Next Steps for a Healthy Gulf of Mexico Watershed
Mississippi Alluvial Valley
Landscape at a Glance
The Mississippi Alluvial Valley (MAV) Focal Area stretches from the confluence of the Ohio and Mississippi Rivers in southern Illinois to the tidally influenced freshwater swamps along the Mississippi River as it drains towards the Gulf of Mexico. The MAV once supported 24 million acres of floodplain forest, swamps, sloughs and riverine habitat. However, this region’s fertile soils have proven to be its undoing; it now has the distinction of being the Southeast’s most deforested region. More than 75 percent of its forest has been lost since European settlement, mostly to agriculture, and much of the remnant forest occurs in small, isolated tracts of limited conservation value. Implementation of flood control measures and the resulting system of levees, dikes, diversions and canals have significantly altered the landscape. For much of its length, the MAV is cut off from the Mississippi River’s natural flood cycles, which further impairs its ecological integrity and directly impacts the Gulf ecosystem by altering hydrologic regimes and sediment budgets that sustain Gulf habitats.
The MAV is critically important as a major migration corridor for many bird species that can be found along the Gulf Coast. More than 40 percent of the waterfowl that breed in North America use the MAV as migratory stopover, wintering or breeding habitat; the alluvial land between the Lower Mississippi River at low-water stage and levees (i.e., batture) is an important corridor for songbird migration north and south. Additionally, at least 107 species of landbirds breed in the MAV geographic region, with 70 of those depending upon bottomland hardwood forests for most or all of their life cycle. Furthermore, more than 100 species of fish occur in the Lower Mississippi River, and numerous threatened and endangered species (e.g. the pallid sturgeon, and the Interior least tern) depend on these valuable habitats. In light of the ecological value of this geography and the myriad stressors it endures, there has been a significant conservation investment in this region over the last few decades. Coupling these values with the economic and societal values of the region offers great promise for continued success. Indeed, the MAV is identified as a key multi-function conservation investment area by the multi-LCC Gulf Hypoxia Initiative-Precision Conservation Blueprint with opportunities for co-production of wildlife, water quality and agricultural benefits. The Service believes that conservation gains from reforestation (>1 million acres since 1992) and hydrologic restoration efforts have been significant and provide momentum for optimism in the decades ahead.
Restoration in the MAV occurs along three primary fronts: bottomland hardwood conservation and restoration to benefit breeding landbirds and the recently delisted Louisiana black bear; hydrologic restoration of wetland habitats to support migrating shorebirds and wintering waterfowl; and engineering of the flood control and transportation infrastructure along the mainstem river to benefit threatened and endangered Interior least terns, fat pocketbook mussels and pallid sturgeon.
The Lower Mississippi Valley Joint Venture has taken the lead on establishing population and habitat objectives for most birds in the region. For migrating shorebirds, these objectives include targets for the killdeer (98,039), the least sandpiper (161,323), the lesser yellowlegs (22,546), the pectoral sandpiper (129,252) and the semipalmated sandpiper (40,259). For wintering waterfowl, these objectives include targets for the American black duck (53,000), the American wigeon (288,000), the canvasback (43,000), the gadwall (430,000), the scaup (1,354,000), the green-winged teal (476,000), the mallard (3,239,000), the northern pintail (329,000), the northern shoveler (89,000), the redhead (60,000), the ring-necked duck (277,000), the ruddy duck (55,000) and the wood duck (1,622,000). The Lower Mississippi Valley Joint Venture also has established objectives for numbers of breeding pairs of landbirds such as the Swainson’s warbler (187,500) and the swallow-tailed kite (320) – which includes both the Atchafalaya Basin and the Mississippi Alluvial Valley.
The Lower Mississippi River Conservation Committee and the Service have cooperated extensively with state and other federal agencies (notably the U.S. Army Corps of Engineers) to develop and implement restoration and recovery plans that outline objectives for other species: supporting a stable population of 2,500 adults of the Interior least tern for 10 years; maintaining a viable population of fat pocketbook mussels in the Lower Mississippi River; and ensuring a self-sustaining, genetically diverse population of 5,000 adult pallid sturgeons.
Beyond the benefit to our trust resource species, restoring the function of river floodplains will provide better spawning and nursery habitat for commercially important floodplain-spawning fish like buffalo and alligator gar. Channel improvements will enhance channel and blue catfish habitat, improve spawning conditions for prey species like gizzard shad and skipjack herring, and increase angling opportunities for Gulf Coast striped bass and other recreational fish species. Improving conditions and land management practices on agricultural lands will reduce erosion, sedimentation, and the amount of nitrates that create hypoxic conditions in the Gulf, ultimately benefiting many marine species. Restoring natural hydrology and bottomland hardwood forest habitats will also benefit numerous frogs, including chorus frogs and tree frogs; bats, like the Rafinesque’s big-eared bat and the southeastern myotis; and crayfish species currently listed as “at risk” (e.g., Yazoo crayfish). Similarly, numerous upland game species will benefit from these restoration practices including the white-tailed deer, the wild turkey, and both the gray and the fox squirrel.
High Priority Actions Based on the Service’s Vision
Permanently conserve and restore large patches of bottomland hardwood forest through voluntary conservation easements and fee acquisition.
- Continue to work with USDA’s NRCS and Farm Service Agency through partnerships, such as the Conservation Delivery Networks established by the Lower Mississippi River Valley Joint Venture, to collaboratively use existing decision support tools (e.g., Forest Breeding Bird Decision Support Model) to identify opportunities for bottomland hardwood forest conservation and restoration in support of area-sensitive breeding songbirds and waterfowl population objectives.
- Facilitate and participate in development of Landscape Conservation Design efforts (e.g., the Gulf Coastal Plains & Ozarks LCC Conservation Blueprint) that reflect partnership-driven conservation and restoration priorities.
- Permanently protect and restore habitats within approved NWR acquisition boundaries, including Cache River and Dale Bumpers White River NWRs, where greater connectivity among protected areas along the Cache River, Bayou DeView, and White River is needed. Work with willing sellers to acquire fee title lands and conservation easements to provide important wildlife habitat, connect conservation lands and protect aquatic resources.
- Engage in restoration of bottomland hardwood forest in areas embedded in large forested landscapes, such as Cache River and White River NWRs, to include planting native oaks, bald cypress, sweetgum and pecan trees to enhance wildlife diversity and prevent soil loss from erosion.
- Engage in hydrological restoration in areas embedded in large forested landscapes, such as Cache River and Dale Bumpers White River NWRs, to improve water flow and quality while simultaneously contributing to the overall health of the Gulf by reducing sediment, nutrient and pollutant runoff.
- Promote the use of Lower Mississippi Valley Joint Venture’s compilation of forested wetland restoration and management recommendations (i.e., “Desired Forest Conditions for Wildlife”) focused on diversifying tree species composition and forest structure within bottomland hardwood stands in the Lower Mississippi Alluvial River Valley to provide productive habitat to sustain populations of priority migratory birds and other forest-dependent wildlife (e.g., Louisiana black bears) in concert with sustainable forestry on both public and private lands.
Restore natural hydrology via re-meandering streams, removing artificial impediments to natural flow, restoring ridge and swale topography, etc.
- Support and implement restoration activities identified by the Lower Mississippi River Conservation Committee. These include the creation, rehabilitation and diversification of main and secondary channels to provide habitat for the endangered pallid sturgeon, the Interior least tern and the fat pocketbook mussel; the restoration of floodplain water bodies; the augmentation of aquatic connectivity with the floodplain; and the enhancement of tributaries and terrestrial habitats (particularly wetland restoration on batture lands, which is the land between a river at low-water stage and a levee).
- Work with state agencies throughout the focal area to develop restoration objectives for floodplain-spawning fish (e.g., the alligator gar) to support strategic conservation of these species and their habitats.
- Educate private landowners on potential options for water management improvements to benefit waterfowl, shorebirds and waterbirds on existing NRCS Wetland Reserve Easements and explore opportunities to help implement these enhancements where they also meet the objectives of individual landowners.
- Leverage the capacity of Lower Mississippi Valley Joint Venture Conservation Delivery Network and the Service’s Partners for Fish and Wildlife Program, and utilize existing USDA NRCS programs and expertise to address shallow water wetland and critical forest management needs on private lands through additional Wetland Reserve Easements in Arkansas, Louisiana and Mississippi.
- Implement habitat maintenance activities such as disking of nuisance vegetation and flooding in moist-soil management units on publicly managed lands to provide habitat for early migratory shorebirds, wading birds, and early migrant waterfowl (July – September).
- Coordinate with the Lower Mississippi River Conservation Committee to implement recommendations from the Congressionally authorized Lower Mississippi River Resource Assessment to maintain navigation and abate flooding while enhancing river-related recreation and public access along with the river’s natural habitats and the species they support. Recommendations include the creation of a Lower Mississippi River Science Technology and Information Center; the study of sediment budgets; the development of a water-quality monitoring program; the compilation of an inventory of ecological resources to support restoration; and the implementation of an invasive species program (particularly for the Asian carp).
Enhance wildlife habitat values and water quality on agricultural and other working lands by improving water management capacity, installation of filter strips and buffers, and other appropriate soil and water conservation measures.
- Expand USDA’s NRCS Migratory Bird Habitat Initiative program and work with private landowners in Louisiana and Mississippi to provide food and critical wetland habitat for migratory bird populations in support of existing Lower Mississippi River Valley Joint Venture objectives for these species.
- Work within the MAV pilot area established by multiple LCCs (through the Mississippi River Basin/Gulf Hypoxia effort) to implement USDA’s NRCS Mississippi River Basin Initiative and other Farm Bill programs (e.g., Agricultural Conservation Easement Program, Environmental Quality Incentives Program, Conservation Reserve Program) to implement nutrient reduction strategies that benefit shorebird and waterfowl species compatible with sustaining agricultural economies.
- Promote the implementation of water conservation practices (e.g. irrigation water recovery systems, improved irrigation delivery techniques) to reduce aquifer depletion and ensure a sustainable water supply for all users.