The Lake Martin Important Bird Area (IBA) is nearly 32,000 acres. It is home to The Nature Conservancy?s Cypress Island Preserve, of which Lake Martin serves as a focal point. There is a boardwalk to allow visitors closer access to the swamp, and a Nature Center will be opening soon at Cypress Island Preserve.
This site includes about 10,000 acres of protected cypress-tupelo swamp and bottomland hardwood forest habitat. It is known as a world-class wading bird rookery, where thousands of pairs of herons, egrets, and other waterbirds nest. It is also the year-round home to over 200 species of resident, wintering, and migratory birds, as well as over 1,200 alligators.
Lake Martin is separated from the Atchafalaya Basin IBA by the Teche Ridge, a 6,000 year old natural levee of a former course of the Mississippi River. Much of the land surrounding Lake Martin has been converted to agricultural uses. Construction of canals, dams and levees have altered the natural hydrology from a system of flowing water to an impoundment surrounded by a manmade levee. Part of that levee is a nature and biking trail.
The lake offers a unique habitat that attracts nearly sixty percent of all birds that regularly occur in Louisiana. The preserve is home to a spectacular wading bird rookery that supports thousands of nesting birds each spring. Nesting White Ibis, Anhinga, Neotropic Cormorant, Snowy Egret, Little Blue Heron, Green Heron, Great Egret, Roseate Spoonbill, Tricolored Heron, Cattle Egret, Yellow-crowned Night-Heron, Black-crowned Night-Heron, and Great Blue Heron may be observed engaging in courtship behaviors, building nests, incubating eggs, and feeding their young. Baldcypress, water tupelo, and buttonbush provide nesting habitat for this suite of birds, while the alligators reduce the populations of some mammalian nest predators such as raccoons, opossums, and mink. The walking levee trail on the Cypress Island Preserve is also a superb place to observe trans-gulf migratory birds, such as Prothonotary Warbler, Northern Parula, and White-eyed Vireo. Other birds frequently observed from the lake shore include Black-bellied Whistling Duck and other waterfowl species, Swallow-tailed Kite and Bald Eagle.
The Lake Martin IBA faces threats from incompatible uses. Incompatible forest management may include unsustainable harvest of trees. Incompatible human uses may include development, conversion of land to agriculture, or recreation activities that disturb wildlife or negatively impact habitat, water quality.
The construction of dams, levees, and canals has altered hydrology in this site, changing the area from a swamp nourished by free-flowing water to an impoundment. Water quality has declined as a result, and constant flooding lowers forest productivity and damages and drowns the vegetation. Problems with water quality are compounded by bird droppings, particularly in the southern section of Lake Martin.
Forest fragmentation harms the ecological integrity of forests across the region. While the Atchafalaya Basin to the east is the largest intact bottomland hardwood forest remaining in the United States, the forests of Lake Martin are cut off from the Basin forests. Fragmentation effects include increased stress on vegetation, increased wind throw during storm events, and may include increased predation, disease, and brood parasitism by the Brown-headed Cowbird.
Invasive aquatic weeds, including bladderwort, water hyacinth, fanwort, coontail, duckweed, and especially hydrilla have obstructed many of the open areas in Lake Martin, killing fish and submerged plants because of the decrease in oxygen levels. Chinese tallow rapidly colonizes large treefall gaps, forest clearings and abandoned farmlands. Tallow is a pioneer species that, in smaller areas, may eventually be shaded out by native tree species, persisting as a minor but significant component of the forest community. In some areas, though, tallow seems to replace itself with minimal natural colonization by hardwoods from the surrounding forest. In such areas, restoration of forest with a more natural species composition will take significant manual and chemical control of tallow.
The Cypress Island Preserve is owned and managed by The Nature Conservancy (TNC) of Louisiana. The preserve was created by a donation of nearly 3,000 acres from Texaco in 1994, and has grown to its current size of 9,300 acres through a second Texaco donation and acquisition of a number of additional tracts by TNC. The conservation area is considered one of the ?Last Great Places? by The Nature Conservancy. The majority of surrounding lands in this IBA are privately owned.
The habitat includes a baldcypress-water tupelo swamp and bottomland hardwood forest. The majority of the site is comprised of forested wetlands although there is also agricultural land around the preserve. Lake Martin, which has a spectacular rookery on it, is a broad shallow lake filled with baldcypress and water tupelo stands. Mature oak, elm, ash, pecan and other classic bottomland hardwood species are found in adjacent forests. Because of bird droppings and reduced water exchange, the lake?s oxygen has decreased, resulting in algal and plant growth in the lake. The Louisiana Department of Wildlife and Fisheries and The Nature Conservancy are working in partnership to manage water quality and other habitat needs at Lake Martin. Installation of a water control system that allows for seasonal drawdown of Lake Martin has improved water quality.
Public uses of the Lake Martin IBA include photography, bird-watching, hiking, fishing, and biking. Hunting is a popular activity throughout much of the IBA, including in parts of Cypress Island Preserve. Trapping is also allowed in parts of the Lake Martin IBA. The Nature Conservancy?s goal in the Cypress Island Preserve is to protect, through preservation and some restoration, 20,000 acres of natural cypress-tupelo swamp and bottomland hardwood forest, of which they now own about 10,000 acres. The protected habitat will support a diverse array of indigenous species of plants and wildlife. A little more than a tenth of the IBA is currently being used for agricultural purposes.