Clive Runnells Family Mad Island Marsh is part of an expansive coastal wetlands system which, 75 years ago, stretched nearly unbroken along the mid- and upper-Texas Gulf Coast. It lies along the Central Flyway, one of four principal North American migratory bird routes. The preserve's upland prairies represents a portion of the remaining 2 percent of the original tallgrass coastal prairies once found across Texas and Louisiana.
The 7,063–acre preserve is home to marsh and wetland habitats dominated by a variety of aquatic and water-tolerant species, including various cordgrasses, glassworts, rushes and cattails. The preserve's upland prairies display different grasses such as bluestem, plains bristlegrass and Texas wintergrass.
Nearly 250 species of birds—including migrating and resident songbirds, shorebirds, wading birds and waterfowl—use the area for nesting, feeding, resting and roosting. The preserve is especially important to wintering waterfowl, which includes 16 species of ducks and four species of geese. The endangered whooping crane has also been known to use Mad Island during their winter stay along the Texas Coast. The annual Matagorda County-Mad Island Marsh Preserve Christmas Bird Count has ranked in the top five national counts since its inception in 1993.
Alternately, the marsh provides habitat for many different marine organisms, such as red drum, blue crabs, brown shrimp, southern flounder and speckled trout. Mad Island Lake and its surrounding wetlands provide a critical nursery for a variety of marine life from adjacent Matagorda Bay. Other animals found on the preserve include alligators, bobcats, armadillos, rattlesnakes, white-tailed deer and coyotes.
This area of the state provides unique habitat for a diversity of wildlife, but its fragile ecosystem has degraded over the years. Through a unique land swap, The Nature Conservancy received 5,700 acres of wetlands and coastal prairies that it later turned over to the Texas Parks and Wildlife Department. That acreage was turned into the Mad Island Wildlife Management Area. In 1989, Clive Runnells donated to The Nature Conservancy 3,148 acres of coastal wetlands and upland prairies directly adjacent to Mad Island.
In 1993 the Conservancy acquired an additional 3,900 acres with more than $1 million from the North American Wetlands Conservation Council. The Nature Conservancy of Texas, National Fish and Wildlife Foundation, Dow Chemical, US EPA, Trull Foundation and Communities Foundation of Texas partnered to raise another $2.5 million for the project.
In 1990, The Nature Conservancy forged a partnership with Ducks Unlimited to restore the wetlands and tallgrass coastal prairies through four habitat management programs:
The Clive Runnells Family Mad Island Marsh Restoration Program increases freshwater inflows to enhance and reestablish marsh habitat through water management, salinity monitoring and other measures. The Ricefield Enhancement Program improves the management of rice fields as feeding and roosting areas for waterfowl primarily through winter flooding. Over a 10-day period in 1990, Mad Island rice fields fed more than 200,000 waterfowl, the largest number recorded at one site along the middle Texas Coast at that time.
The Palustrine Marsh Enhancement Program focuses on restoring key freshwater wetlands that have been lost or altered from past drainage projects. The Uplands Enhancement Program includes controlled grazing and burning to restore the coastal prairies on the preserve. This creates winter foraging areas for geese and sandhill cranes and nesting cover for game and nongame species in upland prairies. By the end of 2001, 650 acres of freshwater wetlands were either created or enhanced, and more than 3,000 acres of coastal prairie had been been restored using prescribed fire, exotic brush control and sustainable cattle grazing. In addition, more than 2,522 acres of tidal wetlands and 1,200 acres of rice field habitat have been enhanced.