The Dead Zone in the Gulf of Mexico hasn't gone away and likely won't until regulations are enacted to curtail farm field runoff of nitrogen fertilizer, says Matt Rota, the senior policy director for the Gulf Restoration Network, based in New Orleans.

Moves toward such regulation, though, are sure to be opposed by farm interests, so this will be an ongoing issue for the foreseeable future among all stakeholders in the entire Mississippi River drainage basin, he added.

Rota will be the keynote speaker Thursday for the three-day Mississippi River Conference at Stoney Creek Inn, Moline.

The seventh annual conference is presented by River Action Inc., based in Davenport, and the Mississippi River Network, a coalition of about 50 local and national organizations.

Although aimed at planners, elected officials, architects, engineers, environmental groups, developers, students and educators, members of the public also are welcome, said Kathy Wine, the executive director of River Action.

Topics of breakout sessions to be led by about 25 speakers include the possible start of container-on-barge shipping on the Upper Mississippi, flood management, marketing the river for tourism and Emiquon, a huge wetlands restoration project at the confluence of the Spoon and Illinois rivers in central Illinois.

A point that Rota hopes to stress in his keynote speech "is the inter-relatedness of the Mississippi River and how we all live in one watershed," he said. "It all flows downstream. We need to be working together if we want to clean up the Mississippi River."

The need to work together — all the way from the headwaters to the Gulf — is one of the reasons Wine is so excited to have more than 15 mayors representing cities from Minnesota to Mississippi signed up to attend.

The mayors, including those of Davenport, Bettendorf, Rock Island, East Moline and Muscatine, are members of a group formed in 2012 called the Mississippi River Cities & Towns Initiative, whose goal is to work and advocate together on issues affecting everyone along the river.

"We have a stellar list of speakers. I believe everyone will come away inspired," Wine said.

"That is why we go to conferences; we discover what we did not know we need to know, and we meet people we did not know we needed to know."

The Dead Zone that Rota will talk about is the area in the Gulf of Mexico off the Louisiana and Texas shores where low oxygen levels caused by excessive nutrient pollution from human activities, coupled with other factors, have depleted the oxygen required to support most marine life in bottom or near-bottom water. This phenomenon was first observed by shrimp fishermen in the 1950s, and scientists began studying it in the 1970s.

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In 1985, scientists began mapping the size of Dead Zone, which fluctuates from year to year depending upon conditions, but never disappears. At the first mapping, the zone was less than 3,000 square miles, and Rota believes the goal should be to keep it contained to that size or smaller.

However, the zone is estimated to be three times that size this year, he said.

"The actions we have taken (so far) have been wholly inadequate," he added.

Most projects have been voluntary, encouraging farmers through financial incentives to install wide buffer strips between fields and waterways, take flood-prone farmland out of production to create dedicated wetlands that hold and filter floodwater, and plant cover crops to stop erosion.

"But the money isn't enough to implement enough practices that get us where we need to go," Rota said.

One step toward addressing the problem would be to set a standard for how much nitrogen can be in a body of water, he said. "The states or the EPA (U.S. Environmental Protection Agency) need to set a nitrogen criterion like there is for arsenic. We don't really have a goal."

If a standard were set, goals and plans could be developed to reach that, he added.