Too many nutrients are flowing into the nation’s rivers and streams—making them one of the largest sources of water pollution. This is the Ecominute and I’m Christian Wagley.
Nutrients, mainly nitrogen and phosphorus, fuel the growth of plants. In the water these nutrients feed microscopic plants called phytoplankton, which form the base of the marine food web.
Excess nutrients wash into waterways from fertilizers and manure applied to farms, golf courses, and suburban lawns, and they fall from the air from emissions by automobiles and power plants. Sewage treatment plants, septic tanks, and animal waste are additional sources. These excess nutrients make phytoplankton grow explosively, turning bays cloudy and blocking light needed by seagrasses, and causing oxygen depletion in the water as phytoplankton die and are consumed by bacteria.
Solutions to nutrient pollution include using fertilizers in the right amounts, switching to slow release fertilizers less likely to wash away, capturing and filtering stormwater runoff from farms and developed areas, and reducing the discharge of sewage.