Why Are Wetlands Important?

Marshland on a cold winter afternoon
Chris Hepburn/Digital Vision/Getty Images

The U.S. Environmental Protection Agency defines wetlands as “lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface.” Environment Canada’s official definition is almost the same wording.

The Ecological Importance of Wetlands

Beyond definitions, wetlands are essential ecological features in any landscape.

They are primary habitat for hundreds of species of waterfowl as well as many other birds, fish, amphibians, reptiles, and insects.

Wetlands naturally filter and recharge the water that later comes out of our faucets downstream. They act like giant sponges, slowing the flow of surface water and reducing the impact of flooding.

Wetlands also prevent soil erosion, and they buffer water bodies from potentially damaging land use activities such as agriculture. And wetlands can remove and store greenhouse gases from the Earth’s atmosphere, slowing the onset of global warming.

More than half of the original 221 million acres of wetlands that existed in the continental U.S. at the time of white settlement were destroyed by the 1980s. The story has been much the same in Canada, with analysts estimating between a 30 and 70 percent of that country’s wetlands lost during the same period.

Billions Spent to Protect and Recover Wetlands

Recognizing the importance of waterfowl and wetlands to North Americans and the need for international cooperation to help in the recovery of this shared resource, U.S. and Canada developed and signed the North American Waterfowl Management Plan in 1986.

Mexico joined in 1993. The three countries have since spent $4.5 billion protecting some 15 million acres of wetlands in jeopardy across the continent.

All three governments have instituted complex regulations whereby developers wanting to fill in wetlands must make a case to justify their project. In many cases builders must create new wetlands elsewhere to “mitigate” losses, though most scientists do not consider man-made wetlands to be ecologically sound.

The key federal law for wetland protection in the United States is the Clean Water Act, which contains a provision (section 404) regulating the filling of navigable waters. Exceptions can be granted through a permit obtained from the U.S. Army Corps of Engineers, but overall the Clean Water Act has been effective at protecting large wetlands. The situation is more tenuous for vernal pools, which are small, temporary wetlands which despite their significant ecological importance are only offered some protection by a handful of state laws.  

What You Can Do to Protect Wetlands

If you are concerned about wetlands you have several options:

  • By keeping up on local building projects and zoning law, you can raise questions about wetlands during the planning process rather than complain after the fact.
  • Volunteering with national or local groups and land trusts that work on wetlands restoration is another way to help. American Rivers and the Izaak Walton League are two leading nonprofits working on wetlands restoration and advocating for wetlands protection in the United States; in Canada, the National Wetland Conservation Fund works with landowners nationwide to protect wetlands, as does Ducks Unlimited Canada.


    Edited by Frederic Beaudry