The Chesapeake Bay Foundation’s (CBF) Virginia Oyster Team is completing its 2021 oyster restoration season today after raising about 3.5 million new oysters on innovative oyster barges docked at CBF’s Brock Environmental Center in Virginia Beach. The barges produced a CBF Virginia record high “spat set” this year—the percentage of oyster larvae that attach to empty shells to become baby oysters. CBF planted most of those oysters, a total of 2.62 million, on sanctuary reefs on the Lynnhaven River. The rest went to CBF volunteer oyster gardeners who are currently raising them for future restoration work.
“This has been a really gratifying season. As they grow, these oyster reefs will filter and clean the water and create habitat for crabs, shrimp, and game fish such as striped bass, red drum, and speckled trout,” said CBF Virginia Oyster Restoration Manager Jackie Shannon. “So many people came together to make this happen, from dedicated oyster restoration volunteers, to our many state, federal and local partners, to the hundreds of oyster gardeners across Tidewater Virginia.”
This summer, 468 CBF oyster gardeners began raising a new generation of oysters around the region. Over the course of a year, these volunteers grow the oysters in cages hung from docks both at home and at public locations. After a year, gardeners return the oysters they have raised to CBF, which places the fully grown oysters on a restored oyster reef protected from harvest.
This year, oyster gardeners returned 99,994 adult oysters to CBF raised over the previous season. These were planted in the Lynnhaven River, Lafayette River, Warehouse Creek, Hampton River, Nansemond River, Elizabeth River and Rappahannock River. Local supporting organizations include the Beazley Foundation, Elizabeth River Project, Friends of the Rappahannock, Lynnhaven River NOW, Nansemond River Preservation Alliance, Rogue Oysters, and the Tides Inn.
CBF’s oyster barges, officially called the Prudence H. & Louis F. Ryan Mobile Oyster Restoration Center, comprise the only mobile oyster center on the Chesapeake Bay. The two linked barges hold six 850-gallon tanks full of circulating river water. To raise oysters for restoration, CBF staff release millions of free-swimming microscopic oyster larvae into these tanks. These larvae attach, or “set,” to empty shells recycled from restaurants and other sources. As the baby oyster spat grow, each shell can become home to 10 or more oysters that are planted on restoration reefs.
In a typical year, only about 10 percent of oyster larvae actually attach to shells, while the rest succumb to natural causes. This year a record-breaking 13 percent of larvae attached to shells in the barges’ tanks, resulting in the production of 780,000 more oysters than expected. A variety of factors could have led to this high set rate, including favorable weather and water conditions, as well as a state-of-the-art water circulation system on the barges.
Continuing pollution reductions under the Chesapeake Clean Water Blueprint will be key to reducing algal blooms, shrinking oxygen-depleted dead zones, and restoring oyster populations.
The oysters planted this year support the Chesapeake Oyster Alliance goal of adding 10 billion new oysters to the Bay by 2025. CBF founded this broad coalition of over 70 partner organizations in Maryland and Virginia working towards increasing the Bay’s oyster population.
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