Of Polar Bears and Pollution
* Migrating chemicals have made the creatures among the most tainted anywhere. Researchers brave the Arctic and risk attack to study them.

By Marla Cone

SVALBARD, Norway — Born at Christmastime, cradled in pure white snow, two newborns are sleeping and suckling, protected by one of the fiercest creatures on Earth.

The brothers were born blind, toothless, a pound apiece, as feeble as kittens. For four months they will nestle in a den carved by their mother on the bleak, snowy banks of a frozen sea. They will gorge themselves on rich, fatty milk, doubling their weight every few weeks.

Etched by harsh winds and ancient glaciers, closer to the North Pole than to Oslo, Svalbard is a brutal place, unforgiving of weaknesses. From the moment of birth — even conception — animals here struggle against the odds. Most polar bears die before their first birthday.

Yet it is an unnatural threat — a man-made one — that is intruding upon this polar bear nursery. Even before they leave the safety of their dens, the cubs carry more pollutants than most other creatures on Earth, having ingested industrial chemicals from their mother's milk.

Recent scientific studies suggest that extraordinary loads of contaminants have migrated to the Arctic and are weakening polar bears and other animals, jeopardizing their survival. Like a giant sink, the remote, icy realm surrounding the North Pole — particularly Norway's Svalbard archipelago — collects many of the world's most toxic chemicals, especially banned industrial compounds called PCBs and pesticides such as DDT.

Scientists have also found that a relatively new contaminant — flame retardants that are still widely applied to furniture and construction materials in the United States — has made its way to the North Pole.

In a phenomenon called the grasshopper effect, chemicals repeatedly evaporate and fall to the ground, hopping across the world in this fashion. Riding northbound winds, they end up above the Arctic Circle, traveling thousands of miles from their points of origin in industrialized regions. Ocean currents also slowly carry chemicals north.

Once in the Arctic, the chemicals stay there. They build up in ice and ocean sediment, enduring for decades — perhaps centuries — and accumulate in the fat of animals, peaking at the top of the food chain.

As a result, the Arctic's most voracious predators are among the most contaminated living organisms ever found. Only Pacific Northwest orcas, Baltic Sea seals and St. Lawrence River belugas have been found with higher doses of PCBs than Svalbard's bears.

Scientists say that the globetrotting contaminants are responsible for an array of symptoms. Recent studies in Norway and Canada show that polar bears' immune cells and antibodies, needed to fight off disease, have been suppressed, and that their levels of testosterone, progesterone, vitamin A and thyroid hormones are altered by PCBs.

Although the evidence is incomplete, scientists think the pollution may be culling Svalbard's older bears and perhaps weakening or killing cubs. Females more than 15 years old are rare, and the population seems small. Researchers have also come across small numbers of strange, pseudo-hermaphroditic bears, ones with mostly female anatomy but also parts of male anatomy.

"Could you realistically put 200 to 500 foreign compounds into an organism and expect them to have absolutely no effect?" said Andrew Derocher, a Canadian scientist with the Norwegian Polar Institute who has tested about 4,000 bears in 20 years of research in the remote reaches of the Arctic.

"I would be happier if I could find no evidence of pollution affecting polar bears," he said, "but so far, the data suggest otherwise."

Sea That Never Melts

It is early evening, nine days after the return of the midnight sun, and the glaciers are casting jagged shadows on the ice below. From the front seat of a helicopter, Derocher is scanning the ice, looking for tracks. "There should be lots of bears just waiting for us here," he says.

Spring has arrived in Svalbard. Brilliant cobalt-blue seawater is shattering its icy shield, splitting the fiords into patches, like frosty white lily pads floating on a pond. But in the northern reaches of Spitsbergen, Svalbard's largest island, the sea never melts. The ice looks as taut as a bedsheet in some spots, as billowy as a down comforter in others. The horizon is lost on overcast days as shades of white blend seamlessly.

This vast, silent prairie, 600 miles from the North Pole, is a favorite spot for polar bear mothers to raise their cubs. Svalbard is home to about 2,000 bears, 10% of the world population.

A 450-pound isbjorn, Norwegian for polar bear, has just abandoned her winter den to begin tutoring her cubs. The mother bear lumbers along, hunting her favorite prey of ringed seals, leaving a zigzag path of 12-inch-wide craters followed by the smaller paw prints of her two sons. A few miles away, Derocher spots the bear family's telltale trail from 300 feet up. Pilot Oddvar Instanes loops, spins and straddles the tracks, following their erratic path for several miles. A seal lounging by a hole in the ice looks up, puzzled by the helicopter's noisy antics.

Only about a dozen people on Earth know how to find and catch a polar bear. The bears' fur is pigment-free, translucent like ice, and each hair's hollow core reflects light. It is easier to spot their tracks than to spot the bears. "She's running here," Derocher says, pointing to a row of bear tracks at the edge of a craggy glacier. "I think she's ahead of us here somewhere."

In the chopper's back seat, Magnus Andersen, his Norwegian colleague, fills a syringe with a tranquilizer. He injects the colorless liquid into a dart and screws it onto a shotgun.

The mother and cubs are now right below them. The pilot dips to about six feet over the mother's head, so close they can see the coarse hair on her back blowing in the wind as she runs. Silently, Andersen kneels on one leg and opens the door. A freezing blast of air slaps him in the face. The blades whip up a whirlwind of snow, masking his view.

As the helicopter chases the bear, spinning in circles perilously close to the ground, Andersen leans out the door, tethered by a thin green cord. He takes aim and fires. The smell of gunpowder wafts through the door.

"OK," Andersen says. A dart sticks out of the bear's rump. Precision is important. If he had hit her in the chest, it would have killed her as sure as a bullet.

Within minutes, the mother starts to wobble, but she isn't going down. Andersen readies another syringe and fires, hitting her in the rump again. She lies on her stomach, eyes open but still, one paw splayed back. The cubs nuzzle her, trying to wake her, then curl up beside her. Peering out over their sleeping mother's back, they are wide-eyed and curious as the craft lands.

Derocher and Andersen step out into the freezing air. They approach cautiously, their boots crunching in the snow. The men circle slowly around the bears.

Derocher is 6 feet 3 and 225 pounds. The mother bear is twice his weight, and a male bear can weigh almost a ton. Derocher and Andersen always carry loaded .44-magnum pistols on their waists. A few years earlier, two young tourists were mauled to death in Svalbard while taking a walk just outside its town of Longyearbyen.

"It's never the bear we're drugging that's dangerous," says Derocher. "It's always the bear you don't see."

The 4-month-old cubs are as adorable and innocent as their mother is deadly. At 45 to 50 pounds apiece, they are about the size of Derocher's 6-year-old daughter and just as harmless. Gloveless, Derocher strokes one's soft, creamy-white fur, and Andersen holds out a finger for the other to sniff and lick. These are the first humans these cubs have seen, and perhaps the last. Andersen gently loops ropes around their necks and tethers them to their mother. If they were to wander away without her, they would die.

Andersen checks the mother's ear for an identifying tag. "She was caught once before," he says.

"When?" Derocher asks.

"In 1994."

Derocher sets down his black toolbox, removes dental pliers and opens the bear's jaw. Leaning inside her gaping mouth, he deftly extracts a tooth, a useless pre-molar the size of a cribbage peg that will be used to confirm her age. She is about 15 years old, and Derocher wonders if this will be her last set of cubs. Older females like her are rarely seen denning in Svalbard, even though polar bears live as long as 28 years in the wild.

Andersen is working on her other end, using a biopsy tool to cut a quarter-inch-in-diameter plug of blubber from her rump. Then he quickly siphons a tube of blood from a vein in a hind leg. Together, the two scientists stretch a rope over the mother to measure her girth and length. Then Derocher and Andersen inject each cub with tranquilizer before taking blood samples. With a clamp, Derocher attaches a tag marked with identifying numbers to the cubs' ears. Drops of blood drizzle onto the snow.

Derocher kneels beside the mother and milks her like a cow to get a small sample of the creamy liquid she is feeding her offspring. The milk, fat and blood will be analyzed at a lab for a suite of chemicals. Then he gently lifts her giant head and puts her lolling tongue back in her mouth. Instanes paints a big brown X on her rump, signaling that she shouldn't be bothered again this year. The cubs are left snoring, all eight paws splayed on the snow. The threesome will sleep two hours, then shake off the drowsiness and go their way.

Andersen and Derocher pack up their toolbox and walk back to the helicopter. It has been 40 minutes since they landed.

Every April for a full month, the scientists work in this frigid wilderness-turned-laboratory, tranquilizing 60 to 100 bears to monitor their health and test for contaminants. It is dangerous business for man and bear. But scientists say it is critical for understanding how wild animals are faring, how much chemicals they carry in their bodies.

"Otherwise," Derocher says, "we would blindly stumble into extinction. My job is to make sure polar bears are around for the long term."

When bad weather sets in or the helicopter breaks down, he and his team are stranded on the ice. Or worse. On a spring day in 2000, two colleagues tracking bears in Canada were killed in a whiteout, which occurs when clouds descend and the ground and sky merge. Their helicopter crashed into a glacier.

Now, when caught in whiteouts, Derocher and his crew fill black garbage bags with rocks and throw them out the window. The direction of the bags tells them where the ground is.

The helicopter lifts off, headed north. Within 10 minutes, they spot more tracks, this time a mother and two plump yearlings. Andersen fills a syringe and rests the shotgun on his leg.

A Frozen Paradise

Derocher, whose towering height, jet-black hair and full beard give him the aura of a big black bear, was raised along the lush banks of British Columbia's Fraser River. Claustrophobic in cities, he heads north, far north, whenever he craves wilderness.

Setting foot in Svalbard in 1996, Derocher thought he had found paradise. Having researched wildlife in Canada, he had a longtime dream: to study polar bears in their purest form, to find a population protected from human contact. Hunting of Svalbard's bears dates to the 16th century, but since 1973, the archipelago has been a national refuge. When Derocher arrived, the population should have fully recovered.

But it wasn't long before he knew something was amiss.

"Things just don't appear right," Derocher told colleagues. Why weren't there more bears? Where were the older ones? It was as if they were still being hunted. Then he came across some bears with mixed female-male anatomy.

"Within the first year, it became pretty darned clear that I wasn't working with an unperturbed population," Derocher says.

As early as 1970, Canadian and European scientists discovered that DDT and PCBs were showing up in seals in the far north. Biologists had visited Arctic Canada and Norway to seek "blanks" — samples of animals expected to be free of contaminants. But in fact, their blanks were as dirty as those from some industrialized regions.

Now, all 12 of the "dirty dozen" contaminants considered capable of inflicting the most ecological damage have been detected at significant levels in the Arctic, said Derek Muir, an Environment Canada researcher.

PCBs, used worldwide as insulating fluids in electrical transformers, and chlorinated pesticides such as DDT, toxaphene, dieldrin and chlordane, were banned in the 1970s in most industrialized nations but persist in the environment, especially the oceans.

From water to plankton to copepods to cod to ringed seals to polar bears — at each step up the food chain, PCBs increase five- to tenfold in a process called bio-magnification. As a result, a polar bear carries a concentration billions of times greater than that in the Arctic Ocean. A mother polar bear stores chemicals from a lifetime of exposure in her fat. The concentration peaks during the winter fast when she gives birth — and then she bequeaths it, via her milk, to her cubs.

Because of their thick fat, big appetites and long, multi-stepped food chain, Arctic animals are repositories for toxic compounds, storing more than animals in temperate zones. They also deplete their fat reserves in winter, which concentrates chemicals in their tissues. The levels of PCBs in Svalbard bears are "alarmingly high," peaking at 80 parts per million, said Janneche Utne Skaare, a scientist with Norway's National Veterinary Institute.

On average, they are 12 times more contaminated than Alaskan bears. Masses of air and ocean water pass by the Norwegian islands, dropping off pollutants that hitchhike from Europe, Russia and the East Coast of North America. Svalbard's other top predators, Arctic foxes and birds of prey, also are highly contaminated.

Most of the concerns about Arctic wildlife center on the ability of the contaminants to suppress immune systems and disrupt sex hormones.

Producing a flood of antibodies to fight off viruses and infections is crucial for an animal's survival. But when Svalbard polar bears are exposed to a flu virus in experiments, they cannot muster as many antibodies as Canadian bears, which have far less PCBs, according to research by Hans Jorgen Larsen of the Norwegian School of Veterinary Science.

In the North Sea, two distemper epidemics, one last year and one in 1988, wiped out an estimated 38,000 seals. Experts specializing in immunotoxicology say the seals' high PCB levels exacerbated the scope of the epidemic. In tests on captive seals, scientists determined that levels of PCBs only one-fifth as high as those found in some Svalbard bears suppress immunity.

Norwegian scientists also have reported that the bears have altered testosterone and progesterone hormones, which could be reducing their fertility and perhaps causing sexual deformities. Of every 100 Svalbard bears captured, three or four have female and partial male genitalia.

Over the last decade, research on a variety of animals elsewhere, including alligators in Florida, birds in the Great Lakes and fish in Europe, has shown that DDT and other contaminants can mimic estrogen or block testosterone, causing feminized or half-male, half-female animals.

The chemicals also might have led to a missing generation of mother bears. Only 11% of Svalbard bears with cubs were over 15 years old, compared with 48% in Canada, said Geir Gabrielsen, the Norwegian Polar Institute's director of ecotoxicology.

Ross Norstrom, a Canadian Wildlife Service toxicologist who is one of the world's leading polar bear experts, worries most about the cubs. He said development of their immune and reproductive systems occurs during the first few months after birth, right when they are hit with the blast of PCBs from mother's milk.

The cubs of mothers with a lot of PCBs in their milk are more likely to die during their first year than cubs of mothers with low PCBs, according to research on Canadian bears. Concentrations were three times higher in denning mothers who wound up losing their cubs than in mothers whose cubs survived.

Skaare says Svalbard's bears are denning more often than others, closer to every two years than three years, which is a sign that their cubs could be dying early, because mothers are supposed to stay with their young for three years before giving birth again. But some scientists, including Derocher, are unconvinced without more evidence because cub survival varies naturally from year to year.

An inherent weakness of wildlife toxicology is in proving cause and effect, says Peter Ross, a Canadian scientist who studies contaminants in seals and orcas. Wild animals face so many variable factors, such as climate and diet, that it is impossible to tease out one factor as the root of a problem. The best scientists can do, he said, is amass evidence, like they have with PCBs. Experiments with lab rats, wild animals, captive seals and even humans all show similar biological changes.

The uncertainty is compounded in Svalbard, where due to its remoteness, scientists don't even have a reliable population estimate or know how often or why bears die.

Yet Norstrom said that after about 15 years of research, scientists are finally on the cusp of proving that PCBs are harming Arctic wildlife. "We're at the threshold, in a lot of ways, with polar bears," he said.

Scientists have only just begun trying to understand newer contaminants that are showing up near the North Pole, especially brominated flame retardants called PBDEs, and perfluorinated chemicals, including some formerly used in Scotchgard.

PBDEs, applied to hard plastic and polyurethane foam, have been detected in every species tested: fish, seals, polar bears, beluga whales, pilot whales and birds. Muir said Arctic levels are low but increasing — doubling every few years — so they will soon catch up to PCBs.

PBDEs, like PCBs, disrupt thyroid hormones, altering the learning ability and behavior of newborn mice exposed to low doses in lab experiments.

The flame retardants probably cause similar problems in wild animals, said Cynthia de Wit of Stockholm University's Institute of Applied Environmental Research. For example, when a bird's brain is altered, it has impaired hunting skills, she said.

But unlike the obvious problems of the past, today's doses of environmental chemicals cause symptoms that are subtle and difficult to diagnose in wildlife.

"These contaminants aren't a sledgehammer," De Wit said. "They might just be a regular hammer."

An Enigmatic Place

Just before 9 p.m., the Polar Institute crew is done for the day, so the pilot turns the helicopter back toward the town of Longyearbyen, the northernmost civilization on Earth. To the north, clouds are closing in on them, threatening a whiteout. But a perfect path of crystalline skies has opened to the south.

The landscape below looks almost voluptuous. Curvaceous, rounded granite peaks are bathed in soft light, awash in hues of icy blue and frosty white. The three men are glowing with the satisfaction — and relief — of knowing they are headed back for a hot dinner and warm bed before they wake up and head out again. They captured six bears on a tank of fuel, and all are safe, men and bears. This is Derocher's last foray into Svalbard before he heads back to his alma mater, the University of Alberta, to start new bear research in Canada.

His seven years in Svalbard weren't enough to illuminate the ecological mysteries of this enigmatic place, and other scientists will carry on the work. The contaminants will continue to haunt the Arctic — frozen in time, slow to heal — for generations.

Derocher peers out the helicopter window and remarks on the clarity of spring's eternal light. He knows winter will descend soon enough, plunging Svalbard into darkness again. And somewhere out there, in the dark, another polar bear will be born.