Marshes and Swamps
Marshes and Swamps, areas in which the land is usually covered with shallow water. They are often transitional features, occurring between dry land and deep bodies of water. Marshes and swamps, along with certain other types of wet areas, are sometimes referred to as wetlands. Among other types of wetlands are bogs and fens.
A great variety of plants are found in marshes and swamps. Among the animals found are frogs, snakes, beavers, muskrats, minks, ducks, and sandpipers.
Although marshes and swamps share some characteristics and the two terms are sometimes used interchangeably, marshes and swamps each have distinguishing features.
Marshes typically have few trees. Plants that grow in marshes include cattails, bulrushes, grasses, sedges, and smartweeds. Freshwater marshes are most common along shores and riverbanks. A prairie pothole is a kind of freshwater marsh common in the prairies of the Great Plains. Saltwater marshes are common in river estuaries, in bays, and behind dune-protected seacoasts. Plants found in saltwater marshes include such salt-tolerant species as eel grass and cord grass.
Swamps are typically wooded. Bald cypress, mangrove, willow, birch, water tupelo, and swamp white oak are among the trees that grow in swamps.
Marshes and swamps are found on every continent except Antarctica. Large expanses occur along the Amazon, Cuib, and Paraguay rivers in South America and the Congo and Nile rivers of Africa, in the lowlands of Southeast Asia, and in parts of northern Canada and Asiatic Russia. In the United States, swamps and marshes are extensive along the Atlantic and Gulf coasts. One of the country's largest swamps is the Okefenokee of Georgia and Florida. Much of Florida's Everglades region consists of marshes and swamps.
Importance of Marshes and SwampsMarshes and swamps are valuable for many reasons. A great variety of wildlife, including many endangered species, lives in marshes and swamps. Some species live there throughout the year; others only during their breeding season. Many animals that live in marshes and swamps are of economic importance, including fish, shellfish, fur-bearing animals, and waterfowl.
Marshes and swamps help control floods by acting as reservoirs for excess water. Much of this water goes to replenish ground-water supplies. Marshes and swamps help purify water by filtering out pollutants, which become trapped in sediment.
Marshes and swamps along shores buffer the action of waves, reducing shoreline erosion and damage to private property during storms. Some swamps are excellent sources of timber. Marshes and swamps offer sites for recreational activities, such as fishing, hunting, and bird-watching.
Conservation of Marshes and SwampsThroughout the world, many marshes and swamps have been drained or altered for such purposes as agriculture, urban development, and mosquito abatement. In addition, many marshes and swamps have been used as dump sites. The destruction of a marsh or swamp often causes such problems as increased flooding, ground water depletion, and loss of wildlife. To prevent these types of problems from occurring, many measures have been taken to conserve marshes and swamps.
The Migratory Bird Hunting and Conservation Stamp Act (1934) authorizes the United States government to raise revenue through a fee on waterfowl hunting; this revenue is used to acquire and restore marshes, swamps, and other wetlands. The Clean Water Act (1972) funded the construction of sewage treatment facilities for reducing the amount of pollution entering marshes and swamps in the United States.
The Ramsar Convention (1971) is a treaty in which more than 50 nations agreed to conserve a total of more than 500 designated wetlands, mostly marshes and swamps frequented by migratory waterfowl.