June 14, 2011

A report released by the U.S. National Oceanic and Atmospheric Administration (NOAA) predicts a 2011 Gulf dead zone of at least 8,500 square miles, which would make it the largest dead zone on record, due to increased stream flows from the flooding of the Mississippi River.

"Stream flows were nearly double normal during May, delivering massive amounts of nutrients to the Gulf, and that's what drives the dead zone," said Don Scavia, Special Counsel to the U-M President for Sustainability, director of the Graham Sustainability Institute and SNRE professor and a member of NOAA's Gulf hypoxia research team.

Farmland runoff containing fertilizers and livestock waste—some of it from as far away as the Corn Belt—is the main source of the nitrogen and phosphorus that cause the annual Gulf of Mexico oxygen-starved, or hypoxic, zone. Each year in late spring and summer, these nutrients flow down the Mississippi River and into the Gulf, fueling explosive algae blooms there.

When the algae die and sink, bottom-dwelling bacteria decompose the organic matter, consuming oxygen in the process. The result is an oxygen-starved region in bottom and near-bottom waters: the dead zone.

The largest dead zone currently on record was 2002's 8,400 square miles. The average over the past five years is about 6,000 square miles.

Read full news article: http://www.snre.umich.edu/newsroom/2011-06-14/researchers_predict_record...

Tara Thean, who writes Time Magazine's Ecocentric blog, quoted Scavia as called the growing dead zones an "ecological time bomb." http://ecocentric.blogs.time.com/2011/06/14/scientists-predict-record-gu...