Frozen Arctic ponds that have persisted for millennia are drying out during the polar summer, according to evidence from Canadian scientists
Marianne Douglas of the Canadian Circumpolar Institute at the University of Alberta together with John Smol, of Queen’s University, have studied these shallow ponds that dot the Arctic landscape for more than two decades. Changes in such environmental features provide an important indication of how particular regions are being affected by climate change. Douglas and Smol have analysed 24 years of detailed data, including water quality and water levels from about forty Arctic ponds. The data represents the longest record of systematic fresh water monitoring in the high Arctic.
Marianne Douglas
The researchers have found a recent lowering of water levels and changes in water chemistry, which they say are with an increase in evaporation/precipitation ratios (E/P) and higher average temperatures. Until recently, these ponds were considered permanent features of the landscape, but in early July 2006, several of the main study ponds had dried up completely and others showed dramatically reduced water levels.
“It was quite shocking to see some of our largest study ponds dry up by early summer,” says Douglas, the ecological ramifications are enormous and might be felt throughout the Arctic ecosystem, she adds. Such changes will most likely affect waterfowl habitat and breeding grounds, affect invertebrate populations, the food supply for insect-eating species, and drinking water for many animals. “These surface water ponds are so important because they are often hotspots of biodiversity and production for microorganisms, plants and animals in this otherwise extreme terrestrial environment.” explains Douglas.
Some of the ponds were 6,000 years old. They’ve been in existence for millennia, adds Douglas. We were really surprised to see bodies of water that had been in existence for over 6,000 years actually disappear, become completely dried up. It was quite shocking to see some of our largest study ponds dry up by early summer.
Further reading
Proc Natl Acad Sci, 2007, in press;
http://dx.doi.org/10.1073/pnas.0702777104
Canadian Circumpolar Institute
http://www.uofaweb.ualberta.ca/polar/index.cfm
John P. Smol’s homepage
http://biology.queensu.ca/faculty/smol.html
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