Think of a giant corridor from Des Moines to Chicago and "you took a great big piece of Saran Wrap over all that area and sucked all the oxygen out," said Nancy Rabalais, executive director of the Louisiana Universities Marine Consortium. "You would have a big problem."
Even without the flooding, signs from early spring flooding and heavy fertilizer use were pointing to a record year for the dead zone, said Louisiana State University professor R. Eugene Turner. Earlier this month, using data from before the floods, Turner predicted the zone would break the 10,000-square-mile mark. Last year it covered 7,900 square miles.
Scientists are also worried that the jump in corn production triggered by heightened demand for ethanol fuel could worsen the dead zone because of the increased use of fertilizers. The big question is whether it will make the zone larger, cause it to last longer or become more oxygen-starved, or some combination of those, DiMarco said.
In May, nearly 500 million pounds of nitrates flowed down the Mississippi, Rabalais said. The algae bloom — the first step of dead zones — started a month early this year, in February, she said.
http://ap.google.com/article/ALeqM5hjCxr04OPsA3ffDOOKPt3-YKljsAD91E0RD80Not from this article but to give you an idea of the size of the dead zone (link is NASA)