Chances are you have had an encounter at one time or another with certain chilly conditions—that fine layer of frost that happens when temperatures drop below freezing and combine with moisture lingering in the air? Typically, in regions where four seasons interchange every year, frost is a quite common occurrence, but have you ever heard of a condition called permafrost? Permafrost is when a thick layer of soil remains frozen all year long, most often in polar regions where the temperatures are well below freezing.
According to a report published by Dyke and Sladen, “in Canada, the northern Hudson Bay lowland includes the largest area of frozen peat plateau bog. This area is home to polar bear denning habitats, caribou forage, carbon storage, and wetland drainage control provided by peat plateaus.” Permafrost occurs perennially on these plateaus and, along with sea ice, is vulernable to climate change. If warmer temperatures occur, the thawing ice has negative and irreversable effects on animal habitats and ecosystems.
In the Hudson Bay area, sea ice is an important environmental factor because, in a study completed by Abraham and McKinnon, it “helps cool the climate and contribute to the occurrence of the most southern continuous permafrost in North America.” The report also discusses that “permafrost grades from‘continuous’ along the Hudson Bay coast; to ‘discontinuous’ towards the south and inland; to isolated patches around James Bay in the south. Permafrost is absent in the most southern reaches of the ecozone+ away from the coast.” With temperatures increasing due to climate change, the sea ice is getting thinner and the thawing of permafrost is occurring. Impacts are apparent now in some areas and are likely to spread which can have negative effects on species and food webs.
The polar bear is an example of a species that depends on sea ice and permafrost for survival. In a report published by Gratton and Westoll, “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 they cannot hunt for seals without solid ice on which to walk.” Permafrost is also important for polar bears because females depend on it to go inland to build their dens and breed. Without it, they cannot raise their cubs leaving the possibility of population collapse. Through this and the ever increasing threat of climate change, we can see the negative impacts the decrease in permafrost and sea ice has on the ecosystem.
Photo Credit: Art Of Albertine
Written by: Alexandra D.