NEW ORLEANS (press release) – As experts gather in New Orleans this week for the State of the Coast conference, new findings from a research consortium co-led by Tulane University warn that much of the sediment flowing through the Mississippi River Delta never reaches the Gulf of Mexico — a troubling sign for the future of Louisiana’s coast.
Tulane University professor Mead Allison, who is co-leading the $22 million Mississippi River Delta Transition Initiative (MissDelta) with Samuel Bentley at Louisiana State University, will be among the speakers on a panel to discuss the group’s preliminary findings on May 22 during a session at the Morial Convention Center.
MissDelta is a five-year effort launched in 2023 and funded by the National Academies of Sciences, Engineering and Medicine’s Gulf Research Program, to evaluate the future of the Bird’s Foot Delta, the southernmost reach of the Mississippi River system that juts into the Gulf and plays a vital role in coastal protection, navigation, fisheries and energy infrastructure.
Data collected during the initiative’s first year-and-a-half reveal that during most river conditions, less than 10% of sediment flowing down the Mississippi reaches the Gulf through the three main passes. Substantial amounts are instead lost above the Head of Passes, exiting through both natural and human-made channels. Sediment loss is especially high during low or average river flows.
“These findings demonstrate the Bird’s Foot is on a degradational trajectory despite much of the river’s sediment being deposited upriver of the deep-water Gulf outlets,” said Allison, a professor in Tulane’s Department of River-Coastal Science and Engineering. “In addition to projecting the future for the Bird’s Foot landmass, we are also interested in what happens to the wetland and what happens to fish, and how does that reverberate up into the local economy? What does that mean for jobs? What does that mean for flooding, and for the overall sustainability of communities both here and further inland? We are going to be trialing possible solutions that are weighed by whether they are mutually beneficial to the ecosystem and to the people that make their living and live down here.”
The State of the Coast session, titled Coupled Natural and Human Coastal Systems in a Changing World, will highlight work from the 14-institution MissDelta consortium. The group is combining observational studies, numerical modeling and socio-economic analysis to predict the delta’s future under various climate and management scenarios, including sea level rise, increased storm frequency and changes in river flow. They are also highlighting workforce development to train a new cadre of coastal scientists who will address these challenges far into the future.
Alongside Tulane and LSU, partner institutions include Xavier University, Dillard University, Southern University, the University of Louisiana at Lafayette and the Water Institute of the Gulf in Baton Rouge, among others.
Researchers aim to produce predictive models through the year 2100 to assess the likelihood of delta collapse, identify management strategies that could slow or reverse degradation, and examine impacts on nearby communities and industries. A key component of the initiative is also training the next generation of coastal scientists, with educational programming spanning from K-12 to post-graduate levels.
During high river discharge in April, Allison’s team, including graduate students from Tulane and UL Lafayette, collected sediment samples to calibrate their numerical models. A follow-up expedition is planned for the fall to study saltwater intrusion, which has recently threatened drinking water in the New Orleans area due to low river flows and backflow through multiple exits beyond the Southwest Pass.
The Bird’s Foot Delta region, despite its importance to national commerce – including $300 million in daily shipborne trade and 60% of U.S. grain exports – is shrinking both above and below sea level. The MissDelta initiative seeks to offer science-based guidance to local, state and federal leaders on how to sustain one of America’s most vital and vulnerable ecosystems.
The State of the Coast conference, Louisiana’s largest statewide conference of its kind, is being hosted by the Coalition to Restore Coastal Louisiana (CRCL) and its partners the Coastal Protection and Restoration Authority and the Water Institute.
