Photograph by Andy Nguyen, Your Shot
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A large fish proves more than a mouthful for a hungry great egret, which lost its prize soon after this shot was snapped. This big bird may be seen across much of the globe, but is nearly always found near water where food is plentiful.

Photograph by Andy Nguyen, Your Shot

Aquatic Ecosystems

Aquatic ecosystems connect people, land and wildlife through water.

Wetlands, rivers, lakes, and coastal estuaries are all aquatic ecosystems—critical elements of Earth’s dynamic processes and essential to human economies and health.

Wetlands connect land and water, serving as natural filters, reducing pollution, controlling floods, and acting as nurseries for many aquatic species. Rivers, lakes, and estuaries serve as important transportation, recreation, and wildlife hubs.

Why Care About Water?

There is the same amount of water on Earth today as there was when the dinosaurs roamed. And just less than one percent of the planet's water is available to meet the daily drinking water, sanitation and food needs of nearly 7 billion people and millions of other species. Learn more about water in all its forms and how you can make a difference.

Learning more about the ecosystems within your watershed—all the water in your region that drains to the same point—can help you better understand how everything is connected and what is at stake with freshwater overuse, pollution, and drought.

Fast Facts

  • Global extinction rates for freshwater species are four to six times higher than those for terrestrial or marine species.
  • Forty percent of all fish species in North America are at risk of extinction.
  • In the U.S., 69 percent of freshwater mussel species, which help to filter water, are at risk of extinction.