Nitrate Levels in Mississippi River Still On the Rise

A new USGS study shows that nitrate levels are continuing to rise in the Mississippi River, including the outlet to the Gulf of Mexico.

Although the nitrate levels have decreased by 21 percent in the Illinois River, the levels in the Mississippi and Missouri rivers are continuing to rise. This also includes an increase in nitrate levels in the Mississippi’s outlet to the Gulf of Mexico, according to results in a new USGS study.

"These results show that solving the problem of the dead zone will not be easy or quick. We will need to work together with our federal and state partners to develop strategies to address nitrate concentrations in both groundwater and surface water," said Lori Caramanian, Department of the Interior deputy assistant secretary for Water and Science. 

"Expanded research and monitoring is absolutely essential to tracking progress in reducing nutrient pollution in the Mississippi River Basin," said Nancy Stoner, acting sssistant administrator for Water at the U.S. Environmental Protection Agency and co-chair of the Hypoxia Task Force. "The federal agencies and states that are part of the Hypoxia Task Force greatly appreciate this work by USGS and how it advances the science in the Mississippi River Basin."

Excessive nitrate levels can influence the hypoxic zone – the “dead zone” that’s characterized by extremely low oxygen levels in bottom or near-bottom waters, degraded water quality, and impaired marine life – in the northern Gulf of Mexico every summer. Reasons for the increases and decreases of nitrate are currently unknown. 

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