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 storm surges that can wash away fragile beaches and coastal communities.

…act as water treatment facilities.

They filter and clean water. Runoff chemicals from urban areas and farms, like those found in fertilizer and manure, often wash into wetlands. Wetland plants, fungi, and algae absorb these harmful chemicals. Other pollutants sink to the bottom where they are buried in soil and sediment.

…are homes for many species.

Many plant and animal species are completely dependent on wetlands for their survival. Two-thirds of fish eaten worldwide depend on wetlands during their life cycle.

…are some of the most diverse ecosystems on Earth.

Wetlands cover only five percent of the United States, but more than one-third of threatened or endangered species in the U.S. live only in wetlands. An additional 20 percent of threatened and endangered species use wetlands during their lifecycles.

…are important to people. Nearly 400 million people live close toand depend onwetlands.

People use wetlands to grow crops like rice. Rice is a staple in the diet for more than half the world. Wetlands are also used for fun, such as fishing and boating. According to the U.S. Fish and Wildlife Service, Americans spend more than $100 billion on wetland-related activities every year.

Wetlands face many threats

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


Development often changes wetlands by removing vegetation and filling or draining wetlands. The land is used to build houses, roads, and shrimp farms.

Invasive Species

The introduction of non‑native plants and animals causes competition for resources and leads to imbalances. If native species die off, the ecosystem gets disrupted.


Rich, organic wetland soil is often drained and converted into agricultural land. And runoff from nearby farmland can hurt wetlands.

Climate Change

The rise in sea levels caused by climate change may lead many coastal wetlands to be permanently flooded by seawater.