All Arctic sea ice habitats that are currently suitable for polar bears have polar bears living in them 1 – even the southern-most regions of Hudson Bay that are well below the Arctic Circle (see previous post on polar bear numbers here).
Have a look at the maps below and see how well the current maximum extent of sea ice correlates with the present range of polar bears around the Arctic.
Fig. 1. Sea ice extent at April 25, 2012, from NSIDC (the winter maximum). Note that although there is sea ice in the Sea of Okhotsk (top right of the map), polar bears do not currently live there nor is there any evidence they ever did1.
Compare to the polar bear’s official range below.
Fig. 2. The global range of the polar bear, showing the 19 regional subpopulations. Map from Polar Bear Specialist Group (PBSG), with a few extra labels added.