Much less stable ice for polar bears, cubs cannibalized

Arctic sea ice conditions are even worse than feared after a survey found that ice detected as older and thicker by satellites is actually thin and fragile, a prominent Canadian researcher reported Friday. University of Manitoba researcher David Barber said experts around the world believed the ice was recovering because satellite images showed it expanding, but the thick, multiyear frozen sheets have been replaced by thin ice that cannot support the weight of a polar bear. “Polar bears are being restricted to a small fringe of where this multiyear sea ice is. As we went further and further north, we saw less and less polar bears because this ice wasn’t even strong enough for the polar bears to stand on,” said Barber, who returned from an expedition to the Beaufort Sea in September. Barber said permanent ice, which is normally up to 30 feet thick, was easily pierced by the research icebreaker he and his team were on. … Scientists also said Friday that shrinking Arctic sea ice may be forcing some hungry polar bears to cannibalize bear cubs. At least seven cases of mature male polar bears eating bear cubs have been spotted this year among the animals around Churchill, Manitoba, said Ian Stirling, a retired Environment Canada biologist who specializes in the Churchill bears. Stirling said evidence suggests the cubs are being killed for food, not just so the male can mate with the sow. …  “As I watched, over the course of five minutes, the entire multiyear ice floe broke up into pieces. This floe was 10 miles across,” said Barber, who holds the Canada research chair in Arctic science at the University of Manitoba. The ice is unable to withstand battering waves and storms because global warming is rapidly melting it at a rate of 27,000 square miles each year, he said. Multiyear sea ice used to cover 90 percent of the Arctic basin, Barber said. It now covers roughly 19 percent. Where it used to be up to 33 feet thick, it’s now 6 feet at most. …

Much less stable ice for polar bears, expert says via The Oil Drum