The Atchafalaya River Basin

At almost a million acres, it is North America's largest floodplain swamp.

The Atchafalaya River Basin's remarkable size, at almost a million acres, reflects its significant ecological, economic and cultural importance. The Atchafalaya boasts an especially high variety of plants and animals that are not only important for nature's sake but for the people who make their living from the region's lands and waters.

In addition to providing critical wildlife habitat, the Atchafalaya River Basin functions as a flood relief outlet and important filter for the Mississippi River, slowing its flow and trapping nutrients and pollution to improve water quality before it empties into the Gulf of Mexico.

Delivering clean, fresh water to the coast fuels the creation of unique wetland habitats that oysters and other aquatic species need to thrive. This process also deposits sediments that are key to growing the deltas in Atchafalaya Bay and Wax Lake, the only instance of coastal land building in Louisiana.

America's Largest Wetland (2:45) Significant in size and environmental importance, the impact of Louisiana's Atchafalaya Basin branches from providing critical habitat for hundreds of species to protecting communities from storm surges and flooding.

River At Risk

In spite of the many important services provided by the Atchafalaya River Basin (wildlife habitat, flood control, water filtering, pollution reduction and others)—valued at billions of dollars annually—the future of the Atchafalaya is at risk. Decades of hydrologic manipulations have disconnected the river and its surrounding floodplain, preventing the natural overflow of water into the backswamp. The resulting faster and straighter flows don't give the water time or space needed for it to be stored and/or filtered by the wetlands. As a result, throughout the Atchafalaya River Basin, we are witnessing degraded water quality, declining forest health and compromised wildlife habitat.

Big tree trunks emerge from slow moving water. — **Cypress Trees** Afternoon light filters through cypress trees and Spanish moss at Lake Martin in Louisiana. © Rory Doyle

Protecting the Atchafalaya

In response, The Nature Conservancy is working to cultivate an enduring appreciation for the Atchafalaya Basin for generations to come. Through land acquisition, we have an opportunity to access more places to pursue on-the-ground monitoring and land stewardship. We are also working with local communities on cultivating a culture of restoration and with partners and scientists in the conservation and academic communities on exploring cutting-edge approaches to complex issues surrounding the conservation of such a vast and diverse swamp forest.

Bird Migration in the Atchafalaya (2:20) Using doppler radar to track migratory birds.

A man wearing a blue shirt and sunglasses raises a hand while talking with people. — **Setting Up Radar** The Nature Conservancy and partners from the University of Oklahoma install doppler radar on a trailer to help with tracking bird migration. © The Nature Conservancy

Guided By Science

TNC is also working with partners on advancing the latest science to study the Atchafalaya River Basin on land, in the water and up in the air. For example, the Atchafalaya is a critical stop-over for a variety of bird species that arrive to rest and refuel during migration. In response and thanks to technology furnished by the University of Oklahoma and land provided by A. Wilbert’s Sons, we have set up doppler radar on a trailer situated in a sugar cane field to monitor bird species visiting the Atchafalaya during spring and fall migration. The data collected will confirm the importance of this habitat to bird populations while informing TNC's future conservation efforts in the region.

In addition to informing TNC's work in the Atchafalaya, this monitoring effort is also part of a more extensive study led by the U.S. Geological Survey to analyze how a changing climate and sea levels are impacting important stop-over habitats for migratory birds. Since the radar can track a flock of birds in real time and across great distances, the data—which is analyzed by a TNC Conservation Fellow studying at the University of Delaware—will provide valuable information about the birds and their patterns throughout the southeast and beyond.