National Wetlands Inventory

Why Map Wetlands?

Why are Wetlands Important?
Wetlands are home to thousands of wetland plants and animals, such as beaver, alligator, crayfish, and insects. Ducks and other migratory birds depend on wetlands to nest, feed, rest, and raise their young. Many fish live, feed and spawn in wetlands. Frogs and salamanders depend on wetlands for all or most of their life. Many plants live nowhere else but in wetlands. A recent analysis suggests that 50 percent of North American birds depend on wetlands. An estimated 46 percent of U.S. endangered and threatened species need wetlands to live.

Wetlands soils absorb water from precipitation, plants slow the water’s flow, and wetlands areas hold and release the water slowly into streams. Natural wetlands do filter out chemicals and fertilizer that people have put on their farms, lawns or discharged from their businesses.

Wetlands provide food such as fish, rice, cranberries, and clams. Many people make a living harvesting natural products from wetlands.

You can birdwatch, view other wildlife, boat, walk, or take photographs in wetlands. Many people fish or hunt in wetlands. Wetlands also provide openspace for beauty and can enhance property values.

How many wetlands do we have?
We estimate there are 107.7 million acres of wetlands, or 5 percent of the land area, in the lower 48 states as of 2004. Many of these wetlands are in the southeast United States. Alaska is estimated to be about 45 percent wetland, and Hawaii is 1 percent wetland.

How does up to date mapping help conserve wetlands and benefit people?
To protect wetlands, you must know what kinds of wetlands you have, where they are, and what is happening to them, ie, their currrent status and the trends of losses or gains. Wetlands are mapped to show their current status, and updated or sampled to show trends in losses or gains. Once wetlands are mapped, many types of wetland assessments can be performed. Wetland assessment is cruicial to: monitor wetland health, make permit decisions, target voluntary wetland restoration activities, maintain biodiversity, restore species, measure mitigation success, undertake watershed management, develop wetland classifications, protect public water supplies, and better implement local land use plans.