has lost more than 1.2 million acres of its original coastal wetlands, including thousands of marsh ponds rich in high-value waterfowl plant foods. Due to the loss of these habitats
and their accompanying food resources, the Louisiana Gulf Coast may now support 3 million fewer ducks than the region did during the 1970s. The causes of these wetland losses are complex, but ultimately the mainline levee system along the Mississippi River prevents fresh water, sediment, and nutrients from flowing into and sustaining the marshes. Once freshwater flows are reduced or eliminated, salt water from the Gulf filters into the marshes, killing aquatic plants and other vegetation that cannot tolerant high salinity levels. Over time, these degraded marshes eventually disappear, reclaimed by the open waters of the Gulf.
Farther west, in Texas
, rapidly growing cities such as Austin, Houston, Dallas–Fort Worth, and San Antonio are straining the state's limited water supplies. This has reduced freshwater flows in many rivers that feed marshes and bays along the Gulf Coast. The results are similar to those in Louisiana—fewer marshes with suitable conditions for growing aquatic plants and fewer ducks wintering in the region. In addition, habitat loss and degradation may reduce survival among ducks that winter in the region, and when spring arrives, the remaining birds may depart their wintering grounds in less than optimal condition. This can delay not only the birds' arrival on the breeding grounds but also nesting, which may reduce waterfowl production.
The Gulf Coast's extensive marshes have been significantly altered and will likely always require active management and restoration efforts to sustain them. Conserving high-quality waterfowl wintering habitats—including marsh ponds rich in aquatic vegetation—is the objective of Ducks Unlimited's Gulf Coast Initiative
. Through this effort, DU and its partners are working to restore coastal wetlands through freshwater diversions, the beneficial use of dredge material, development of water-control infrastructure, and other methods. DU also supports and advocates implementation of large-scale diversions of fresh water and sediment from the Mississippi River to rebuild coastal marshes in southeast Louisiana. Sustaining North America's most important waterfowl wintering area will require broad public support and a long-term commitment by all who value the Gulf Coast's threatened wetlands and the communities and traditions that depend on them. For more information about how you can support DU's Gulf Coast Initiative, visit the DU website at ducks.org/DUinitiatives
Dr. Tom Moorman is director of operations in DU's Southern Region.