Posted onMay 3, 2023|Comments Off on 17th century documents & 1970s ice maps show sea ice habitat in Svalbard has always varied greatly
Historical records show that sea ice extent along the west coast of Svalbard, Norway varied greatly in the 1600s and that there is currently more ice than was usually present at this time of year in the 17th century.
April through early June is when polar bears need sea ice the most–for feeding on newborn seals and for finding mates–and so far this spring, bears in the Western European Arctic around Svalbard, Norway have had an abundance of ice. In fact, there is only a little less ice than was normal for the late 1970s and apparently, quite a bit more than was often present in the 1600s.
Posted onJanuary 28, 2015|Comments Off on Claim of range-contraction of polar bears due to declines in summer sea ice doesn’t hold up
Have polar bears suffered a contraction of their historical range due to recent declines in summer sea ice? Buried in a recent journal article lies such a claim, one I can’t recall having seen before. That makes it worth close examination.
A drawing of polar bears on St. Matthew Island that accompanied the May 1, 1875 Harper’s Weekly Journal of Civilization article written by Henry Elliot. See here.
The assertion appears in the introduction of a recently published paper that got a lot of attention online (“Implications of the Circumpolar Genetic Structure of Polar Bears for Their Conservation in a Rapidly Warming Arctic” by Peacock and colleagues (2015), discussed previously here, news coverage here and here).
Here is how the authors put it:
“There is already evidence of change in the contemporary distribution of polar bears. For example, polar bears, once common in Newfoundland , are now seen there only infrequently and in small numbers. Similarly, polar bears once regularly summered on St. Lawrence and St. Matthew islands in the Bering Sea [30–32]. Now they are irregularly observed in the Bering Sea and do not spend summers on St. Matthew Island. Although these changes in polar bear distribution may also have been related to overharvest, the recent reductions in the extent of sea-ice due would prevent current and regular use of these areas.” [my emphasis]
There are three main reasons the claim doesn’t hold up to scrutiny: Continue reading
Comments Off on Claim of range-contraction of polar bears due to declines in summer sea ice doesn’t hold up
You must be logged in to post a comment.