"In Lake of the Woods, Growing Algae Blooms Puzzle Scientists"

"In the dog days of summer, Nick Anthony wouldn't swim in Lake of the Woods unless some money was involved.

'It gets green,' he said. 'For sure. It would take a pretty good bet from a buddy to jump in. It's pretty nasty.'

That green is a layer of blue-green algae. Most years around August sections of Lake of the Woods get covered over by the stuff, sometimes inches thick."

John Enger reports for Minnesota Public Radio July 27, 2014.