Walruses threatened by sea ice melt

Extreme Arctic sea ice melt forces thousands of walruses ashore in Alaska

Survival of walruses threatened as they wash ashore on a remote barrier island just before Obama is due to visit region to draw attention to climate change

The Guardian,

27 August, 2015

The extreme loss of Arctic sea ice due to climate change is forcing thousands of walruses to crowd ashore on a remote barrier island off Alaska, and threatening their survival.

Barack Obama will be the first US president to visit the Alaskan Arctic on 31 August on a three-day tour to draw attention to the drastic consequences of climate change for the Arctic, such as warming winters and the rapid retreat of sea ice.

The first reported sighting of animals forced to come ashore in the Chukchi Sea was by a photographer on 23 August, and confirmed by villagers in the remote hamlet of Point Lay late on Thursday, the US Fish and Wildlife Service said. 

Such landings, forced by the absence of sea ice on which to rest and feed, put the animals at risk of stampede in the limited space of the barrier island.

The animals are easily spooked by aircraft or onlookers, government scientists warned. Trampling deaths are one of the biggest natural risks.

Sea ice cover in the winter months fell to a new low this year because of climate change and abnormal weather patterns.

Some scientists believe the Arctic could be entirely ice-free in the summer months by the 2030s – with profound effects for local indigenous communities that rely on the ice, as well as wildlife that depend on extreme conditions.

Since 2000, the forced migration of walruses and their young to barrier islands such as Point Lay – known as a “haul out” – has become an increasingly regular occurrence, according to US government scientists.

“Many walruses seem to prefer the barrier islands just north of the native village of Point Lay to haul out,” Jim MacCracken, a supervisory wildlife biologist with the fish and wildlife service, said.

Last year, as many as 40,000 animals, mainly females and their young, were forced ashore. It was the biggest known haul-out of its kind in the US Arctic, according to government scientists. The Federal Aviation Authority re-routed flights and bush pilots were told to keep their distance to avoid a stampede.

Agency scientists said about 60 young walruses were killed because of crowding and stampedes.

“Walruses often flee haulouts in response to the sight, sound, or odor of humans or machines. Walruses are particularly sensitive to changes in engine noise and are more likely to stampede off beaches when planes turn or fly low overhead,” Andrea Medeiros, a spokeswoman for the fish and wildlife service, said in an email.

The villagers have been dreading the prospect of a repeat record haul-out – and earlier this month appealed to outsiders to keep away from the area.

“We do not believe that these sorts of visits are in the best interest of the walruses and they do not align with the haul out protection role we have developed and measures we set in place to prevent disturbances,” Leo Ferreira III, the Point Lay tribal president said in a statement distributed by US government agencies.

Gary Braasch, an environmental photographer, said he first spotted the walruses coming ashore on the southern end of the barrier island, about two miles from the hamlet of Point Lay, on the evening of 23 August.

Braasch has spent about a decade photographing evidence of climate change in Alaska, and had been tracking the movement of tagged walruses through the US Geological Survey mapping projects.

“What they looked like by eye was three brown smudges along the beach. They were not visible as individual animals,” he said. But he said the blown-up images revealed large numbers of animals. “Certainly they were in the low thousands at that point.” 

Fish and Wildlife Service officials accused Braasch of violating flight safeguards and putting the animals at risk – a charge he rejected. “Several of our biologists looked at the images and noted that it appeared that many animals were on shore and appeared to be agitated and fleeing the area,” Medeiros said. “Harassing walrus is against the law. Operating an aircraft in a manner which results in harassing or disturbing walruses is prohibited by the Marine Mammal Protection Act.”

Braasch said the pilot did not overfly the barrier island, and intentionally flew several hundred feet beyond the Fish and Wildlife flight guidelines to avoid the risk of stampede. He said he took his photograph from more than a mile away. “We were not even close to the limits they set.”

He confirmed the government agency had been in contact about flight concerns.

The plight of the walrus

Stranded Walrus Are A ‘New Phenomenon’ And We Don’t Know How Bad It Will Get

In this aerial photo taken on Sept. 23, 2014 and released by NOAA, some 1500 walrus are gather on the northwest coast of Alaska.

Think Progress,

1 October, 2014

The gathering of 35,000 walrus on a beach in northwest Alaska this week after they couldn’t find their preferred resting grounds of summer sea ice was a notable occurrence in terms of its sheer size, but it wasn’t an isolated event.

Walrus have been gathering on Alaska’s shore in huge numbers almost every year since 2007, a relatively new phenomenon that has scientists working to determine how this change in resting grounds affects the walrus’ behavior, food supply, and health. Typically, Pacific walrus, which don’t have the stamina to swim indefinitely and depend on sea ice for places to rest periodically, follow sea ice in the Bering Sea as it recedes north in the summer, ending up in the Chukchi Sea off the coast of Alaska. This year — and every year since 2007 besides 2008, when there was just enough sea ice left for the walrus to make use of — all the summer sea ice disappeared, causing a record 35,000 walrus to convene on an Alaska beach.

This is a real change that we see thousands and tens of thousands of animals coming to shore and resting together

Tony Fischbach is a wildlife biologist with the U.S. Geological Survey who’s a member of the Walrus Research Programin Anchorage, Alaska. He told ThinkProgress that when summer sea ice is at normal levels, only a small number of walrus will come to shore in Alaska — numbers typically in the tens or sometimes low hundreds of animals. This mass convergence of walrus — most of whom are females and calves — is a new phenomenon, he said.

“Under historical conditions, there has always been sea ice over the Chukchi Sea over the summer,” he said. “This is a real change that we see thousands and tens of thousands of animals coming to shore and resting together in these large haul-outs.”

There are always concerns about disease transmission when large numbers of animals convene, Fischbach said, but in past years disease hasn’t caused problems. Trampling is also a concern in groups this large — in past years, more than 100 calves have died in Alaska due to trampling, and in Russia, more than 1,000 have died. Fischbach said he doesn’t foresee trampling being a major problem this year, however, despite the fact that some dead walruses have already been discovered.

But besides these immediate concerns on the lives and health of these creatures, the major haul-outs represent a change in behavior that leads to questions as to how walrus will adapt to shrinking sea ice levels.

“The massive concentration of walruses onshore — when they should be scattered broadly in ice-covered waters — is just one example of the impacts of climate change on the distribution of marine species in the Arctic,” Margaret Williams, managing director of the World Wildlife Fund’s Arctic program, said.

Walrus wait until sea ice starts forming again to start their fall migration south. 

That usually puts the start of their fall migration around mid-September, but this year’s lack of sea ice — and the subsequent stopover of the walrus in Alaska — is delaying their migration, Fisbach said. That probably won’t result in any mismatches in food availability when they reach their destination, Fisbach said, since the mollusks and benthic creatures such as worms, crustaceans and sea cucumbers that they feed on are available year-round, but it’s still a break from the norm.

CREDIT: NATIONAL SNOW AND ICE DATA CENTER

Under normal conditions, during their fall migration, walrus rest briefly on sea ice before returning to the sea to forage for food and continue on their way South. But Fisbach said that these huge groups of walrus can remain on the Alaska shore for three to five weeks at a time, with individual walrus entering the sea to forage and returning to the beach to rest periodically. Fisbach said this behavior raises “lots of questions” about whether the walrus will run out of food in the surrounding area, due to the high numbers of walrus competing for food.

“Occupying these areas and foraging these areas concentrates tens of thousands of walruses in a smaller area that is already known to be less rich than their off-shore foraging ground, and there is a concern that they could deplete the resources,” he said. “We don’t have a good measure of that — these are simply hypotheses or concerns we have.”

Some of the 35,000 walrus have been taking long trips offshore to forage, Fisbach said, while others have been sticking close to shore. Journeying farther out to sea may grant the walrus access to better food supplies, but it could also mean that they’re expending more calories than they’re gaining, Fischbach said. He’s working on a project that involves attaching radio tracking devices to the walrus so that he can track their behavior in the group — where and how often they go to forage and how often they rest — and compare it to historical data on walrus behavior.

Fischbach also said that, despite the fact that the walrus have convened on the shores of Alaska and Russia for the past several ice-free summers, he isn’t certain that the walrus will continue to gather in large numbers in the same places.

“For us, it really appears that this is a new phenomenon for walruses. How they respond in the long term is an open question,” he said. “Will they continue to have this pattern of coming to shore [and] being aggregated in a large group in the future, or will they deplete the local forage areas and choose other areas to rest? We don’t know…they’re wild animals and they’re responding to many factors we aren’t able to perceive.”

Loss of sea ice in the Pacific walrus’ range has led to calls to put the species on the Endangered Species List. The current population of the species is estimated at more than 200,000 individuals, but as the earth continues to warm and sea ice continues to retreat, some are worried that walrus populations will take a hit.