Polar bear habitat in Canada and japanese Alaska in contrast at finish of June 2012-2020
Reposted from Polar Bear Science
Posted on June 29, 2020 |
Here’s a fast evaluate and distinction of sea ice habitat for polar bears in Canada and the Southern Beaufort area of japanese Alaska close to the top of June, 2012-2020.
Similarities between Hudson Bay ice/open water within the sea ice charts beneath are putting. Ice cowl on the finish of June proven in these charts since 2012 reinforces the actual fact, documented within the peer-reviewed literature, that there was no continued declining development in dates of sea ice breakup for Western and Southern Hudson Bay since 1998 at the very least (Castro de la Guardia et al. 2017; Lunn et al. 2016). WH bears are nonetheless on the ice.
As a consequence, latest declarations of impending doom for Hudson Bay polar bears, based mostly on claims of lowered inhabitants measurement and well being of those subpopulations – which in any case are statistically insignificant for WH and SH (Obbard et al. 2018; Dyck et al. 2017) – should be because of another trigger (Crockford 2020).
In all areas, winds relatively than soften because of elevated temperatures drive a lot of the enlargement of open water presently of 12 months.
The one chart I’ve for 2012 (the 12 months of the lowest-since-1979 summer season ice minimal) is for 20 June (there isn’t any official archive of those explicit charts) :
So, for comparability I embody beneath the 21 June chart for 2020:
REFERENCES
Castro de la Guardia, L., Myers, P.G., Derocher, A.E., Lunn, N.J., Terwisscha van Scheltinga, A.D. 2017. Sea ice cycle in western Hudson Bay, Canada, from a polar bear perspective. Marine Ecology Progress Sequence 564: 225–233. http://www.int-res.com/abstracts/meps/v564/p225-233/
Crockford, S.J. 2020. State of the Polar Bear Report 2019. International Warming Coverage Basis Report 39, London. pdf right here.
Dyck, M., Campbell, M., Lee, D., Boulanger, J. and Hedman, D. 2017. Aerial survey of the Western Hudson Bay polar bear sub-population 2016, last report (26 June 2017). Standing report 2017-xx, Nunavut Division of Atmosphere, Wildlife Analysis Part. Igloolik, Nunavut. pdf right here.
Lunn, N.J., Servanty, S., Regehr, E.V., Converse, S.J., Richardson, E. and Stirling, I. 2016. Demography of an apex predator on the fringe of its vary – impacts of adjusting sea ice on polar bears in Hudson Bay. Ecological Purposes 26(5): 1302-1320. DOI: 10.1890/15-1256
Obbard, M.E., Stapleton, S., Szor, G., Middel, Okay.R., Jutras, C. and Dyck, M. 2018. Estimating the abundance of the Southern Hudson Bay polar bear subpopulation with aerial surveys. Arctic Science https://doi.org/10.1139/AS-2018-0004
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