RESTON, Va. — A new report released by the U.S. Geological Survey (USGS) describes how advanced optical sensor technology is being employed in the Mississippi River basin to accurately track the nitrate pulse to the Gulf of Mexico, according to a press release.

Excessive springtime nitrate runoff, from agricultural land and other sources in the Mississippi drainage, flows into the Mississippi River and then downstream into the Gulf of Mexico, stated the release.

The release reported that the excess nitrate contributes to the Gulf of Mexico hypoxic zone, an area with low oxygen known commonly as the “dead zone,” and this past summer 2014, the dead zone covered approximately 5,052 square miles.

To improve accuracy of nitrate load estimates to the Gulf of Mexico, USGS is using the new sensor technology to collect nitrate concentration every hour, continued the release.

This data can also be utilized to make it easier to detect any changes in nitrate levels related to basin management and to track progress toward the goal of reducing the overall size of the dead zone, noted the release.

“High frequency data from these sensors has revealed considerable variability in nitrate concentrations in small rivers and streams,” said USGS Researcher Brian Pellerin. “However, we were surprised to see nitrate concentrations vary by as much as 20 percent in a week in a river as large as the Mississippi River without similar changes in streamflows.”

Read the entire release here.