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This World Water Day, a Salute to the Unsung Heroes of Clean Water

Photo: Snuffbox mussels
Snuffbox mussels, which are threatened in their range across the Eastern U.S. Photo by Mike Hoggarth, USFWS


We don’t see or hear them, but every day they quietly go about their work–filtering and cleansing our rivers and streams. And if we don’t act soon, they’ll disappear from the workforce just when we need them most.

I’m talking about shiny pigtoes, monkeyface, pink heelsplitter, and purple wartyback–freshwater mussels with funny names that belie the seriousness of their labors. They suck water in, filter out bits of algae, bacteria and other tiny particles, and then release it back to the river cleaner than before.

One mussel alone can cleanse as much as a gallon of water per hour. Add up the work of a whole mussel community, and you get a virtual water treatment plant.

According to Ethan Nedeau, an expert on the freshwater mussels of New England, even half the population of mussels at work in a one-half mile segment of New Hampshire’s Ashuelot River can help cleanse more than 11.2 million gallons of water a day–roughly the quantity of household water used by 112,000 people.

The United States ranks first in the world in the number of known species of freshwater mussels–292, compared with just 10 in all of Europe. But we’re losing these “living filters” all too fast.

Today 69 percent of U.S. freshwater mussel species are to some degree at risk of extinction or already extinct. The most diverse assemblage of freshwater mussels ever known was located in the middle stretch of the Tennessee River in northern Alabama. Before the damming of the river in the early 1900s, 69 mussel species had been spotted in this reach; 32 of them have apparently disappeared, with no recording sightings in nearly a century.

My favorite freshwater mussel is the orange-nacre mucket (Lampsilis perovalis), found only in the rivers and streams of Alabama’s Mobile River basin. Like many freshwater mussels, the orange-nacre mucket has a fascinating life cycle and exhibits some of the most sophisticated mimicry in the animal kingdom.

The females essentially use their offspring to lure fish into helping them colonize new stream bottoms. They package their larvae at the end of jelly–like tubes that can extend eight feet out into the water. To fish swimming by, the larvae dancing in the riffles of the river current looks like a tasty minnow. When the fish bites, the tube breaks, releasing the larvae into the stream. A few of the offspring attach to the fish’s gills and hitchhike around with their finned host for a week or two, absorbing nutrients and growing along the way. Finally, the young mussels drop off, float to the river bottom, and colonize new territory–and before long begin their vital task of water purification.

Along with 16 other threatened or endanged mussel species in the Mobile watershed, the orange-nacre mucket is at risk of extinction—in large part due to excessive pollution and dams that have diminished the river habitat they need to survive.

To me, the loss of such industrious, fascinating creatures diminishes more than our water quality–it diminishes our natural heritage and our world.

Only habitat improvements, in some cases combined with mussel breeding and release efforts, can save these and the other 200 freshwater mussel species at risk nationwide.

So as we celebrate World Water Day, I hope we also celebrate the freshwater mussels that help keep our waters clean and healthy–and commit to efforts to conserve them.

Because I bet we’ll miss these little creatures with the whimsical names when they’re gone.


Sandra Postel is director of the Global Water Policy Project and lead water expert for National Geographic’s Freshwater Initiative.  She is the author of several acclaimed books, including the award-winning Last Oasis, a Pew Scholar in Conservation and the Environment, and one of the “Scientific American 50.”


  1. Alok Patel
    New York
    July 22, 2013, 5:15 am

    I think that I have seen in the Bear Grylls show. He use to see these type of animals who pour the water easily. So He use to get a fresh water drink in the sea.

  2. Jefry
    January 28, 2013, 6:06 am

    no need to wait for world water day, every day we have to keep our water sources clean environment because water was among the important factors in our lives ..

  3. NAWAZ
    October 25, 2012, 2:10 pm

    wild life always attracts me. I love to discover new life, new place.. Very informative article to learn many things unknown to me once.. 🙂

  4. akiyuki@ganja
    June 25, 2012, 11:35 am

    Thanks for sharing such great article. It is very informative and valuable. Keep it up.

  5. Übersetzung Deutsch Englisch
    May 16, 2012, 3:53 am

    I love reading through an article that will make men and women think. Also, thank you for allowing me to comment!

  6. Alejandro
    United States
    May 15, 2012, 7:27 pm

    I live on the Puget Sound, we have tons of mussels but they say that they’re poison.

  7. Online Shop
    May 10, 2012, 3:08 am

    What a good article to read. I didn’t realize about Snuffbox mussels before.

  8. Good books
    May 3, 2012, 11:14 pm

    Most people do not realize how important shell fish are for cleaning the water.

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  9. San Francisco Movers
    San Francisco
    April 24, 2012, 1:45 pm

    If we don’t act soon, we’ll lose many parts of our ecosystem that are vital to our planet and our way of life.

  10. Marvine
    April 18, 2012, 10:02 pm

    Most species that become extinct are never scientifically documented.
    thanks to national geographic to warn “us” 🙂


  11. kevin bogaard
    April 16, 2012, 6:05 am

    Found quite a lot of these recently, but in the Netherlands.. Funny to see this article here now 🙂

    Fotoboek maken

  12. kerja
    April 3, 2012, 11:36 am

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  13. Josh
    March 17, 2012, 10:36 am

    Thanks for enlightening us on Snuffbox Mussells. I have lived near the coast in New England for many years and have never encountered any…probably not a good sign

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    March 1, 2012, 3:53 am

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  15. Lillie Miskin
    February 28, 2012, 4:56 pm

    I love reading through an article that will make men and women think. Also, thank you for allowing me to comment!

  16. Laureana
    February 27, 2012, 3:00 am

    Nature always fascinates me by the way she keeps everything “in balance”. This article is very enlightening.

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    February 22, 2012, 9:32 am

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