National Geographic Society Newsroom

Can Oyster Eaters Save Oysters?

By Rachel Kaufman It seems totally counterintuitive. After all, the Chesapeake Bay is in a pickle right now because its oyster population, which once filtered impurities from the Bay at a rate of 50 gallons of water per oyster per day. The entire volume of the bay (about 19 trillion gallons) was purified every week....

By Rachel Kaufman

It seems totally counterintuitive. After all, the Chesapeake Bay is in a pickle right now because its oyster population, which once filtered impurities from the Bay at a rate of 50 gallons of water per oyster per day. The entire volume of the bay (about 19 trillion gallons) was purified every week. Now, with less than 10 percent of the bay’s original oyster population remaining, it would take a year for the oysters to filter the same water.

(Read more about the critical role of oysters from National Geographic Fellow Sandra Postel.)

Photograph by Willard Culver


So why would eating oysters save them? Aren’t they overfished already?

Yes, but oyster farms are booming.

“Oyster farms can be definite environmental positives,” says Roger Mann, with the Virginia Institute of Marine Science at the College of William & Mary. “Whether they are sitting in the bottom filtering the water or sitting in a cage filtering the water, they’re still filtering the water.”

Simply put, the more oyster aquaculture is done, the more benefits for the waters.

Bruce Wood, owner of Dragon Creek Seafood & Produce in Montross, Va., has seen the effects with his own eyes. When he started his aquaculture operation, in a creek that empties into the Potomac and ultimately the Chesapeake Bay, 10 acres of nearby river were too polluted to use for oyster farming. Not anymore. It helps that he’s using a variety of oyster bred for its tolerance to low salinity waters and disease, which means that even in environments too harsh for wild oysters, his commercially-bred ones can begin filtering the water, improving the environment, and eventually “hopefully reconstitute the native oyster,” Wood said.

Photograph by James L. Amos

Here’s another way eating oysters can help them: Wood’s started a program with one of the restaurants he supplies, Hank’s Oyster Bar in Washington, D.C., where the restaurant will save diners’ shells and send them back to the bay, where they will become the base for new oysters, both cultivated and wild. Without some sort of base, be it shells, stones, or reef balls, similar to what are used to help restore coral reefs, the adult oysters sink into the muddy river bottom and die.

Tossing shells back into the water isn’t a brand new idea, but surprisingly, getting the shells back from restaurants is a relatively recent practice.

The Maryland Department of Natural Resources (DNR) has been re-shelling the bay for decades, getting its shells by dredging elsewhere in the bay. In 2008, though, a sport-fishing group argued that dredging for shells stirred up too much sediment and damaged an important fishing area. So earlier this year, the Maryland DNR piloted its own shell recycling program, picking up 25,000 bushels of shells from two dozen area restaurants.

North Carolina has been running a similar program since 2003, offering a small tax credit for restaurants that participate, but that one’s collected an average of only 14,000 bushels a year.

But the Chesapeake Bay Foundation, which started an oyster shell recycling program in 2007, just two years later announced that it was going to return to focusing on its reef ball program. “The shell is harder and harder to come by,” CBF spokesman Tom Zolper says, “and the reef balls have habitat qualities that are beneficial.” He notes that oysters seem to prefer vertical variety, which reef balls provide and a pile of shells do not, and that the balls, which are made of concrete, deter poachers who would otherwise dredge shellfish from the water.

So is eating oysters a cure-all for the Bay? Maybe not, but it’s more tasty than a ball of cement. So grab your squeeze of lemon and slurp away.

(Find more about freshwater issues at National Geographic’s freshwater website.)

rachel-headshot.jpgRachel Kaufman is a writer and editor covering science and the environment, emerging technology, and a potpourri of other topics. Her freelance writing career has taken her inside Victorian-era “castles,” French patisseries, and a haunted train tunnel, and in addition to her work for National Geographic News, her byline has appeared in the Washington Post,, and CNN/Money. Rachel grew up outside Minneapolis and received her B.A. in English and journalism from Adelphi University on Long Island, but finds her constitution (and temperament) far better agrees with the swampy air of her adopted hometown, Washington D.C. Her blog and portfolio can be found at and she tweets about science, journalism, and video games at @rkaufman.



About National Geographic Society

The National Geographic Society is a global nonprofit organization that uses the power of science, exploration, education and storytelling to illuminate and protect the wonder of our world. Since 1888, National Geographic has pushed the boundaries of exploration, investing in bold people and transformative ideas, providing more than 14,000 grants for work across all seven continents, reaching 3 million students each year through education offerings, and engaging audiences around the globe through signature experiences, stories and content. To learn more, visit or follow us on Instagram, Twitter and Facebook.

Meet the Author

Author Photo David Max Braun
More than forty years in U.S., UK, and South African media gives David Max Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. In his 22-year career at National Geographic he was VP and editor in chief of National Geographic Digital Media, and the founding editor of the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directed the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. A regular expert on National Geographic Expeditions, David also lectures on storytelling for impact. He has 120,000 followers on social media: Facebook  Twitter  LinkedIn