Global warming has changed northern bodies of water

There are no lakes left on our planet that are in a pristine state.

An extensive international study shows that global warming has changed the communities in arctic lakes in the Polar Regions. Northern lakes and the organisms that live in them are known to be very susceptible to the slightest change in climate and to other external factors.

A recent study analysed the sediments gathering on the bottoms of bodies of water, as they are indicative of the biological production of a lake in chronological layers. The study was conducted by 26 researchers targeting 55 lakes in different parts of Canada, Russia, Spitzbergen (Norway), and Finnish Lapland. The Finnish team, headed by Professor Atte Korhola, consisted of researchers from the Environmental Change Research Unit of the Department of Biological and Environmental Sciences, University of Helsinki.

“We spent ten years collecting material for the study, beginning from the mid-1990s,” says Jan Weckström, Docent. The results of the study clearly show that even the remotest areas have not escaped global warming caused by human action. There simply are no pristine lakes in the world anymore.

Changes were evident both in the composition of the communities as well as in their diversity. The degrees of change varied locally so that the most dramatic changes had taken place where, according to measurements, the climate had warmed the most. All in all, the changes were greater towards the north. The observation is supported by climate models which show that the climatic warming increases nearer the poles.

“Global warming is, largely, but not solely, due to human actions. Research aims to give accurate data on how much of global warming is caused by humans and how much by other factors,” Weckström concludes.

Text: Mirja Mäenpää
Photo: Digital Photo DTP Oy
1.3.2005
www.helsinki.fi/digitalcommunications

Translation: Valtasana Oy

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