What You Need to Know

…are like giant sponges.

They prevent flooding. During heavy rains, they collect and hold water. They also protect coastal areas from storms. These can wash away beaches and communities.

…act to clean and filter water.

Chemicals found in fertilizer often wash into wetlands. Wetland plants, fungi, and algae soak up these harmful chemicals. Other things that pollute the water sink to the bottom. There they are buried in soil.

…are homes for many species.

Many kinds of plants and animals depend on wetlands to survive. Two-thirds of fish eaten worldwide depend on wetlands during their life cycle.

…have a variety of ecosystems.

Wetlands cover only five percent of the United States. Yet more than one-third of the threatened species in the U.S. live only in wetlands. Another 20 percent use wetlands during their lives.

…are important to people.

Nearly 400 million people live close to wetlands. People depend on them. They use wetlands to grow crops. Wetlands are also used for fun. People fish and boat on them. Americans spend more than $100 billion on wetland activities every year.

wetlands face many threats

As much as half the world’s wetlands have disappeared since 1900. Still, they have great value to people and wildlife.


People change wetlands by removing the plants that live there. They drain the wetlands to build houses and roads.

Invasive Species

Introducing plants and animals from other areas causes native species to compete. If native species die off, the ecosystem is disturbed.


Wetland soil is often made into land for farming. The extra water, or runoff, from nearby farms can hurt wetlands.

Climate Change

Climate change has caused a rise in sea levels. As a result, many coastal wetlands may be flooded forever.