Reviving Gulf of Mexico's "Dead Zone" - Brief Article

USA Today (Society for the Advancement of Education), June, 1999

Researchers are studying ways to control the rush of nitrogen and other chemicals that flow into the Mississippi River watershed each spring and ultimately turn more than 7,000 square miles of the Gulf of Mexico into a "dead zone." Nitrogen and other nutrients cause hypoxia, whereby excess nutrients, such as nitrogen and phosphorus, accumulate in a body of water and cause algae to flourish into algal blooms. These blooms thrive on nitrates and phosphates and deplete the water of nearly all dissolved oxygen. Hypoxia in the Gulf stems from human activities in the Mississippi River watershed, which encompasses more than 40% of the U.S.

"The answers to controlling hypoxia essentially come down to using nature to take care of our problems while protecting its biodiversity," explains William Mitsch, professor of natural resources, Ohio State University, Columbus. "These solutions embrace ecotechnology, which includes restoring or building wetlands and riparian buffer zones along waterways.

"Hypoxia is the result of living in an over-fertilized society. We fertilize the living daylights out of the Midwest. Ecotechnology establishes some degree of natural landscape between human activity and waterways." Riparian zones, belts of vegetation next to a waterway, and wetlands both serve as filtering systems. Each essentially "cleans" runoff water of fertilizer by-products.

Other potential solutions to hypoxia include reducing the initial disposal of nutrients into waterways, increasing the ability of a watershed to assimilate nutrients, and changing the hydrology of the Mississippi Basin.