ANN ARBORSpring floods across the Midwest are expected to contribute to a very large and potentially record-setting 2013 Gulf of Mexico "dead zone," according to a University of Michigan ecologist and colleagues who released their annual forecast today, along with one for the Chesapeake Bay.
The Gulf forecast, one of two announced by the National Oceanic and Atmospheric Administration, calls for an oxygen-depleted, or hypoxic, region of between 7,286 and 8,561 square miles, which would place it among the 10 largest on record.
The low end of the forecast range is well above the long-term average and would be roughly equivalent to the size of Connecticut, Rhode Island and the District of Columbia combined. The upper end would exceed the largest ever reported (8,481 square miles in 2002) and would be comparable in size to New Jersey.
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 hypoxic zone. In its 2001 and 2008 action plans, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, a coalition of federal, state and tribal agencies, set the goal of reducing the five-year running average areal extent of the Gulf hypoxic zone to 5,000 square kilometers (1,950 square miles) by 2015.
Little progress has been made toward that goal. Since 1995, the Gulf dead zone has averaged 5,960 square miles, an area roughly the size of Connecticut.
"The size of the Gulf dead zone goes up and down depending on that particular year's weather patterns. But the bottom line is that we will never reach the action plan's goal of 1,950 square miles until more serious actions are taken to reduce the loss of Midwest fertilizers to the Mississippi River system, regardless of the weather," said U-M aquatic ecologist Donald Scavia, director of the Graham Sustainability Institute, who contributes
|Contact: Jim Erickson|
University of Michigan