Entire Lakes Feel Effects Of Climate Warming, University Of Alberta Study Shows

"We study these lakes as models of global change," said Michelutti. "If you think of these lakes as sentinels of change they are telling us that recent warming, attributable in part to human activities, has already begun and the result is a dramatic change in the way that entire ecosystems function."

Michelutti and his research team, including his supervisor, Dr. Alexander Wolfe, from the U of A's Department of Earth and Atmospheric Sciences, used an innovative technique developed at the U of A called reflectance spectroscopy. It allowed them to "see" in wavelengths what the human eye can't and to learn about the chemical composition of the sediment in six lakes on Baffin Island. In this case, they found major increases in the concentration of chlorophyll a--a good indicator of overall ecosystem production. The research is published in the current issue of Geophysical Research Letters.

What is alarming about these findings is the magnitude and the timing of the changes, says Michelutti. "For the last several thousand years, chlorophyll a concentrations in our study lakes were very low and showed little variability--until approximately 150 years ago when chlorophyll a increased rapidly and reached unprecedented levels. The timing of these changes corresponds to the start of the Industrial Revolution and when humans first started having a major impact on global atmospheric chemistry," said Michelutti.

"Increased aquatic production due to climate warming has been predicted for many years, but until now has never been demonstrated," he said. "So, we were not totally surprised by our findings; however, the rate and magnitude of the changes that we recorded are definitely alarming, especially when taken in the context of the last several thousand years of variation."

Michelutti's work was supported by the Natural Sciences and Engineering Research Council of Canada.

The University of Alberta in Edmonton is one of Canada's premier teaching and research universities serving more than 35,000 students with some 8,000 faculty and staff. It is renowned in a number of areas including for the ground breaking diabetes treatment "The Edmonton Protocol", being home to the National Institute for Nanotechnology, producing cutting edge natural resource engineering advances and for scholarly research in English literature.