Tens of thousands of walruses are gathering on the northern coast of Alaska with an unknown future in creation.
Their numbers have been steadily growing during the past few years, shown in Tony Fischback’s diary, a wildlife biologist with the U.S. Geological Survey (USGS) in Alaska.
“This is very unusual in the larger context of walrus behavior,” says Fischback. “Traditionally, they follow the ice north into the Chukchi Sea and forage the shallows between Alaska and Russia.”
The walrus that inhabit the Bering and Chukchi seas normally come ashore in small numbers of a dozen or a few hundred, about 20 percent of their population, with most remaining on the ice.
But there has been almost no ice in these waters in the past years. Sunlight reflected on the ice of the Arctic Sea keeps polar regions cool and moderates climate around the globe. The ice has been dramatically shrinking to its third lowest level during the past 30 years, according to the U.S. National Snow and Ice Data Center. Since the era of industrialization swept the country, average temperatures on the globe have warmed nearly 1 degree Celsius, about 1.8 degrees Fahrenheit, much of it caused by human activities producing greenhouse gases like carbon dioxide. The gas, which traps heat, has increased from 284 parts per million (PPM) in the atmosphere to more than 380 ppm today.
Left without the ice the walrus had depended on to survive, they’ve been hauling themselves onto the shores near Point Lay on Alaska’s North Slope.
“We’re noticing that we’re not seeing the calves we expected to see, one calf for every three to four females,” Fischbach says. “It’s possibly higher calf mortality, all due to changing habitat.”
It’s changing the cost of making a living for the walrus. Fischbach said, “Instead of rolling off the ice and having your food right there, they might have to commute.”
Walrus mothers have been having a particularly hard time caring for their calves who rely on their mother’s for two years and on nursing for the first seven months. On the floating ice, mothers spend the summer lounging with their young and leave their calves to dive into the water for clams and invertebrates on the sea’s bottom, then resurface with nourishment for their young and themselves. Without the ice, they now have to swim long tiring distances that keep them away from nursing their calves.
The sea to land migration brings other threats for the walrus. Danger of being hunted by polar bears, who are also being driven onto land, has increased at the same time. A food shortage will also be faced as acidification of the Arctic waters rises and prevents clam and mussels from building their shells.
Last year, a sudden stampede to the water at Alaska’s Icy Cape crushed 131 walruses, most of them youth, ClimateWire reported. As the sea ice continues to recede during summer months, more ships will be able to sail through their habitat, potentially scaring the older females, who weigh about one ton, and causing more frantic stampedes. This year the Fish and Wildlife Service has asked boats, planes and hunters to keep a respectful distance from the pods.
The USGS reports “a clear trend of worsening conditions for the subspecies.” The report concluded that there is a 40 percent chance of Pacific walrus being extinct by the end of this century.
The federal government is expected to decide in 2011 if the Pacific walrus needs Endangered Species Act protection.