1,000-year-old Arctic ponds disappearing due to global warming
3/7/2007 15:34
Research has uncovered alarming evidence that high Arctic ponds, many of
which have been permanent bodies of water for thousands of years, are completely
drying out during the polar summer. These shallow ponds, which dot the Arctic
landscape, are important indicators of environment change and are especially
susceptible to the effects of climate change because of their low water
volume. As reported yesterday in the newest issue of Proceedings of the
National Academy of Sciences (PNAS), Marianne Douglas and John Smol, two leading
Canadian environmental scientists, studied these unique Arctic ponds for the
past 24 years, collecting detailed data such as water quality and water levels
from approximately 40 ponds. Collectively, this data represents the longest
record of systematic limnological (the science of the properties of fresh water)
monitoring from the high Arctic. Over the 24 years the researchers spent
monitoring the ponds, they recorded evidence of recent lower water levels and
changes in water chemistry consistent with an increase in evaporation/
precipitation ratios (E/P) and warmer temperatures. Until recent years, the
ponds of the study sites were permanent features of the landscape, but in early
July 2006, because of warming trends in the Arctic, several of the main study
ponds dried up completely, whereas others had dramatically reduced water
levels. "It was quite shocking to see some of our largest study ponds dry up
by early summer," said Douglas. The ecological ramifications of these changes
are likely severe and will be felt throughout the Arctic ecosystem, says
Douglas. It would affect waterfowl habitat and breeding grounds, invertebrate
population dynamics and food for insectivores and drinking water for animals, to
name only a few. "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," said Douglas.
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