Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022;45(1):89-100.
doi: 10.1007/s00300-021-02974-6. Epub 2021 Nov 22.

An on-ice aerial survey of the Kane Basin polar bear (Ursus maritimus) subpopulation

Øystein Wiig  1 , Stephen N Atkinson  2 , Erik W Born  3 , Seth Stapleton  4 , Todd Arnold  5 , Markus Dyck  2 , Kristin L Laidre  3   6 , Nicholas J Lunn  7 , Eric V Regehr  6
Affiliations

An on-ice aerial survey of the Kane Basin polar bear (Ursus maritimus) subpopulation

Øystein Wiig et al. Polar Biol. 2022.

Abstract

There is an imminent need to collect information on distribution and abundance of polar bears (Ursus maritimus) to understand how they are affected by the ongoing decrease in Arctic sea ice. The Kane Basin (KB) subpopulation is a group of high-latitude polar bears that ranges between High Arctic Canada and NW Greenland around and north of the North Water polynya (NOW). We conducted a line transect distance sampling aerial survey of KB polar bears during 28 April-12 May 2014. A total of 4160 linear kilometers were flown in a helicopter over fast ice in the fjords and over offshore pack ice between 76° 50' and 80° N'. Using a mark-recapture distance sampling protocol, the estimated abundance was 190 bears (95% lognormal CI: 87-411; CV 39%). This estimate is likely negatively biased to an unknown degree because the offshore sectors of the NOW with much open water were not surveyed because of logistical and safety reasons. Our study demonstrated that aerial surveys may be a feasible method for obtaining abundance estimates for small subpopulations of polar bears.

Keywords: Abundance; Aerial survey; Distance sampling; Kane Basin; North Water Polynya; Polar bear; Ursus maritimus.

PubMed Disclaimer

Conflict of interest statement

Conflict of interestThe authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1
Transects surveyed and polar bear (Ursus maritimus) groups sighted during an aerial survey of the Kane Basin subpopulation during April–May, 2014. Transects and sightings are overlaid on a MODIS image (1 km resolution; available: http://modis.gsfc.nasa.gov/) collected on 5 May 2014. Sea ice in southeastern Kane Basin (i.e., to left of figure legend) was not sampled due to safety and logistical constraints presented by the North Water polynya and because we anticipated very low densities of polar bears (see text). Position of the Kane Basin subpopulation of polar bears in the Arctic is shown in upper left corner. Positions of surrounding subpopulations Norwegian Bay, Lancaster Sound and Baffin Bay are indicated
Fig. 2
Fig. 2
Estimated detection probabilities of polar bear (Ursus maritimus) clusters to front- and rear seat observers as a function of distance from transect line, as estimated from the mark-recapture submodel of program MRDS. The effect of rough ice (red line) is plotted for the front-seat observer, whereas the effect of reduced visibility out to 75 m is plotted for the rear seat observer. Note that rear seat observers detected 1 of 3 available bears at 0–75 m, so detection probability was not 0 in this range
Fig. 3
Fig. 3
Histograms summarizing sighting distances and estimated detection functions a Uniform cosine, b Uniform polynomial, c Hazard rate, d Half normal from an aerial survey of the Kane Basin polar bear (Ursus maritimus) subpopulation, April–May, 2014. See Table 3 for model statistics
See this image and copyright information in PMC

References

    1. Aars J, Marques TA, Buckland ST, Andersen M, Belikov S, Boltunov A, Wiig Ø. Estimating the Barents Sea polar bear subpopulation size. Mar Mamm Sci. 2009;25:35–52. doi: 10.1111/j.1748-7692.2008.00228.x. - DOI
    1. Aars J, Marques T, Lone K, Andersen M, Wiig Ø, Fløystad IMB, Hagen SB, Buckland S. The number and distribution of polar bears in the western Barents Sea area. Polar Res. 2017;36(1):1374125. doi: 10.1080/17518369.2017.1374125. - DOI
    1. Amstrup SC. Polar bears and climate change: certainties, uncertainties, and hope in a warming world. In: Watson RT, Cade TJ, Fuller M, Hunt G, Potapov E, editors. Gyrfalcons and ptarmigan in a changing world. Boise: The Peregrine Fund; 2011. pp. 11–20.
    1. Amstrup SC, Marcot BG, Douglas DC. A Bayesian network modeling approach to forecasting the 21st century worldwide status of polar bears. In: DeWeaver ET, Bitz CM, Tremblay LB, editors. Arctic sea ice decline: observations, projections, mechanisms and implications. Washington, DC: Geophys Mono Ser 180, American Geophysical Union; 2008. pp. 213–268.
    1. Arnold TW. Uninformative parameters and model selection using Akaike’s Information Criterion. J Wildl Manag. 2010;74:1175–1178. doi: 10.1111/j.1937-2817.2010.tb01236.x. - DOI

LinkOut - more resources