Monday, February 26, 2007

My Dear Students: Polar Bears Offer a Lesson If We Listen

I am in Churchill Manitoba. The welcome sign at the train depot says it’s the Polar Bear Capital of the World. And I haven’t seen a bear. This town lies at the end of a northern spur railroad that touches the edge of the arctic. Southward, peat, marsh, swamp and fen spread all the way to Manitoba. Northward, at this time of year it’s almost solid ice to the poles.

Churchill still has bears. The reason I haven’t seen one is that they are busy right now. The males are out on the ice, working hard to get as fat as they can while they can. The females are deep inland conserving their energy having just birthed cubs. The bears’ yearly cycle depends intimately on the rhythmic freezing and thawing of the ice on Hudson Bay.

Every year, extreme cold freezes Hudson Bay in October. It melts again in June or July. The ring seal, the bears’ primary source of food is available only when the bears can walk the sea ice. As soon as the ice melts, the bears enter a fast until it freezes again. Due to their forced fast off the ice, the bears’ driving purpose during winter is to consume as much fat as possible. They grab a seal where it surfaces to breathe and strip it of its blubber, which is much higher in calories than the meat, leaving the rest for the arctic fox which follow them to take advantage of what the polar bears leave behind. Because of the seasonal thaw, Churchill’s nine hundred or so bears make for dry land as the ice breaks up. There, if healthy, they go into a restful waking summer hibernation, surviving on the fat stores built up over the winter.

Nick studies Churchill’s bears. We talked in the dining hall of the Churchill Northern Studies Center while he waited for the weather to warm and clear. I entered conversation by asking if I could ask a question about polar bears. “Any question about polar bears is just fine with me,” he said.

He has a dream job. He searches for bears by helicopter, stuns them, and weighs and tags them. He tracks them from year to year and looks for trends in the health of Churchill’s bear population.

Nick is tall and thin, with narrow shoulders and a big smile. He looks a little bit like a polar bear himself. I asked what path led him to be an expert in polar bears. He told me the story: It was a matter of taking a different path home from studying for exams.

“Usually I went one way, but this time I took a different street. There on a light post was a little notice that was a different color from those around it. I would never have noticed it if it weren’t a different color. It was about the size of a sticky note. It said they were looking for someone to join a polar bear study, lab work only. No field work. I think that’s why I got it. Everyone wants to do field work. I don’t believe in fate or anything. It was just luck. And now the job I have, it was the same way. The guy who had it before me was supposed to have it for three years and he left a year early. I was just finishing up my Ph.D. in seals and they were looking for someone with a Ph.D. and polar bear experience. Oddly, that was me.”

Nick’s a biologist, but he calls himself an historian. The bears he studies are in trouble and their story will soon be a thing of the past. Every year the ice breaks up earlier. These days, it’s happening up to two weeks sooner than it did a few decades ago. As a result the bears are having to spend more time away from their food source. Land-based prey, even though bears have been known to snack on it, just won’t cut it. When the bears break their fast, they just increase their metabolism. Churchill’s bears are hungry and unlikely to make it through the next fifty years as a population.

What’s happening to these bears is different from the dangers faced by the beaver, the spotted owl, the whooping crane and the bald eagle.
Unlike twentieth century endangered species, these twenty-first century bears aren’t simply losing their habitat, being poisoned or being over-used as a resource. Lost habitat can sometimes be mitigated. We can stop using pesticides. Hunting practices can be changed. Instead of local causes, global human activity is changing the local climate on which Churchill’s bears depend.

Elevated levels of CO2 and methane in the century and a half since the Industrial Revolution have warmed the earth. It’s not that CO2 and methane are atmospheric newcomers. It’s that humanities’ collective lust for fossil fuels and the energy they provide has displaced our planet’s stores of carbon from inside the earth to the atmosphere and large scale agriculture is increasing the amount of methane released from decompositon of organic matter. Global atmospheric carbon and methane and global temperatures correlate directly: as carbon and methane increase, so does the global average temperature.

Warming is happening the quickest in the Arctic and its environmental impact is most dramatic at the edge of the arctic ecosystem. Ask around Churchill and anyone will tell you that things aren’t like they used to be. Winter is shorter. The open water season is longer. Change is happening fastest in the Arctic because there is so much more land mass in the northern hemisphere and land absorbs more heat annually during the warm season than water. In addition, as soon as some ice is lost, more follows. Ice reflects heat far better than water. These are changes in the local climate that local or regional or even Canadian national policies alone can’t undo.

The polar bear mothers, who are the subject of Nick’s spring work, have it hardest. After a summer on land, using as little energy as possible, Churchill’s mother bears go to their dens in and around the Wapusk National Park. There they fast, waiting out their pregnancy until cubs are born in February. Once the cubs are born they nurse on milk forty percent rich in fat. By the time they emerge from their dens in February, eight months into a fast, they weigh only one-fourth what they did when they walked off the ice in the spring. Nick is looking for mothers on their way to feed on seal pups. He’s seeing bears with less fat on them and with fewer cubs. The earlier breakup of the ice means a twenty-five percent reduction in feeding time and it shows.

I asked him how it felt to be studying a population that was struggling. “It’s sad. I hope to be able to tell the story of the bears. And hopefully someone will listen.”

The question with which I’d approached Nick was about a story I’d heard that I couldn’t find confirmed in the literature about bears. People around Churchill report that the bears’ lust for seal oil extends to petrol. Leave gas cans or an oil drum lying around and sooner or later, the bears will go to great lengths to lick it clean. I asked Nick if the bears were attracted to oil because of their craving for fat. Nothing in the Arctic is as oily as seal, except for oil.

Nick refuted the local reports saying he didn’t see any evidence of bears being particularly attracted to oil. He said he’d seen plenty of oil drums left full and untouched surrounded by hundreds of bears. He chocked the reports up to the curiosity of polar bears. “They’ll investigate anything,” he said, “and if they get it on them, they want to clean it off, so it looks like they want to eat it.”

Maybe the rumors of bears being attracted to petrol are a projection of human beings’ seemingly insatiable appetite for it. Wherever bears and humans have co-existed without industrialization they have occupied similar niches. In the Pacific Northwest, bears and humans survived together for centuries on salmon and berries. In the Arctic North bears and humans survived together on ring seal. Since industrialization, goods move all over the word and people no longer rely on local food sources. The needs of bears and humans have seemingly diverged. You can get beef in the Arctic more easily these days than ring seal, and in Seattle, sushi’s more plentiful than coast trailing blackberries. The polar bear’s desire for oil stored in the body of the seal is about survival. Humanity’s desire for oil stored in the body of the earth is different.

In spite of what we know about climate change and risks it presents to the global ecosystem as we know it, the human lust for fossil fuels is unabated. According to a recent report commissioned by the governments of the US and Canada, Russia, Denmark, Iceland, Sweden, Norway and Finland, climate change will make those fuels easier to come by than ever:

Rising global temperatures will melt areas of the Arctic this century, making them more accessible for oil and natural gas drilling. . . . Warmer temperatures would make it easier to drill and ship oil from the Arctic. . . . Offshore oil exploration and production are likely to benefit.” (http://www.energybulletin.net/3072.html, retreived 02-17-2007)

The report went on to decline to estimate how high energy prices would have to be to justify drilling in the region. With increased demand for oil, the prices may go high enough. More demand means increasing use and increasing use means that more and more carbon will find its way into our skies. More carbon means higher temperatures. Higher temperatures mean less ice. Less ice means hungry bears.

As if that weren’t enough, oil drilling and shipping in the Arctic pose an additional threat to bears. In the late eighties a small group of Canadian researchers decided to conduct a trial. They were concerned for what might happen to the bears in the event of an oil spill. They captured four bears and dipped two of them in oil tainted water. They were poised to measure what the dipping would do to the insulative quality of the bears’ fur. To their surprize, as soon as the bears emerged, the polar bear compulsion to be clean took over. The bears licked themselves spotless and had soon died of poisoning, in spite of the horrified researchers’ efforts to save them.

Churchill’s polar bears aren’t likely to fare better than the two who died in the study. Even barring an oil spill, forced to come off the ice sooner, many don’t have the stores of fat to see them through their long summer fast. Fewer survive. Fewer mothers give birth to fewer cubs. In the last decade, Churchill’s population of bears has declined by twenty-five percent. Given current climate models, spring will continue to occur sooner for at least the coming 50 years. The bears of Churchill occupy the southern range of habitat for a global species that spans three continents.

I asked Nick what he thinks will happen. “Well,” he said, “that depends. Some climate models predict that all the Arctic ice will break up. Some say less. I think what’s most likely is probably somewhere in between. Perhaps they’ll move north. Maybe they won’t. Either way, Churchill’s bears are going to disappear.”

“Do you think it will be in your lifetime?” I asked.

“Yes. Probably.”

Luckily for us, Churchill’s bears won’t disappear from one day to the next. They’ll continue to do their best hunting on the ice that remains. And Nick will be there to observe changes in their habits and population. And he will tell the story. The question is, will we listen?

3 comments:

CR said...

Hi Jana, Really fascinating blog, have enjoyed following your adventures! You may get to wear your parka here in Tumwater, they predict more snow showers. (We had snow showers last week, although I prefer to think of snow as "thermally challenged rain".) See you soon,
Singing Busdriver

BMS said...

sounds like you had a blast on you trip and hope you give us some great information when you get back

Samantha Chandler said...

Oh. I am so sad. So sad that our individual habits, and our country's habit of consuming and wasting are causing the deaths of so many plants, creatures, and people.
I want to teach my students to be hopeful, and yet I despair.
Thank you for this eloquent reminder of all that is at stake, and all that we must do to help at least slow this reckless journey that we are taking everyone on, and, at the least find revolutionary ways to stop and repair the destruction that is otherwise sure to happen.
You help bring me hope that this is possible.