The Mississippi River’s Bird’s Foot Delta, a vital ecological and economic region, faces rapid deterioration because of rising sea levels, sediment shortages and invasive species.
Louisiana State University (LSU) and Tulane researchers, backed by a $22 million federal grant, are conducting a multiyear study to understand the delta’s challenges and develop strategies to mitigate its decline.
Recent expeditions have revealed that 80 percent of the river’s sediment no longer reaches the delta, accelerating erosion.
This Landsat satellite image from October 3, 2011, shows the Bird’s Foot Delta, where the largest river in the United States empties into the Gulf of Mexico. In this false-color image, land vegetation appears pink, while the sediment in the surrounding waters is bright blue and green.
USGS/ESA
Why This Matters
The Bird’s Foot Delta is a critical hub for biodiversity, supporting migratory birds, fish and other wildlife.
It also sustains thousands of people who depend on its resources for fishing, hunting and tourism. Additionally, the delta serves as a key shipping gateway, with major ports like Baton Rouge and New Orleans relying on its waterways for access to North America’s largest river system.
If it disappears, these communities will face economic devastation, while the loss of marshland could exacerbate flooding and reduce natural barriers against hurricanes.
The delta’s decline also mirrors global challenges for other major deltas, such as the Nile and Mekong, making it a bellwether for worldwide coastal sustainability efforts.
What To Know
The Bird’s Foot Delta is facing severe erosion, with rising sea levels and land sinking exacerbating the situation.
Over the years, the construction of upstream dams has drastically reduced the amount of sediment reaching the delta, a vital component for land building.
The delta’s coast is sinking by as much as 2.5 centimeters per year, leading to the loss of approximately 10 city blocks of wetland daily.
Adding to the problem is the invasion of Nipponaclerda biwakoensis, an insect from China that has severely damaged Phragmites australis reeds, which are crucial for stabilizing the land.
In some areas, the once-dominant reeds have shrunk from covering 80 percent of the region in 2012 to just 25 percent in 2022, according to a study published in Nature Communications.
These combined forces have set the delta on a path of rapid deterioration.
The shipping industry, a major part of the economy for nearby cities like Baton Rouge and New Orleans, is also at risk. The Mississippi River’s shipping lanes pass through the delta, with thousands of vessels navigating these waters annually.
If the delta continues to erode, it could threaten the navigability of these waterways, severely affecting the flow of goods and regional economies.
This loss of land also puts local communities, whose livelihoods depend on fishing, hunting and tourism, in jeopardy.
In response, scientists from LSU and other institutions are using advanced tools to study the area. They are mapping the seafloor, studying sediment cores and modeling the delta’s dynamics to understand how it’s changing and how those changes can be mitigated.
What People Are Saying
Mead Allison, a coastal geologist at Tulane University who is researching the shifting delta, told Science: “[The Bird’s Foot] is one of the most threatened places in America, if not the Earth. What are we going to do about it? Is there anything we can do?”
The U.S. Geological Survey says on its website: “In the past, these marshes were naturally replenished by the Mississippi River sediment supply, but human activities have disrupted this natural process—causing these sediments to instead go straight down the river’s channel and into the Gulf of Mexico.
“Coastal Louisiana continues to lose protective wetlands at an alarming rate, leaving coastal communities with fewer natural defenses against hurricanes and storms,” the website adds.
Jameson Woodall, applied coastal environmental science senior at LSU, said in a statement: “The work of predicting the future of the Bird’s Foot Delta will give community members a realistic look at what their home will look like over future generations.”
What Happens Next
Scientists and authorities are exploring solutions, including dredging river channels to redirect sediment to the delta and planting reeds to stabilize eroded areas.
While some areas have seen promising recovery, projections suggest much of the Bird’s Foot Delta could vanish without significant intervention. The LSU team aims to finalize its research in the coming years, providing a road map for saving the delta and offering insights to protect deltas worldwide.
Reference
Elsey-Quirk, T., Lynn, A., Jacobs, M. D., Diaz, R., Cronin, J. T., Wang, L., Huang, H., & Justic, D. (2024). Vegetation dieback in the Mississippi River Delta triggered by acute drought and chronic relative sea-level rise. Nature Communications, 15(1), 3518. https://doi.org/10.1038/s41467-024-47828-x
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