Dermowatch: A Web-Based Approach for Managing Perkinsus Marinus Disease of Oysters




Ray, Sammy M., Thomas M. Soniat, and Enrique V. Kortright

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Texas Natural Resource Conservation Commission


A web site called DermoWatch ( has been established to help manage Perkinsus marinus (Dermocystidium marinum) disease of eastern oysters, Crassostrea virginica. The main page provides the most recent data for nine stations in Galveston Bay, Texas. Data include water temperature (T) and salinity (S), weighted incidence (WI) and percent infection, and estimated time to a critical level of disease (tCrit). Archived historical data for each site is available from the main page and via a map of the Bay. With a utility called the Dermo Calculator, the web site is useful wherever Dermo disease is found. The Dermo Calculator allows anyone with information on water T and S, oyster length (L), and initial WI of disease to calculate a tCrit. A prototype utility has been developed that uses real-time values for water T and S from a fixed monitoring station. The utility requires input of the time period of interest and L; it returns, in graphical form, a time course of T, S and tCrit. More frequent values of T and S permit more frequent estimates of tCrit and should increase the reliability of the model.


pg. 142