Weighted Prevalence of Perkinsus marinus (Dermo) infections in hatchery-produced oysters planted ON natural oyster bars in the Chesapeake Bay in restoration efforts are correlated with the weighted prevalence of native oysters upon which the hatchery oysters were planted.

Maryland has embarked upon an aggressive oyster restoration program with intensive planting of hatchery-reared spat-on-shell (very young oysters attached to oyster shell).  The restoration offers a plethora of opportunities to learn much about oyster biology, ecology and disease epidemiology.

Many of the targets of restoration are natural oyster bars (NOBs) that are essentially derelict with low densities of oysters after harvest and disease have reduced their populations.  However, many natural oysters remain - just at densities that are too low for harvest or population sustainability. Hatchery spat planted on these NOBs come into relatively close proximity to the native population.  While conducting monitoring of the planted hatchery shell, we have concurrently sampled native populations on many restored NOBs.  Diagnosis of the hatchery spat and native oysters revealed a strong correlation of weighted prevalence of P. marinus in the hatchery spat with the weighted prevalence found in the native populations. These findings could have significant ramifications on the management strategies for oyster harvest and restoration in Maryland waters.

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