By Erica Goode, The New York Times, December 18, 2016
|A polar bear visiting the arctic whaling village of Kaktovik in search of food. Photo: Josh Haner, The New York Times.|
KAKTOVIK, Alaska — Come fall, polar bears are everywhere around this Arctic village, dozing on sand spits, roughhousing in the shallows, padding down the beach with cubs in tow and attracting hundreds of tourists who travel long distances to see them.
At night, the bears steal into town, making it dangerous to walk outside without a firearm or bear spray. They leave only reluctantly, chased off by the polar bear patrol with firecracker shells and spotlights.
On the surface, these bears might not seem like members of a species facing possible extinction.
Scientists have counted up to 80 at a time in or near Kaktovik; many look healthy and plump, especially in the early fall, when their presence overlaps with the Inupiat village’s whaling season.
But the bears that come here are climate refugees, on land because the sea ice they rely on for hunting seals is receding.
The Arctic is warming twice as fast as the rest of the planet, and the ice cover is retreating at a pace that even the climate scientists who predicted the decline find startling.
Much of 2016 was warmer than normal, and the freeze-up came late. In November, the extent of Arctic sea ice was lower than ever recorded for that month. Though the average rate of ice growth was faster than normal for the month, over five days in mid-November the ice cover lost more than 19,000 square miles, a decline that the National Snow and Ice Data Center in Colorado called “almost unprecedented” for that time of year.
In the southern Beaufort Sea, where Kaktovik’s 260 residents occupy one square mile on the northeast corner of Barter Island, sea ice loss has been especially precipitous.
The continuing loss of sea ice does not bode well for polar bears, whose existence depends on an ice cover that is rapidly thinning and melting as the climate warms. As Steve Amstrup, chief scientist for Polar Bears International, a conservation organization, put it, “As the sea ice goes, so goes the polar bear.”
An Imperfect Symbol
The largest of the bear species and a powerful apex predator, the charismatic polar bear became the poster animal for climate change.
Al Gore’s 2006 film, “An Inconvenient Truth,” which depicted a lone polar bear struggling in a virtually iceless Arctic sea, tied the bears to climate change in many people’s minds. And the federal government’s 2008 decision to list polar bears as threatened under the Endangered Species Act — a designation based in part on the future danger posed by a loss of sea ice — cemented the link.
But even as the polar bear’s symbolic role has raised awareness, some scientists say it has also oversimplified the bears’ plight and unwittingly opened the door to attacks by climate denialists.
“When you’re using it as a marketing tool and to bring in donations, there can be a tendency to lose the nuance in the message,” said Todd Atwood, a research wildlife biologist at the United States Geological Survey’s Alaska Science Center. “And with polar bears in particular, I think the nuances are important.”
Few scientists dispute that in the long run — barring definitive action by countries to curb global greenhouse gas emissions — polar bears are in trouble, and experts have predicted that the number will decrease with continued sea ice loss. A 2015 assessment for the International Union for Conservation of Nature’s Red List projected a reduction of over 30 percent in the number of polar bears by 2050, while noting that there was uncertainty about how extensive or rapid the decline of the bears — or the ice — would be. A version of the assessment was published online Dec. 7 in the journal Biology Letters.
But the effect of climate change in the shorter term is less clear cut, and a populationwide decline is not yet apparent.
Nineteen subpopulations of polar bears inhabit five countries that ring the Arctic Circle — Canada, the United States, Norway, Greenland and Russia.
Of those, three populations, including the polar bears in the southern Beaufort Sea, are falling in number.
But six other populations are stable. One is increasing. And scientists have so little information about the remaining nine that they are unable to gauge their numbers or their health.
In their analysis, the researchers who conducted the Red List assessment concluded that polar bears should remain listed as “vulnerable,” rather than be moved up to a more endangered category.
Yet numbers aside, scientists are seeing other, more subtle indicators that the species is at increasing risk, including changes in the bears’ physical condition, body size, reproduction and survival rates. And scientists have linked some of these changes to a loss of sea ice and an increase in ice-free days in the areas where the bears live.
Climate-change denialists have seized on the uncertainties in the science to argue that polar bears are doing fine and that sea ice loss does not pose a threat to their survival. But wildlife biologists say there is little question that the trend, for both sea ice and polar bears, is downward. The decline of a species, they note, is never a steady march to extinction.
“It’s not going to happen in a smooth, linear way,” said Eric Regehr, a biologist at the federal Fish and Wildlife Service in Anchorage who took part in the 2015 assessment and presented the findings at a meeting in June of the International Union’s Polar Bear Specialist Group.
From Sea to Shore
A dozen polar bears pick through the bone pile that sits just outside town. Men from the whaling crews had dumped the carcass of a bowhead whale on the pile earlier in the day. As two visitors watch from the safety of a pickup truck a few hundred yards away, the bears devour the leftover meat and blubber.
The Inupiat people, who have been whaling here for thousands of years, believe that a whale gives itself to the crew that captures it. Once the animal’s body is pulled to shore, water is poured over it to free its spirit.
Even a few decades ago, most polar bears in the southern Beaufort Sea remained on the ice year-round or, if they did come to shore, stopped only briefly. The sea ice gave them ready access to seals, the staple of their high-fat diet.
But as the climate has warmed, the spring thaw has come earlier and the fall freeze later. The pack ice that was once visible from Kaktovik even in summertime has retreated hundreds of miles offshore, well beyond the southern Beaufort’s narrow continental shelf. The edge of the pack ice is now over deep water, where seals are few and far between and the distance to land is a long swim, even for a polar bear.
As a result, researchers have found, a larger proportion of the bears in the southern Beaufort region are choosing to spend time on shore: an average of 20 percent compared with 6 percent two decades earlier, according to a recently published study by Dr. Atwood of the Geological Survey and his colleagues that tracked female bears with radio collars. And the bears are staying on land longer — this year they arrived in August and stayed into November — remaining an average of 56 days compared with an average of 20 days two decades ago.
“It’s one of two choices: Stay with the pack ice, or come to shore,” Dr. Atwood said of the southern Beaufort bears. “If they sit on that ice and those waters are very deep, it will be harder for them to find nutrition.”
The shifts that researchers are seeing go beyond where polar bears decide to spend their summers.
In the southern Beaufort Sea and in the western Hudson Bay — the two subpopulations studied the most by researchers — bears are going into the winter skinnier and in poorer condition.
They are also smaller. And older and younger bears are less likely to survive than in the past.
“You see it reflected through the whole population,” said Andrew Derocher, a professor of biological sciences at the University of Alberta, who has studied polar bears for 32 years. “They just don’t grow as fast, and they don’t grow as big.”
‘An Urgency’ to Visit
The proliferation of polar bears in Kaktovik in the fall has drawn wildlife photographers, journalists and climate-change tourists to the village, filling its two small hotels or flying in from Fairbanks for the day on chartered planes.
About 1,200 people came to view the bears in 2015, and the number is increasing year by year, according to Robert Thompson, an Inupiat guide who owns one of six boats that take tourists to view the bears.
Some visitors are surprised at the bears’ darkened coats, dirty from rolling in sand and whale remains. “They don’t look like polar bears,” one man from the Netherlands said. “But it does not matter. I will Photoshop them when I get home.”
Susan Trucano, who arrived in early September with her son, Matthew, said they wanted to see polar bears in the wild before they were driven to extinction.
“It was an urgency to come here,” Ms. Trucano said. “My fear was that we would lose the opportunity of seeing these magnificent animals.”
The increasing tourism has been a financial boon for some people in Kaktovik, but it has upset others. Tourists take up seats on the small commercial flights in and out of the village during the fall months when the bears are there, crowding out residents who need to fly to Anchorage or Fairbanks. And some visitors wander through town snapping pictures without asking permission, or get in the way of the rituals that accompany the whale hunt. Last year, an intrusive tourist nearly came to blows with one of the whaling captains.
For the most part, polar bears and people have coexisted peacefully here. Village residents are tolerant of the bears — “They could break right in here, but they know the rules,” said Merlyn Traynor, a proprietor of the Waldo Arms Hotel — and with the whale remains, they have little reason to come after humans.
But as the Arctic ice continues to shrink, bears are arriving in poorer condition and are staying longer, even as the number of tourists increases. Interaction between bears and humans is becoming more common, as it has in other parts of the Arctic, exposing the polar bears to more stress and the people to more danger.
So far, there have been no attacks on humans, but there have been some close calls.
“They never used to come into town, or maybe occasionally, like once a year or so,” Mr. Thompson said. “Now they’re in town every night.”
Polar bear experts say they worry that at some point the number of bears seeking food here will exceed what is available.
“When polar bears are fat and happy and in good condition, they’re not that big of a threat,” said James Wilder, an expert who recently completed a study of polar bear attacks on humans. “But when they get skinny and nutritionally stressed, you’ve got to watch out.”
A Habitat Endangered
Threatened species like lions or wolves face predictable threats: poaching and hunting, or the encroachment of human settlements on their habitat.
But the biggest threat to the polar bear is something no regulatory authority involved in wildlife conservation can address: the unregulated release of carbon dioxide and other greenhouse gases into the atmosphere.
Sport hunting once posed a significant danger to polar bears, greatly shrinking their numbers in some areas until 1973, when an agreement among the Arctic countries restricted hunting to members of indigenous groups, and the populations began to rebound.
For many researchers, the most pressing question is how many days a polar bear can survive on land without the steady source of high-fat nutrition that seals usually provide.
“A bear needs sea ice in order to kill seals and be a polar bear,” said Dr. Regehr of the Fish and Wildlife Service. “That’s a bottom line.”
Some scientists have suggested that the bears might learn to survive on other types of food — snow geese, for example — or that they might learn to catch seals in the water, without relying on the ice as a platform.
But most researchers say that is unlikely.
Such changes usually evolve over thousands of years, said David Douglas, a research wildlife biologist at the Geological Survey, who spoke at the specialists group meeting.
But the loss of sea ice “is taking place over potentially a very rapid time frame, where there may not be a lot of time in polar bear generations to home in on behaviors that could give some advantage,” he said.
Much depends on how much of the ice disappears. Under some climate models, if steps are taken to control greenhouse gas emissions, the species could recover. And some evidence suggests that during an earlier warming period polar bears took refuge in an archipelago in the Canadian Arctic.
In Kaktovik, at least for now, whales are providing the bears with an alternative source of food. But dead whale is not a polar bear’s preferred cuisine.
“The bears are not here because we hunt whales,” said Mr. Thompson. “They’re here because their habitat has gone away, and it’s several hundred miles of open water out there.”