• Photo: Close-up of a man with a giant catfish

    Mekong Giant Catfish

    World's Largest Scaleless Freshwater Fish

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About Megafishes

Biologist Zeb Hogan leads the Megafishes Project, a three-year effort to document the 20-some species of freshwater fish at least 6.5 feet (2 meters) in length or 220 pounds (100 kilograms) in weight. These fish are losing the fight for survival, as pollution, overfishing, and construction threaten the rivers and lakes they call home.

Donate to the Megafishes Project and help protect these freshwater giants.

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    Megafishes News

    The world's largest freshwater fish are losing the fight for survival, as pollution, overfishing, and construction threaten the rivers and lakes they call home.

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    Preparing for a Water-Limited World

    "Our water problem turns out to be much more worrisome than our energy situation," writes Freshwater Fellow Sandra Postel in a new book.

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    A Freshwater Story Interactive

    Earth is a water wealthy planet, but only a tiny portion of its water is available to support people and aquatic species. Learn more about how much freshwater there is, and where it's found.

Why Care About Water?

The National Geographic Society’s freshwater initiative is a multi-year global effort to inspire and empower individuals and communities to conserve freshwater and the extraordinary diversity of life that rivers, lakes, and wetlands sustain.

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Freshwater Advocates

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    Sandra Postel

    Sandra is a leading authority on international freshwater issues and is spearheading our global freshwater efforts.

  • Photo: Jon Waterman at the end of the Colorado River

    Jonathan Waterman

    He's paddled the Colorado River from its headwaters to the delta, in an effort to bring awareness to this mighty river at risk.

  • Photo: Osvel Hinojosa Huerta

    Osvel Hinojosa Huerta

    For more than 15 years, Osvel Hinojosa Huerta has been resurrecting Mexico's Colorado River Delta wetlands.

For More Inspiration »

From National Geographic Magazine

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    Feed the World

    National Geographic explores how we can feed the growing population without overwhelming the planet in our food series.

Freshwater Advocates

  • sandra new headshot.jpg

    Sandra Postel

    Sandra is a leading authority on international freshwater issues and is spearheading our global freshwater efforts.

  • Photo: Jon Waterman at the end of the Colorado River

    Jonathan Waterman

    He's paddled the Colorado River from its headwaters to the delta, in an effort to bring awareness to this mighty river at risk.

  • Photo: Osvel Hinojosa Huerta

    Osvel Hinojosa Huerta

    For more than 15 years, Osvel Hinojosa Huerta has been resurrecting Mexico's Colorado River Delta wetlands.

For More Inspiration »

Explore Freshwater

Change the Course logoChange the Course: Help Save the Colorado River