Midwest floods will make a bigger Gulf dead zone

JULY 17, 2008
Record flooding in the American Midwest will likely bring a record "dead zone" to the Gulf of Mexico this summer, according to a new report.
Donald Scavia, a researcher at the University of Michigan’s School of Natural Resources and Environment, says the "growth of these dead zones is an ecological time bomb" that puts Gulf of Mexico fisheries at risk.
LSU scientist R. Eugene Turner agrees with that assessment. He says this year’s record dead zone, which is roughly the size of New Jersey, is due in large part to an increase in nitrogen-based fertilizers brought on by an increase in corn production in the Midwest. Nutrients from the corn fields are washed into streams that feed the Mississippi River, flow downstream and ultimately rob the Gulf of the oxygen needed to support marine life.
The dead zone usually covers 6,000 to 7,000 square miles off the Louisiana and Texas coastlines. The massive floods this year will cause a much bigger runoff and will mean a dead zone spreading over more than 8,500 square miles, according to Scavia’s prediction.
"Without determined local, regional and national efforts to control them, we are putting major fisheries at risk," Scavia said. He also measures the annual, growing dead zone in Chesapeake Bay.
The Gulf supplies 72 percent of U.S. harvested shrimp, 66 percent of U.S. oysters, and 16 percent of commercial fish, according to national fisheries data.
According to Turner, fish and shrimp cannot live in the dead zone, causing fishermen who are already hard pressed by the cost of diesel to have to go farther into the Gulf to drop their nets.