Dead zones haunt Green Bay as manure fuels algae blooms

"Yet the old pollution culprits of heavy industry and human sewage are no longer the primary drivers of the problem; the amount of phosphorus pouring from their pipes into Green Bay is just a fraction of what it was four decades ago.....So what is the problem?  Take a look at Wisconsin's license plate. The answer lies in the farm fields just above the sailboat flying across a blue lake."