Next Steps for a Healthy Gulf of Mexico Watershed
Landscape at a Glance
The Chenier Plain Focal Area is a rich and complex mixture of wetlands, uplands and open water that extends roughly 200 miles from Galveston Bay, Texas, to Vermilion Bay, Louisiana. It runs from the expansive coastal marshes bordering the Gulf shore through the coastal prairie into areas of intensive crop cultivation.
The Chenier Plain is a popular destination for nature watchers, anglers and hunters, who come from around the world to experience the abundance and diversity of its natural resources. With its location at the terminus of the Central and Mississippi Flyways, coastal wetlands in this focal area are extremely important for waterfowl and serve as the primary wintering site for up to 5.8 million ducks. The area also has productive estuaries, nearby forests and grasslands, and expansive tidal wetland systems. The coastal waters of the Chenier Plain Focal Area contribute substantially to the nation’s commercial fishery landings, particularly for shrimp, blue crab, oysters and Gulf menhaden operations. Large numbers of migrating birds also use the Chenier Plain ecosystem, with its bottomland hardwood forests, oak islands, and agricultural areas serving as important stopover habitat for songbirds and shorebirds.
Despite the region’s rich bounty, alterations of the natural processes that formed it have changed the landscape in unanticipated and undesirable ways. These alterations include the construction and management of navigation channels and locks, drainage and irrigation canals, and diversions. While these alterations of the landscape have resulted in important benefits for society, the changes to the natural character of the landscape have also resulted in a loss in the abundance and diversity of plants and animals. For example, when sediments are removed from navigation channels, they are usually sequestered in placement areas or disposed of offshore. The resulting channel enables ships passage to a port, but tons of sediment that help build deltas, shorelines and beaches are lost from the system. Similarly, typical flood mitigation strategies convert natural streams into single purpose landscape features, which reduces flood risk but simultaneously remove fish and wildlife habitat, reducing recreational opportunities and degrading water quality. Much of the landscape on the northern edge of the Chenier Plain has been converted from coastal tallgrass prairie for agricultural purposes, increasing the nation’s food supply but decreasing habitat for grassland and wetland plants and animals.
Recent storms and the resulting loss of ecotourism visitation have provided a sobering reminder to all stakeholders that natural resource infrastructure is not only important for the viability of fish and wildlife, but to people and their communities as well. The Service believes that integrating social and environmental perspectives to appreciate how people and wildlife are interlinked is perhaps the greatest conservation need in this focal area. Developing such an approach to problem-solving and making investments towards collaborative actions would allow us to conserve wildlife while simultaneously meeting the resource needs of the human population.
Hydrologic restoration in the Chenier Plain – particularly those targeting freshwater wetlands and bottomlands – supports population objectives that have been established by the Gulf Coast Joint Venture for many wetland-dependent species in the region. These include migrant shorebirds such as stilt sandpipers (476,690) and western sandpipers (349,332); and resident or wintering waterfowl such as mottled ducks (259,505), green-winged teal (1,602,248), gadwall (>972,000), mallards (>560,000) and pintails (>520,000). Numerous colonial waterbirds, like little blue herons, roseate spoonbills and white-faced ibises are also beneficiaries of wetland restoration work, along with secretive marshbirds like king rails and least bitterns. The grassland habitats of this region provide habitat for the species of conservation concern, the LeConte’s sparrow (132,939 individuals), and other grassland-dependent species like loggerhead shrikes and eastern meadowlarks.
The Gulf Coast Joint Venture has assessed flooded rice fields and other inland palustrine wetlands in the Texas and Louisiana portions of this focus area relative to the needs of target waterfowl populations, and on average only 37 percent of the approximately 64,000-acre winter habitat objective for Texas is met, while the approximately 49,000-acre objective for Louisiana is consistently attained.
While many of the proposed actions in this focal area specifically list trust resource species as their targets, implementation of these actions will be advantageous to many other species. For example, large-scale hydrologic restoration efforts to improve conditions in coastal wetlands to benefit birds will also benefit fisheries species such as estuarine fish, shrimp, blue crabs and oysters by improving habitat and water quality. Restoring coastal prairie habitat will not only benefit grassland dependent birds but also provide habitat for other declining species such as the Northern scarlet snake, ornate and three-toed box turtle, muskrat, crayfish and pig frog as well as a wide array of plant species characteristic of the coastal prairie.
High Priority Actions Based on the Service’s Vision
Restore hydrologic processes including watersheds and diversions (e.g., Salt Bayou Project) to restore and enhance wetlands and aquatic habitats to enhance fisheries and habitat for wetland dependent species.
- Develop approaches for restoring sustainable beach and dune barrier systems within the focal area to combat sediment loss, relative sea level rise and erosion.
- Develop and implement approaches to reduce flow velocity, and restore historical tidal flux of high salinity waters into the estuarine systems, in order to ensure productivity of coastal wetlands. These can include installing siphons; restoring historic channel dimensions; enabling high flow diversions that reduce and or minimize flood risk; and placing sediment in subsided submerged and emergent lands.
- Restore freshwater inputs into estuarine habitats that can restore and extend the duration of the hydroperiod (i.e., the period in which the soil area is waterlogged). On conservation lands, explore opportunities to redirect high flow waters onto landscapes where drainage improvement projects have reduced hydroperiod intensity and duration. This can result in higher quality wetland habitats, as well as possibly improve water quality and reduce flooding risks.
- Study the landward migration of tidal waters, sea-level rise, sediment aggradation and vegetation changes and develop strategies to proactively adapt to maintain tidal habitats on the coastal landscape in the future.
- Stabilize seasonal salinity patterns to reduce or eliminate rapid changes within the system that lead to the loss of stable vegetation communities.
- Work with willing landowners to conserve coastal floodplain bottomlands along rivers that allow for high flow events and long-term maintenance of riverine bottomlands.
- Identify lands for conservation through voluntary easement or acquisition that can then be used for hydrologic restoration projects supported by landowners and/or drainage and flood management districts to yield significant benefits for the public through wildlife conservation, water quality improvements, beneficial use of dredged material and reduced flooding risks.
- Work with drainage and flood management districts to restore hydrology on conservation lands and improve flood risk reduction efforts.
Restore landscapes and interrupted sedimentary processes by incorporating beneficial use of dredged material, direct dredging and erosion protection with willing public and private land managers.
- Work specifically with navigation interests to encourage sediment management practices that retain sediment in the coastal and nearshore environment rather than disposed of in offshore placement areas.
- Design and develop sites that would be available to receive sediments removed for navigation purposes and promote the beneficial use of dredge material to restore important fish and wildlife habitats, such as tidal marsh, bird islands and barrier island headlands.
- Work with partners to investigate possible impacts on society from changes that would result from the re-establishment of natural sedimentary and hydrologic processes.
- Work with navigation partners and landowners along the Gulf Intracoastal Waterway and other navigational channels to more effectively use dredged material to enhance degraded wetlands, thereby protecting shorelines and potentially reducing the dredging frequency.
- Where applicable, apply living shorelines treatments or other methods to reduce erosion and rebuild degraded wetlands.
Conserve coastal prairie landscapes by recovering historic wetland pothole and mound complexes and re-introducing native prairie species on former agricultural (rice) lands to support pollinators, grassland and wetland dependent species like the mottled duck and bobwhite quail, and wintering waterfowl, waterbirds and shorebirds.
- Identify remnant coastal prairie sites with intact geomorphology of mounds and freshwater marsh wetlands in the former range of the coastal prairie. This information can be used to explore easement, acquisition or restoration opportunities with willing private landowners.
- Develop a strategy to conserve and restore coastal prairie habitat on high priority private and public lands to meet habitat objectives for target species, including the application of prescribed fire.
- Coordinate the implementation of a strategy and apply prescribed fire to coastal prairies and marshes to sufficiently maintain target species population and habitat objectives with partners.
- Utilize cooperative prairie management associations to maintain seral stages needed for grassland, prairie and wetland dependent species. Management activities can include prescribed fire, mowing, invasive species control, and grazing methods and approaches.
- Where they do not exist, establish new prairie restoration cooperatives that provide opportunities for members for restoration-related equipment sharing, and reference donor sites for native seed, cultivation and propagation (including of upland and wetland plant stocks needed for restoration).
- Develop opportunities with drainage and flood management districts to restore hydrology on conservation lands, improve water quality of associated receiving waters and reduce flooding risks to landowners and communities.
- Employ monitoring efforts to understand the range of results that different management actions have for target species and taxa.
- Provide incentive-based opportunities for private landowners to work with conservation partners and water management entities to develop and integrate wetlands with agricultural activities so that habitat is provided for wildlife, water quality improvement and reduced flood risks in coastal wetlands. These agriculture-wetland systems are one alternative to replacing converted wetland systems historically present in the coastal prairie and Chenier Plain region.
- Encourage the expansion of the USDA’s NRCS Migratory Bird Habitat Initiative program and work with private landowners in Texas and Louisiana to provide food and critical wetland habitat for migratory bird populations in support of existing Gulf Coast Joint Venture objectives for these species.