Wetlands Functions and Values
Wetlands provide many benefits at very little cost. They are unique and vital ecological resources. They contribute to the national economy by producing natural resources and goods. The many different types and locations of wetlands make measuring their benefits difficult. However, regardless of where or what kind of wetland it is, there are some basic reasons that make wetlands so very important. These reasons include commercial values, recreational values, wildlife habitats, water quality management, storm buffers, erosion control, and flood control.
Commercial and Recreational Values
Wetlands provide opportunities for many popular recreational activities such as boating, hiking, hunting, fishing, and bird-watching. More than half of all U.S. adults (98 million) hunt, fish, birdwatch, or photograph wildlife. These activities, which rely on wetlands, add an estimated $60 million to the national economy. Their economic value lies in the variety of commercial products they provide, such as food, fiber, lumber, and energy resources. Bottomland forests, one type of wetland, are sources of lumber, adding more than $10 billion to the economy annually. Coastal wetlands serve as spawning areas and nursery grounds for shellfish and sport and commercial fish, insuring the continued success of the $26 billion commercial fishing industry. Coastal wetlands are also habitats for many furbearing mammals that provide for a strong fur market. Additionally, in many coastal and river delta wetlands, grazing and haying of wetland vegetation are extremely important to livestock producers.
Wetlands Value as Wildlife Habitats
One reason wetlands are so important is the unique wildlife and vegetation they support. They are among the most productive natural ecosystems on the earth. They produce great quantities of plants, some of which could not live anywhere else. Some of the plants specific to wetlands are cattails, swamp rose, spider lilies, and cypress trees. Many of the wetland plants provide food, shelter, and nesting areas for the animals that also make wetlands their home. Wetlands are major breeding grounds for various resident and migratory birds. They are migratory stopovers for many species of waterfowl, wading birds, shorebirds, and songbirds. Many species of invertebrates, amphibians, reptiles, and mammals depend on wetlands for survival. In fact, at least one third of the nation's threatened or endangered species live in wetland areas. Wetlands are extremely important refuges for this plentiful variety of wildlife. Wetlands are diverse and support an incredible diversity of life.
Wetlands Help Maintain Water Quality
Wetlands are also important in the way they interact with the environment around them. They are natural reservoirs and erosion controllers, and they function as natural sewage systems. When rain sinks into the ground, it is stored in naturally occurring underground depressions. This prevents the water from immediately flowing into streams, rivers, lakes, or the gulf or ocean. The specially adapted plants that live in the wetlands act as flood controllers and as water purifiers. The vegetation slows the water enough so that sediment and chemicals in the water can settle to the bottom. As the water is cleaned the plants absorb the chemicals that are released. The plants then convert the chemicals to usable substances and eventually pass on these nutrients to the animals in the ecosystem. The ability of wetlands to recycle nutrients and to take suspended materials and chemicals out of the water is a critical and unique function.
Wetlands Help Control Erosion and Flooding
Vegetated wetlands help to hold together banks of lakes, rivers, and the beach rim that are often prone to serious erosion problems. When wetlands are converted and the vegetation is removed or damaged, soil erosion increases. Instead of serving as a sediment trap, wetlands become a sediment source. Wetlands also help to control flooding. When water levels are high due to storms and flooding, the heavy, spongy vegetation absorbs the water and slows its flow. The combined action of storing and slowing can lower flood heights and reduce the water's erosive power. The presence of only 15% of a watershed in wetlands can reduce flooding peaks by as much as 60%. Additionally, the slowed water drops soil that builds up, forming higher, more insulated ground where terrestrial grasses and hardwoods can take root, reducing the force of erosion even more. Maintaining wetlands near developed areas may be the least expensive insurance policy homeowners and business owners can purchase to protect their property.
Act as Storm Buffers
Coastal wetlands adjacent to the Gulf of Mexico serve an extremely important storm surge protection function when tropical storms or hurricanes come ashore. Research has shown that for every mile of vegetative wetlands, storm surge height can be reduced by one foot. Coastal wetlands such as brackish marshes, bottomland forest, and barrier islands absorb enormous amounts of wave energy and hold large quantities of water that would otherwise allow storms to do much more damage inland.