The bacterial enumeration was calculated from the hemolymph (CFU/ml), the whole oyster homogenate (CFU/g) and hemocyte monolayer (CFU/ml) samples, and subsequently log10 transformed before analysis. Each figure or table shows the mean plus standard error for that data point. A two-way ANOVA with post-hoc comparisons using Tukey's method (XLSTAT, Addinsoft, New York, NY) were performed to compare treatment, month, and treatment*month for all samples. A P value ≤0.05 was considered statistically significant and letters indicate statistical differences. The summer results represent four independent experiments and the fall results represent three independent experiments.