Walruses as polar bear prey and sea ice were on my mind last night and I remembered that we DO have detailed sea ice information for 1978 and 1972 – from the sea ice atlas put together by University of Alaska Fairbanks (UAF), which has ice concentration maps for Alaska going back to 1850 — and for every year up to 2013 (reported previously here).
Chukchi Sea walrus, June 2014. US Fish and Wildlife Service.
I’ve copied some of the ice maps below.
It is clear that ice was available close to Wrangel Island in 1972 when walruses chose to haul out on the island in huge numbers. And in 1978, there was ice present to the north of the walrus herd, but they had moved away from the ice to get to St. Lawrence Island, where they hauled out in large numbers.
This means it is more likely that food resources were the issue, not sea ice.
UPDATE OCTOBER 3 2014:
See another interesting follow-up elsewhere: Walrus inconsistencies
Posted in Life History, Sea ice habitat, walrus
Tagged Chukchi Sea, climate change, Fay, global warming, ice levels, Kelly, mass mortality, Point Lay, sea ice atlas, sea ice declines, sea ice maps, St. Lawrence Island, stampede, UAF, walus, Wrangel Island, WWF
Large haulouts of walruses — such as the one making news at Point Lay, Alaska on the Chukchi Sea (and which happened before back in 2009) — are not a new phenomenon for this region over the last 45 years and thus cannot be due to low sea ice levels. Nor are deaths by stampede within these herds (composed primarily of females and their young) unusual, as a brief search of the literature reveals.
The attempts by WWF and others to link this event to global warming is self-serving nonsense that has nothing to do with science.
UPDATE October 3, 2014: See below. Also, do see follow-up posts here, here, and especially, here.
UPDATE October 23, 2014: A briefing paper summary is here and a video version of that paper (“The Walrus Fuss” — 3 1/2 minutes long) here.
There is also a follow-up post on the situation here.
Posted in Advocacy, Sea ice habitat, walrus
Tagged Chukchi Sea, climate change, Fay, global warming, ice levels, Kelly, mass mortality, Point Lay, sea ice declines, St. Lawrence Island, stampede, walus, WWF