dead zone

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."