Permafrost thaw slumps in the western Canadian Arctic are releasing record amounts of mercury into waterways, according to new research by University of Alberta ecologists.
Mercury is a naturally occuring contaminant that is toxic to humans and other animals in large quantities as it accumulates in organisms and food webs. Sediments in permafrost are estimated to store more mercury than Earth’s oceans, atmosphere, and soil combined. And, as climate change causes permafrost to thaw, the mercury stored in permafrost becomes available for release into the surrounding environment.
“Concentrations of mercury were elevated for at least 2.8 kilometres downstream of thaw slumps,” says Kyra St. Pierre, Vanier Scholar PhD student, who co-led the study with fellow graduate students Scott Zolkos and Sarah Shakil in the Department of Biological Sciences. “This suggests that some mercury from thaw slumps may be transported for many kilometres through downstream ecosystems, and into larger waterways.”
The issue is exacerbated by rising temperatures and increasing precipitation in the Canadian Arctic due to climate change.