PREVALENCE, INTENSITY, AND DETECTION OF BONAMIA-OSTREAE IN OSTREA-EDULIS L IN THE DAMARISCOTTA RIVER AREA, MAINE

Oysters, Ostrea edulis, collected from three locations in the Damarisc otta River area, Maine, were examined for the presence of Bonamia ostr eae four times between June 1994 and April 1995. Overall prevalence wa s 5% (13 of 291), with no significant differences between sampling sit es or dates. All but one of the infections were classified as ''low'' intensity. Results obtained with histological preparations and stained blood smears were similar. Results obtained with the immunofluorescen ce technique were unclear. No fluorescent B. ostreae cells were observ ed with monoclonal antibody (MAB) 20B2. Even though MAB 15C2 was in 75 % agreement with results obtained by standard histological preparation s, the fluorescence was faint. Condition index was not significantly d ifferent between infected and uninfected oysters. Although B. ostreae is present in the Damariscotta River area, the development of disease and mortality may be precluded by the low density of oysters in natura l beds and the relatively cold winters.