[Grant]

Another problem with lawns is that grass has very shallow root structures, and is a very poor filter for runoff. More runoff = more nutrient for blooms. Natural, native vegetation is far more effective in reducing runoff into the lake. It's not just fertilized lawns that help promote cyanobacteria blooms. Cyanobacteria occurs naturally -- almost everywhere. There's lots in the average shovelful of topsoil. And it's always in the lake. Not all varieties are toxic, but many are. But the combination of excess nutrients and warmer water causes these big blooms. More nutrients + More warm water = blooms of greater frequency, magnitude and duration.