USGS Sensors Track Nitrate Down the Mississippi River

A new USGS article, published on October 13 by the American Chemical Association in Environmental Science and Technology, describes how advanced optical sensor technology is being used in the Mississippi River basin to accurately track the nitrate pulse to the Gulf of Mexico.  Concentrations and loads were observed at daily to annual time steps, with considerable variability in concentration-discharge relationships over the course of a two year study.   Accurately quantifying nitrate loading from the Mississippi River is important for predicting summer hypoxia in the Gulf of Mexico and targeting nutrient reduction within the basin.  The monitoring stations used for this study are operated in cooperation with numerous local, state, and other federal agencies and supported by the USGS National Stream Quality Accounting Network,Cooperative Water Program, and the National Water-Quality Assessment Program.  For more information or questions, please contact Brian Pellerin,