NEW ORLEANS – Every year the state of Louisiana loses land at an astonishing rate, but through new modeling, researchers are getting a better sense of the threats posed to the ecosystem and those who live in the bayou country.
Researchers estimate Louisiana has lost enough wetlands since the 1950s to cover the entire state of Rhode Island.
Experts say some of the critical marshes are underwater by rising sea levels, and others have been subject to disasters.
A study published in the Journal of Geophysical Research tracked the changes and examined the root causes of the ongoing event.
To the surprise of some, a primary driver of the wetlands’ disappearance was not directly tied to Mother Nature but the role of humans.
The study found that coastal and river engineering was the primary cause of losses rather than rising seas, hurricanes and other catastrophic events.
Researchers said they narrowed down the root causes of wetland loss by examining satellite imagery and taking observations.
Surveys found that some parts of coastal Louisiana continually lose more soil than others.
Imagery showed the Terrebonne and Barataria regions, south of the Mississippi River, have experienced the most land loss.
Researchers tied the negative land trends to levees and thousands of miles of man-made canals along the Mississippi River that simply have held back or diverted the flow of essential sediments.
"The Louisiana coastal system is highly engineered," Daniel Jensen, lead author and postdoctoral researcher at NASA’s Jet Propulsion Laboratory, said in a statement. "But the fact that ground has been gained in some places indicates that, with enough restoration efforts to reintroduce fresh water supply and sediment, we could see some wetland recovery in the future."
Wetland restoration project underway
The National Oceanic and Atmospheric Administration said a $181 million restoration project of 1,200 acres of marsh is underway in lower Louisiana but when compared to the overall yearly sediment loss, the scope of the project is simply a drop in the bucket.
The effort is expected to wrap up in 2023, and by completion, more than 8 million cubic yards of sediment will have been piped into the project.
Engineers said a combination of man-made dikes and vegetation should act as barriers to prevent erosion from the multi-million dollar effort.
If the project is successful, species of fish and wildlife will strengthen the ecosystem and possibly help lessen coastal hazards by returning the region to a more natural state.
Parts of Louisiana’s Barataria Basin were significantly impacted by the Deepwater Horizon oil spill in 2010, and officials said additional wetlands are under consideration for restoration projects in the future.