To grow a new oyster population, one must first build a reef onto which spat (aka settled oyster larvae) can congregate, sometimes in clusters as large as 50. And the best material on which to grow new oysters is, indeed, the shells of old ones.
“We treated oyster shells as a trash item before,” says Johannes. “We saved it for landfills and making driveways and things like that.”
Now, however, notes Allison Albert Guercio, marketing manager of the Oyster Recovery Partnership, science has shown that “the oyster shell is literally the building block upon which new reefs are created.”
To build new reefs — and thus encourage population growth — empty oyster shells are first aged for a year to kill off any remaining meat or parasites. The clean shell is then placed in tanks and cages, an environment to which oyster larvae are introduced. They cling to the shells, growing into new, thriving populations.
“Sometimes you have like 50 oysters on one shell,” says Johannes. “One to 50 — as many shells fit on that shell — and then it’ll just kind of grow out from that, like a little cluster. Which is good!”
Once established, these clusters can be installed within the Chesapeake’s ecosystem; the CBF added 14 million oysters to Maryland waters, including 10 million to the Tred Avon River, in 2020 .
Of course, oyster shells don’t grow on trees. To gain access to used shells, associations like ORP and CBF have two options: buy from shucking houses to the tune of about $6.75 per bushel, or rely on donations. If you needed a reason to patronize your local oyster-centric happy hour, this is it.
To collect empty shells, the volunteer-based CBF works with about 15 restaurants in the DC area and cycles about 1,200 bushels per year. ORP, which boasts a full-time staff, launched its own Shell Recycling Alliance in 2010 and works with a whopping 340 restaurants. In 2019, at its peak, the Shell Recycling Alliance collected 36,000 bushels of shell in one year.
“Partnership is part of our name,” says Guercio. “And we really can’t do what we do without a network of partners.”
Or, you know, you could just leave the oysters in the bay, and let the spat settle on them. But then, nobody would be left feeling good that they had done their part to save the oysters.
The Wombat has Rule 5 Sunday: Late Night With The Alabama Cheer Squad up and at 'em.