The goal of reducing the size of the low-oxygen "dead zone" in the Gulf of Mexico to 2,000 square miles by 2015 probably will not be reached, but conditions need to start improving, says the official who coordinates hypoxia reduction efforts for the U.S. Environmental Protection Agency.
Darrell Brown, chief of EPA's Coastal Management Branch, was a keynote speaker for a one-day workshop sponsored by the Leopold Center for Sustainable Agriculture at Iowa State University. The October 16 workshop also had support from ISU's Center for Agricultural and Rural Development.
"This is a complex problem that will require cooperation and action from a number of people at a number of levels," Brown told more than 125 scientists, policymakers and other stakeholders who gathered for the workshop last week in Ames. "While we're trying to reduce the size of the hypoxic zone in the Gulf, we also want to improve the quality of the water throughout the 31 states in the watershed and make sure the communities and economic sectors are not harmed in the process."
Half of N pollution is from corn-bean fields
Although hypoxia is a global problem with more than 400 eutrophic zones worldwide, the size of the Gulf's hypoxic area has more than doubled since annual measurements began in 1985. In 2008, the dead zone was about 8,000 square miles, larger than the state of Massachusetts. This tied the second-largest zone on record, which was 8,800 square miles in 2001. The long-term average is 5,300 square miles; the five-year average is 6,600 square miles.
Brown says studies show that five states in the Upper Mississippi River Basin, including Iowa, contribute about 75% of the excess nitrogen and phosphorous nutrients that flow into the Mississippi River and lead to a low-oxygen "dead zone" in the Gulf of Mexico every summer. He said research also shows that about half of the nitrogen is from corn-soybean production, and 37% of the phosphorus is from livestock pasture on agricultural lands.
Window for discussion is rapidly closing
ISU economics professor Cathy Kling was a member of the EPA's Science Advisory Board that completed its review of the science related to hypoxia in December 2007. She said the report generated substantial interest in the research community, and a realization that many important questions remain unanswered and the solutions often are heavily interdisciplinary.
"My goal in helping to plan this conference was to keep the conversation going," says Kling, who chaired the planning committee. "This is a step in the process of continuing to provide the research-based science that is needed to support adaptive management solutions to this highly complex and long-term problem."
Leopold Center Director Jerry DeWitt says he was pleased with the discussions, but added that action needs to follow. "Our window for thinking, talking and planning for this issue is rapidly closing," he says. "There are things we can and must do that will reduce nutrient runoff. It's clear that what we're doing is not enough and we need to have a more active, visible engagement of the agriculture community on this issue."
Other presentations looked at current research on nutrient reduction strategies in Iowa including improvement of local water quality, watersheds, landscape design, modeling and monitoring, and the water implications of biofuels production in Iowa. Information from the presentations will be posted on the conference web site as they are available, see www.card.iastate.edu/hypoxia.