With the ice melting out from under them, Western Hudson Bay's polar bears began swimming back to shore last week . . . nearly four weeks ahead of their average return date in the 1980s. Biologist Alysa McCall reports that several polar bears have been sighted on land since July 6th. Some are roaming close to the town of Churchill. Others are swimming near the shore.
The early loss of their seal-hunting grounds forced the bears to leave behind the bounty of young and naïve seal pups that help them pack on fat reserves. Once onshore, they enter a prolonged fasting period until the Bay freezes again in the fall.
"Every day off the ice is a day the bears can't hunt seals," says Dr. Andrew Derocher, a professor of biological sciences at the University of Alberta and longtime scientific advisor to PBI. "But early summer melts--and late freeze-ups--are straining their ability to survive. There's a limit to how long the bears can fast."
For polar bears in seasonal ice areas like Western Hudson Bay, home to Churchill's polar bears, summer thaws and fall freeze-ups are part of an age-old pattern. What's different now, though, is that the ice-free periods are becoming longer and longer. As a result, scientists are seeing more and more thin polar bears and a steep drop in the number of cubs.
The Western Hudson Bay polar bears are just one population of 19. They live at the southern edge of the polar bear's range and are considered the most vulnerable. Scientists say the extended ice-free seasons on Hudson Bay are a harbinger of what's to come for polar bears further north unless we take action to reduce greenhouse gas emissions.
Polar bears in seasonal and divergent ice areas in the Arctic are facing a tough summer, with June sea ice covering the smallest extent ever observed for this time of year. The ice retreat has forced some bears ashore earlier than normal and
others to endure long swims in search of a hunting platform of ice--journeys that are especially hard on cubs. The National Snow and Ice Data Center (NSIDC) reports that the June melt covers an area the size of Canada and Alaska combined.
This year's melt has been below the 2007 record low since early June, and 2012 may break the record for the lowest summer sea ice extent. Vagaries of winds, air pressure patterns, and currents can affect the final outcome, but with temperature extremes in Churchill and other areas, the Arctic Ocean will be warming rapidly over the summer.
Whatever finally happens, the trend in sea ice losses is clear and underscores the need for action. That action must come not from those who live near the polar bear's home--but from you and me. Visit our website to discover how you can become part of the momentum to make a low-carbon lifestyle the norm, not the exception.