Every summer, U.S. Geological Survey biologist Tony Fischbach gets a glimpse of a world few people get to see. On a small skiff in the Chukchi Sea, he and a team of scientists look for groups of walruses resting on the sea ice.
They wear all white, to blend in with the landscape and approach slowly with the motor running low. Then Fischbach aims and shoots his crossbow, embedding a satellite tag in the thick walrus skin.
Its an action Fischbach has repeated hundreds of times over the last five years. Once the tags are in place, Fischbach can monitor the walrus movements for about two months. Those “walrus diaries,” as Fischbach calls them, are summed up in a research paper published last month:
“Based on this we can really quantify their utilization of the Chukchi Sea and identify areas that are the focus points of their foraging and identify areas that are really not used. And that can be useful for people who want to make environmental plans.”
Shell is using the information. The company’s main exploratory site in the Chukchi Sea right now, the Burger Prospect, is on the southern boundary of Hanna Shoal, a hot spot for walrus foraging in July and August. Marine mammal observers with the company reported seeing 8,700 walruses from it’s drilling and support ships this summer. But Shell says there were no significant disturbances or injury to the animals.
Scientists expected walruses to be hauled out on shore by the time Shell began exploratory drilling in September, as they have in recent low ice years. But this year Fischbach says the animals found enough sparse ice to rest on, even after the main pack ice retreated far north:
“Some of these pieces of ice, we call them sparse but they can be substantial, enough to cause problems for ships trying to operate in the area and enough to provide a platform for these walruses to utilize.”
Starting in 2007, when the ice disappeared, walruses began hauling out on Alaska’s north coast. And when the walruses are on shore, they don’t have access to the rich food supplies of the ocean.
Fischbach’s walrus diaries have revealed animals forced on shore are willing to swim huge distances to find food. Last year, nearly half of the walruses wearing satellite tags swam 240 miles, round trip, to Hanna Shoal:
“We saw them making these extraordinary trips, where they would travel far offshore for up to two weeks, they would go off and reoccupy these open sea conditions over the Hanna shoals. They would forage there intensively and then they would do this long swim without foraging, just headed right back, get some rest and do it again. So this is a very novel behavior, basically they’re commuting to get to their groceries.”
USGS scientists are currently studying how costly that commute is for walruses. It is likely an expensive trip. Instead of paying for gas, the animals are paying by expending many more calories to reach their food.
The land haul outs also leave calves vulnerable to trampling deaths, when walruses get spooked by noise and stampede into the water. Rebecca Taylor is a researcher at USGS who co authored a recent study that models how trampling deaths of young walruses might ultimately affect the population. She says calf deaths have a much bigger impact on the population than adult animals taken in subsistence harvest:
“On a one walrus per one walrus basis, we expect it to have a greater affect on the population than harvest, so that’s something we need to be watching, and we need to be thinking about that.”
In 2007, the first year walruses came to shore in Alaska and Russia, Russian biologists estimated that as many as 10,000 walruses died in trampling deaths, double the annual harvest amount. Since then, wildlife managers and locals in both countries have worked to prevent the unnecessary deaths.
“It made us aware of what we can do for the wildlife we depend on.”
Willard Neakok is a resident of Point Lay and a member of the Alaska Eskimo Walrus Commission. Neakok has helped lead an effort in Point Lay to make sure aircraft, boats and even tourists don’t disturb the walrus haul outs. He says the community has come together to protect the animals:
“I’m sure that about 80 percent of our residents are also concerned about the mortality of young calves and the preservation of the walrus.”
Neakok says he’s worried for the future of the species. And biologist Tony Fischbach says there is reason for concern. But how much concern? Fischbach says that will require much more study in the years ahead.
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Annie Feidt is the broadcast managing editor at Alaska Public Media. Reach her at afeidt@alaskapublic.org. Read more about Annie here.
