|
 Hit
by a double whammy
of toxic chemicals and global
climate change, polar bears face extinction
It is late April, nine days since the return of the midnight sun, and a
450-pound polar bear and her cubs walk on the finger of
a frozen fjord. Spring has arrived on the Norwegian
archipelago of Svalbard, a favorite nursery for polar bears. About 670 miles
from the North Pole, the mother bear lumbers along in her hunt for ringed seals,
leaving a zigzagged path of 12-inch-wide craters followed by the smaller paw
prints of her two young sons.
A few miles away, from the
front seat of a helicopter, scientist Andy Derocher has spotted the family’s
fresh trail. The chopper’s pilot loops, spins, and straddles the tracks,
following their erratic path for several miles. “She’s running here,’’ Derocher
tells the pilot, pointing to the edge of a craggy glacier. “I think she’s ahead
of us here somewhere.”
One of the world’s leading
polar bear experts, Derocher is monitoring the health of a species imperiled by
a double whammy of toxic chemicals and global climate change. He and other
wildlife biologists now predict that some populations of the world’s 22,000 to
25,000 polar bears could become extinct by the end of this century.
 Born at Christmastime, cradled
in pure white snow, polar bears emerge blind, toothless, a pound apiece, as
feeble as kittens. Yet before they even leave the safety
of their dens on Svalbard, polar
bear cubs already harbor more pollutants in their bodies than
most other creatures on the planet. Mother polar bears store a lifetime
of chemicals in their fat and then bequeath them, via their milk,
to their young.
Several hundred of the
industrialized world’s most toxic chemicals, especially PCBs and organochlorine
pesticides such as DDT, have transformed Svalbard and much of the Arctic into a
giant chemical repository, and polar bears into its unintentional lab rats.
Newcomers are joining the older chemicals there, including flame retardants
called PBDEs and a compound used in the manufacture of Teflon. Originating
mostly in North America and northern Europe, the pollutants hitchhike to
Svalbard, Greenland, and other remote reaches of the Arctic on northbound winds
and ocean currents. There, they magnify in animals each step up the food web,
leaving polar bears, killer whales, and other top predators highly contaminated.
Scientific studies suggest that
these extraordinary loads of chemicals are weakening polar bears, culling the
old and the young. Their immune cells and antibodies have been suppressed, and
their sex hormones, thyroid hormones, and even their bone composition have been
altered. And perhaps most curious of all, small numbers of strange
pseudohermaphroditic bears have been discovered. Of every 100 female bears
captured on Svalbard, three or four have partial male genitalia.
“Could you realistically put
200 to 500 foreign compounds into an organism and expect them to have absolutely
no effect?” asks Derocher. “I would be happier if I could find no evidence of
pollution affecting polar bears, but so far, the data suggest otherwise.”
 While
toxic substances are jeopardizing bears, the melting
of the Arctic is a more immediate threat to their survival. In Canada’s western
Hudson Bay, the sea ice where they hunt seals breaks up three weeks earlier now
than 30 years ago, polar bears have
declined from 1,200 in 1985 to
fewer than 950 in 2004. That same year, marine biologists in Alaska
reported finding four drowned polar bears, perhaps because they were unable to
swim long distances to reach solid ice. Forty wildlife scientists, representing
all five nations inhabited by polar bears, adopted a resolution last June
declaring that the bears are “susceptible to the effects of pollutants” and
those effects are exacerbated by the stresses of global warming.
In 20 years of Arctic research,
first with the Norwegian Polar Institute and now with the University of Alberta,
Derocher has captured and tested more than 4,000 bears. It is dangerous work,
but the only way that scientists can monitor their health. Scanning the ice
below, he has picked up the bear family’s trail, and soon the mother and cubs
are below the helicopter. In the backseat, Norwegian scientist Magnus Andersen
injects a syringe of tranquilizer into a dart and screws it onto a shotgun. The
helicopter spins in circles perilously close to the ground to give Andersen a
clear shot. He leans out the open door, takes aim, and fires. Hit in the rump,
the mother wobbles, but she isn’t going down. Andersen readies another syringe
and fires again. The bear lies down on her stomach, one giant paw splayed back.
The two cubs nuzzle her, trying to awaken her, then curl up beside her.
The cubs, only four months old,
are wide-eyed and curious as the helicopter lands and the scientists cautiously
approach on foot, their boots crunching in the crusty snow. Derocher sets down
his black toolbox, removes some dental pliers, and opens the sleeping bear’s
jaw, deftly extracting a tooth the size of a cribbage peg that will be used to
confirm her age. Andersen slices a quarter-inch-diameter plug of blubber from
her rump with a biopsy tool and siphons a tube of blood from a vein in her inner
thigh. Then Derocher kneels beside the mother and milks her to sample the creamy
liquid she is feeding her sons. The milk, fat, and blood will be analyzed for a
suite of chemicals. Before departing, the scientists tranquilize the cubs. The
threesome will snooze for a couple of hours, then shake off the drowsiness and
continue on their way.
Aloft again, the helicopter
glides north between Svalbard’s snow-draped peaks until Derocher spots more
tracks—this time, a mother and two yearlings. Relishing the clarity of spring’s
eternal light, the scientists know that polar winter will soon descend, plunging
Svalbard into darkness again. Into that darkness the next generation of ice
bears will be born—to a very uncertain future. 
This article has been made possible by the Foundation for National Progress,
and
the Investigative Fund of Mother Jones . www.motherjones.com
Important Note : January 18. 2007
Under
pressure from a lawsuit filed by NRDC, National Resource Defense Council,
the Center
for Biological Diversity and other partner groups, the Bush administration has
announced that it is formally proposing to protect the polar bear under the
Endangered Species Act -- a crucial first step toward saving the bear from the
ravages of global warming. In the second round of this historic fight, we will
be mobilizing one million Americans to show their strong support for this
proposed protection and to fight off opposition from industry. But first, we
must prevail on the administration to hold public hearings -- not only in
Alaska, but across the lower 48 states -- so concerned Americans have a chance
to speak out in person in defense of polar bears.
www.nrdc.org
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