US Corn Boom Threatens Sea Life: Pesticide Runoff Continues To Pollute Gulf

JEFFERSON, Iowa - Because of rising demand for ethanol, American farmers are growing more corn than at any time since the Depression. And sea life in the Gulf of Mexico is paying the price.

The nation's corn crop is fertilized with millions of pounds of nitrogen-based fertilizer. And when that nitrogen runs off fields in Corn Belt states, it makes its way to the Mississippi River and eventually pours into the Gulf, where it contributes to a growing "dead zone" - a 7,900-square-mile patch so depleted of oxygen that fish, crabs, and shrimp suffocate.