09/10/2024 | News release | Distributed by Public on 09/10/2024 13:18
Growing up in Louisiana, I was always aware of water and the rivers that carry it to the Gulf of Mexico. Despite this, I did not gain an understanding of the importance of the Mississippi River until I learned its history. The coast of southeastern Louisiana was formed by gradual shifts in the Mississippi River, depositing sediment and providing freshwater necessary for marsh creation and land building. Today, the Mississippi River has been firmly cemented in place by levees and other control structures down to the Gulf of Mexico. The mouth of the Mississippi River, known as the Bird's Foot Delta, is rich in ecological potential and a diverse array of wildlife.
When visiting the Bird's Foot Delta, context is necessary to understand the issues that threaten it and the possible solutions. The Mississippi River-and especially the delta-is a battleground between human control and natural processes. Seasonal river flooding historically built and nourished wetlands but is prevented now by human-built levees, which act like guide rails for the river and are necessary to prevent the devastation floods can inflict on riverside communities.
A cow grazes in the marsh bordering the river's channel.However, without this natural flooding, wetlands outside of the levee system are disconnected from the river and the sediment and fresh water they rely on, causing a slow decline in flora and fauna.
Without the levees, the river would naturally change routes to maintain a fast and efficient flow, but in its current course, the water slows enough at the river's delta outfall to drop significant amounts of sediment. These accrued sediment loads require regular dredging to deepen the channel for navigation.
Human control of the river allows boats to safely transport goods from deep within the United States to international hubs, but not without environmental costs. These mechanisms that are utilized to control the river for economic benefit disrupt natural deltaic and estuarine processes that support wildlife. The river is leveed and dredged until the end of the Bird's Foot Delta is so large that barges and tankers can safely navigate through it, yet wildlife still exists within the ecosystems supported by the river.
Estuarine ecosystems are formed when freshwater sources meet the ocean-a saltwater source-and gradually combine. Productive habitats are created in these estuaries and a diverse array of species rely on these habitats for survival.
On a recent trip to the Bird's Foot Delta, I explored the Pass a Loutre Wildlife Management Area (WMA) and viewed many species inhabiting the surviving wetlands. Although I am a Louisiana native, I had never traveled to the mouth of the Mississippi River and was treated to an ecotour with Delta Discovery Tours.
Marsh grasses populate most of the Bird's Foot Delta and native tree species including willows, oaks, cypress, and ash trees grow in elevated areas, providing root growth that holds sediment in place and slows erosion. Many non-native and invasive species dot the landscape as well, especially where fishing camps sit along the waterways.
Beautiful native lotus plants grow in bunches, their large lily pads creating cover for waterfowl and habitat for fish species while white flowers sit above. Birds are visible constantly, including snowy egrets, yellow-crowned night herons and black-necked stilts.
These quiet areas of habitat are located only a football field away from the main channel of the river that supports international commerce. While taking in all of the wildlife, I could see tanker ships on the horizon traveling to the Gulf of Mexico and beyond, a reminder of the economic importance of maintaining the delta. Despite the heavy traffic, many species populate the main channel, including ospreys that build nests on wooden markers and cows that roam the remaining land bordering the channel.
Although there are many natural areas in south Louisiana where native wildlife can be observed, the Bird's Foot Delta is unique. It is one of the few remaining areas where water from the Mississippi flows into shallow basins instead of the Gulf of Mexico, since levees prevent the natural formation of channels upriver, and its marshes benefit from the influx of fresh water and sediment.
I've been lucky to explore much of coastal Louisiana, from Marsh Island to Cocodrie to Jean Lafitte Nature Preserve, and the Bird's Foot Delta is another example of what we stand to lose in Louisiana without intervention.
As sea levels rise and erosion of Louisiana's coast continues, the flora and fauna that inhabit the area will be threatened and suffer from this wetland degradation. Despite this bleak possibility, some solutions can slow the erosion of wetlands and increase the opportunity for wildlife to adapt. River diversions have the most potential as they mimic natural processes to rebuild and support habitats.
I had the pleasure of joining a Restore the Mississippi River Delta field trip to Neptune Pass in May, where a major channel has changed the marsh drastically, depositing sediment and creating land. Currently, the Mid-Barataria Sediment Diversion is the largest proposed project of this type. Other restoration projects include using dredge material for marsh creation, tree plantings, and building shoreline protection structures.
Communities are also impacted by the degradation of Louisiana wetlands since estuarine ecosystems protect them from sea level rise, storm surges, and coastal flooding. This structural protection is maintained by marsh restoration and conservation efforts, but coastal communities also largely benefit from the preservation of economic assets and opportunities (navigation channels, seafood industry, etc.)
The Bird's Foot Delta shows us what the river is capable of when we reconnect its sediment and fresh water to our wetlands. Projects with this goal not only protect and restore these spots on Louisiana's coast now but ensure that these vital areas are there for Louisianans to enjoy for generations to come.