by Mary Ann Gratton
While climate change continues to be a topic of discussion around the world -- particularly following the United Nations Climate Change Conference held recently in Copenhagen -- a UTSC researcher has been conducting research on Arctic permafrost that raises many of the same issues discussed in Denmark.
Professor Bill Gough, a climatologist and the vice-dean, graduate education and program development at UTSC, has been studying permafrost and Arctic sea ice for the past ten years, and has traveled to Hudson Bay for the past three summers. His studies aim to shed more light on the relationship between permafrost and polar bear habitats.
For a polar bear, the thickness of sea ice is a matter of life and death. If the ice is too thin, melts too early or freezes too late, it can mean weight loss or even starvation, since the bears cannot hunt for seals unless they have solid ice on which to walk. Although polar bears can store fat in their bodies for months and thus withstand a lack of food, a loss of sea ice can mean longer periods of hunger, cannibalization, and an ultimate decline in numbers for a species already considered one of the most at-risk animal populations and an indicator of the consequences of climate change.
Permafrost is just as vital to the polar bear population as sea ice. Permafrost is frozen ground whose temperature remains below zero degrees Celsius for at least two years. When female bears go inland, they depend on permafrost to build their dens. Without permafrost, their dens will collapse, resulting in the destruction of a habitat crucial to the future of bear populations.
Gough and his colleague, bear biologist Martyn Obbard of the Ontario Ministry of Natural Resources (MNR), are conducting a joint project on sea ice, permafrost and polar bears around Hudson Bay. The MNR-funded project has enabled the pair to conduct research from a location near the First Nations town of Peawanuck, Ontario. Two graduate students, Andrew Tam and Kevin Middell, have recently joined the project.
The team’s research has confirmed that there is continuous permafrost along the Hudson Bay coast of northern Ontario on which the ecosystem depends, but it is vulnerable to climate change. “This band of permafrost is not likely to extend more than 20 kilometres inland, and is highly at risk of disappearing through climate change,” says Gough. “Although my own interests are in physics and geography, this research has a strong connection to biology, and the polar bear has become the canary in the mine for climate change, so we feel this research can have worldwide implications.”
When the seasonal ice melts, the bears come on shore, where food is scarce. “When they go out on the ice, they gorge on seals and come back on land until the ice re-forms. They typically lose weight while on land. The male bears just hang around, while the female bears go inland to create dens to have their offspring.” Male bears show no family loyalty and will eat offspring if they are hungry, so females hide their offspring and continue to nurse until the latter are big enough to wean and can learn to hunt for seals.
While in the field, Gough has used increasingly sophisticated technology to detect permafrost and study its thickness and temperature, examining the permafrost in depth and returning in subsequent seasons to measure changes. “We’ve also been asking, in a climate change context, how this will change, and whether there will be a degradation of polar bear habitat so that it’s not sustainable on land.”
“Professor Gough’s research on Arctic permafrost and sea ice is very timely and highly relevant to ecosystems, biodiversity and communities in the Canadian north,” said Professor Malcolm Campbell, vice-principal (research) at the University of Toronto Scarborough. “In fact, Professor Gough’s research has far-reaching implications that extend to global-level impacts of climate change. This work is yet another example of the vital environmental research being conducted by many of our faculty members at UTSC.”