ABSTRACT
The shellfish producers world-wide consider depuration as one of the main options for preserving the viability of their industry. The faster rate of bacterial elimination from polluted shellfish that can be achieved in a recirculating system was confirmed by K. Sangrungruang. The levels of various bacterial species in the depuration water depend on their ability to survive and multiply at different temperatures. The recirculation rate should be such that the rate of kill of bacteria in the depuration water by ultraviolet irradiation exceeds the rate of bacterial multiplication. The recirculation rate of the water in the depuration plant has an important effect on the efficiency of oyster depuration. The etiological agent was a Norwalk virus and the oysters had been harvested from waters that had suffered extreme sewage pollution due to persistent heavy rainfall. The problem is intrinsically linked to the pollution of oyster farming waters with human sewage and associated pathogenic microorganisms.
