Norwegian Bay (NW)

A population size of 1203 was estimated in 1998. The population is now data deficient, previously thought to be declining.

Status table outtake

Size Sea ice metrics Human-caused removals 2010–2014
Estimate /
95% CI
Year Method Change in spring ice retreat / Change in fall ice advance (days per decade) Change in summer sea ice area (percent change per decade) 5-yr mean Last year
Potential Actual Potential Actual
203
115-291
1997Physical capture-recapture-1.3/4.3-2.342.241
See also the complete table (all subpopulations)

Comments, vulnerabilities and concerns

Initial PVA simulations resulted in population decline after 10 years, however vital rates from 2 populations were pooled for the analyses. Projections of decline were also high because of small sample size. Current data are >15 years old; small population.

Status and delineation

Norwegian Bay subpopulation mapThe Norwegian Bay area. See also the complete map (all subpopulations).

The Norwegian Bay subpopulation appears to be genetically unique (Malenfant et al. 2016). This subpopulation is bounded by heavy multi-year ice to the west, islands to the north, east, and west, and polynyas to the south (Stirling et al. 1993, Stirling 1997; Taylor et al. 2008). Data collected during mark-recapture studies, and from satellite radiotracking of adult female polar bears, it appears that most of the polar bears in this subpopulation are concentrated along the coastal tide cracks and ridges along the north, east, and southern boundaries (Taylor et al. 2001). The most current (1993 – 97) estimate is 203 ± 44 (SE; Taylor et al. 2008). Survival rate estimates for the NW subpopulation were derived from pooled Lancaster Sound and NW data because the subpopulations are adjacent and the number of bears captured in NW was too small to generate reliable survival estimates. The 5-year mean harvest (2009/10 – 2013/14) has been well below a sustainable harvest level for that population size. Population data are dated.

References

Canadian Wildlife Service. 2009. Nunavut consultation report – Consultations on the proposed listing of the Polar Bear as Special Concern under the Species at Risk Act. Report submitted to the Nunavut Wildlife Management Board in accordance with Step 3.8 of the Memorandum of Understanding to Harmonize the Designation of Endangered Species under the Nunavut Land Claims Agreement and the Species at Risk Act, 249 pp. [available at: http://assembly.nu.ca/library/Edocs/2009/001149-e.pdf].

Derocher, A. E., Lunn, N. J. and Stirling, I. 2004. Polar bears in a warming climate. Integr Comp Biol 44:163-176.

Howell, S.E.L., Tivy, A., Yackel, J.J. and McCourt S. 2008. Multi-year sea-ice conditions in the Western Canadian Arctic Archipelago region of the Northwest Passage: 1968-2006. Atmosphere-Ocean, 46:229-242.

Kingsley, M. C. S., Stirling, I. and Calvert, W. 1985. The distribution and abundance of seals in the Canadian High Arctic, 1980-82. Can. J. Fish. Aquat.Sci. 42:1189-1210.

Malenfant, R.M., Davis, C.S., Cullingham, C.I., Coltman, D.W. 2016 Circumpolar genetic structure and recent gene flow of polar bears: a reanalysis. PLoS ONE 11(3): e0148967. doi:10.1371/journal. pone.0148967.

Markus, T., Stroeve, J. C. and Miller J. 2009. Recent changes in Arctic sea ice melt onset, freezeup, and melt season length. J. Geophys. Res. 114:C12024, doi:10.1029/2009JC005436.

Maslanik, J., Stroeve, J., Fowler, C. and Emery W. 2011. Distribution and trends in Arctic sea ice through spring 2011. Geophys. Res. Letters 38:L13502, doi:10.1029/2011GL047735.

Sou, T. and Flato G. 2009. Sea ice in the Canadian Arctic Archipelago: modeling the past (1950-2004) and the future (2041-60). J. Climate 22:2181-2198.

Stirling, I. 1997. The importance of polynas, ice edges and leads to marine mammals and birds. J. Mar. Syst. 10:9-21.

Stirling, I., Andriashek, D. and Calvert, W.1993. Habitat preferences of polar bears in the western Canadian Arctic in late winter and spring. Polar Rec. 29:13-24.

Taylor, M.K., Laake, J., McLoughlin, P.D., Cluff, H.D. and Messier, F. 2008. Mark-recapture and stochastic population models for polar bears of the high Arctic. Arctic 61:143-152.

Taylor, M.K., Akeeagok, S., Andriashek, D., Barbour, W., Born, E.W., Calvert, W., Cluff, H.D., Ferguson, S., Laake, J., Rosing-Asvid, A., Stirling, I. and Messier, F. 2001. Delineating Canadian and Greenland polar bear (Ursus maritimus) populations by cluster analysis of movements. Can. J. Zool. 79:690-709.