October 30, 2024

BATON ROUGE, LA – It’s not news that Louisiana wetlands are disappearing at an astounding rate—nearly 30 square miles annually, per the U.S. Geological Survey. With every acre lost of the three million acres that make up the state’s wetland ecosystem, also lost are species and habitats that are unique to the state and provide protection from hurricanes and flooding.

Thanks to a Phase 1 $25,000 LSU Big Idea Research Grant from the Provost’s Fund, LSU Civil and Environmental Engineering Assistant Professor Aaron Bivins is leading a team that includes LSU Oceanography & Coastal Sciences Associate Professors Matthew Hiatt, Giulio Mariotti, and Tracy Quirk in coming up with efficient and faster ways of growing vegetation and bringing in sediment to keep wetlands in place using microorganisms.

“The Mississippi River is one of the most engineered rivers in the world,” Bivins said. “In order to provide flood protection, we’ve built all of these levees, which is great for not flooding our cities. But the downside of that is all the sediment that used to come down the river during flood events would be deposited in the delta, and that’s what built the land over time. The river delta is fed by all that sediment that comes downstream. Now that we’ve built all the levees, we’ve disconnected the river delta from its sediment source, the river itself.”

Bivins says land-building projects involve getting the sediment back into the deltas.

“There are diversions, which are large-scale, and then you have wetland creation or restoration on an individual case-by-case basis,” he said. “What’s currently being done is putting the fill material in, bringing the sediment in, and letting nature run its course. All of these natural processes that have sustained the delta for years are great, but they’re a bit slow. It takes time.”

Bivins says there’s a natural succession of ecosystems that includes microorganisms, sediment/soil, plants, and water where vegetation ultimately grows and helps hold the sediment in place, with the sediment eventually becoming soil with organic content, which creates new land.

“The idea in our proposal is taking a look at these natural processes and identifying some ways to engineer the microbial aspects to be faster and more efficient,” he said.

What’s unique about the Mississippi River delta, according to Bivins, is that it has moved over time, creating a gradient of smaller deltas within the larger delta and all of the deltas are in different life stages. This gives his team the ability to take measurements along the smaller deltas and look at the changes over time that are occurring in the microbes and soil. 

“We want to see if we can identify some of these deltas strategically, then set up instrumentation and experimental stations to look at this land formation over longer durations,” Bivins said. “Based upon what we observe, we want to find ways to accelerate or amplify those natural microbial processes. It’s land, which we desperately need.”

Bivins’ hope is that his team will be able to garner more funding for this research, with the ultimate goal being that within a decade, there will be a wetlands observatory at LSU that will change how deltas are managed throughout the world.

Hear more about the project from Bivins by clicking here.

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Contact: Libby Haydel
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