The U.S. Fish and Wildlife Service has declined for now to create artificial floating platforms for Pacific walrus that come ashore in Alaska because they lack summer sea ice.
The agency’s decision came in response to a suggestion by a wildlife advocacy group to place experimental rafts over a prime Chukchi Sea feeding area 100 miles off Alaska’s coast, Geoffrey Haskett, Alaska regional director for the U.S. Fish and Wildlife Service, said in a letter Monday.
“We do not think such a measure is needed at this time,” Haskett said in the letter to Rick Steiner of Oasis Earth.
An estimated 35,000 Pacific walrus were photographed Sept. 2 near Point Lay in what has become an annual September phenomenon tied to shrinking sea ice attributed to climate warming.
Walrus dive to feed on clams, sea snails and other food on the ocean bottom but cannot swim indefinitely. In recent years, sea ice has receded north beyond the shallow continental shelf to water that exceeds 2 miles deep, beyond the diving range of an adult walrus.
The trend continued this year. The National Snow and Ice Data Center said the Arctic hit its summer minimum last week with 1.7 million square miles of sea ice, down 240,000 square miles from 2014. It’s the fourth lowest level on record for summer sea ice in September.
Walrus in large numbers were first spotted on the U.S. side of the Chukchi Sea in 2007.
When the animals are grouped shoulder to shoulder in massive herds, they are subject to stampedes if startled by an airplane, hunter or polar bear. The carcasses of more than 130 mostly young walruses were counted after a stampede in September 2009 at Alaska’s Icy Cape.
The potential disturbance caused by artificial platforms to walrus could outweigh the benefits, Haskett said.
“Rafts would have to be deployed and retrieved annually and deployment would likely have to occur after thousands of animals have already occupied the area,” Haskett said in his letter.
Though a small number of rafts are technically feasible, he said, the logistics, permitting and public relations challenges would be immense and expensive.
“To be effective at the population level, rafts would have to accommodate 10,000-20,000 animals,” he said.
A walrus on a beach covers about 1.1 square meters. The service would have to provide a minimum of 11 to 22 square kilometers of rafts, he said.