Oysters are nature’s filtration machines, and there used to be enough of them in the Chesapeake Bay to filter and clean all that water in three days. Now, there are so few oysters it takes more than a year.
So, environmentalists are trying to rebuild the population by growing oysters.
And one of the so-called oyster gardens is in an unlikely place-- Baltimore’s polluted inner harbor. It’s part of the Chesapeake Bay Foundation’s Baltimore Initiative.
Director Terry Cummings gathered about 20 volunteers at the Downtown Sailing Center, under the Domino Sugar sign, one recent rainy Saturday afternoon to help with the gardening. First, he had to explain about spat, baby oysters that attach themselves to oyster shells that have been cleaned up just for this purpose. A shell typically holds between three to ten oyster babies.
"If you look at it, this spat is really tiny tiny," Cummings said, "about half the size of a dime."
Cummings and his colleague Pat Beall pulled bags of oyster shells from the water. They were loaded with spat grown from larvae at the University of Maryland’s Horn Point Laboratory in Cambridge.
The volunteers dumped the shells into steel cages, randomly pulling 10 shells from each cage to count spat to get an average, then tied the cages to the pier and dropped them back into the water. The cages will stay there until next spring and with luck the spat will keep growing. The volunteers will come by monthly to clean the outsides of the cages to make sure the spat are getting plenty of water and food.
Dana Vlk, one of the volunteers, lives nearby. She and her husband moved to the city 15 months ago.
"We were really shocked by the quality of the water and the whole trash situation in general," she said.
There’s no question, Baltimore’s Inner Harbor is a mess.
The biggest problem is fecal bacteria from millions of gallons of untreated sewage that pours into the harbor each year from spills on tributaries like the Jones Falls and the Gwynns Falls. You can add to the mix trash and storm water runoff.
Still, Camera Thomas, the program manager for Healthy Harbor Initiative, said the oysters should do just fine. And they’re not the only ones.
"You’d be surprised about how much actually lives in the harbor," she said. "I’ve seen eels, otters, fish, crabs. There is life in the harbor."
But these oysters aren’t miracle workers and no one expects them to make a dent in the harbor’s pollution. Next spring they’ll be loaded on a boat and moved to an oyster reef at Fort Carroll, near the Key Bridge at the mouth of the Patapsco River. The goal is to put five million oysters on that reef over the next five years.
Cummings says the oysters on the reef are living and filtering the water. But so far the water isn’t clean enough for them to reproduce. And that’s the key.
"If we can get them to start reproducing that would make a significant difference," he said. "And maybe you’d see measurable water quality improvements. But we are not saying that at this point."
The Inner Harbor project is a small version of oyster replenishment programs going on throughout Maryland and Virginia. There’s Harris Creek near Saint Michael’s, where about 350 acres of oyster reefs are being restored. And in Tidewater, Virginia oysters are being replenished in the Lafayette River.
Peyton Robertson, the director of the Chesapeake Virginia office of the National Oceanic and Atmospheric Administration, said oyster replenishment is about “getting the engine started.”
"So if we can get these engines going for oyster reproduction, then we expect those oysters will be able to repopulate other areas of the bay," he explained.
The smaller programs like the one in Baltimore allow people to get involved and get their hands dirty. Sue Tjornehoj, who moved to Baltimore four years ago, said becoming an oyster gardener is a dream come true for her.
"Moving out here, falling in love with the Chesapeake Bay and knowing the importance of oysters," Tjornehoi said, "It was like I would like to know more about them."
Tjornehoi and the other volunteers will get to accompany their oysters on the boat to Fort Carroll next spring.
Chesapeake: A Journalism Collaborative is funded with grant support from the Clayton Baker Trust, The Bancroft Foundation, Michael and Ann Hankin, The Jim and Patty Rouse Foundation, The Rob and Elizabeth Tyler Foundation, and the Mid-Shore Community Foundation.