989). Ringed Seals also use natural cracks along pressure ridges and leads in the sea ice for surfacing and breathing. In Lakes Ladoga and Saimaa, the Baltic Sea, the White Sea, and the Sea of Okhotsk, Ringed Seals haul out and pup on ice but rest on shore during the ice-free period (Sipilä and Hyvärinen 1998, Kelly et al. 2010).|
Reported mean age at sexual maturity for female Ringed Seals varies in the literature from 3.5 to 7.1 years (Holst and Stirling 2002, Krafft et al. 2006). Males likely do not participate in breeding before they are 8-10 years old. Body sizes vary considerably between regions (Frost and Lowry 1981, Sipilä and Hyvärinen 1998). Ringed seals are long lived, with ages close to 50 reported (Lydersen and Gjertz 1987). Regional productivity rates are variable; reproductive success depends on many factors including prey availability, the relative stability of the ice, and sufficient snow accumulation prior to the commencement of breeding (Lukin 1980, Smith 1987, Lydersen 1995).
A single pup is born in late February-early March for the Ladoga, Saimaa, and Baltic subspecies (Sipilä and Hyvärinen 1998) and March-May for the others (Frost and Lowry 1981). Most births occur in subnivean lairs excavated in snow that accumulates near ice ridges or shorelines. Lairs provide thermal protection against cold air temperatures and high wind chill and afford at least some protection from predators (Smith 1976, Smith and Stirling 1975, Gjertz and Lydersen 1986). For Arctic Ringed Seals, lactation lasts an average of 39 days and pups are weaned at approximately 20 kg (Lydersen and Kovacs 1999). Females become receptive for mating towards the end of the lactation period, similar to other phocid seals.
Ringed Seals molt from mid-May to mid-July and during that period they spend quite a bit of time hauled out (Reeves 1998). Feeding intensity is at a minimum during molting (Ryg et al. 1990).
Although they may dive to more than 500 m (Born et al. 2004), in many areas where they feed the water is not that deep and dives are correspondingly shallower (Gjertz et al. 2000).
Outside the breeding and molting seasons, Ringed Seal distribution is correlated with food availability (e.g., Simpkins et al. 2003, Freitas et al. 2008). Numerous studies of their diet have been conducted, and although there is considerable regional variation several patterns emerge. Most Ringed Seal prey are small, and preferred prey tend to be schooling species that form dense aggregations. Fishes are usually in the 5-10 cm length range and crustacean prey in the 2-6 cm range. Typically, a variety of 10-15 prey species are found, with no more than 2-4 dominant prey species for any given area. Fishes are generally more commonly eaten than invertebrates, but diet is determined to some extent by availability of various types of prey during particular seasons as well as by preference, which in part is influenced by energy content of various available prey (Reeves 1998, Wathne et al. 2000). Commonly eaten prey include Polar Cod, Arctic Cod, Saffron Cod, Redfish, Herring, and Capelin in marine waters (Lowry et al. 1980, Holst et al. 2001, Labansen et al. 2007), and Smelt, Vendance, Perch, Roach, Stickleback, and Burbot in lakes (Sipilä and Hyvärinen 1998). Invertebrate prey species seem to become more important in the open-water season and often dominate the diet of young animals (Lowry et al. 1980, Holst et al. 2001). Large Amphipods, Krill, Mysids, Shrimps, and Cephalopods are all eaten by Ringed Seals and can be very important in some regions at least seasonally (Agafonova et al. 2007).
Polar Bears are the most important predator of Arctic Ringed Seals in most parts of their range and they are also eaten by Killer Whales and Walruses. Wolves, Wolverines, Foxes, Gulls, and Ravens may also prey on Ringed Seals, especially pups, in other areas (Reeves 1998).
|Systems:||Terrestrial; Freshwater; Marine|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||18.6|
|Movement patterns:||Not a Migrant|
|Use and Trade:||
Humans have hunted Ringed Seals in the Arctic since the arrival of people to the region millennia ago (e.g., Murdoch 1893, Riewe and Amsden 1979). They are a fundamental subsistence food item for most coastal dwelling northern indigenous peoples. Reeves et al. (1998) reported a combined estimate of 10,000 taken per year from the Bering, Chukchi, and western Beaufort Seas by Russians and Alaska Natives. They also estimated that the annual removal of Ringed Seals in the Canadian Arctic was in the “high tens of thousands”, and that in the 1980s, including animals killed and lost, the harvest was between 60,000 and 80,000, and may have exceeded 100,000 in some years. Another substantial annual harvest occurs in Greenland with nearly 100,000 taken per year in the 1970s and approximately 70,000 taken annually in the early1990s (Teilmann and Kapel 1998).
Commercial harvests of Ringed Seals in the early to mid-20th century were sometimes large and probably had significant local impacts on the respective populations. Harvest statistics reported for western Russia by Belikov and Boltunov (1998) suggest that maximum catches earlier in the 20th century exceeded the total allowable catches (TACs) significantly, with harvests of up to 8,900 in the White Sea (1912), 13,200 in the Russian Barents Sea (1962), and 13,200 in the Kara Sea (1933). Those harvests are thought to have dropped considerably in recent decades, though there are no available data. Reporting of harvest statistics and enforcement of TACs is difficult to manage in outlying areas, and the harvest of Ringed Seals in eastern Russia is largely unknown.
Although Ringed Seals in the Baltic and Lakes Ladoga and Saimaa were hunted in the past, hunting is no longer allowed (Sipilä and Hyvärinen 1998, Härkönen et al. 1998).
Ringed Seals carry loads of organochlorine and heavy metal contaminants from industry and agriculture that have been implicated in uterine pathology in Baltic Seals (Bergman and Olsson 1986), and high concentrations of mercury in Saimaa Seals is thought to have reduced pup production in the 1960s and 1970s (Sipilä and Hyvärinen 1998, Kostamo et al. 2002). However, following restrictions on the use and release of persistent organic pollutants (POPs) into the environment, contaminant levels are dropping rapidly in the Baltic (Kostamo et al. 2002). The same is true with regards to POPs in Arctic populations (Wolkers et al. 2008). Oil contamination poses poorly known risks to Ringed Seals. The greatest impacts would likely result if spills occurred during the pupping season or if food resources were negatively affected (Smith 1987, Reeves 1998).
Manipulation of water levels, recreational snow machine operation, net-fishing, boating, tourism, and development of cottages on the shoreline have been noted as threats to the Ringed Seals in Lake Saimaa, and industrial pollution, net fishing and poaching, as well as disturbance of on-shore summer haulout groups have been highlighted as threats for the Ladoga Seals (Sipilä and Hyvärinen 1998, Agafonova et al. 2007). Predation by Red Fox, Wolves, feral and domestic Dogs, and even birds of prey, are also risks for these lake Seals (e.g., Kunnasranta et al. 2001). By-catch in fisheries and other negative impacts associated with fisheries conflicts seem at present to be the major threat to Saimaa and Ladoga Seals (Kokko et al. 1998, Sipilä and Hyvärinen 1998, Verevkin 2002, Sipilä 2003, Agafonova et al. 2007).
Global warming may pose the greatest threat to Ringed Seals of all subspecies if it leads to large losses of the stable ice habitat required for pupping and rearing their young (Tynan and DeMaster 1997, Learmonth et al. 2006, Kovacs and Lydersen 2008, Laidre et al. 2008). Early break-up of the ice results in poor condition of pups and higher mortality rates (Smith and Harwood 2001). Associated changes in precipitation and weather patterns could also negatively affect Ringed Seal populations if there is insufficient snow cover to protect pups in lairs in the spring (Stirling and Derocher 1993, Ferguson et al. 2005, Kelly et al. 2010, Hezel et al. 2012, Iacozza and Ferguson 2014). Pups born outside lairs have a very low chance of survival; the pups are so small that even large Gulls can be predators if they are exposed (Lydersen and Smith 1989). Declining trends in reproduction and survival of pups have already been noted in some regions that have been attributed to earlier break-up of the sea ice over recent decades and concomitant changes in the marine ecosystem (Ferguson et al. 2005, Stirling 2005). Reductions in arctic sea ice could have quite dramatic effects via prey availability if Polar and Arctic Cod populations are negatively impacted.
Reductions in sea ice cover will likely lead to increased human activity in arctic regions in the form of shipping and resource extraction industries, with associated increased threat of marine accidents and pollution discharge (Pagnan 2000). An increase in human-created noise in the arctic environment could cause marine mammals, including Ringed Seals, to abandon areas (Tynan and DeMaster 1997) although studies to date suggest relatively minor impacts of development (Davis et al. 1991; Moulton et al. 2002, 2003, 2005; Blackwell et al. 2004). However, over-flights by aircraft certainly cause disturbance to Ringed Seals if flights occur by helicopter at less than 1,500 m distance or by fixed-winged aircraft at closer than 500 m (Born et al. 1999).
|Conservation Actions:||Ringed Seals are protected by a variety of laws and quotas in different parts of their range, but even within Europe the legal provisions are not always being fully implemented in domestic law (Wilson et al. 2001). The population in Lake Saimaa has been protected since 1955, and additional protection has been afforded via the establishment of two national parks within the lake, and regulation of shoreline development. Similarly, the hunting of Seals in Lake Ladoga was prohibited in 1980 (Sipilä and Hyvärinen 1998). In the USA, the Marine Mammal Protection Act of 1972 allows Ringed Seals to be harvested only by Alaskan Native hunters for subsistence purposes, and that Act generally prohibits all other forms of taking except where specifically permitted. In 2012, the Arctic, Okhotsk, and Baltic subspecies were listed as threatened, and the Ladoga subspecies was listed as endangered, under the US Endangered Species Act; the Saimaa subspecies was listed as endangered in 1993. State Nature Reserves at Franz Josef Land and in the White and Kara seas protect large areas of Ringed Seal habitat in the western Russian Arctic, and quotas and licensing of hunting have been in place in various parts of the Russian Federation for decades (Belikov and Boltunov 1998). Baltic Ringed Seals were protected from all killing by the Soviet Union in 1980, by Sweden in 1986, and by Finland in 1988 (Härkönen et al. 1998).|
Agafonova, E. V., Verevkin, M. V., Sagitov, R. A., Sipilä, T., Sokolovskay, M. V. and Shahnazarova, V. U. 2007. The Ringed Seal in Lake Ladoga and the Valaam Archipelago. Baltic Fund for Nature of Saint-Petersburg Naturalist Society, St. Petersburg State University & Metsähallitus, Natural Heritage Servives, Vammalan Kirjapaino OY., Vammala, Finland.
Belikov, S.E. and Boltunov, A.N. 1998. The ringed seal (Phoca hispida) in the western Russian Arctic. In: M.P. Heide-Jørgensen and C. Lydersen. (eds), Ringed seals in the North Atlantic., pp. 63-82. NAMMCO Scientific Publications, Volume 1, Tromso.
Bergman, A. and Olsson, M. 1986. Pathology of Baltic grey seal and ringed seal females with special reference to adrenocortical hyperplasia: is environmental pollution the cause of a widely distributed disease syndrome? Finnish Game Research 44: 47-62.
Blackwell, S. B., Greene, C. R. and Richardson, W. J. 2004. Drilling and operational sounds from an oil production island in the ice-covered Beaufort Sea. Journal of the Acoustical Society of America 116: 3199-3211.
Born, E. W., Riget, F. F., Dietz, R. and Andriashek, D. 1999. Escape responses of hauled out ringed seals (Phoca hispida) to aircraft disturbance. Polar Biology 21: 171-178.
Born, E.W., Teilmann, J., Acquarone, M. and Rigét, F.F. 2004. Habitat use of ringed seals (Phoca hispida) in the North Water Area (North Baffin Bay). Arctic 57: 129-142.
Committee on Taxonomy. 2014. List of marine mammal species and subspecies. Society for Marine Mammalogy. Available at: https://www.marinemammalscience.org/species-information/list-of-marine-mammal-species-subspecies/. (Accessed: 4 February 2014).
Davis, R. A., Richardson, W. J., Thiele, L., Dietz, R. and Johansen, P. 1991. Report on underwater noise. The state of the Arctic environment. Arctic Centre, University of Lapland, Rovaniemi, Finland.
Ferguson, S. H., Stirling, I. and Mcloughlin, P. M. 2005. Climate change and ringed seal (Phoca hispida) recruitment in western Hudson Bay. Marine Mammal Science 21(1): 121-135.
Freitas, C., Kovacs, K.M., Ims, R.A., Fedak, M.A. and Lydersen, C. 2008. Ringed seal post-moulting movement tactics and habitat selection. Oecologia 155: 193-204.
Frost, K. J. and Lowry, L. F. 1981. Ringed, Baikal and Caspian seals Phoca hispida Schreber, 1775; Phoca sibirica Gmelin, 1788; and Phoca caspica Gmelin, 1788. In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Vol. 2: Seals, pp. 29-53. Academic Press.
Fulton, T.L. and Strobeck C. 2010. Multiple markers and multiple individuals refine true seal phylogeny and bring molecules and morphology back in line. Proceedings of the Royal Society B 277: 1065-1070.
Gjertz, I. and Lydersen, C. 1986. Polar bear predation on ringed seals in the fast-ice of Hornsund, Svalbard. Polar Research 4: 65-68.
Gjertz, I., Kovacs, K.M., Lydersen, C. and Wiig, Ø. 2000. Movements and diving of adult ringed seals (Phoca hispida) in Svalbard. Polar Biology 23: 651-656.
Härkönen, T., Stenman, O., Jussi, M., Jussi, I., Sagitov, R. and Verevkin, M. 1998. Population size and distribution of the Baltic ringed seal (Phoca hispida botnica). In: M. P. Heide-Jorgensen and C. Lydersen (eds), Ringed seals in the North Atlantic, pp. 167-180. NAMMCO Scientific publication.
Heide-Jørgensen, M.-P. and Lydersen, C. 1998. Ringed seals in the North Atlantic. Volume 1. NAMMCO, Tromsø, Norway.
Hezel, P.J., Zhang, X., Bitz, C.M., Kelly, B.P. and Massonnet, F. 2012. Projected decline in spring snow depth on Arctic sea ice caused by progressively later autumn open ocean freeze-up this century. Geophysical Research Letters 39: L17505.
Holst, M. and Stirling, I. 2002. A comparison of ringed seal (Phoca hispida) biology on the east and west sides of the North Water Polynya, Barfin Bay. Aquatic Mammals 28: 221-230.
Holst, M., Stirling, I. and Hobson, K. A. 2001. Diet of ringed seals (Phoca hispida) on the east and west sides of the North Water Polynya, northern Baffin Bay. Marine Mammal Science 17(4): 888-908.
Iacozza, J. and Ferguson, S.H. 2014. Spatio-temporal variability of snow over sea ice in western Hudson Bay, with reference to ringed seal pup survival. Polar Biology 37: 817-832.
IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-1. Available at: www.iucnredlist.org. (Accessed: 30 June 2016).
Kelly, B.P., Bengtson, J.L., Boveng, P.L., Cameron, M.F., Dahle, S.P., Jansen, J.K., Logerwell, E.A., Overland, J.E., Sabine C.L., Waring, G.T. and Wilder, J.M. 2010. Status review of the ringed seal (Phoca hispida). U.S. Department of Commerce, NOAA Technical Memorandum NMFS-AFSC-212..
Kokko, H., Lindström, J., Ranta, E., Sipilä, T. and Koskela, J. 1998. Estimating the demographic effective population size of the Saimaa ringed seal (Phoca hispida saimensis Nordq.). Animal Conservation 1: 47-54.
Kostamo, A., Hyvärinen, H., Pellinen, J. and Kukkonen, J. V. K. 2002. Organochlorine concentrations in the Saimaa ringed seal (Phoca hispida saimensis) from Lake Haukivesi, Finland, 1981-2000. Environmental Toxicology and Chemistry 21(77): 1368-1376.
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.
Krafft, B. A., Kovacs, K. M., Frie, A. K., Haug, T. and Lydersen, C. 2006. Growth and population parameters of ringed seals (Pusa hispida) from Svalbard, Norway, 2002-2004. ICES Journal of Marine Science 63: 1136-1144.
Kunnasranta, M., Hyvarinen, H., Sipila, T. and Medvedev, N. 2001. Breeding habitat and lair structure of the ringed seal (Phoca hispida ladogensis) in northern Lake Ladoga in Russia. Polar Biology 24: 171-174.
Labansen, A. L., Lydersen, C., Haug, T. and Kovacs, K. M. 2007. Spring diet of ringed seals (Pusa hispida) from north-western Spitsbergen, Norway. ICES Journal of Marine Science 64: 1246-1256.
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.
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.
Lowry, L. F., Frost, K. J. and Burns, J. J. 1980. Variability in the diet of ringed seals, Phoca hispida, in Alaska. Canadian Journal of Fisheries and Aquatic Sciences 37: 2254-2261.
Lukin, L. R. 1980. Habitat of White Sea ringed seal in the initial period of postnatal development. Soviet Journal of Marine Biology 6: 266-269.
Lydersen, C. 1995. Energetics of pregnancy, lactation and neonatal development in ringed seals (Phoca hispida). In: A. S. Blix, L. Walløe and Ø. Ulltang (eds), Developments in Marine Biology 4: Whales, seals, fish and man, pp. 319-327. Elseview, Amsterdam, The Netherlands.
Lydersen, C. and Gjertz, I. 1987. Population parameters of ringed seals (Phoca hispida Schreber 1775) in Svalbard area. Canadian Journal of Zoology 65: 1021-1027.
Lydersen, C. and Kovacs, K. M. 1999. Behaviour and energetics of ice-breeding, North Atlantic phocid seals during the lactation period. Marine Ecology Progress Series 187: 265-281.
Lydersen, C. and Smith, T.G. 1989. Avian predation on ringed seal Phoca hispida pups. Polar Biology 9: 489-490.
Moulton, V. D., Richardson, W. J., Elliot, R. E., Mcdonald, T. L., Nations, C. and Williams, M. T. 2005. Effects of an offshore oil development on local abundance and distribution of ringed seals (Phoca hispida) of the Alaskan Beaufort Sea. Marine Mammal Science 21(2): 217-242.
Moulton, V. D., Richardson, W. J., McDonald, T. L., Elliott, R. E. and Williams, M. T. 2002. Factors influencing local abundance and haulout behaviour of ringed seals (Phoca hispida) on landfast ice of the Alaskan Beaufort Sea. Canadian Journal of Zoology 80: 1900-1917.
Moulton, V. D., Richardson, W. J., Williams, M. T. and Blackwell, S. B. 2003. Ringed seal densities and noise near and icebound artificial island with construction and drilling. Acoustics Res. Letters Online-ARLO 4: 112-117.
Murdoch. 1893. Seal catching at Point Barrow. Smithsonian Miscellaneous Collections 34.
Nyakatura, K. and Bininda-Emonds, O.R.P. 2012. Updating the evolutionary history of Carnivora (Mammalia): a new species-level supertree complete with divergence time estimates. BMC Biology 10: 12.
Pacifici, M., Santini, L., Di Marco, M., Baisero, D., Francucci, L., Grottolo Marasini, G., Visconti, P. and Rondinini, C. 2013. Generation length for mammals. Nature Conservation 5: 87–94.
Pagnan, J. L. 2000. Arctic marine protection. Arctic 53: 469-476.
Reeves, R. R. 1998. Distribution, abundance and biology of ringed seals (Phoca hispida): an overview. NAMMCO Scientific Publications 1: 9-45.
Reeves, R. R., Wenzel, W. G. and Kingsley, M. C. S. 1998. Catch history of ringed seals (Phoca hispida) in Canada. In: M. P. Heide-Jorgensen and C. Lydersen (eds), Ringed seals in the North Atlantic, pp. 100-129. NAMMCO Scientific Publications.
Rice, D.W. 1998. Marine Mammals of the World: Systematics and Distribution. Society for Marine Mammalogy, Lawrence, Kansas.
Riewe, R.R. and C.W. Amsden. 1979. Harvesting and utilization of pinnipeds by lnuit hunters in Canada's eastern High Arctic. In: A.P. McCartney (ed.), Thule Eskimo Culture: An Anthropological Retrospective. Mercury Series 88, pp. 324-348. Archaeological Survey of Canada, Ottawa, Canada.
Ryg, M., Smith, T. G. and Øritsland, N. A. 1990. Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) on Svalbard. Canadian Journal of Zoology 68: 470-475.
Simpkins, M.A., Hiruki-Raring, L.M., Sheffield, G., Grebmeier, J.M. and Bengtson, J.L. 2003. Habitat selection by ice-associated pinnipeds near St. Lawrence Island, Alaska in March 2001. Polar Biology 26: 577-586.
Sipilä, T. 2003. Conservation biology of Saimaa ringed seal (Phoca hispida saimensis) with reference to other European seal populations. Department of Ecology and Systematics, Division of Population Biology, University of Helsinki, Painolinna Oy , Savonlinna.
Sipilä, T. and Hyvärinen, H. 1998. Status and biology of Saimaa (Phoca hispida saimensis) and Ladoga (Phoca hispida ladogensis) ringed seals. In: M. P. Heide-Jorgensen and C. Lydersen (eds), Ringed seals in the North Atlantic, NAMMCO.
Smith, T. G. 1976. Predation of ringed seal pups (Phoca hispida) by the arctic fox (Alopex lagopus). Canadian Journal of Zoology 54: 1610-1616.
Smith, T. G. 1987. The ringed seal, Phoca hispida, of the Canadian western Arctic. Canadian Bulletin of Fisheries Research and Aquatic Sciences 216.
Smith, T. G. and Harwood, L. A. 2001. Observations of neonate ringed seals, Phoca hispida, after early break-up of the sea ice in Prince Albert Sound, Northwest Territories, Canada, spring 1998. Polar Biology 24: 215-219.
Smith, T. G. and Stirling, I. 1975. The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures. Canadian Journal of Zoology 53: 1297-1305.
Stirling, I. 2005. Reproductive rates of ringed seals and survival of pups in Northwestern Hudson Bay, Canada, 1991-2000. Polar Biology 28: 381-387.
Stirling, I. and Calvert, W. 1979. Ringed Seal. Mammals in the Seas, Vol. II pinniped species summaries and report on sirenians, pp. 66-69. FAO Fisheries.
Stirling, I. and Derocher, A. E. 1993. Possible impacts of climatic warming on polar bears. Arctic 46: 240-245.
Teilmann, J. and Kapel, F. O. 1998. Exploitation of ringed seals (Phoca hispida) in Greenland. In: M. P. Heide-Jorgensen and C. Lydersen (eds), Ringed seals in the North Atlantic, pp. 130-151. NAMMCO, Scientific Publication.
Tynan, C.T. and DeMaster, D.P. 1997. Observations and predictions of arctic climatic change: potential effects on marine mammals. Arctic 50: 308-322.
Verevkin, M. V. 2002. The results of aircraft survey of Ladoga ringed seals. In: P. I. Danilov and V. Zimin (eds), Dynamics of game animal populations in Northern Europe. Proc. 3rd Intern. Symp. (16-20 June 2002, Sortavala, Karenlia, Russia), pp. 202-204. Petrozavodsk, Sortavala, Karenlia, Russia.
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.
Wilson, S. C., Mo, G. and Sipilä, T. 2001. Legal protection for seals in small populations in European community and Mediterranean Coastal Waters. Mammalia 65: 335-348.
Wolkers, H., Krafft, B., van Bavel, B., Helgason, L. B., Lydersen, C. and Kovacs, K. M. 2008. Biomarker responses and decreasing contaminant levels and in ringed seals (Pusa hispida) from Svalbard, Norway. Journal of Toxicology and Environmental Health.
|Citation:||Lowry, L. 2016. Pusa hispida. The IUCN Red List of Threatened Species 2016: e.T41672A45231341.Downloaded on 25 February 2018.|