Enhanced Depuration System for Shellfish Industry. Co-PI: The primary goal is to improve consumer safety by reducing the levels of pathogens including vibrios in live shellfish through accessible, non-lethal, post-harvest processing. We are testing proprietary disinfecting technologies: SteelBlue (SB) - a water purification process, and Puradigm Air (PA) a photo-catalytic oxidation, alone and in combination compared to conventional UV disinfection. SteelBlue, by altering properties such as surface tension, disperse-ability and solvating properties of water, drives insoluble substances to nano-sized dimensions. It works with all water types and requires no external energy source. Puradigm destroys bacteria, mold, fungus and volatile organic compounds by incorporating photon and ultraviolet energy activating a catalyst. Both technologies work well in other industrial and aquaculture applications, but have never been tested with bivalves. We are conducting a series of controlled experiments over 24 months to ascertain effective treatment of pathogen levels by these technologies. Suitability of using these new technologies with live shellfish will be tested in an array of recirculating saltwater systems (n = 4). Each experimental system consists of a single 100-L fiberglass tanks equipped with a mag-drive pump, mechanical and chemical filtration, and one of four disinfection treatments (UV, SB, PA, or SB + PA). All four experimental tanks are co-located in 2,000-L water bath to modulate temperature. Prior to stocking systems were filled with artificial seawater adjusted to the salinity of where the oysters were sourced. Systems were run for 24-hr to allow water temperature to equilibrate, and then stocked (50 oysters/tank). Oysters were tested for fecal coliform and then held for 48 hr. In the next phase of the project oysters will be collected from each experimental tank at 0, 12, 24 and 44 hrs. and tested for reduced fecal coliform, total vibrios, Vibrio vulnificus and pathogenic Vibrio parahaemolyticus. Multiple preliminary trials will be done to determine the effective dose of the respective disinfection treatments (UV, SB, PA or SB + PA) to ensure that the pathogens are mitigated without harming the oysters. Once this is established we will repeat this experiment a minimum of three times to ensure the validity of our results.
Environmental Assessment, Subcontractor: Support the work of Duffield Associates on the project in the Town of Chincoteague by working closely with the consultant, Town of Chincoteague, Virginia Department of Environmental Quality and other interested parties to assess the potential impact on shellfish growing areas and the shellfish industry of wastewater disposal from the Town of Chincoteague into the Chincoteague Channel.