Strains of Eastern oysters (Crassostrea virginica) have been selectively bred for tolerance to the diseases MSX and Dermo that are serious oyster pathogens in Chesapeake Bay. These oyster strains carry a characteristic genetic fingerprint that is evident when certain molecular markers are examined. This molecular genetic profile will be established for the oysters that are planted at restoration sites. After these disease tolerant oysters are planted on constructed oyster reefs, the oysters are expected to spawn and their offspring will provide a new cohort of disease resistant oysters that will settle and grow in the estuary. The purpose of this monitoring element is to provide genetic information on the oyster spat on and near the restoration site. Spat will be collected at the end of the recruitment season in the fall and examined for the presence of the molecular markers that indicate a relationship with the disease tolerant parent oysters. The proportion of spat originating from disease tolerant parent oysters will be estimated as an indication of parental spawning success. Continued sampling of oysters over subsequent generations should indicate the general success of releasing disease tolerant stocks for restoration.