by Carl Safina
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Two hundred yards away, the paddling bear latches its grappling hooks into a broad, jagged floe and hoists itself back into the Arctic air. It rolls itself dry and rubs its face in the snow, leaving several bloody shrouds, then yawns out its black tongue before it, too, conks out in a contented sprawl.
* * *
We would have gone up Hinlopen Strait but ice prevented it. Instead, we turned along the northeasternmost island of Nordausland, Svalbard’s “cold corner” (which, in Svalbard, is saying something).
The shoreline curves toward a glacier that has been calving icebergs, which, under the pressure of many centuries, glow a translucent, neon blue. The point meets a flat gray sea with a flat gray gravel shore under a flat gray sky.
About fifty Walruses are lying on the gravelly point. Huge animals, Walruses reach forty-two hundred pounds. These are all males, of assorted ages. Females are farther north somewhere, tending pups on ice. While molting, as now, they shed all their hair at once. I listen to them snorting, and can almost feel them scratching themselves with that mittenlike flipper-hand. The insulation-compromised animals, like these, stay out of the frigid water for three weeks—so, no food. (Walruses’ unique mouths can suck clams and scallops from their shells. They can eat a few thousand clams at a feeding.) They’re huddling for warmth. The benefits apparently outweigh the tusks, but they continually jostle and poke one another with their ivory rakes. I’ll bet they’re capable of worse. One has a tusk broken off just a couple of inches from the gum. It’s difficult to imagine the force of the blow required to crack it off like that.
Europeans, of course, were after those ivory tusks. From the hundreds of thousands of Walruses here when people first found them, perhaps one in a thousand escaped slaughter. Today a few thousand Walruses make up Svalbard’s recovering population. Unlike seals, whose pups balloon in weight and are off the teat in a month or two, Walruses’ shellfish diet translates to thin, low-fat milk, forcing them to suckle pups for over two years. Consequently, Walrus populations cannot rebuild rapidly.
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Nordausland lies locked beneath a massive cap of perpetual ice that meets the sea as an enormous white palisade running as far as I can see. Attached to that wall of ice is shore-fast sea ice covering an area about five miles by two, ten square miles of frozen ocean. Foggy haze veils the farther distances, cocooning us into a kind of white dream.
Out on the sea ice lie about 150 Ringed Seals; they appear as subtle in the vastness as black poppy seeds scattered on a white dance floor. And for about every fifteen seals, a Polar Bear—an extraordinary accumulation of white terror.
Only about twenty-five thousand Polar Bears stalk the coasts and frozen ocean of the entire Arctic world. (Not the Antarctic; Polar Bears depicted consorting with penguins indicate an artist’s geographic dyslexia.) About three out of five of the world’s Polar Bears live in Canada. The population that ranges from Svalbard east across the entire Barents Sea to Novaya Zemlya numbers only about three thousand.
People with guns early on saw the white bears as fearless, deadly, having valuable fur, and worth shooting at every opportunity. Svalbard banned hunting in 1972. Stefan recounts, “It wasn’t actually hunting. Baited gun traps, hanging bait on ships’ rails for ‘guaranteed kill’ sport shoots, shooting from helicopters—it was just ridiculous.”
People still hunt them elsewhere, though most Polar Bear populations are in trouble. Baffin Bay’s population dropped almost a third between the late 1990s and 2008. Canadian scientists recommended limiting the hunting to sixty-four bears annually. Inuit tribal elders insisted that they were seeing far more bears than ever before. Scientists said that’s because bears forced ashore by melting ice were venturing into settlements to eat garbage, unattended dog food, and dogs themselves. Scientists project statistics of decline and stress; Natives say Polar Bears are everywhere. The Inuit-controlled body that sets hunting limits upped the number from the scientists’ recommended sixty-four bears—to 105. That Baffin bear population ranges between Canada’s Nunavut Territory and Greenland, and Greenland added for its hunters another 68, for a total planned kill of 173 bears from that population. Reported the Economist, “Even without the rampant poaching that takes place in Greenland, 12 percent of the Baffin bears are set to be turned into blankets, mukluks and stews.” James Qillaq of Canada’s Nunavut Territory, who chairs the Kanngiqtugaapik Hunters and Trappers Organization, scoffed at the notion that hunting could be a problem. “Numbers are just numbers,” he said. “We live here, so we know what’s really going on. We can hunt anytime we want, anywhere we want, no matter what anybody says.”
But more than hunting by humans, shrinking sea ice threatens the bears because without ice, the ice bear cannot hunt seals. Scientists expect Polar Bear numbers to decline about 1 percent each year. Where ice is melting faster, the bear is already having trouble; where temperatures remain cool, Polar Bears still do well. Stefan says sea ice near here has thinned a lot in the last few decades, but Svalbard is home to probably the healthiest Polar Bear population remaining on Earth.
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The bears in view, widely scattered and, white on white, hard to see, become more visible through a telescope. Most rest. One sits at a seal’s breathing hole, patiently attentive. One strides regally across distant ice looking very much the monarch of the realm. As people might bow their heads to royalty, the seals raise theirs.
Equal and opposite imperatives link these two animals: the Polar Bear’s to hunt, catch, kill, and eat the Ringed Seal, and the seal’s to avoid the foregoing. Named for its circle-marked fur, the Ringed Seal is the most abundant Arctic seal, and the smallest; adults weigh about 150 pounds.
Although it needs to forage in the sea and breathe air, the Ringed Seal has a way to live far into continuous sea ice, miles from open water. From below, it works continually with its strong foreflippers and well-developed claws to maintain three or four breathing holes in ice up to six feet thick. The Ringed Seal is the only Arctic seal that creates breathing holes. (The Antarctic Weddell Seal does, too.) You may find other seals breathing in wide cracks called “leads” and among broken floes or along the open-water edges of the ice. But the Ringed Seal can occupy expanses of solid ice—and the Polar Cod under it—that are simply unavailable to other seals.
Cat-and-mouse: A bear pads across the vast frozen sea. Eventually it finds a nearly invisible hole. It can smell whether the hole’s been active. There it takes a number and sits, or lies down, completely still, its chin on the ice, waiting.
“But it’s not so easy,” says Stefan. Ringed Seals can stay underwater for up to half an hour. They often dive to 150 feet, occasionally to 500, foraging in the frigid dark. The seal’s Achilles’ heel is its need for air. It rises toward the light at the end of infinity. But it knows the danger. Before it bursts into air for that needed inspiration, it blows a bubble to clear any skim ice, trying to determine whether all’s clear. If a bear makes a premature move as the water is disturbed, the seal swims to another hole. If the seal does not detect a bear, and there is, indeed, a bear, then the moment the seal’s snout punctures the surface, the bear’s teeth burst through its skull.
In spring, Ringed Seals dig dens into snowdrifts on the ice above their breathing holes. There, females give birth. The dens, designed to protect the seals from bears, can be rather elaborate and multichambered. Stefan believes that Polar Bears can smell seal-pupping lairs two miles away. If a polar bear smells or hears life in the lair, it rises up on its hind legs and, with its forepaws, smashes through the roof.
Over an average year, a polar bear kills about forty Ringed Seals. Nearly half are pups caught in their lairs during April and May. Another third are newly weaned pups taken in June and July. When the pups are weaned, they weigh fifty pounds. The naïve weaners give a Polar Bear its greatest opportunity to accumulate the fat necessary to carry it through the year.
If a Ringed Seal avoids bears for a couple of years, Ste
fan explains, “it becomes wise, and Polar Bears rarely get them.” They can live for up to thirty years, though any that live that long must have some bear stories to tell. Despite the horrific risks and the hostile environment, many seals do survive, populating the ice.
In summer, Ringed Seals must lie on the ice next to their hole while molting. Even their best vigilance is not foolproof. Polar Bears have been known to swim under the ice and pop up inside the seal’s own breathing hole.
* * *
If a Ringed Seal can be a meal, a Bearded Seal, at up to seven hundred pounds, is a banquet. A Polar Bear detecting a Bearded Seal sleeping at the ice edge may slide into the water. Within perhaps sixty yards it will slip under the surface, holding its breath while closing in. The seal will experience only the sudden white explosion as the bear erupts and bounds onto the ice. With the bear coming from the seal’s only sanctuary, the seal may have no escape route. But even when pounced on by a firmly gripping thousand-pound bear, an adult Bearded Seal may splay its flippers and, with its nails dug into the ice, drag both itself and the bear into the water. If it succeeds in getting into its element, the seal can submerge, spin, and break the bear’s grip. No encounter has a predetermined outcome. Polar Bears succeed in catching their prey an average of once out of every ten attempts. Usually, the seal escapes.
A bear can eat 150 pounds of blubber and meat in one meal. A female needs plenty of fat. Polar Bears mate in spring, but the fertilized egg does not implant and begin developing until autumn. That makes pregnancy rather provisional; if the bear fails to bulk on enough fat, her body is not heavily committed to the pregnancy and may abort and resorb the tiny fetuses. Males and nonbreeding females continue to roam and hunt in the months-long darkness. But around October or November, a pregnant female digs a cave in a deep snowdrift, usually on land. There she sleeps away most of her pregnancy and her delivery. She may also den in deep snow on sea ice. A bear who enters a drifting den may, with new cubs, emerge six hundred miles away. That’s what it means to be an ocean bear.
Cubs are born in November and December, after only two months of true gestation. They weigh only about one pound, the size of a guinea pig. At a fraction of 1 percent of adult body weight, they’re more like the semilarval young of marsupials than the infants of most placental mammals.
During all her time in the den, the mother does not defecate or urinate. Her fat gets used—producing water in the process, letting her maintain her fluid levels—but her muscle mass remains constant. Meanwhile, she is excreting milk so rich it contains 30 percent fat, more like seal milk than the milk of other bears. By the time she emerges, around March, her cubs weigh about twenty pounds each. She has not had a good meal for six, perhaps eight months—the longest period of food deprivation of any mammal—and may have lost more than half her weight.
In March or April, with the temperatures well below zero Fahrenheit (−10°C) and the sun returning, the mother is pressed. Growing cubs make food a constant issue. But she can’t just focus on hunting. She must also avoid males, who may kill her cubs. And when she is hunting, her cubs, lacking patience and the art of stalking, slow her down and spoil some of her opportunities.
She’s got just a few months to recover from her depleted winter condition and to bulk up for the next summer. So she’ll really need a good spring hunting season. In milder springs, ice that’s shrunk by 30 to 40 percent makes seals much more concentrated on the remaining ice, and melted birthing lairs leave pups visibly exposed. Those times heavily favor the bears; they’ve been known to eat almost 100 percent of seal pups under such conditions.
But a pup eaten when it weighs ten pounds is not there to be eaten when it would weigh much more. A bear can get more than five times as much energy from a weaned pup than from a newborn. Heavy predation on newborn pups, as happens in milder springs, lowers the bears’ overall energy intake. If the spring ice breaks up early, say, by June, the bears miss out on Ringed Seal weaners because they’ve eaten most of them as pups, and they miss out on the later influx of Harp, Hooded, Ribbon, Spotted, and Bearded Seals because there’s too little ice for hunting. Polar Bears forced ashore in June face a nine-month fast. So in warmer years the body condition of bears, especially females nursing growing cubs, is much worse come winter—a severe challenge to survival.
In Hudson Bay, Canada, spring breakup has been happening about three weeks earlier in recent years. Lean, hungry bears forced ashore by early ice breakup come scavenging, and increasingly often get into conflict with people. Stefan says that around Hudson Bay during the last twenty years or so, pregnant females’ average weight has dropped from 640 pounds to 500 pounds. To have a successful pregnancy, it’s believed a female Polar Bear must weigh at least 430 pounds.
“In the other regions,” Stefan says, “juvenile survival is dropping.” In Alaska, females are increasingly emerging from birthing dens without any cubs. In the Beaufort Sea off Alaska, the number of cubs seen per hundred females has halved in just a decade.
So far, Svalbard’s bears don’t seem to be suffering these problems. About one in three cubs survives the two and a half years to independence. That may sound low, but it’s stable.
* * *
But going into dens too skinny isn’t the bears’ only problem. Though many industrialized nations have banned PCBs (used worldwide in electrical transformers) and pesticides such as DDT, toxaphene, dieldrin, and chlordane, they persist in soil and water, especially the ocean. Traveling up each link in the food chain, from water to planktonic plants to planktonic animals to small fishes to larger ones, to seals to bears, these chemicals accumulate in each link. A Polar Bear’s body has chemical concentrations billions of times greater than the seawater. During winter, when she loses weight, a female’s pollutants become most concentrated. In her rich milk, she bequeaths those chemicals to her cubs. Mothers whose cubs die inside their dens have PCB concentrations three times higher than mothers whose cubs emerge. Cubs emerging from the den to get their first glimpse of the world are already among the world’s most contaminated animals.
That’s bad for their immune systems. PCB levels only one-fifth as high as in some Svalbard bears suppress immunity in captive seals. Svalbard Polar Bears exposed to flu virus cannot muster as many antibodies as Canadian bears carrying far less PCBs.
Contaminants also damage the bears’ delicate sexual systems. Svalbard bears suffer altered testosterone and progesterone hormones, apparently causing them to stop breeding abnormally young. Of females with cubs here, only about one in ten are over fifteen years old, compared with one in two in Canada. And 3 percent of Svalbard bears show gross sexual abnormality, having both female and male genitalia.
“The good news,” Stefan adds, “is the PCBs and DDT are declining.” So is mercury, in Svalbard, at least. Danish researchers analyzing four hundred hair samples from bears killed over several centuries found that mercury contamination increased sharply starting in the 1890s to 1973, peaked during 1965–74 (at levels fourteen times higher than those in hair samples hundreds of years old), but by 2001 had declined 25 percent from the peak. Mercury comes mostly from burning coal. The researchers credited stricter European environmental standards for the decline. In parts of the Arctic subject to more fallout from Asia, mercury levels increased.
The bad news is newer chemicals. Polar Bears contain small amounts of compounds used in Teflon and formerly used in Scotchgard, as well as in flame retardants. Manufacturers put flame retardants in furniture, carpet padding, electronics, and plastics. Obviously, the intent is to keep people safe; no one thought these chemicals would poison wildlife and people. The most abundant flame retardant in Svalbard bears comes from a compound used in foam cushions. Flame retardants get magnified as they move from prey to predator; one compound was seventy times more concentrated in Polar Bears than in the Ringed Seals from which they’d gotten it.
Virtually every person tested on Earth now contains traces of flame retardants. After the milk of many U.S. women
was found to carry concentrations approaching those that altered the brains of newborn lab mice, Europe and various U.S. states banned some of these chemicals. (They also disrupt thyroid function and sex hormones and impair motor skills, memory, and learning.) The rapid buildup in Arctic Ringed Seals stabilized soon after the ban, and, as a result, concentrations in seals and bears—and women—will probably decline. So there’s hope.
* * *
As we’re watching two distant bears moving across the seal-flecked ice, Stefan is telling me that the most difficult time for cubs is between the time they separate from their mother and the time they’re about five years old. That smaller, whiter bear we’d seen the other day, waiting for those two to leave the remains of that seal, was probably in that category. Most young Polar Bears die from starvation. But a few survive to be thirty years old.
Isbjörn may be the monarch. But the monarch is not the realm. The ice bear requires ice. So do Ringed, Harp, Hooded, Bearded, Ribbon, and Spotted Seals. So do Ivory and Ross’s Gulls, the Bowhead Whale, and the unicornlike Narwhal. The Walrus. That’s just the beginning of a longer list of animals dependent on ice.
Consider the bear’s main prey. Ringed Seals never come onto land. When the ocean freezes, they live on and under the ice. When the ice vanishes, they stay in the ocean. Bears cannot attack them in the water. Does that mean that without ice, Ringed Seals would live safely at sea? Remember, Ringed Seals give birth in snow caves above sea ice. Other seals, too, give birth on sea ice. Already, the Harp Seals whose white pups have long been subjected to the controversial fur hunt are drowning by the hundreds of thousands as the ice melts from under them. An end to ice would mean an end to birth.