http://www.theglobeandmail.com/servlet/story/RTGAM.20080722.wlakes22/BNStory/National/home

“After completing one of the longest-running experiments ever conducted on a lake, researchers from the University of Alberta, the Freshwater Institute and the University of Minnesota found global efforts to restrict the use of nitrogen-based fertilizers near lakes may have instead exacerbated the problem.

“David Schindler, a University of Alberta biologist considered Canada’s top water expert and one of the paper’s lead researchers, said algae blooms are still able to thrive by drawing nitrogen from the air.”