One of the most frequent complaints voiced by cottagers to local officials is that water in their lakes periodically tastes or smells bad.

A common cause of such problems is blooms of small algae (microscopic plants) that thrive in some of these lakes. Although the frequency of taste and odour complaints seems to be growing steadily, it is unclear whether the problems themselves are increasing or if local users are more sensitized to these issues.

A study published in the current edition of the scientific journal Freshwater Biology examines sediment from 50 lake bottoms in the Muskoka-Haliburton region of Ontario. The results show taste and odour-causing algae have increased in 90 per cent of these lakes since the early 1800s, with a marked rise over the past two decades.

This phenomenon can't be blamed solely on "local human impact," says team member John Smol, Canada Research Chair in Environmental Change and co-head of Queen's University's Paleoecological Environmental Assessment and Research Laboratory (PEARL). "It's a complex of patterns, which we think involves some combination of acidic deposition and climate change," explains Dr. Smol.

"The timing indicates that these patterns are the result of one or more human-caused stresses operating at a broad, regional scale," says lead investigator Andrew Paterson, a former doctoral student at Queen's. "We present new evidence suggesting that disturbances such as acid rain and climatic warming may produce significant, unprecedented changes to the algae of inland lakes, with important implications for water quality."

Lake water that smells and tastes foul can be traced to a variety of sources, including chemical pollution and dead
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Contact: Nancy Dorrance
dorrance@queensu.ca
613-533-2869
Queen's University
8-Mar-2004