Baffin Bay (BB)

In 1998, the population size was estimated to be 2,074. A 2004 estimate of less than 1,600 bears was simulated from birth and death rates estimated in 1998 and harvest rates from Greenland and Canada. On-going re-assessment, new estimate expected by the end of 2014.

Status table outtake

Size Trend Sea ice metrics Human-caused removals 2010–2014
Estimate /
95% CI
Year Method Relative to historic level
(approx. 25-yr past)
Current (approx. 12-yr
period centered on present)
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
1546
690-2402
2004PVA
(Based on physical capture-recapture estimate from 1998)
Data deficientDeclining-7.3/5.2-18.9144149132137
See also the complete table (all subpopulations)

Comments, vulnerabilities and concerns

Harvest, current and projected habitat decline, declining body condition. Population estimate for 2004 is simulated from vital rates measured in 1997. 100% of PVA runs resulted in population decline after 10 years. Subpopulation is currently being re-assessed using genetic capture-recapture.

Status and delineation

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

Based on the movements of adult females with satellite radio-collars and recaptures of tagged animals, the Baffin Bay (BB) subpopulation of polar bears is bounded by the North Water Polynya to the north, Greenland to the east and Baffin Island, Nunavut, Canada to the west (Taylor and Lee 1995, Taylor et al. 2001, Laidre et al. 2012). A distinct southern boundary at Cape Dyer, Baffin Island, is evident from the movements of tagged bears (Stirling et al. 1980; Peacock et al. 2012) and from polar bears monitored by satellite telemetry (Taylor et al. 2001). This boundary overlaps with the northern boundary of the Davis Strait subpopulation. Studies of microsatellite genetic variation have not revealed significant differences between polar bears in BB and neighboring Kane Basin, although there was significant genetic variation between polar bears in BB and those in Davis Strait (Paetkau et al. 1999; Peacock et al. 2015). However, polar bears in northern Davis Strait cluster with BB and Kane Basin bears with polar bears from the Canadian Archipelago proper into the Canadian Archipelago genetic cluster (Peacock et al. 2015 ). An initial subpopulation estimate of 300 – 600 bears was based on mark-recapture data collected in spring (1984 – 1989) in which the capture effort was restricted to shore-fast ice and the floe edge off northeast Baffin Island. However, work in the early 1990’s showed that an unknown proportion of the subpopulation is typically offshore during the spring and, therefore, unavailable for capture. A second study (1993 – 1997) was carried out during September and October, when all polar bears were ashore in summer retreat areas on Bylot and Baffin islands (Taylor et al. 2005). Taylor et al. (2005) estimated the number of polar bears in BB at 2,074 ± 226 (SE). The most recent (2004) abundance estimate was estimated to be 1,600 bears by Taylor et al. (2005) based on simulations using vital rates from the 1993-1997 capture study and pooled Canadian and Greenland harvest records up to 2004. This abundance estimate presented to the Joint Commission under the Greenland and Canada MOU, is recognized as being out of date and current status in BB is unclear. The sub-population is currently undergoing re-assessment and a new abundance estimate is expected by the end of 2015.

References

Laidre, K.L., Born, E.W., Gurarie, E., Wiig, O., Dietz, R. and Stern, H. 2012. Females roam while males patrol: divergence in breeding season movements of pack.ice polar bears (Ursus maritimus). Proceedings of the Royal Society B 280: 1-10.

Peacock, E., Laake, J., Laidre, K.L., Born, E.W. and Atkinson, S.N. 2012. The utility of harvest recoveries of marked individuals to assess polar bear (Ursus maritimus) survival. Arctic 65: 391-400.

Peacock, E., Sonsthagen, S.A., Obbard, M.E., Boltunov, A., Regehr, E.V., Ovsyanikov, N., Aars, J., Atkinson, S.N., Sage, G.K., Hope, A.G., Zeyl, E., Bachmann, L., Ehrich, D., Scribner, K.T., Amstrup, S.C., Belikov, S., Born, E., Derocher, A.E., Stirling, I., Taylor, M.K., Wiig, Ø., Paetkau, D., and Talbot, S.L. 2015. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic. Plos One 10: e112021.

Paetkau, D., Amstrup, S.C., Born, E.W., Calvert, W., Derocher, A.E., Garner, G.W., Messier, F., Stirling, I., Taylor, M.K., Wiig, Ø., and Strobeck, C. 1999. Genetic structure of the world's polar bear populations. Molecular Ecology 8: 1571-1584.

Rode, K.D., Peacock, E., Taylor, M., Stirling, I., Born, E.W., Laidre, K.L. and Wiig, Ø. 2012. A tale of two polar bear populations: ice habitat, harvest, and body condition. Population Ecology 54: 3-18.

Stirling, I., Calvert, W., and Andriashek, D. 1980. Population ecology studies of the polar bear in the area of southeastern Baffin Island. 44 ed. pp. 33 pp.

Taylor, M. and Lee, J. 1995. Distribution and abundance of Canadian polar bear populations: A management perspective. Arctic 48: 147-154.

Taylor, M.K., Akeeagok, S., Andriashek, D., Barbour, W., Born, E.W., Calvert, W., Dean Cluff, H., 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.

Taylor, M.K., Laake, J., McLoughlin, P.D., Born, E.W., Cluff, H.D., Ferguson, S.H., Rosing-Asvid, A., Schweinsburg, R. and Messier, F. 2005. Demography and viability of a hunted population of polar bears. Arctic 58:203-214.