According to the results of a survey conducted by the Maryland Department of Natural Resources (DNR), oyster abundance has increased in state waters for the second consecutive year and more of the bivalves are withstanding pressures from pollution and disease.
The 2012 Fall Oyster Survey, which has monitored the status of the state’s oyster population since 1939, found a 93 percent oyster survival rate—the highest since 1985—and a lower-than-average prevalence of MSX and dermo, two diseases that have decimated the Chesapeake Bay’s native oysters in recent decades.
In a news release, DNR Fisheries Service Director Tom O’Connell attributed these successes to the establishment of oyster sanctuaries, which are closed to harvest and which could allow oysters to build up a natural disease resistance.
Maryland is currently restoring oyster reefs in the Harris Creek and Little Choptank River sanctuaries, as part of a federally mandated effort to restore oyster populations in 20 Bay tributaries by 2025.
Read more about the 2012 Fall Oyster Survey results.
Harris Creek is a tributary of the Choptank River. Located on Maryland’s Eastern Shore, the waterway has been thrust into the spotlight as the first target of the oyster restoration goals set forth in the Chesapeake Bay Executive Order: to restore oyster populations in 20 Bay tributaries by 2025. Existing reefs will be studied, bars will be built, larvae will be raised and spat-on-shell will be planted in this federally mandated attempt to boost populations of the native bivalve.
Already home to productive and protected oyster reefs, Harris Creek’s good water quality and moderate salinity should allow for high rates of reproduction and low rates of disease—both critical factors in ensuring oyster survival. Indeed, natural “spat set,” or the settling of wild oysters on reefs, was observed in Harris Creek last year, and continued natural spat set could reduce the number of hatchery-raised oysters that are needed to complete the restoration plan.
Over the past two centuries, oyster populations across the Bay have experienced a dramatic decline. Habitat loss, disease and historic over-harvesting have taken their toll, and populations now stand at less than one percent of historic levels. But as filters of water and builders of reef habitat, oysters are critical to the health of the Bay.
As of December 2012, reef construction and seeding for more than a quarter of Harris Creek’s 377 targeted acres were complete, and partners project that more than half of the construction and seeding for the rest of the creek’s reefs will be complete by the fall of 2013.
But it will take a lot for a reef and a tributary to be deemed “restored.” Partners will look not just for the presence of oysters, but for the expansion of oyster populations in the years following restoration efforts. The goal is an ambitious one, but many believe the Harris Creek project will serve as a model for the restoration of other tributaries in support of the Executive Order goal.
Video produced by Steve Droter.