Oyster farms are booming in the Chesapeake Bay - entrepreneurs lease farmable acres from and grow oysters in cages to meet rising demand from consumers. This aquaculture is actually good for the environment. While aquaculture can be environmentally suspect, scientists studying Chesapeake Bay say that farming oysters is making the bay healthier by helping remove pollutants. Basically, the more oysters you eat, the better it is for the environment.

The Chesapeake Bay is the world’s second-largest estuary. Its sheltered waters used to be littered with wild oysters, dating back to the 1600s. Decades of overharvesting, pollution, and disease reduced the wild-oyster population to just 1 percent of its historic numbers over the last century. It’s a story that’s been repeated all over the world, as 85 percent of all shellfish populations have been decimated.

But oysters are on the rise again in the bay through a mix of artificial-reef restoration projects and innovative farming techniques, like those on display at Pleasure House Oysters, that have farmers growing the bivalves in metal cages just below the surface. The rate of oyster farming in Maryland’s section of the Chesapeake Bay has grown 20 times over since 2012. Oysters are like environmental scrubbers: each one can filter up to 50 gallons of water per day, removing nitrogen and phosphorous from the water, the two biggest pollutants in the bay. The reefs that oysters establish as they grow become habitat that attracts multiple other species of shellfish and fish, all of which help contribute to a healthy ecosystem and make oysters a keystone species for estuaries like the Chesapeake. Because of the oyster’s importance, the Nature Conservancy has several ongoing large-scale oyster-reef restoration projects in the bay, with a goal of restoring wild reefs in ten of its key tributaries by 2025.

The Nature Conservancy has already restored 693 acres of reefs in the Chesapeake Bay.. The goal is to restore 428 acres of oyster reefs in the Piankatank River by 2025, which would make it the largest oyster-restoration project in the world. It’s unlikely that wild-oyster populations will ever reach their historical levels again, but the hope is to create enough wild-oyster reefs in the bay that the population becomes self-sustaining.

The Nature COnservancy has also been studying how commercial oyster farms affect the bay’s water quality. It recently released a new study showing that these aquaculture projects hold promise; a five-acre aquaculture operation offers the filtering equivalent of an acre of wild-oyster reefs.

“What we learned is that these farms are a net positive to the system,” says Andy Lacatell, Virginia’s Chesapeake Bay program director for the Nature Conservancy, who spearheaded the study on aquaculture. “The oysters they’re growing are making a contribution to cleaning the bay. Aquaculture isn’t a silver bullet, but it’s part of the solution. There’s a benefit to having those oysters in the water.”

“Chesapeake Bay is ground zero for oyster restoration,” Bryer says. “We have the largest native-oyster restoration project on the planet, and the aquaculture industry has quintupled in the last five years. People are using the bay as a model to jump-start restoration and aquaculture projects in Australia, New Zealand, Germany, the Gulf Coast.”

More than 50 percent of the world’s seafood comes from aquaculture now. In some places, that’s a good thing, in some places, it’s not a good thing. If the oysters are grown responsibly, eat them. Increase the demand, increase the value of an oyster. This is a rare food product that is doing a really good thing for the environment. 

Sources: https://www.mdsg.umd.edu/topics/oysters/oyster-aquaculture-and-restoration 
http://dnr.maryland.gov/fisheries/pages/aquaculture/shellfish.aspx 
https://www.cbf.org/blogs/save-the-bay/2018/08/now-is-not-the-time-to-limit-oyster-aquaculture.html