One of the most common forms of environmental degradation is eutrophication of lakes and ponds due to nutrient pollution. Nearly all of the bodies of water on Long Island have been affected by nutrient pollution in the form of nitrogen and phosphorus. Fertilizer containing high levels of nitrogen and phosphorus is washed into nearby surface water, accelerating the process of eutrophication. Common signs of eutrophication include murky green water and foul odor. Nutrient pollution is also responsible for harmful algal blooms which can be toxic to aquatic organisms, birds and mammals, including humans.