In an extraordinary phenomenon, an estimated 10,000 walruses have gathered on a small barrier island near Point Lay in Alaska. Spotted by scientists from NOAA last Friday, the walruses have come ashore as shrinking Arctic sea ice leaves the mammals without areas on which to give birth, and without diving platforms from which they can hunt. While a dramatic and horrifying commentary on the effects of global warming, the massive gathering of walruses also poses a threat to the safety of the young among the herd.
Each year, arctic sea ice reaches its annual minimum in September. On September 12 1,500-4,000 walruses had been observed on the beach near Point Lay. By September 22, that number had reached 5,500-8,000. On September 27, when NOAA conducted an aerial survey in the region (to observe whale populations in the region), the number of walruses had jumped to 10,000.
While this is a new phenomenon, it is not the first year that the walruses have come ashore in large numbers; herds appeared in 2007 and again in 2009 before 30,000 converged on the beach in 2011. TheAPexplains that in intervening years, remnant ice provided a safe haven.
In situations such as the current one, the summer sea ice decline has reached north beyond the waters of the continental shelf and into the Arctic Ocean. This leaves the edge of the sea ice sitting over waters that are 10,000 feet deep—too deep for the walruses to be able to dive to the bottom and hunt for the snails, clams and worms on which they subsist.
With the huge number of walruses packed into such a small area, scientists and marine experts are concerned that a stampede could pose a threat to the young among the herd. The presence of a polar bear or human could cause a fright among the herd. A stampede that took place in 2009 at Alaska’s Icy Cape left the “carcasses of more than 130 mostly young walruses,” in its wake.
The walruses face additional risks from the haulout. According to the Fish and Wildlife Service such events “will expose all individuals, but especially calves, juveniles, and females, to increased levels of stress from depletion of prey, increased energetic costs to obtain prey,” alongside the aforementioned “trampling injuries and mortalities.”
The Fisheries and Wildlife Service has been working to reduce the risk of disturbances on the island that might trigger a stampede, it is not clear if the government shutdown has affected their work.
And for those of you who saw this amazing photograph of a walrus hanging out a top a submarine and thought “maybe he needed to chill and had no place else to go,” well, you might have been onto something.
Via AP/Huffington Post
Lead image © NOAA