|Scientific Name:||Pusa hispida|
|Species Authority:||(Schreber, 1775)|
Phoca hispida Schreber, 1775
|Taxonomic Notes:||There are five recognized subspecies: P. h. hispida, Arctic Ringed Seal; P. h. botnica, Baltic Sea Ringed Seal; P. h. ladogensis, Lake Ladoga Ringed Seal; P. h. saimensis, Lake Saimaa Ringed Seal, and P. h. ochotensis, Sea of Okhotsk Ringed Seal.
The Ringed Seal has been moved back and forth between the genus name Pusa and Phoca in recent decades. Current common usage generally follows Rice’s (1998) classification of Ringed Seals as Pusa, though this is certainly not universal.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Kovacs, K., Lowry, L. & Härkönen, T. (IUCN SSC Pinniped Specialist Group)|
|Reviewer(s):||Kovacs, K. & Lowry, L. (Pinniped Red List Authority)|
P. h. hispida - Has a very large population size and broad distribution, however, there are future concerns for Arctic Ringed Seals with climate change impacts on Arctic sea ice; negative influences of climate change are already being documented in some parts of the subspecies range. Hence, this subspecies will need regular review.
P. h. botnica is currently showing an increase because of positive trends in one (its primary) breeding site, but there were recent-past population-wide declines, and current declines in some parts of its range. Additionally, climate change is likely to have a negative impact on this subspecies.
P. h. ladogensis has declined dramatically in recent decades. By-catch in fishing gear is the primary cause for the current declines, but climate change impacts are likely to be additive in the near future.
P. h. saimensis – The Saimaa Ringed Seal is a very small population that faces on-going threats from high mortality in fishing gear and virtually complete reproductive failure in recent years due to poor ice conditions within its limited range.
P. h. ochotensis – Ringed Seals in the Sea of Okhotsk have not been censused since the late 1960s. Population numbers and trends are unknown. Population work on this subspecies should be a high priority as climate change impacts are likely to have negative consequences for Ringed Seals in the Sea of Okhotsk.
For the global assessment at the species level, the Arctic Ringed Seals' numerous status and broad distribution leads to the classification of Least Concern for this species. However, given the risks posed by climate change to all Ringed Seal subspecies, including the Arctic Ringed Seals, this species should be reassessed within a decade.
|Range Description:||Ringed seals have a circumpolar distribution throughout the Arctic Basin including records of individuals near the North Pole (Rice 1998); arctic 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 extend into some lake and river systems in Northern Canada (Heide-Jørgensen and Lydersen 1989). Separate populations occur in the Baltic Sea, Lake Ladoga in the Russian Federation, Lake Saimaa in Finland, and the Sea of Okhotsk south to northern Japan (Frost and Lowry 1981, Reeves 1998). Extralimital records for ringed seals extend far south on both sides of the Atlantic, to New Jersey in the west and Portugal in the east. In the Pacific vagrants have been recorded south to the Zhejiang in China and southern California (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:||
|Range Map:||Click here to open the map viewer and explore range.|
P. h. hispida
The world-wide population size of arctic ringed seals is not accurately known. Citing many factors such as the vast geographic area occupied by the species, its highly variable distribution within areas that have been surveyed, the unknown relationship between the numbers of seals observed versus those not seen, and other factors, Frost and Lowry (1981) state that it is “unwise to attempt an estimate of the world population of this subspecies” (P. h. hispida). Despite numerous surveys at specific locales conducted since, Reeves (1998) believes that “this conclusion remains appropriate.”
Nevertheless, published world-wide population estimates exist including 6-7 million (Stirling and Calvert 1979) and 2.5 million (Miyazaki 2002). Some recent survey and pup production data are available from parts of the arctic ringed seal’s range (e.g. Frost and Lowry 2004, Bengtson et al. 2005, Moulton et al. 2005, Krafft et al. 2006), but these data are limited in spatial scope. Little information is available from large parts of the ringed seal’s arctic range, such as the eastern parts of the Russian Federation (but see Ognetov 1993). Decreased pup production and survival have recently been documented in some areas that have been attributed to climate change (e.g. Ferguson et al. 2005, Stirling 2005).
P. h. botnica
During the past century Baltic ringed seals declined precipitously from 190,000-220,000 to approximately 5,000 by the late 1970s (Harding and Härkönen 1999). The principle reason for the decline was over-harvesting, but low fertility caused by organochlorines and other contaminants may also have inhibited natural population growth during the decades following protection. The population of P. h. botnica was estimated to be between 5,000 and 8,000 individuals in the late 1990s; during 1998-2006 the number of ringed seals in Bothnia Bay, where about 75% of the population resides, has increased at a rate of 4.3 % per year (Karlsson et al. 2007). However, in the Gulf of Riga it is thought that the 1,400 seals counted in 1996 have been experiencing a steady decline since that time. The small subpopulation in the Gulf of Finland (~300 animals) has showed no increase since 1994. Current sea ice trends in the Baltic and future projections for the next 30 years pose a major threat to all southern populations in the Baltic; only the Bay of Bothnia is likely to retain fairly good winter sea-ice habitat for ringed seals (Meier et al. 2004).
P. h. ladogensis
The size of the P. h. ladogensis population was thought to be about 20,000 at the start of the 20th century, but bounties were paid to reduce the population and by the 1970s there were approximately 10,000 animals remaining (Agafonova et al. 2007). In 2001, the aerial survey of the basking population counted 2,000 (+-70) individuals on the ice (Verevkin 2002), which suggests a total population size of 3,000 to 5,000 seals (Agafonova et al. 2007).
By-catch in fishing gear is the major source of mortality in this population. Deaths due to this source alone account for 10-16% of the population annually (Verevkin et al. 2006), which is clearly unsustainable. The Ladoga ringed seal is listed in the Red Data Book of the Russian Federation.
P. h. saimensis
The number of P. h. saimensis in Lake Saimaa fell below 200 individuals in the early 1980s (Sipilä and Hyvärinen 1998). Thereafter, for a short period the population was increasing (to 240 in 2000, Sipilä 2003, Auvinen et al. 2005), reaching a maximum estimate of 280 in 2005 individuals for a brief time (Sipilä and Kokkonen 2008). A population viability analysis conducted by Ranta and Lundberg (2006, unpublished) suggested a potential for optimism regarding the survival of this population, as did projections in Sipilä (2006). But climate change impacts on Saimaa seal habitat were not incorporated into these predictions (Sipilä and Kokkonen 2008), nor was much attention paid to the fact that the population within the lake system is geographically subdivided (Sipilä at al. 2005), and the subdivision could markedly increase the future rate of inbreeding (Palo et al. 2003). Currently, mortality induced by fisheries by-catch is significant (Kokko et al. 1998, Sipilä and Hyvärinen 1998, Sipilä 2003). This mortality source, in addition to very high pup mortality during 2005-2007, is expected to cause this population to once again decline (Sipilä and Kokkonen 2008).
P. h. ochotensis
In the Sea of Okhotsk estimates for ringed seal abundance in 1968 and 1969 were 818,000 and 865,000 respectively (Reeves 1998). The population of P. h. ochotensis was estimated to be 800,000-1,000,000 by Miyazaki (2002). However, in reality no recent data are available and current population trends are unknown.
|Habitat and Ecology:||
Arctic ringed seals are in many respects the “classic” ice-seal. The subspecies P. h. hispida and P. h. ochotensis use sea ice exclusively as their breeding, moulting and resting (haulout) habitat, rarely if ever coming onto land (Smith and Stirling 1975, Frost and Lowry 1981, Kelly 1988). Their ability to create and maintain breathing holes in sea 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 (e.g., Lydersen and Smith 1989). Each seal builds several lairs so that they can escape if a predator attacks one of their structures; ringed seals have co-evolved with their principal predator, the polar bear (Ursus maritimus) over the last tens of thousands of years (Stirling and Øritsland 1995). Arctic foxes (Alopex lagopus) are also an important predator in some coastal areas (Smith 1976, Lydersen 1998). In addition to the constructed holes and lairs, ringed seals also use natural cracks along pressure ridges and leads in the sea ice for breathing.
Reported mean age at sexual maturity (MAM) for ringed seals females varies in the literature from 3.5 – 7.1 years (Holst and Stirling 2002, Krafft et al. 2006). Males likely do not participate in breeding before they are 8 and 10 years old. The average size of adults 10 years and older varies between locations and different age cohorts, but averages of 115-136 cm in length and 40-65 kg in weight have been reported, with males being slightly larger than females (Smith 1973, Frost and Lowry 1981, Smith 1987, Lydersen and Gjertz 1987). Ringed seals are long lived, with ages close to 50 reported (e.g. Lydersen and Gjertz 1987). Reproductive rates of adult female ringed seals vary between 0.45-0.86 (see Reeves 1998), with a maximum of 0.91 (Lydersen and Gjertz 1987). Regional production rates are variable; reproductive success depends on many factors including prey availability, the relative stability of the ice, sufficient snow accumulation prior to the commencement of breeding, etc. (e.g., Lukin 1980, Kelly 1988, Smith 1987, Lydersen 1995).
A single pup, weighing 4.0-4.5 kg, is born in the spring (March to May), with most pups being born in early April (Frost and Lowry 1981). In Lake Saimaa and in the southern part of Baltic Sea pups are born somewhat earlier, in late February or early March (Pälsi 1924, Sipilä 2003). Births occur in subnivean lairs excavated in snow that accumulates upwind and downwind of ice ridges (Smith and Stirling 1975, Furgal et al. 1996), or in cavities occurring between blocks of ice in pressure ridges (McLaren 1958, Kelly 1988). Lairs provide thermal protection against cold air temperatures and high wind chill and afford at least some protection from foxes and polar bears (Smith 1976, 1980, Smith and Stirling 1975, Gjertz and Lydersen 1986). A female will move a young pup between lairs within her complex of lairs (usually 4-6 per female) if one lair is attacked by a predator; older pups are able to shift between structures independently as they develop swimming skills in the first weeks of life (Lydersen and Hammill 1993a,b). Lactation lasts an average of 39 days and pups are weaned at approximately 20 kg (Lydersen and Kovacs 1999). Females mate towards the end of the lactation period, similar to other phocid seals. Shore-fast ice is considered to be the most important habitat for pupping, although the importance of pack ice is not well known; this habitat is used at least in the Davis Strait and in the Barents Sea (e.g. Wiig et al. 1999).
Ringed seals moult from around mid-May to mid-July when they spend quite a bit of time hauled out on ice at the edge of the permanent pack ice, or on remnant land-fast ice along coastlines (Reeves 1998). Feeding intensity is at a minimum at this time (Ryg et al. 1990).
Outside the breeding and moulting seasons, arctic ringed seals are distributed in waters of nearly any depth; their distribution is strongly correlated with seasonally and permanently ice-covered waters and food availability (e.g. Simpkins et al. 2003, Freitas et al. 2008).
Many studies of the diet of arctic ringed seal diet have been conducted and although there is considerable variation in the diet regionally, several patterns emerge. Most ringed seal prey is small, and preferred prey tends to be schooling species that form dense aggregations. Fishes are usually in the 5-10 cm 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 invertebrate prey, but diet is determined to some extent by availability of various types of prey during particular seasons as well as preference, which in part is guided by energy content of various available prey (Reeves 1998, Wathne et al. 2000). Polar cod (Boreogadus saida) is often reported to be the most important prey species for ringed seals (see Labansen et al. 2007 for review). Young polar cod (≤2 yrs) are often found closely associated with sea ice, living under and even in spaces within sea ice (Falk-Petersen et al. 1986). Ringed seals also eat a variety of other members of the cod family, including arctic cod (Arctogadus glacialis; Holst et al. 2001), and saffron cod (Eleginus gracilis) with the latter being particularly important during the summer months in Alaskan waters (Lowry et al. 1980). Redfish (Sebastes spp.), capelin (Mallotus villosus) and herring (Clupea harengu) are also important in the diet of arctic ringed seals in some regions. Invertebrate prey seems to become more important to ringed seals in the open-water season and often dominates the diet of young animals (e.g. Lowry et al. 1980, Holst et al. 2001). Large amphipods (e.g. Themisto libellula), krill (e.g. Thysanoessa inermis) mysids (e.g. Mysis oculata), shrimps (e.g. Pandalus spp., Eualus spp., Lebbeus polaris, Crangon septemspinosa) and cephalopods (e.g. Gonatus spp.) are all eaten by ringed seals and can be very important in some regions at least seasonally.
Ringed seals in the Baltic sea as well as in Lakes Saimaa and Ladoga use ice for breeding and moulting, but are forced to haul out on islands and shorelines during the summer season when ice is not available. Their general season patterns are similar to those of arctic dwelling ringed seals. One notable difference in social structure is that Ladoga ringed seals form large herds during the open water period; this behaviour of mass haulouts is concentrated in the Valamm Nature Park (Agafonova et al. 2007).
Saimaa and Ladoga ringed seals are confined to freshwater lakes where they prey on a wide variety of fish and some invertebrates, especially smelt (Osmerus eperlanus), vendace (Coregonus albula), burbot (Lota lota), perch (Perca fluviatalis), roach (Rutilus rutilus), whitefish (Coreogonus lavaretus) and other fishes in small quantities (Sipilä and Hyvärinen 1998, Agafonova et al. 2007).
|Systems:||Terrestrial; Freshwater; Marine|
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 coastally dwelling northern peoples. Reeves (1998) reported an annual quota for shore-based hunters in the Sea of Okhotsk of 7,500 and a combined estimate of 10,000 taken per year from the Bering, Chukchi, and Western Beaufort Sea by Russians and Native Alaskans. Further, Reeves (1998) estimates that the annual removal of ringed seals in the Canadian Arctic is in the “high tens of thousands” at present, and that in 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 early 1990s (Teilmann and Kapel 1998).
Commercial harvests of ringed seals in the early to mid-20th century at southern latitudes were sometimes large and probably had significant local impacts on the respective populations. Annual harvests of 72,000 from 1955 to 1965 in the Sea of Okhotsk, 20,000 in the Baltic Sea, as well as commercial harvests in Lakes Ladoga and Saimaa (Reeves 1998, Sipilä and Hyvärinen 1998) all provide examples of the negative effect of localized over-harvesting on ringed seal populations. Kokko et al. (1997) have suggested that the sustainable harvest level for Baltic ringed seals at the end of the 1990s was close to zero (Kokko et al. 1997). Harvest statistics reported for Western Russia by Belikov and Boltunov (1998) suggest that maximum catches earlier in this 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). These 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.
Ringed seals carry loads of organochlorine and heavy metal contaminants from human industry and agriculture which 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, levels are dropping rapidly in the Baltic (e.g. Kostamo et al. 2002). The same is true with regards to POPs in Arctic populations (e.g. Wolkers et al. 2008). Oil contamination poses poorly known risks to ringed seal populations. The greatest impacts would likely result if spills occurred during the pupping season or if food resources were negatively effected (Smith 1987, Reeves 1998).
Manipulation of water levels, recreational snow machine operation, net-fishing, boating, tourism and development of cottages on the shoreline at Lake Saimaa 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 Lake Ladoga ringed seals (Sipilä and Hyvärinen 1998, Agafonova et al. 2007). Predation by red fox (Vulpes vulpes), wolves (Canis lupus), 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 the two subspecies of ringed seals occupying Lakes Saimaa and Ladoga (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 in all subspecies if it leads to large losses of the stable ice habitat required by ringed seals for pupping and rearing their young (Tynan and DeMaster 1997, Learmonth et al. 2006, Kovacs and Lydersen 2008, also see Laidre et al. 2008). Early break-up of the ice results in poor condition of pups and higher mortality rates (e.g. Smith and Harwood 2001). Associated changes in precipitation and weather patterns could also negatively effect 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). 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 (e.g. 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).
Ice is also needed by ringed seals for moulting, resting, and in some populations foraging, but the type of ice and its stability is more flexible outside the breeding season, though northern ringed seals still exhibit a clear preference for areas with considerable ice coverage (Simpkins et al. 2003, Freitas et al. 2008). Reductions in arctic sea ice could have quite dramatic effects via prey availability if polar and arctic cod populations are negatively impacted. Climate change impacts could be particularly acute for ringed seals living in restricted habitats such as the Ladoga and Saimaa Lake populations (Learmonth et al., 2006), and possibly also for ringed seals in the Okhotsk and Baltic Seas (see Meier et al. 2004). In Lake Saimaa there was an abnormally high lair mortality of pups in 2006 and 2007 because of poor ice and snow conditions (Sipilä et al. 2007).
Reductions in sea ice cover will likely lead to increased human activity in the Arctic 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). Disturbance seems to be disruptive to haulout groups in Lake Ladoga during summer and routine day-tourism seems to have caused the desertion of at least two previously used sites (Agafonova et al. 2007, Verevkin et al. 2007). However, it must be noted that Moulton et al. (2002, 2003, 2005) found no more than slight effects on ringed seals from construction, drilling and operation of the Northstar offshore island oil production facility in the Beaufort Sea, and other assessments of industrial activities in the Arctic suggest relatively minor impacts on ringed seals (Kelly et al. 1988, Davis et al. 1991, Blackwell et al. 2004), though over-flights by aircraft certainly cause disturbance to ringed seals if flights occur by helicopter at less than 1,500 m and 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 United States 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 (Angliss and Outlaw 2005). 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 (Belikov and Boltunov 1998). Quotas and licensing of hunting have been in place in various parts of the Russian Federation for decades (Belikov and Boltunov 1998), though this has done little to stop the decline of ringed seals in Lake Ladoga. 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.
Angliss, R. P. and Outlaw, R. B. 2005. Alaska marine mammal stock assessments. NOAA Technical Memorandum NMFS-AFSC.
Auvinen, H., Jurvelius, J., Koskela, J. and Sipilä, T. 2005. Comparative use of vendace by humans and Saimaa ringed sea in Lake Pihlajavesi. Finland. Biol. Conserv. 125: 381-389.
Belikov, S. E. and Boltunov, A. N. 1998. The ringed seal (Phoca hispida) in the western Russian Arctic. In: M.P. Heide-Jorgensen and C. Lydersen. (eds), Ringed seals in the North Atlantic., pp. 63-82. NAMMCO Sci. Publ.
Bengtson, J.L., Hiruki-Raring, L.M., Simpkins, M.A. and Boveng, P.L. 2005. Ringed and bearded seal densities in the eastern Chukchi Sea, 1999-2000. Polar Biology 28: 833-845.
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.
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.
Falk-Petersen, I. B., Fridvoll, V., Gulliksen, B. and Haug, T. 1986. Occurrence and age/size relations of polar cod, Boreogadus saida (Lepechin), in Spitsbergen coastal waters. Sarsia 71: 235-245.
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.
Frost, K. J., Lowry, L. F., Pendleton, G. and Nute, H. R. 2004. Factors affecting the observed densities of ringed seals, Phoca hispida, in the Alaskan Beaufort Sea, 1996-99. Arctic 57: 115-128.
Furgal, C. M., Kovacs, K. M. and Innes, S. 1996. Characteristics of ringed seal, Phoca hispida, subnivean structures and breeding habitat and their effects on predation. Canadian Journal of Zoology 74: 858-874.
Gjertz, I. and Lydersen, C. 1986. Polar bear predation on ringed seals in the fast-ice of Hornsund, Svalbard. Polar Research 4: 65-68.
Hammill, M. O., Lydersen, C., Ryg, M. and Smith, T. G. 1991. Lactation in the ringed seal (Phoca hispida). Canadian Journal of Fisheries and Aquatic Sciences 48: 2471-2476.
Harding, K. C. and Härkönen, T. J. 1999. Development in the Baltic grey seal (Halichoerus grypus) and ringed seal (Phoca hispida) populations during the 20th century. Ambio 28: 619-627.
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.
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.
IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org. (Accessed: 5 October 2008).
Karlsson, O., Härkönen, T. and Bäcklin, B.-M. 2007. Seals on the increase [In Swedish -Sälar på uppgång]. Havet 2007: 84-89.
Kelly, B. P. 1998. Ringed seal. In: J. W. Lentfer (ed.), Selected marine mammals of Alaska: species accounts with research and management recommendations, pp. 57-75. U.S. Marine Mammal Commission, Washington, DC, USA.
Kokko, H., Lindstrom, J. and Ranta, E. 1997. Risk analysis of hunting of seal populations in the Baltic. Conservation Biology 11: 917-927.
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. 1986. Studies of the ringed seal (Phoca hispida Schreber 1775) in its breeding habitat in Kongsfjorden, Svalbard. Polar Research 4: 57-63.
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 Hammill, M. O. 1993a. Diving in ringed seal (Phoca hispida) pups during the nursing period. Candian Journal of Zoology 71: 991-996.
Lydersen, C. and Hammill, M. O. 1993b. Activity, milk intake and energy consumption in free-living ringed seal (Phoca hispida) pups. Journal of Comparative Physiology B 163: 433-438.
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, G. G. 1989. Avian predation on ringed seal Phoca hispida pups. Polar Biology 9: 489-490.
McLaren, I. A. 1958. The biology of the ringed seal (Phoca hispida Schreber) in the eastern Canadian Arctic. Fisheries Research Board of Canada 118: 1-97.
Meier, H. E. M., Descher, R. and Halkka, A. 2004. Simulated distributions of Baltic Sea-ice in warming climate and consequences for the winter habitat of the Baltic ringed seal. AMBIO 33: 249-256.
Miyazaki, N. 2002. Ringed, Caspian, and Baikal seals Pusa hispida, P. caspica, and P. sibirica. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 1033-1037. Academic Press.
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.
Ognetov, G. N. 1993. Characteristics of distribution of ringed seal (Pusa hispida) on shore ice of the Eastern Siberian Sea. Russian Journal of ecology 24: 111-117.
Pagnan, J. L. 2000. Arctic marine protection. Arctic 53: 469-476.
Palo, J. U., Hyvärinen, H., Helle, E., Makinen, H. S. and Vainola, R. 2003. Postglacial loss of microsatellite variation in the landlocked Lake Saimaa ringed seal. Conservation Genetics 4: 117-128.
Pälsi, S. 1924. Suomenlahden jäiltä. Otava, Porvoo.
Ranta, E. and Lundberg, P. 2006. The Saimaa ringed seal: Demography, population dynamics and conservation. Evaluation report about Saimaa seal population status and management of population. Metsähallitus, Natural Heritage Ser. And Theoretical Ecology, Univ.Lund & Integrative Ecol. Unit, Univ. Helsinki.
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.
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. 2006. The past and future size of the Saimaa ringed seal (Phoca hispida saimensis) population. (In English and in Russian). In: V. M. Belkovich, A. N. Smelova and A. N. Boutunov (eds), Marine Mammals of the Holarctic, Collection of Scientific Papers. Saint Petersburg, Russia.
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.
Sipilä, T. and Kokkonen, T. 2008. Saimaannorppakannan tila vuonna 2007. Ilmaston muutoksen vaikutus sekä sen aiheuttaman haitan kompensoinnista. Metsähallitus, Etelä- Suomen Luontopalvelut, julkaisematon asiakirja nro 657/41/2008.17 s.
Sipilä, T., Koskela, J. T. and Kokkonen, T. S. 2005. Spatial differences in the changes of population size of the Saimaa ringed seal. In: E. Helle, O. Stenman and M. Wikman (eds), Symposium of the Biology and Management of seals in Baltic Area, Kala- ja riistaraportteja No 346, Riista- ja kalatalouden tutkimuslaitos, Helsinki, Finland.
Sipilä, T., Koskela, J. T. and Kokkonen, T. S. 2007. Global warming - serious threat to Saimaa ringed seal population - Abstract. 17th Biennial Conference on the Biology of Marine Mammals. Cape Town, South-Africa.
Smith, T. G. 1973. Population dynamics of the ringed seal in the Canadian eastern Arctic. Bulletin of Fisheries Research, Canada 181.
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.
Stirling, I. and Øritsland, N. A. 1995. Relationships between estimates of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic. Canadian Journal of Fisheries and Aquatic Sciences 52: 2594-2612.
Teilmann, J. and Kapell, 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.
Verevkin, M., Sokolovskay, M., Agafonova, E., Shahnazarova, V., Sipilä, T. and Sagitov, R. 2007. The haul-out behavior of the Ladoga ringed seals is very sensitive to the disturbance. 17th Biennial Conference on the Biology of Marine Mammals. Cape Town, South-Africa.
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.
Verevkin, M. V., Medvedev, N. and Sipilä, T. 2006. By-catch mortality of the Ladoga seal (Phoca hispida ladogensis) population. Marine Mammals of the Holarctic, 4th International Conference: 130-133. St Petersburg, 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.
Wiig, O., Derocher, A. E. and Belikov, S. E. 1999. Ringed seal (Phoca hispida) breeding in the drifting pack ice of the Barents Sea. Marine Mammal Science 15(2): 595-598.
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:||Kovacs, K., Lowry, L. & Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008. Pusa hispida. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 01 September 2015.|