Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats

References

• Aarkrog A., Baxter M.S., Bettencourt A.O., Bojanowski R., Bologa A., Charmasson S., Cunha I., Delfanti R., Duran E., Holm E., Jeffree R., Livingston H., Mahapanyawong H., Nies S., Osvath I., Pingyu L., Povinec P., Sanchez A., Smith J., Swift D. A comparison of doses from 137Cs and 210Po in marine food: a major international study. Journal of Environmental Radioactivity. 1997; 34: 69–90.
   Google Scholar
• Aars J., Marques T.A., Buckland S.T., Andersen M., Belikov S., Boltunov A., Wiig Ø. Estimating the Barents Sea polar bear subpopulation size. Marine Mammal Science. 2009; 25: 35–52.
   Web of Science ®Google Scholar
• Aars J., Plumb A. Polar bear cubs may reduce chilling from icy water by sitting on mother's back. Polar Biology. 2010; 33: 557–559.
   Web of Science ®Google Scholar
• Amstrup S.C. Human disturbance of denning polar bears in Alaska. Arctic. 1993; 46: 246–250.
   Web of Science ®Google Scholar
• Amstrup S.C., DeWeaver E.T., Douglas D.C., Marcot B.G., Durner G.M., Bitz C.M., Bailey D.A. Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence. Nature. 2010; 468: 955–958.
   PubMed Web of Science ®Google Scholar
• Amstrup S.C., Gardner C. Polar bear maternity denning in the Beaufort Sea. Journal of Wildlife Management. 1994; 58: 1–10.
   Web of Science ®Google Scholar
• Amstrup S.C., Marcot B.G., Douglas D.C. DeWeaver E.T., etal. A Bayesian network approach to forecasting the 21st century worldwide status of polar bears. Arctic sea ice decline: observations, projections, mechanisms, and implications. 2008; Washington, DC: American Geophysical Union. 213–268.
   Google Scholar
• Andersen M., Aars J. Short-term behavioural response of polar bears to disturbance by snowmobiles. Polar Biology. 2008; 31: 501–507.
   Web of Science ®Google Scholar
• Andersen M., Derocher A.E., Wiig Ø., Aars J. Movements of two Svalbard polar bears recorded using geographical positioning system satellite transmitters. Polar Biology. 2008; 31: 905–911.
   Web of Science ®Google Scholar
• Andersen M., Derocher A.E., Wiig Ø., Aars J. Polar bear (Ursus maritimus) maternity den distribution in Svalbard, Norway. Polar Biology. 2012; 35: 499–508.
   Web of Science ®Google Scholar
• Andersen M., Gwynn J.P., Dowdall M., Lydersen C. Radiocaesium in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea. Science of the Total Environment. 2006; 363: 87–94.
   Web of Science ®Google Scholar
• Andersen M., Hjelset A.M., Gjertz I., Lydersen C., Gulliksen B. Growth, age at sexual maturity and condition in bearded seals (Erignathus barbatus) from Svalbard, Norway. Polar Biology. 1999; 21: 179–186.
   Web of Science ®Google Scholar
• Andersen M., Lie E., Derocher A.E., Belikov S.E., Bernhoft A., Boltunov A.N., Garner G.W., Skaare J.U., Wiig Ø. Geographic variation of PCB congeners in polar bears (Ursus maritimus), from Svalbard to the Chukchi Sea. Polar Biology. 2001; 24: 231–238.
   Web of Science ®Google Scholar
• Anonymous. Proceedings of the first international scientific meeting on the polar bear at Fairbanks, Alaska. 6–10 September 1965. 1966; Washington, DC: Bureau of Sport Fisheries and Wildlife, US Department of the Interior, and University of Alaska.
   Google Scholar
• Anonymous. Meeting of the parties to the 1973 Agreement on the Conservation of Polar Bears. 2009. 17–19 March 2009, Tromsø, Norway. Outcome of meeting. Accessed on the internet at http://pbsg.npolar.no/export/sites/pbsg/en/docs/Outcome_MOP2009.pdf on 31 March 2016.
   Google Scholar
• Anonymous. 2010. Meld. St. 10 (2010–2011). Melding til Stortinget. Oppdatering av forvaltningsplanen for det marine miljø i Barentshavet og havområdene utenfor Lofoten. (Meld. St. 10 [2010–2011]. Report to the Storting [white paper]. First update of the Integrated Management Plan for the Marine Environment of the Barents Sea–Lofoten Area.) Oslo: Norwegian Ministry of the Environment.
   Google Scholar
• Arthur S.M., Manly B.F.J., McDonald L.L., Garner G.W. Assessing habitat selection when availability changes. Ecology. 1996; 77: 215–227.
   Web of Science ®Google Scholar
• Åsbakk K., Aars J., Derocher A.E., Wiig Ø., Oksanen A., Born E.W., Dietz R., Sonne C., Godfroid J., Kapel C.M.O. Serosurvey for Trichinella in polar bears (Ursus maritimus) from Svalbard and the Barents Sea. Veterinary Parasitology. 2010; 172: 256–263.
   Web of Science ®Google Scholar
• Atkinson S.N., Ramsay M.A. The effects of prolonged fasting on the body-composition and reproductive success of female polar bears (Ursus maritimus). Functional Ecology. 1995; 9: 559–567.
   Web of Science ®Google Scholar
• Barrett G.W., Vandyne G.M., Odum E.P. Stress ecology. Bioscience. 1976; 26: 192–194.
   Web of Science ®Google Scholar
• Barrie L.A., Gregor D., Hargrave B., Lake R., Sherer R., Tracey B., Bidleman T. Arctic contaminants: sources, occurrence and pathways. Science of the Total Environment. 1992; 122: 1–74.
   PubMed Web of Science ®Google Scholar
• Belikov S.E. Distribution and structure of dens of female polar bears in Wrangel Island. Bears. Their Biology and Management. 1980; 4: 117–118.
   Google Scholar
• Belikov S.E., Garner G.W., Wiig Ø., Boltunov A.N., Gorbunov Y.A. Polar bears of the Zevernaya Zemlya Archipelago of the Russian Arctic. Ursus. 1998; 10: 33–40.
   Google Scholar
• Benjaminsen T. Age determination and the growth and age distribution from cementum growth layers of bearded seals at Svalbard. Fiskeridirektoratets Skrifter Serie Havundersøkelser. 1973; 16: 159–170.
   Google Scholar
• Bernhoft A., Skaare J.U., Wiig Ø., Derocher A.E., Larsen H.J.S. Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus) at Svalbard. Journal of Toxicology and Environmental Health. 2000; 59: 561–574.
   PubMed Web of Science ®Google Scholar
• Bernhoft A., Wiig Ø., Skaare J.U. Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environmental Pollution. 1997; 95: 159–175.
   PubMed Web of Science ®Google Scholar
• Blaszczyk M., Jania J.A., Hagen J.O. Tidewater glaciers of Svalbard: recent changes and estimates of calving fluxes. Polish Polar Research. 2009; 30: 85–142.
   Web of Science ®Google Scholar
• Blix A.S., Lentfer J.W. Modes of thermal protection in polar bear cubs—at birth and on emergence from the den. American Journal of Physiology. 1979; 236: 67–74.
   Google Scholar
• Borchers D.L., Buckland S.T., Zucchini W. Estimating animal abundance. Closed populations. 2002; London: Springer.
   Google Scholar
• Bowes G.W., Jonkel C.J. Presence and distribution of polychlorinated biphenyls (PCB) in Arctic and Subarctic marine food chains. Journal of the Fisheries Research Board of Canada. 1975; 32: 281–286.
   Google Scholar
• Braathen M., Derocher A.E., Wiig Ø., Sørmo E.G., Lie E., Skaare J.U., Jenssen B.M. Relationships between PCBs and thyroid hormones and retinol in female and male polar bears. Environmental Health Perspectives. 2004; 112: 826–833.
   PubMed Web of Science ®Google Scholar
• Bradley M.J., Kutz S.J., Jenkins E., O'Hara T.M. The potential impact of climate change on infectious diseases of Arctic fauna. International Journal of Circumpolar Health. 2005; 64: 468–477.
   PubMedGoogle Scholar
• Brown J.E., Kolstad A.K., Brungot A.L., Lind B., Rudjord A.L., Strand P., Føyn L. Levels of 99Tc in seawater and biota samples from Norwegian coastal waters and adjacent seas. Marine Pollution Bulletin. 1999; 38: 560–571.
   Web of Science ®Google Scholar
• Buckland S.T., Anderson D.R., Burnham K.P., Laake J.L., Borchers D.L., Thomas L. Advanced distance sampling. 2004; Oxford: Oxford University Press.
   Google Scholar
• Burek K.A., Gulland F.M.D., O'Hara T.M. Effects of climate change on Arctic marine mammal health. Ecological Applications. 2008; 18: 126–134.
   Web of Science ®Google Scholar
• Burns J.J. Ridgway S.H., Harrison R.J. Bearded seal Erignathus barbatus Erxleben, 1777. Handbook of marine mammals. Vol. 2. Seals. 1981; London: Academic Press. 145–170.
   Google Scholar
• Bytingsvik J., Lie E., Aars J., Derocher A.E., Wiig Ø., Jenssen B.M. PCBs and OH-PCBs in polar bear mother–cub pairs: a comparative study based on plasma levels in 1998 and 2008. Science of the Total Environment. 2012; 417: 117–128.
   PubMed Web of Science ®Google Scholar
• Carroll J., Wolkers H., Andersen M., Rissanen K. Bioaccumulation of radiocaesium in Arctic seals. Marine Pollution Bulletin. 2002; 44: 1366–1371.
   PubMed Web of Science ®Google Scholar
• Cheek A.O., Kow K., Chen J., McLachlan J.A. Potential mechanisms of thyroid disruption in humans: interaction of organochlorine compounds with thyroid receptor, transthyretin, and thyroid-binding globulin. Environmental Health Perspectives. 1999; 107: 273–278.
   PubMed Web of Science ®Google Scholar
• Comiso J.C. A rapidly declining perennial sea ice cover in the Arctic. Geophysical Research Letter. 2002; 29 L1956.
   Web of Science ®Google Scholar
• Comiso J.C., Parkinson C.L., Gersten R., Stock L. Accelerated decline in the Arctic sea ice cover. Geophysical Research Letter. 2008; 35 L01703.
   Web of Science ®Google Scholar
• Core Writing Team Pachauri R.K., Reisinger A. Climate change 2007. Synthesis report. Contribution of Working Groups I, II and III to the fourth assessment report of the Intergovernmental Panel on Climate Change. 2007; Geneva: Intergovernmental Panel on Climate Change.
   Google Scholar
• De March B.G.E., de Wit C.A., Muir C.G., Braune B.M., Gregor D.J., Norstrom R.J., Olsson M., Skaare J.U., Stange K. Wilson S.J. Persistent organic pollutants. AMAP assessment report: Arctic pollution issues. 1998; Oslo: Arctic Monitoring and Assessment Programme. 183–371.
   Google Scholar
• DeMaster D.P., Kingsley M.C.P., Stirling I. A multiple mark and recapture estimate applied to polar bears. Canadian Journal of Zoology. 1980; 58: 633–638.
   Web of Science ®Google Scholar
• Derocher A.E. Population ecology of polar bears at Svalbard, Norway. Population Ecology. 2005; 47: 267–275.
   Web of Science ®Google Scholar
• Derocher A.E., Aars J., Amstrup S.C., Cutting A., Lunn N.J., Molnar P.K., Obbard M.E., Stirling I., Thiemann G.W., Vongraven D., Wiig Ø., York G. Rapid ecosystem change and polar bear conservation. Conservation Letters. 2013; 6: 368–375.
   Web of Science ®Google Scholar
• Derocher A.E., Andersen M., Wiig Ø., Aars J., Hansen E., Biuw M. Sea ice and polar bear den ecology at Hopen Island, Svalbard. Marine Ecology Progress Series. 2011; 441: 273–279.
   Web of Science ®Google Scholar
• Derocher A.E., Andriashek D., Arnould J.P.Y. Aspects of milk composition and lactation in polar bears. Canadian Journal of Zoology. 1993; 71: 561–567.
   Web of Science ®Google Scholar
• Derocher A.E., Lunn N.J., Stirling I. Polar bears in a warming climate. Integrative and Comparative Biology. 2004; 44: 163–176.
   PubMed Web of Science ®Google Scholar
• Derocher A.E., Stirling I. Observations of aggregating behaviour in adult male polar bears (Ursus maritimus). Canadian Journal of Zoology. 1990; 68: 1390–1394.
   Web of Science ®Google Scholar
• Derocher A.E., Stirling I. Aspects of survival in juvenile polar bears. Canadian Journal of Zoology. 1996; 74: 1246–1252.
   Web of Science ®Google Scholar
• Derocher A.E., Stirling I. Maternal investment and factors affecting offspring size in polar bears (Ursus maritimus). Journal of Zoology. 1998; 245: 253–260.
   Web of Science ®Google Scholar
• Derocher A.E., Wiig Ø., Andersen M. Diet composition of polar bears in Svalbard and the western Barents Sea. Polar Biology. 2002; 25: 448–452.
   Web of Science ®Google Scholar
• Derocher A.E., Wiig Ø., Bangjord G. Predation of Svalbard reindeer by polar bears. Polar Biology. 2000; 23: 675–678.
   Web of Science ®Google Scholar
• Derocher A.E., Wolkers H., Colborn T., Schlabach M., Larsen T.S., Wiig Ø. Contaminants in Svalbard polar bear samples archived since 1967 and possible population level effects. Science of the Total Environment. 2003; 301: 163–174.
   PubMed Web of Science ®Google Scholar
• Dietz R., Basu N., Braune B., O'Hara T., Scheuhammer T., Sonne C., Andersen M., Andreasen C., Andriashek D., Asmund G., Aubail A., Baagøe H., Born E.W., Chan H.M., Derocher A.E., Grandjean P., Knott K., Kirkegaard M., Lunn N., Messier F., Obbard M., Olsen M.T., Peacock E., Renzoni A., Rigét F.F., Skaare J.U., Stern G., Stirling I., Taylor M., Wiig Ø., Wilson S., Aars J. What are the toxicological effects of mercury in Arctic biota?. Science of the Total Environment. 2013; 443: 775–790.
   PubMed Web of Science ®Google Scholar
• Dietz R., Rigét F.F., Sonne C., Born E.W., Bechshøft T., McKinney M.A., Letcher R.J. Three decades (1983–2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 1. Legacy organochlorine contaminants. Environment International. 2013; 59: 485–493.
   PubMed Web of Science ®Google Scholar
• Durner G.M., Douglas D.C., Nielson R.M., Amstrup S.C., Mcdonald T.L., Stirling I., Mauritzen M., Born E.W., Wiig Ø., DeWeaver E., Serreze M.C., Belikov S.E., Holland M.M., Maslanik J., Aars J., Bailey D.A., Derocher A.E. Predicting 21st century polar bear habitat distribution from global climate models. Ecological Monographs. 2009; 79: 25–58.
   Web of Science ®Google Scholar
• Evans T.J., Fischbach A., Schliebe S., Manly B., Kalxdorff S., York G. Polar bear aerial surveys in the eastern Chukchi Sea: a pilot study. Arctic. 2003; 56: 359–366.
   Web of Science ®Google Scholar
• Ferguson S., Taylor M., Born E., Rosing-Asvid A., Messier F. Activity and movement patterns of polar bears inhabiting consolidated versus active pack ice. Arctic. 2001; 54: 49–54.
   Web of Science ®Google Scholar
• Ferguson S., Taylor M., Rosing-Asvid A., Born E., Messier F. Relationships between denning of polar bears and conditions of sea ice. Journal of Mammalogy. 2000; 81: 1118–1127.
   Web of Science ®Google Scholar
• Ferguson S.H., Taylor M.K., Messier F. Influence of sea ice dynamics on habitat selection by polar bears. Ecology. 2000; 81: 761–772.
   Web of Science ®Google Scholar
• Fischbach A.S., Amstrup S.C., Douglas D.C. Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes. Polar Biology. 2007; 30: 1395–1405.
   Web of Science ®Google Scholar
• Frair J.L., Nielsen S.E., Merrill E.H., Lele S.R., Boyce M.S., Munro R.H.M., Stenhouse G.B., Beyer H.L. Removing GPS collar bias in habitat selection studies. Journal of Applied Ecology. 2004; 41: 201–212.
   Web of Science ®Google Scholar
• Freitas C., Kovacs K.M., Andersen M., Aars J., Sandven S., Mauritzen M., Pavlova O., Lydersen C. Importance of fast ice and glacier fronts for female polar bears and their cubs during spring in Svalbard, Norway. Marine Ecology Progress Series. 2012; 447: 289–304.
   Web of Science ®Google Scholar
• Furgal C.M., Innes S., Kovacs K.M. Characteristics of ringed seal, Phoca hispida, subnivean structures and breeding habitat and their effects on predation. Canadian Journal of Zoology. 1996; 74: 858–874.
   Web of Science ®Google Scholar
• Gau R.J., Mulders R., Ciarniello L.J., Heard D.C., Chetkiewicz C.B., Boyce M., Munro R., Stenhouse G., Chruszcz B., Gibeau M.L., Milakovic B., Parker K.L. Uncontrolled field performance of Televilt GPS-simplex (Tm) collars on grizzly bears in western and northern Canada. Wildlife Society Bulletin. 2004; 32: 693–701.
   Web of Science ®Google Scholar
• Gerland S., Gascard J.C., Ivanov B., Nielsen C.P., Nilsen E., Pavlova O., Leu E., Tverberg V., Barrault S. Azzolini R. Fast ice evolution in Kongsfjorden compared with other Svalbard fjords. Extended abstract. 8th Ny-Ålesund seminar. 16–17 October 2007. Cambridge, UK. Polarnet Technical Report. 2007; Rome: Earth and Environment Department, National Research Council. 44–46.
   Google Scholar
• Gerland S., Hall R. Variability of fast-ice thickness in Spitsbergen fjords. Annals of Glaciology. 2006; 44: 231–239.
   Google Scholar
• Gerland S., Renner A.H.H., Godtliebsen F., Divine D., Løyning T.B. Decrease of sea ice thickness at Hopen, Barents Sea, during 1966–2007. Geophysical Research Letter. 2008; 35 L06501.
   Web of Science ®Google Scholar
• Gutleb A.C., Cenijn P., van Velzen M., Lie E., Ropstad E., Skaare J.U., Malmberg T., Bergman A., Gabrielsen G.W., Legler J. In vitro assay shows that PCB metabolites completely saturate thyroid hormone transport capacity in blood of wild polar bears (Ursus maritimus). Environmental Science & Technology. 2010; 44: 3149–3154.
   PubMed Web of Science ®Google Scholar
• Haarpaintner J., Haugan P.M., Gascard J.C. Interannual variability of the Storfjorden (Svalbard) ice cover and ice production observed by ERS-2 SAR. Annals of Glaciology. 2001; 33: 430–436.
   Web of Science ®Google Scholar
• Haave M., Ropstad E., Derocher A.E., Lie E., Dahl E., Wiig Ø., Skaare J.U., Jenssen B.M. Polychlorinated biphenyls and reproductive hormones in female polar bears at Svalbard. Environmental Health Perspectives. 2003; 111: 431–436.
   PubMed Web of Science ®Google Scholar
• Hallstadius L., Holm E., Persson B., Aarkrog A., Nilsson K. 137Cs in the Svalbard area. Third international symposium. Radiological protection—advances in theory and practice. Proceedings. Vol. 2. 1982; Reading: Society for Radiological Protection. 500–505.
   Google Scholar
• Harington C.R. The life and status of the polar bear. Oryx. 1965; 8: 169–176.
   Google Scholar
• Harington C.R. Denning habits of the polar bear (Ursus maritimus Phipps). Canadian Wildlife Service Report Series. 1968; 5: 1–30.
   Google Scholar
• Haug T., Nilssen K.T., Øien N., Potelov V. Seasonal distribution of harp seals (Phoca groenlandica) in the Barents Sea. Polar Research. 1994; 13: 163–172.
   Web of Science ®Google Scholar
• Hedberg G.E., Derocher A.E., Andersen M., Rogers Q.R., DePeters E.J., Lonnerdal B., Mazzaro L., Chesney R.W., Hollis B. Milk composition in free-ranging polar bears (Ursus maritimus) as a model for captive rearing milk formula. Zoo Biology. 2011; 30: 550–565.
   Web of Science ®Google Scholar
• Heggberget T., Bjørge A., Swenson J.E., Syvertsen P.O., Wiig Ø., Øien N. Pattedyr. (Mammalia.)orsk Rødliste 2006. (2006 Norwegian Red List.). 2006; Trondheim: Artsdatabanken. 365–372.
   Google Scholar
• Houghton J.T., Ding Y, Griggs D.J., Noguer M., van der Linden P.J., Dai X., Maskell K., Johnson C.A. Climate change 2001. The scientific basis. Contribution of Working Group I to the third assessment report of the Intergovernmental Panel on Climate Change. 2001; Cambridge: Cambridge University Press.
   Google Scholar
• Høyland K.V. Ice thickness, growth and salinity in Van Mijenfjorden, Svalbard, Norway. Polar Research. 2009; 28: 339–352.
   Web of Science ®Google Scholar
• Hunter C.M., Caswell H., Runge M.C., Regehr E.V., Amstrup S.C., Stirling I. Climate change threatens polar bear populations: a stochastic demographic analysis. Ecology. 2010; 91: 2883–2897.
   PubMed Web of Science ®Google Scholar
• Isaksen K., Wiig Ø. Seasonal distribution of harbour seals, bearded seals, white whales and polar bears in the Barents Sea. Norsk Polarinstitutt Meddelelser. 1995; 136: 47–59.
   Google Scholar
• Iversen M., Aars J., Haug T., Alsos I.G., Lydersen C., Bachmann L., Kovacs K.M. The diet of polar bears (Ursus maritimus) from Svalbard, Norway, inferred from scat analysis. Polar Biology. 2013; 36: 561–571.
   Web of Science ®Google Scholar
• Jenssen B.M. Endocrine-disrupting chemicals and climate change: a worst-case combination for Arctic marine mammals and birds?. Environmental Health Perspectives. 2006; 114: 76–80.
   PubMed Web of Science ®Google Scholar
• Jensen S.K., Aars J., Lydersen C., Kovacs K.M., Åsbakk K. The prevalence of Toxoplasma gondii in polar bears and their marine mammal prey: evidence for a marine transmission pathway?. Polar Biology. 2010; 33: 599–606.
   Web of Science ®Google Scholar
• Johnson C.J., Heard D.C., Parker K.L. Expectations and realities of GPS animal location collars: results of three years in the field. Wildlife Biology. 2002; 8: 153–159.
   Web of Science ®Google Scholar
• Jonkel C.J. Some comments on polar bear management. Biological Conservation. 1970; 2: 115–119.
   Google Scholar
• Jonkel C.J., Kolenosky G.B., Robertson R., Russell R.H. Further notes on the polar denning habits. International Conference on Bear Research and Management. 1972; 2: 142–158.
   Google Scholar
• Kershaw P.J., Baxter A. The transfer of reprocessing wastes from north-west Europe to the Arctic. Deep-Sea Research Part II. 1995; 42: 1413–1448.
   Web of Science ®Google Scholar
• Kingsley M.C.S., Stirling I., Calvert W. The distribution and abundance of seals in the Canadian High Arctic, 1980–82. Canadian Journal of Fisheries and Aquatic Science. 1985; 42: 1189–1210.
   Web of Science ®Google Scholar
• Kovacs K.M., Haug T., Lydersen C. Sakshaug E. Marine mammals in the Barents Sea. Ecosystem Barents Sea. 2009; Trondheim: Tapir Academic Press. 453–496.
   Google Scholar
• Kovacs K.M., Lydersen C., Overland J.E., Moore S.E. Impacts of changing sea-ice conditions on Arctic marine mammals. Marine Biodiversity. 2011; 41: 181–194.
   Google Scholar
• Krafft B.A., Kovacs K.M., Lydersen C. Distribution of sex and age groups of ringed seals, Pusa hispida, in the fast-ice breeding habitat of Kongsfjorden, Svalbard. Marine Ecology Progress Series. 2007; 335: 199–206.
   Web of Science ®Google Scholar
• Larsen T. The trapping and study of polar bears, Spitsbergen, 1966. Polar Record. 1967; 13: 589–593.
   Google Scholar
• Larsen T. Polar bear Thalarctos maritimus research in Spitsbergen. Oryx. 1970; 10: 368–372.
   Google Scholar
• Larsen T. Air and ship census of polar bears in Svalbard (Spitsbergen). Journal of Wildlife Management. 1972; 36: 562–570.
   Web of Science ®Google Scholar
• Larsen T. Polar bear denning and cub production in Svalbard, Norway. Journal of Wildlife Management. 1985; 49: 320–326.
   Web of Science ®Google Scholar
• Larsen T. Population biology of the polar bear (Ursus maritimus) in the Svalbard area. Norsk Polarinstitutt Skrifter 184. 1986; Oslo: Norwegian Polar Institute.
   Google Scholar
• Larsen T., Jonkel C., Vibe C. Satellite radio-tracking of polar bears between Svalbard and Greenland. International Conference on Bear Research and Management. 1983; 5: 230–237.
   Google Scholar
• Larsen T.S., Stirling I. The agreement on the conservation of polar bears—its history and future. Report Series 127. 2009; Tromsø: Norwegian Polar Institute.
   Google Scholar
• Lentfer J.W. Polar bear tagging in Alaska, 1968. Polar Record. 1969; 14: 459–462.
   Google Scholar
• Lentfer J.W. Polar bear denning on drifting sea ice. Journal of Mammalogy. 1975; 56: 716–718.
   Web of Science ®Google Scholar
• Lentfer J.W., Hensel R.J. Martinka C.J., McArthur K.L. Alaskan polar bear denning. Bears—their biology and management. A selection of papers from the Fourth International Conference on Bear Research and Management held at Kalispell, Montana, USA. February 1977. 1980; Washington, DC: Bear Biology Association. 101–108.
   Google Scholar
• Letcher R.J., Bustnes J.O., Dietz R., Jenssen B.M., Jorgensen E.H., Sonne C., Verreault J., Vijayan M.M., Gabrielsen G.W. Exposure and effects assessment of persistent organohalogen contaminants in Arctic wildlife and fish. Science of the Total Environment. 2010; 408: 2995–3043.
   PubMed Web of Science ®Google Scholar
• Letcher R.J., Klasson-Wehler E., Bergman Å., Paasivirta J. Passivirts J. Methyl sulfone and hydroxylated metabolites of polychlorinated biphenyls. The handbook of environmental chemistry. 2000; Berlin: Springer. 315–359.
   Google Scholar
• Lie E., Larsen H.J.S., Larsen S., Johnsen G.M., Derocher A.E., Lunn N.J., Norstrom R.J., Wiig Ø., Skaare J.U. Does high organochlorine (OC) exposure impair the resistance to infection in polar bears (Ursus maritimus)? Part I. Effect of OCs on the humoral immunity. Journal of Toxicology and Environmental Health Part A Current Issues. 2004; 67: 555–582.
   PubMed Web of Science ®Google Scholar
• Lie E., Larsen H.J.S., Larsen S., Johansen G.M., Derocher A.E., Lunn N.J., Norstrom R.J., Wiig Ø., Skaare J.U. Does high organochlorine (OC) exposure impair the resistance to infection in polar bears (Ursus maritimus)? Part II. Possible effect of OCs on mitogen- and antigen-induced lymphocyte proliferation. Journal of Toxicology and Environmental Health Part A Current Issues. 2005; 68: 457–484.
   PubMed Web of Science ®Google Scholar
• Lindenmayer D.B., Likens G.E. Adaptive monitoring: a new paradigm for long-term research and monitoring. Trends in Ecology & Evolution. 2009; 24: 482–486.
   PubMed Web of Science ®Google Scholar
• Lønø O. The polar bear (Ursus maritimus Phipps) in the Svalbard area. Norsk Polarinstitutt Skrifter 149. 1970; Oslo: Norwegian Polar Institute.
   Google Scholar
• Lunn N.J., Schliebe S., Born E.W. Polar bears. Proceedings of the 13th Working Meeting of the IUCN/SSC Polar Bear Specialist Group 23–28 June 2001. 2002; Nuuk, Greenland. Gland: IUCN Species Survival Commission.
   Google Scholar
• Lydersen C., Wolkers H., Severinsen T., Kleivane L., Nordøy E.S., Skaare J.U. Blood is a poor substrate for monitoring pollution burdens in phocid seals. Science of the Total Environment. 2002; 292: 193–203.
   PubMed Web of Science ®Google Scholar
• Marchesini G.R., Meimaridou A., Haasnoot W., Meulenberg E., Albertus F., Mizuguchi M., Takeuchi M., Irth H., Murk A.J. Biosensor discovery of thyroxine transport disrupting chemicals. Toxicology and Applied Pharmacology. 2008; 232: 150–160.
   PubMed Web of Science ®Google Scholar
• Mauritzen M. Patterns and processes in female polar bear space-use. 2002; University of Oslo. PhD thesis.
   Google Scholar
• Mauritzen M., Belikov S.E., Boltunov A.N., Derocher A.E., Hansen E., Ims R.A., Wiig Ø., Yoccoz N. Functional responses in polar bear habitat selection. Oikos. 2003; 100: 112–124.
   Web of Science ®Google Scholar
• Mauritzen M., Derocher A.E., Wiig Ø. Space-use strategies of female polar bears in a dynamic sea ice habitat. Canadian Journal of Zoology. 2001; 79: 1704–1713.
   Web of Science ®Google Scholar
• Mauritzen M., Derocher A.E., Wiig Ø., Belikov S.E., Boltunov A., Hansen E., Garner G.W. Using satellite telemetry to define spatial population structure in polar bears in the Norwegian and western Russian Arctic. Journal of Applied Ecology. 2002; 39: 79–90.
   Web of Science ®Google Scholar
• McKinney M.A., Iverson S., Fisk A.T., Sonne C., Rigét F.F., Letcher R.J., Arts M.T., Born E.W., Rosing-Asvid A., Dietz R. Global change effects on the long-term feeding ecology and contaminant exposures of East Greenland polar bears. Global Change Biology. 2013; 19: 2360–2372.
   Web of Science ®Google Scholar
• McKinney M.A., Letcher R.J., Aars J., Born E.W., Branigan M., Dietz R., Evans T.J., Gabrielsen G.W., Peacock E., Sonne C. Flame retardants and legacy contaminants in polar bears from Alaska, Canada, East Greenland and Svalbard, 2005–2008. Environment International. 2011; 37: 365–374.
   PubMed Web of Science ®Google Scholar
• Mckinney M.A., Peacock E., Letcher R.J. Sea ice-associated diet change increases the level of chlorinated and bromiated contaminants in polar bears. Environmental Science & Technology. 2009; 43: 4334–4339.
   Web of Science ®Google Scholar
• Molnár P.K., Derocher A.E., Klanjscek T., Lewis M.A. Predicting climate change impacts on polar bear litter size. Nature Communications. 2011; 2: 186.
   Web of Science ®Google Scholar
• Molnár P.K., Derocher A.E., Lewis M.A., Taylor M.K. Modelling the mating system of polar bears: a mechanistic approach to the allee effect. Proceedings of the Royal Society B. 2008; 275: 217–226.
   Web of Science ®Google Scholar
• Molnár P.K., Derocher A.E., Thiemann G.W., Lewis M.A. Predicting survival, reproduction and abundance of polar bears under climate change. Biological Conservation. 2010; 143: 1612–1622.
   Web of Science ®Google Scholar
• Molnár P.K., Klanjscek T., Derocher A.E., Obbard M.E., Lewis M.A. A body composition model to estimate mammalian energy stores and metabolic rates from body mass and body length, with application to polar bears. Journal of Experimental Biology. 2009; 212: 2313–2323.
   Web of Science ®Google Scholar
• Morales J.M., Haydon D.T., Frair J., Holsiner K.E., Fryxell J.M. Extracting more out of relocation data: building movement models as mixtures of random walks. Ecology. 2004; 85: 2436–2445.
   Web of Science ®Google Scholar
• Muir D.C.G., Backus S., Derocher A.E., Dietz R., Evans T.J., Gabrielsen G.W., Nagy J., Norstrom R.J., Sonne C., Stirling I., Taylor M.K., Letcher R.J. Brominated flame retardants in polar bears (Ursus maritimus) from Alaska, the Canadian Arctic, East Greenland, and Svalbard. Environmental Science & Technology. 2006; 40: 449–455.
   PubMed Web of Science ®Google Scholar
• Muir D.C.G., Norstrom R.J., Simon M. Organochlorine contaminants in the Arctic marine food chains: accumulation of specific polychlorinated biphenyls and chlordane-related compounds. Environmental Science & Technology. 1988; 22: 1071–1079.
   PubMed Web of Science ®Google Scholar
• Nilssen K.T., Pedersen O.P., Folkow L.P., Haug T. Food consumption estimates of Barents Sea harp seals. NAMMCO Scientific Publications. 2000; 2: 9–27.
   Google Scholar
• Nilsson A.E., Huntington H.P. Arctic pollution 2009. 2009; Oslo: Arctic Monitoring and Assessment Programme.
   Google Scholar
• Nordøy E.S., Folkow L.P., Potelov V., Prichtchemikhine V., Blix A.S. Migratory patterns and dive behaviour of Barents Sea harp seals. Abstracts: the World Marine Mammal Science Conference. Monaco. 1998; January. 20–24 La Rochelle: Center for Research on Marine Mammals. 97.
   Google Scholar
• Norheim G., Skaare J.U., Wiig Ø. Some heavy metals, essential elements, and chlorinated hydrocarbons in polar bear (Ursus maritimus) at Svalbard. Environmental Pollution. 1992; 77: 51–57.
   PubMed Web of Science ®Google Scholar
• Norstrom R.J., Belikov S.E., Born E.W., Garner G.W., Malone B., Olpinski S., Ramsay M.A., Schliebe S., Stirling I., Stishov M.S., Taylor M.K., Wiig Ø. Chlorinated hydrocarbon contaminants in polar bears from eastern Russia, North America, Greenland, and Svalbard: biomonitoring of Arctic pollution. Archives of Environmental Contamination and Toxicology. 1998; 35: 354–367.
   PubMed Web of Science ®Google Scholar
• Obbard M.E., Thiemann G.W., Peacock E., DeBruyn T.D. Polar bears. Proceedings of the 15th working meeting of the IUCN Polar Bear Specialist Group 29 June–3 July 2009. 2010; Gland: International Union for the Conservation of Nature. Occasional Paper of the IUCN Species Survival Commission 43.
   Google Scholar
• Oehme M. Dispersion and transport paths of toxic persistent organochlorines to Arctic—levels and consequences. Science of the Total Environment. 1991; 106: 43–53.
   PubMed Web of Science ®Google Scholar
• Oksanen A., Åsbakk K., Prestrud K.W., Aars J., Derocher A.E., Tryland M., Wiig Ø., Dubey J.P., Sonne C., Dietz R., Andersen M., Born E.W. Prevalence of antibodies against Toxoplasma gondii in polar bears (Ursus maritimus) from Svalbard and East Greenland. Journal of Parasitology. 2009; 95: 89–94.
   Web of Science ®Google Scholar
• Olsen G.H., Mauritzen M., Derocher A.E., Sørmo E.G., Skaare J.U., Wiig Ø., Jenssen B.M. Space-use strategy is an important determinant of PCB concentrations in female polar bears in the Barents Sea. Environmental Science & Technology. 2003; 37: 4919–4924.
   Web of Science ®Google Scholar
• Olsson M., Andersson Ö., Bergman Å., Blomkvist G., Frank A., Rappe C. Contaminants and diseases in seals from Swedish waters. Ambio. 1992; 21: 561–562.
   Web of Science ®Google Scholar
• Øritsland N.A. Temperature regulation of the polar bear (Thalarctos maritimus). Journal of Comparable Biochemistry and Physiology Series A. 1970; 37: 225–233.
   Google Scholar
• Oskam I.C., Ropstad E., Dahl E., Lie E., Derocher A.E., Wiig Ø., Larsen S., Wiger R., Skaare J.U. Organochlorines affect the major androgenic hormone, testosterone, in male polar bears (Ursus maritimus) at Svalbard. Journal of Toxicology and Environmental Health Part A. 2003; 66: 2119–2139.
   PubMed Web of Science ®Google Scholar
• Oskam I.C., Ropstad E., Lie E., Derocher A.E., Wiig Ø., Dahl E., Larsen S., Skaare J.U. Organochlorines affect the steroid hormone cortisol in free-ranging polar bears (Ursus maritimus) at Svalbard, Norway. Journal of Toxicology and Environmental Health Part A. 2004; 67: 959–977.
   PubMed Web of Science ®Google Scholar
• Overrein Ø. Virkninger av motorferdsel på fauna og vegetasjon: kunnskapsstatus med relevans for Svalbard. (Effects of motorized traffic on fauna and vegetation: the status of knowledge relevant for Svalbard.) Report Series 119. 2002; Tromsø: Norwegian Polar Institute.
   Google Scholar
• Parks E.K., Derocher A.E., Lunn N.J. Seasonal and annual movement patterns of polar bears on the sea ice of Hudson Bay. Canadian Journal of Zoology. 2006; 84: 1281–1294.
   Web of Science ®Google Scholar
• Parovshchikov V.Y. A study on the population of polar bear, Ursus (Thalarctos) maritimus Phipps, of Franz Joseph Land. Acta Societatis Zoologicae Bohemoslovenicae. 1964; 28: 167–177.
   Google Scholar
• Pentreath R.J., Jefferies D.F., Talbot J.W., Lovett M.B., Harvey B.R. Transuranic cycling behaviour in marine environment. IAEA-TECDOC-265. 1982; Vienna: International Atomic Energy Agency.
   Google Scholar
• Pilfold N.W., Derocher A.E., Stirling I., Richardson E., Andriashek D. Age and sex composition of seals killed by polar bears in the Eastern Beaufort Sea. PLoS One. 2012; 7(7):e41429 10.1371/journal.pone.0041429.
   Google Scholar
• Polar Bear Range States. Circumpolar action plan: conservation strategy for polar bears. A product of the representatives of the parties to the 1973 Agreement on the Conservation of Polar Bears. 2015. Accessed on the internet at http://naalakkersuisut.gl/en/Naalakkersuisut/Departments/Fiskeri-Fangst-og-Landbrug/Isbjorn/The-Circumpolar-Action-Plan-and-Executive-Summary on 21 June 2016.
   Google Scholar
• Polischuk S.C. Organochlorine dynamics in free-ranging polar bears and their cubs. 1999; University of Saskatchewan. PhD thesis.
   Google Scholar
• Polischuk S.C., Norstrom R.J., Ramsay M.A. Body burdens and tissue concentrations of organochlorines in polar bears (Ursus maritimus) vary during seasonal fasts. Environmental Pollution. 2002; 118: 29–39.
   PubMed Web of Science ®Google Scholar
• Prestrud P., Stirling I. The international Polar Bear Agreement and the current status of polar bear conservation. Aquatic Mammals. 1994; 20: 1–12.
   Google Scholar
• Ramsay M., Stirling I. Fidelity of female polar bears to winter den sites. Journal of Mammalogy. 1990; 71: 233–236.
   Web of Science ®Google Scholar
• Reeves R.R. Distribution, abundance and biology of ringed seals (Phoca hispida): an overview. NAMMCO Scientific Publications. 1998; 1: 9–45.
   Google Scholar
• Regehr E.V., Hunter C.M., Caswell H., Amstrup S.C., Stirling I. Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice. Journal of Animal Ecology. 2010; 79: 117–127.
   PubMed Web of Science ®Google Scholar
• Regehr E.V., Lunn N.J., Amstrup S.C., Stirling L. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay. Journal of Wildlife Management. 2007; 71: 2673–2683.
   Web of Science ®Google Scholar
• Richardson E., Stirling I., Hik D.S. Polar bear (Ursus maritimus) maternity denning habitat in western Hudson Bay: a bottom-up approach to resource selection functions. Canadian Journal of Zoology. 2005; 83: 860–870.
   Web of Science ®Google Scholar
• Rigét F., Bossi R., Sonne C., Vorkamp K., Dietz R. Trends of perfluorochemicals in Greenland ringed seals and polar bears: indications of shifts to decreasing trends. Chemosphere. 2013; 93: 1607–1614.
   Web of Science ®Google Scholar
• Rode K.D., Amstrup S.C., Regehr E.V. Reduced body size and cub recruitment in polar bears associated with sea ice decline. Ecological Applications. 2010; 20: 768–782.
   PubMed Web of Science ®Google Scholar
• Rondinini C., Rodrigues A.S.L., Boitani L. The key elements of a comprehensive global mammal conservation strategy. Philosophical Transactions of the Royal Society B. 2011; 355: 2591–2597.
   Google Scholar
• Sahanatien V., Derocher A.E. Monitoring sea ice habitat fragmentation for polar bear conservation. Animal Conservation. 2012; 15: 397–406.
   Web of Science ®Google Scholar
• Sander G., Hanssen-Bauer I., Bjørge A., Prestrud P. Miljøovervåking av Svalbard og Jan Mayen—MOSJ. Report Series 123. 2005; Tromsø: Norwegian Polar Institute.
   Google Scholar
• Shapiro I., Colony R., Vinje T. April sea ice extent in the Barents Sea, 1850–2001. Polar Research. 2003; 22: 5–10.
   Web of Science ®Google Scholar
• Skaare J.U., Bernhoft A., Derocher A., Gabrielsen G.W., Goksøyr A., Henriksen E., Larsen H.J., Lie E., Wiig Ø. Organochlorines in top predators at Svalbard—occurrence, levels and effects. Toxicological Letters. 2000; 112/113: 103–109.
   Web of Science ®Google Scholar
• Smith T.G. Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat. Canadian Journal of Zoology. 1980; 58: 2201–2209.
   Web of Science ®Google Scholar
• Smith T.G., Lydersen C. Availability of suitable land-fast ice and predation as factors limiting ringed seal populations, Phoca hispida, in Svalbard. Polar Research. 1991; 10: 585–594.
   Web of Science ®Google Scholar
• Smith T.G., Stirling I. The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures. Canadian Journal of Zoology. 1975; 53: 1297–1305.
   Web of Science ®Google Scholar
• Sonne C. Health effects from long-range transported contaminants in Arctic top predators: an integrated review based on studies of polar bears and relevant model species. Environmental International. 2010; 36: 461–491.
   PubMed Web of Science ®Google Scholar
• Stirling I. Midsummer observations on behavior of wild polar bears (Ursus maritimus). Canadian Journal of Zoology. 1974; 52: 1191–1198.
   Web of Science ®Google Scholar
• Stirling I., Andriashek D. Terrestrial maternity denning of polar bears in the eastern Beaufort Sea area. Arctic. 1992; 45: 363–366.
   Web of Science ®Google Scholar
• Stirling I., Andriashek D., Calvert W. Habitat preferences of polar bears in the western Canadian Arctic in late winter and spring. Polar Record. 1993; 29: 13–24.
   Google Scholar
• Stirling I., Archibald W.R. Aspects of predation of seals by polar bears. Journal of the Fisheries Research Board of Canada. 1977; 34: 1126–1129.
   Web of Science ®Google Scholar
• Stirling I., Derocher A.E. Possible impacts of climatic warming on polar bears. Arctic. 1993; 46: 240–245.
   Web of Science ®Google Scholar
• Stirling I., Derocher A.E. Effects of climate warming on polar bears: a review of the evidence. Global Change Biology. 2012; 18: 2694–2706.
   PubMed Web of Science ®Google Scholar
• Stirling I., Lunn N.J., Iacozza J. Long-term trends in the population ecology of polar bears in western Hudson Bay in relation to climatic change. Arctic. 1999; 52: 294–306.
   Web of Science ®Google Scholar
• Stirling I., McEwan E.H. Caloric value of whole ringed seals (Phoca hispida) in relation to polar bear (Ursus maritimus) ecology and hunting behavior. Canadian Journal of Zoology. 1975; 53: 1021–1027.
   Web of Science ®Google Scholar
• Strand P., Howard B.J., Aarkrog A., Balonov M., Tsaturov Y., Bewers J.M., Salo A., Sickel M., Bergman R., Rissanen K. Radioactive contamination in the Arctic—sources, dose assessment and potential risks. Journal of Environmental Radioactivity. 2002; 60: 5–21.
   Web of Science ®Google Scholar
• Taylor M.K., Demaster D.P., Bunnell F.L., Schweinsburg R.E. Modelling the sustainable harvest of female polar bears. Journal of Wildlife Management. 1987; 51: 811–820.
   Web of Science ®Google Scholar
• Taylor M.K., Laake J., McLoughlin P.D., Born E.W., Cluff H.D., Ferguson S.H., Rosing-Asvid A., Schweinsburg R., Messier F. Demography and viability of a hunted population of polar bears. Arctic. 2005; 58: 203–214.
   Web of Science ®Google Scholar
• Taylor M.K., Lee L.J. Distribution and abundance of Canadian polar bear populations: a management perspective. Arctic. 1995; 48: 147–154.
   Web of Science ®Google Scholar
• Thiemann G.W., Iverson S.J., Stirling I. Polar bear diets and Arctic marine food webs: insights from fatty acid analysis. Ecological Monographs. 2008; 78: 591–613.
   Web of Science ®Google Scholar
• Tryland M., Derocher A.E., Wiig Ø., Godfroid J. Brucella sp antibodies in polar bears from Svalbard and the Barents Sea. Journal of Wildlife Diseases. 2001; 37: 523–531.
   Web of Science ®Google Scholar
• Tryland M., Neuvonen E., Huovilainen A., Tapiovaara H., Osterhaus A., Wiig O., Derocher A.E. Serologic survey for selected virus infections in polar bears at Svalbard. Journal of Wildlife Diseases. 2005; 41: 310–316.
   Web of Science ®Google Scholar
• Verreault J., Muir D.C.G., Norstrom R.J., Stirling I., Fisk A.T., Gabrielsen G.W., Derocher A.E., Evans T., Dietz R., Sonne C., Sandala G.M., Taylor M.K., Nagy J., Letcher R.J. Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Svalbard, East Greenland, Alaska and the Canadian Arctic during 1999–2002. Science of the Total Environment. 2005; 351: 369–390.
   Web of Science ®Google Scholar
• Villanger G.D., Jenssen B.M., Fjeldberg R.R., Letcher R.J., Muir D.C.G., Kirkegaard M., Sonne C., Dietz R. Exposure to mixtures of organohalogen contaminants and associative interactions with thyroid hormones in East Greenland polar bears (Ursus maritimus). Environment International. 2011; 37: 694–708.
   PubMed Web of Science ®Google Scholar
• Vinebrooke R.D., Cottingham K.L., Norberg J., Scheffer M., Dodson S.I., Maberly S.C., Sommer U. Impacts of multiple stressors on biodiversity and ecosystem functioning: the role of species co-tolerance. Oikos. 2004; 104: 451–457.
   Web of Science ®Google Scholar
• Vongraven D. Guest editorial: the ballyhoo over polar bears. Polar Research. 2009; 28: 323–326.
   Web of Science ®Google Scholar
• Vongraven D., Aars J., Amstrup S., Atkinson S.N., Belikov S.E., Born E.W., DeBruyn T.D., Derocher A.E., Durner G., Gill M., Lunn N., Obbard M.E., Omelak J., Ovsyanikov N., Peacock E., Richardson E., Sahanatien V., Stirling I., Wiig Ø. A circumpolar monitoring framework for polar bears. Ursus Monograph Series 5. Ursus 23. 2012; 1–66.
   Google Scholar
• Vongraven D., Peacock E. Development of a pan-Arctic monitoring plan for polar bears: background paper. CAFF Monitoring Series Report 1. 2011; Akureyri: Conservation of Arctic Flora and Fauna.
   Google Scholar
• Watts P.D., Hansen S.E. Cyclic starvation as a reproductive strategy in the polar bear. Symposia of the Zoological Society of London. 1987; 57: 305–318.
   Google Scholar
• Wiig Ø. Distribution of polar bears (Ursus maritimus) in the Svalbard area. Journal of Zoology. 1995; 237: 515–529.
   Web of Science ®Google Scholar
• Wiig Ø. Survival and reproductive rates for polar bears at Svalbard. Ursus. 1998; 10: 25–32.
   Google Scholar
• Wiig Ø. Are polar bears threatened?. Science. 2005; 309: 1814–1815.
   Web of Science ®Google Scholar
• Wiig Ø., Aars J., Born E.W. Effects of climate change on polar bears. Science Progress. 2008; 91: 151–173.
   PubMedGoogle Scholar
• Wiig Ø., Amstrup S., Atwood T., Laidre K., Lunn N., Obbard M., Regehr E., Thiemann G. Ursus maritimus. 2015. The IUCN Red List of threatened species 2015, e.T22823A14871490, http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T22823A14871490.en. Accessed on the internet at http://www.iucnredlist.org/details/22823/0 on 27 May 2016.
   Google Scholar
• Wiig Ø., Derocher A. Garner G.W. Application of aerial survey methods to polar bears in the Barents Sea. Marine mammal survey and assessment methods. 1999; Rotterdam: Balkema. 27–36.
   Google Scholar
• Wiig Ø., Derocher A.E., Belikov S.E. Ringed seal (Phoca hispida) breeding in the drifting pack ice of the Barents Sea. Marine Mammal Science. 1999; 15: 595–598.
   Web of Science ®Google Scholar
• Wilson K.A., Evans M.C., Di Marco M., Green D.C., Boitani L., Possingham H.P., Chiozza F., Rondinini C. Prioritizing conservation investments for mammal species globally. Philosophical Transactions of the Royal Society B. 2011; 366: 2670–2680.
   Web of Science ®Google Scholar
• Wolkers H., Krafft B.A., van Bavel B., Helgason L.B., Lydersen C., Kovacs K.M. Biomarker responses and decreasing contaminant levels in ringed seals (Pusa hispida) from Svalbard, Norway. Journal of Toxicology and Environmental Health. 2008; 71: 1009–1018.
   PubMed Web of Science ®Google Scholar
• Yasuda T., Arai N. Fine-scale tracking of marine turtles using GPS-Argos PTTs. Zoological Science. 2005; 22: 547–553.
   Web of Science ®Google Scholar
• Zeyl E., Ehrich D., Aars J., Bachmann L., Wiig Ø. Denning-area fidelity and mitochondrial DNA diversity of female polar bears (Ursus maritimus) in the Barents Sea. Canadian Journal of Zoology. 2010; 88: 1139–1148.
   Web of Science ®Google Scholar