Mississippi River Flooding Likely to Contribute to Record Gulf of Mexico "Dead" Zone

In a news release issued on June 14, the USGS, in conjunction with NOAA, estimated that the Gulf of Mexico hypoxic ("dead") zone may end up being the largest ever, due in large part to excessive nitrogen contamination entering the Gulf accompanying this spring's Mississippi River flooding. The release states, in part, "The Gulf of Mexico's hypoxic zone is predicted to be larger than average this year, due to extreme flooding of the Mississippi River this spring, according to an annual forecast by a team of NOAA-supported scientists from the Louisiana Universities Marine Consortium, Louisiana State University and the University of Michigan. The forecast is based on Mississippi River nutrient inputs compiled annually by the U.S. Geological Survey (USGS).

"Scientists are predicting the area could measure between 8,500 and 9,421 square miles, or an area roughly the size of New Hampshire. The largest hypoxic zone measured to date occurred in 2002 and encompassed more than 8,400 square miles."

A copy of the Louisiana Universities Marine Consortium and Louisiana State University report (PDF file) that underlies the USGS news release (entitled "2011 Forecast: Summer Hypoxic Zone Size, Northern Gulf of Mexico," prepared with support from the NOAA Center for Sponsored Coastal Ocean Research, Coastal Ocean Program) can be viewed or downloaded here.