Stephanie Westby, a biologist with the National Oceanic and Atmospheric Administration (NOAA), cruised in a boat toward a barge a carrying a mountain of baby oysters.
“We are watching about 27 million juvenile oysters being planted into Harris Creek,” Westby said, as a hose blasted the oysters off the deck into the waterway, which is a tributary to the Choptank River and Chesapeake Bay.
The $31 million Harris Creek project is one of the largest and best-protected oyster restoration efforts ever attempted on the East Coast. NOAA is working with the Maryland Department of Natural Resources, the U.S Army Corps of Engineers, and the Oyster Recovery Partnership, to plant about 400 million oysters inside a protected sanctuary.
In this no-harvesting zone, sonar helps the scientists aim the baby oysters on top of reefs re-built with granite and recycled shells.
“The genesis of the large-scale oyster project is trying to bring back the oysters for the ecosystem services that they provide for the Chesapeake Bay,” Westby said, as she picked up some healthy oysters dredged out of the creek earlier that day.”
“By ecosystem services, I mean the tremendous fish habitat they offer for a lot of species of fish and crabs -- and also for their incredible filtration capacity,” Westby said. “Oysters are filter feeders, and just in the process of eating they can actually make the water more clear, which is important for our underwater grasses. And they can actually pull nitrogen out of the water, and nitrogen is one of the top pollutants to the Chesapeake Bay.”
Scientists in Virginia and Maryland recently found that restored oyster reefs in the Chesapeake Bay can absorb up to 10 times more nitrogen than areas of the estuary without healthy reefs, providing new evidence that replanting and rebuilding oyster reefs can clean up the nation’s largest estuary, according to the researchers study, “Denitrification and Nutrient Assimilation on a Restored Oyster Reef.”
The Chesapeake Bay Foundation is active in oyster restoration, growing young oysters for planting in the Bay, building “reef balls” to provide good habitat, and encouraging oyster gardening.
Oyster planting efforts have been going on for decades in the Chesapeake Bay. The intent has always been the same: to bring back the Bay’s keystone species, which was decimated by overfishing, pollution, and disease.
But in the past, some oyster restoration projects have had trouble, in part because oysters were killed by diseases caused by parasites. Over the last eight years, however, more oysters are surviving, in part because they appear to be evolving resistance to an invasive parasite called MSX.
“Disease has abated, to some extent,” said Mike Naylor, shellfish program director for the Maryland Department of Natural Resources. “ And that is why we have seen some localized increases in oysters in the last few years.”
Other past oyster restoration projects have not flourished because the shellfish were planted in areas that were open to harvesting. And so, the oysters were quickly scooped out again by watermen. Other oysters were planted in sanctuaries, but harvested illegally. It was a cycle that was sometimes criticized as a “put and take” fishery.
“This is totally different,” Naylor said of the Harris Creek project. “This is put and leave alone, and allow to expand.”
The 4,500 acre Harris Creek oyster sanctuary was created in 2009 by Governor Martin O’Malley’s administration. His Department of Natural Resources that year more than doubled the amount of no-harvesting zones in the state’s portion of the Chesapeake Bay, which now protect 24 percent of the Bay’s remaining reefs.
The new approach, being tested here in Harris Creek, is to focus on the oysters, not the oystermen. However, watermen will likely benefit more in the long run. Studies have suggested that protected reefs generate multitudes of oyster larvae, fish and crabs that spread out to populate a much wider area.
So watermen who object about being excluded from the sanctuaries -– will likely end up with a boatload more to catch.
By Tom Pelton
Chesapeake Bay Foundation