9 states deemed biggest dead zone contributorsBy Bruce Alpert
Times-Picayune; 30 January 2008
They produce bulk of nutrient runoff
WASHINGTON — Increasing pressure on federal regulators to impose mandatory reductions in agricultural runoff, a new government report says that nine states in the Mississippi River Basin contribute most of the nutrients in the northern Gulf of Mexico that threaten the viability of the nation’s largest and most productive fisheries.
The U.S. Geological Survey report examined factors contributing to excessive levels of nutrients in the Mississippi River that create areas of hypoxia — low oxygen levels — resulting in the large dead zone that forms off Louisiana’s coast every summer. The zone kills bottom-dwelling organisms in the Gulf.
According to the report, Illinois, Iowa, Indiana, Missouri, Arkansas, Tennessee, Ohio, Kentucky and Mississippi make up only one-third of the 31-state Mississippi River drainage area, but contribute more than three-quarters of the nitrogen and phosphorus in the Gulf.
The use of nitrogen-based fertilizers to support corn and soybean crops contributes the most to the nutrient runoff, the report said. But waste from unconfined animals produces higher levels of phosphorus than previously known, according to the report.
Benjamin Grumbles, the Environmental Protection Agency’s assistant administrator for water, said the study shows that farms are "overfeeding the Gulf" with nutrients. He said that federal and state regulators must develop plans to provide the Gulf with a "more balanced diet."
Grumbles said the Hypoxia Task Force he oversees hopes to come up with recommendations next month to deal with the problem.
There was a voluntary agreement in 2001 to reduce runoff, but Tuesday’s report indicates shortcomings with that approach. Calls for mandatory reductions, however, likely will be opposed by the farm lobby.
Earlier this month, Iowa State University estimated it would cost $613 million a year to cut farm-field phosphorus runoff by 40 percent and nitrates by 25 percent, reflecting levels recommended in earlier EPA proposals. The study was partially financed by the Iowa Farm Bureau Federation, which says that regulators should determine costs before mandating specific reductions in nutrient levels.
Midwest farms were named as the major culprits in another study released Tuesday by Yale University concerning high carbon dioxide levels in some portions of the Mississippi River. The report said that Midwestern farms sent water into the Mississippi equal to the size of five Connecticut Rivers during the past 50 years. The higher water levels are responsible for the increases in carbon dioxide levels, the Yale report said.
"It’s like the discovery of a new large river being piped out of the Corn Belt," said Pete Raymond, lead author of the study and associate professor of ecosystem ecology at the Yale School of Forestry & Environmental Studies.
Researchers said the carbon dioxide is changing the chemistry of the river’s water and is a threat to marine life.
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Bruce Alpert can be reached at email@example.com or (202) 383-7861.