Global warming threat to future of Scotland's lochs
Saturday 19 March 2005
GLOBAL warming will cause the bottom layers of Scotland’s deepest freshwater lochs to stagnate and rise in temperature, threatening their sensitive ecology, The Scotsman has learned.
In particular the survival of the Arctic char, one of our least known and most endangered fish species, could be put in jeopardy.
Freshwater lochs such as Loch Lomond, Loch Doon and Loch Morar have a layered structure where the surface and deep waters differ in temperature and density. To keep the bottom layers fresh, the layers have to mix, and for this to happen they have to reach a similar temperature and density for a time. This normally happens in winter when the surface waters cool.
But biologists at Glasgow University have found that if the climate warms as predicted, the surface waters will not cool sufficiently for the layers to mix.
The findings are corroborated by studies in France where research revealed that a mere 1C change in air temperature would be enough to upset the thermal mixture of famous continental lakes including Germany’s Lake Ammersee and Lake Annecy in France.
from: The Scotsman