What are wetlands? Wetlands are areas where water covers the soil, near the surface of the soil all year long or during long periods of time. Wetlands are covered by plants, ranging from marsh grasses to trees. These plants must be able to live in soil without oxygen during parts of the growing season. Some wetlands are far from open water. These are formed where rainwater collects or where groundwater raises to the surface. Wetlands can be characterized as swaps, tidal marshes, coastal wetlands, and estuaries. Wetlands can be found from the tundra to the tropics. Antarctica is the only place where there are no wetlands.
Animals and plants depend on wetlands for survival. 1/3 of the threatened or endangered species make their home in wetlands, and nearly 1/2 use wetlands during some part in their lives. Commercial and game fish breed and raise their young in coastal marshes and estuaries. Many species of fish like flounder and sea trout depend on wetlands for food, shelter, and breeding areas. Shell fish also depend on a wetland habitat. Many birds use coastal inland wetland. These birds use wetlands as resting, feeding, breeding, or nesting grounds during certain times of the year. The wetlands in Texas are one of the most important waterfowl wintering areas in the Central Flyway.
Wetlands help improve and maintain water quality of streams, rivers, lakes, and estuaries. Because of the location of wetlands they intercept runoff from humans before it reaches the ground water or large bodies of water. Wetlands act like a filter. Runoff and surface water pass through the soil and removes or transforms the pollutants through chemical, physical, and biological processes. The Bottomland Hardwood Swamp in South Carolina removes pollutants from the watershed equal to a five million dollar sewage treatment plan. In Georgia scientist have estimated that for every 2,500 acres of wetlands it saves one million dollars in water pollution control annually.