It was a hot, sunny day and Steve Carpenter couldn’t believe the view from his second-floor office on the shoreline of Lake Mendota. As far out as he could see from his perch in the Hasler Laboratory for Limnology – west to the UW-Madison Rowing team’s boat house and east all the way to the Edgewater Hotel and James Madison Park – the calm, still water looked just like teal-blue paint.

It was a massive bloom of toxic blue-green algae and “it is the worst one I’ve seen in a long time,” says Carpenter, director of the UW-Madison’s Center for Limnology. “It’s been many, many years since I’ve seen one this bad.”

In fact, the bloom that hit Madison last Friday, June 16th, was one of the largest blooms to mar Mendota’s shoreline since the summers of 1993 and 1994, he says.