The USGS has released an online, interactive decision support system that provides easy access to six newly-developed regional models describing how rivers receive and transport nutrients from natural and human sources to sensitive waters, such as the Gulf of Mexico.

Excessive nutrients in the nation's rivers, streams and coastal areas are a major issue for water managers, because they cause algal blooms that increase costs to treat drinking water, limit recreational activities, threaten valuable fisheries, and can be toxic to humans and wildlife.

“Protecting ecosystems like the Great Lakes and Gulf of Mexico is critical to ensuring that those areas continue to be important economic engines for our nation. These new models and the decision support system are excellent tools that will help states, water managers, and federal agencies target sources and areas in order to design effective nutrient reduction strategies to improve water quality,” said Lori Caramanian, Deputy Assistant Secretary, Water and Science, Department of Interior and a member of the Mississippi River Gulf of Mexico Watershed Nutrient Task Force.

"A majority of the nation's estuaries are moderately to highly impacted by nutrient pollution which threatens living resource habitats, causes oxygen-depleted 'dead zones' and can fuel harmful algae blooms," said Dr. Robert Magnien, Director of NOAA's Center for Sponsored Coastal Ocean Research. "This USGS decision support system represents a major advance in the availability of sound scientific information to enable the effective management of this growing threat to our valued coastal resources and economies."

Each region and locality has a unique set of nutrient sources and characteristics that determine how those nutrients are transported to streams.

"Using the decision support system, users can evaluate combinations of source reduction scenarios that target one or multiple sources of nutrients and see the change in the amount of nutrients transported to downstream waters – a capability that has not been widely available in the past," said Stephen Preston, USGS hydrologist and coordinator for these regional models.

For example, the decision support system indicates that reducing wastewater discharges throughout the Neuse River Basin in North Carolina by 25 percent will reduce the amount of nitrogen transported to the Pamlico Sound from the Neuse River Basin by three percent; whereas a 25 percent reduction in agricultural sources, such as fertilizer and manure, will reduce the amount of nitrogen by 12 percent.