Although only about 140 miles long, the Atchafalaya River is the fifth-largest ocean-discharging river in North America, said Andy Nyman, associate professor of wetland wildlife management in the LSU AgCenter's School of Renewable Natural Resources, at a recent two-day conference on the Atchafalaya River held in Baton Rouge, La.
The conference brought together more than 150 faculty members from Louisiana universities and representatives from a variety of state and federal agencies along with other interested individuals to share information and “foster a holistic understanding of the river,” said Nyman.
The organizers wanted to “get everyone in the same room and find out what we know,” said Natalie Snider on why the conference was held.
Snider, science director for the Coalition to Restore Coastal Louisiana and one of the conference organizers, said the planners initially expected to conduct a half-day seminar for a couple of dozen people. But after the call for papers went out, the response was so overwhelming they ended up putting together the two-day event.
The purpose of the meeting was to review what people know about the river and its associated environments, to report on recent and ongoing research and to identify information gaps that complicate decision making by land managers, water managers and policymakers, the organizers said.
Albert Hindrick, with the Louisiana Department of Environmental Quality in Baton Rouge, applauded the program.
DEQ is trying to keep up with the science and technical aspects of the river basin as well as government policies and regulations, he said. It's important to keep up with water quality in basin — especially nutrients and dissolved oxygen.
Jennifer Fiore, a lawyer with Milling Benson Woodward L.L.P. in Baton Rouge, attended the conference because her firm is involved in litigation in the basin. “I'm interested in getting a better understanding of the basin as a whole,” she said.
“First and foremost, the Atchafalaya Basin is a floodway,” Timothy Matte, mayor of Morgan City, La., said during a panel discussion on the final day of the conference. “Our existence depends on management of that floodway.
“We appreciate the valuable resource the basin is,” he added, pointing to recreational activities, commercial fisheries and the oil and gas industry as examples.
Matte said as the southern gateway into the basin, Morgan City is looking forward to new tourism opportunities surrounding the river.
“I'm always learning new information about what's going on in this system,” said Rudy Sparks, vice president of lands and timber with Williams Inc. in Patterson, La.
Sparks said privately owned land in the basin totals between 300,000 and 400,000 acres. “I think it's imperative that whatever you do, you incorporate the landowners at the front end,” he said. “If you include landowners on the front end, you'll get more support.”
Sparks said landowners are interested in managing responsibly. “What is it we want it to be?” Sparks asked. “Then we can start putting plans in place.”
More than 30 presentations over the two-day period provided participants with insights into the wide range of research being done in the Atchafalaya Basin.
Scientists reported on the use of satellite imagery, dendrochronology (tree ring analysis), water-level and water-quality monitoring and a variety of other research methods they use to study the floodway, delta, coastal marshes and coastal waters that comprise the basin.
“I learned about things I didn't know were going on,” said Harry Roberts, a marine geologist with the Coastal Studies Institute in the Department of Oceanography and Coastal Sciences at LSU.
Roberts, who was a presenter on the final afternoon, said the program researchers and agency representatives opportunities for working together.
In the end, more than 30 presentations provided participants with insights into the wide range of research being done in the Atchafalaya Basin.
The basin was formed thousands of years ago as the Mississippi River shifted over the years, said Lamar Hale, a project manager with the U.S. Army Corps of Engineers New Orleans district. Today, it covers about 1,400 square miles.
“The Mississippi River carved, constricted, destroyed, rebuilt and reshaped the lower deltaic valley,” he said.
A report in the 1950s said that if left alone, the Atchafalaya would capture the Mississippi River, so the corps built the Old River Control Structures at the juncture of the Mississippi, Atchafalaya and Red rivers, he said.
As a result, as the Atchafalaya became a distributary of the Mississippi, the Old River Control Structures divert 30 percent of Mississippi flow to join the flow from the Red River and form the Atchafalaya River. Over time, other natural and manmade changes in the basin have had their effect.
The Atchafalaya carries 100 percent of the sediment from the Red River and 25 percent of the sediment from the Mississippi river, said Daniel Kroes, of the U.S. Geological Survey in Reston, Va.
Water in the basin comes from varying sources and moves in different directions, and canals in the basin change the hydrology and water quality, affecting the direction of water flow, he said.
Sediments from incoming streams and areas where two streams come together create conditions that cause stagnation, Kroes said. The faster stream with higher elevation forms a “hydraulic dam” with its sediments, and the slower water backs up and becomes stagnant.
Water in the basin also is affected by natural levees, manmade levees, cuts and canals, said Richard Day of the U.S. Geological Survey's National Wetlands Research Center in Lafayette, La.
Farther down the river, the Atchafalaya Delta is the only actively building delta in the Gulf of Mexico, said Michael Carloss with the Louisiana Department of Wildlife and Fisheries in New Iberia, La.
The growth of the delta is the result of sediments being deposited by the river channeling sediments from the Mississippi River, he said. And sediments from the Atchafalaya River navigation channel are removed by maintenance dredging by the U.S. Army Corps of Engineers and used to create and restore dredged-material islands.
“The Atchafalaya Delta is truly a dynamic area” with many species of birds, Carloss said. He added that the delta has very few invasive plant species in new vegetative growth on new islands.
While speakers early in the program addressed the hydrology and formation of the river basin, later speakers talked about how the river influences plants and animals, both on land and in the water.
Since 1950, nutrients have increased three times while the floodplain has decreased, said Amy Scaroni, a graduate student in the LSU AgCenter's School of Renewable Natural Resources.
The evolution has been from lake to cypress swamp to bottomland forest, she said. “The basin is filling in.”