Dead zones in US coastal waters, rivers and lakes are due to the paradoxical oversupply of nutrients like nitrogen and phosphorus, which wash into water bodies from farms and residential lawns. The nutrient pollution produces algae blooms on the surface, while under the algae blooms the water is depleted of oxygen, creating anoxic or dead zones where plant and animal life are unsustainable. Some algae blooms are toxic, like the one in Lake Erie which shut down the water supply in Toledo, OH, in 2014.