Floods may yield record Gulf 'dead zone'

Scientists predict floodwaters that decimated river cities in the Midwest also will whack the Gulf of Mexico, pushing the so-called dead zone to a record size.

Researchers from Louisiana State University and the Louisiana Universities Marine Consortium forecast the dead zone - an area that during summer doesn't have enough oxygen at depth to support marine life - will cover 10,084 square miles, an area about the size of Massachusetts.

The expected growth in the zone renews debate over soil conservation in the nation's breadbasket and whether farmers adding corn acres for the ethanol industry is a significant contributing factor.

Researchers such as Eugene Turner of LSU blame farmers and the ethanol industry, but an official of the Iowa Farm Bureau Federation disputes that contention, adding that corn acres are down in Iowa this year.

Since 1990, the dead zone off the coasts of Louisiana and Texas has averaged a shade over 6,000 square miles, depending largely on the flow of the Mississippi River. The area of low oxygen, or hypoxia, is caused by a large algae bloom fed by nitrogen and phosphorus from crop fertilizers, dead plants, lawn chemicals and sewage that run down the Mississippi.

When the algae die, they consume oxygen. That disrupts one of the world's most lucrative shrimp fisheries.

The flow in the Mississippi is up 75 percent from last year. Researchers expect nitrogen levels of water running into the Gulf will be 37 percent higher than last year, the highest on record. The forecast is based on nitrate measurements in the Mississippi at Baton Rouge.

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