Volunteer ‘gardeners’ have now raised one million oysters in Baltimore’s harbor

A project to help replenish the region’s diminished oyster numbers while simultaneously cleaning the water in Baltimore’s harbor today marked a million-bivalve milestone.

Volunteer oyster “gardeners” have now planted 1 million oysters in the city’s harbor, per an announcement this morning from the Great Baltimore Oyster Partnership.

Led by the Chesapeake Bay Foundation and the Waterfront Partnership of Baltimore’s Healthy Harbor Initiative, the project raises baby oysters for nine months in cages along the harbor. By the time they’re fully grown, each oyster can naturally filter as many as 50 gallons of water daily while also trapping pollutants like phosphorous and nitrogen. Volunteers from sponsor companies regularly clean the cages.

After those nine months are up, volunteers transport the oysters on boats and dump them out onto a protected sanctuary reef on the Patapsco River at Fort Carroll, where the nonprofits are building a much larger sanctuary for 5 million oysters.

Baltimore’s million volunteer-grown oysters have joined about 2 million bivalves raised so far from “huge growing tanks” at the Chesapeake Bay Foundation’s oyster restoration center in Shady Side, spokesman AJ Metcalf said.

With roughly 3 million oysters now planted out on Fort Carroll, the foundation plans to add another 2 million within the next year to achieve its target of five million by 2020, a mark set in 2014.

Healthy Harbor Initiative executive director Adam Lindquist said they’ve had “more corporate volunteers this year than ever before.”

The effort began with five partners—Brown Advisory, Constellation, Legg Mason, T. Rowe Price and BGE—but has grown to also include Morgan Stanley, MOM’s Organic Market, RK&K and Whitman Requardt & Associates.

The CBF has reported the oysters at Fort Carroll are thriving, with a 70 percent survival rate (wild oysters survive at a rate of about 1 percent by comparison, the foundation said) and the bivalves themselves growing in size by about 40 percent.

The push to plant oysters around the Patapsco, as well as the Chesapeake Bay more broadly, comes after researchers found the region’s oyster population fell to just 0.3 percent of its numbers during the early 1800s. Factors include overfishing, habitat loss and diseases that have wiped out the bivalves during periods of drought.

Locally, the oysters are “a piece of the larger effort to clean up Baltimore’s harbor and the water around Baltimore,” Metcalf said.

While couching that progress on the push to make Baltimore’s harbor swimmable is a complex effort that goes beyond planting baby oysters, Lindquist offered some basic math that suggests this is a positive for the city.

“When mature, the 1 million oysters we have planted will filter 50 million gallons of water every day, so that is a big increase in filtering capacity in the Patapsco River.”