Subarctic lakes reportedly drying up at faster rates

Desiccated lakes near Churchill, Manitoba

Desiccated lakes in Wapusk National Park near Churchill, Manitoba are shown. Desiccation of shallow lakes has occurred recently in response to lower-than-average snowmelt runoff. This phenomenon appears unprecedented over the last 200 years. Photo by Hilary White

Researchers say a decrease in snowfall may be responsible for the desiccation or drying up of subarctic lakes at a rate not seen in 200 years.

Seventy shallow lakes near Old Crow, Yukon and Churchill, Manitoba were studied between 2010 and 2012. Most lakes were less than a meter or 39 inches deep and located on relatively flat terrain while surrounded by scrubby vegetation.

Average winter precipitation, particularly in the Churchill area, declined by nearly 30 inches between 2010 and 2012 compared to averages recorded between 1971 and 2000.

Frédéric Bouchard, a postdoctoral fellow at Université Laval’s Department of Geography and the Centre for Northern Studies and a co-author of the study, said in a news release about the research that precipitation in the form of snow represents about 30% to 50% of the annual water supply.

Isotopic analyses conducted on phytoplankton remains in lakebed sediment indicate that the lakes have maintained water balance for 200 years, but were disrupted a few years ago.

Many of the shallowest lakes could dry up completely if the trend continues of dry summers and less snowy winters as has been forecasted in climate models.

“It’s difficult to predict all the repercussions of this habitat loss,” said Bouchard, “but it’s certain that the ecological consequences will be significant.”

Researchers from Université Laval in Quebec, Wilfrid Laurier University in Waterloo, Brock University in St. Catharines, and the University of Waterloo conducted the study that was published last month by the scientific journal Geophysical Research Letters.

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