Study: Northern Canada Ponds Drying Up
Pastor Dale Morgan
Jul 2, 5:14 PM EDT
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Study: Northern Canada Ponds Drying Up*
By RANDOLPH E. SCHMID
AP Science Writer
WASHINGTON (AP) -- Ponds that have provided summertime water in the high
arctic for thousands of years are drying up as global warming advances,
Canadian researchers say. Falling water levels and changes in chemistry
in the ponds first were noticed in the 1990s, and by last July some of
the ponds that dot the landscape were dry, according to a report in
Tuesday's Proceedings of the National Academy of Sciences.
John P. Smol of Queens University in Kingston, Ontario, and Marianne S.
V. Douglas of the University of Alberta in Edmonton have been studying
about 40 ponds on Ellesmere Island in northern Canada since 1983.
The ponds are habitat for algae and invertebrates such as insect larvae,
and waterfowl use them.
Smol likens the warming conditions to a pot of soup on a stove.
"If you take the lid off, it is similar to what we are observing in
these ponds. The soup will slowly decrease in volume and it will get
saltier and saltier as the water evaporates, leaving the salts behind."
That same evaporation process is taking place with these ponds, he said.
Weather records show there has been no decline in rain and snowfall in
the region and, while some arctic ponds have drained when the permafrost
melted beneath them, these ponds sit above bedrock.
Douglas and Smol were able to use paleological techniques to trace the
history of the ponds back thousands of years. "We basically followed
them from cradle to the grave," Smol said.
Changes set in about a century ago, he said, with more mosses growing
and shorter periods of ice, followed by lowering water levels and
increasing salinity until some dried up completely.
In addition to the ponds, the researchers also reported a drying of
nearby wetlands.
In the 1980s they often needed to wear hip waders to make their way to
the ponds, they noted, while by 2006 the same areas were dry enough to burn.
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On the Net:
Proceedings of the National Academy of Sciences: http://www.pnas.org