Discussion
As has been reported by other studies (Westlund et. at., 2017; Romero et. al., 2002; A Arfken et. al., 2017; Pierce 2016) the results indicate that oysters maintain similar microbial communities over time. The study found that control oysters maintained a common community of microbes in their overall body system throughout the experiemnt. However, we observed significant compositional variation between experimental groups and control groups within the genus' Pseudoalteromonas, Vibrio, and Nocardia. The genus nocardia, a known oyster pathogen, was found only within the atrazine treated groups. Interestingly, during the 30-day exposure period no significant relative abundance was observed for this genus in throughout all three treatment groups, however, after the 30-day rest period a significant relative abundance was detected for the same genus. This suggests that atrazine induced a delayed bacterial reaction within those treatment groups. Conversely vibrio species were found to undergo a large reduction in relative abundance within all three experimental groups both during the 30-day exposure period and after the 30-day recovery period.
Interestingly, the populations of bacterial species that were negatively affected by the presence of atrazine continued to sustain low abundance after a30-day rest period, indicating that atrazine may have lasting effects (greater than 1 month) in the population dynamics of C. virginica.
Conclusion
Extended experiments with more time points, as well as repeated challenges, would help to further elucidate the role of oyster-associated microbial communities to the overall physiological functioning of the host. This research provides a vital baseline for future research aimed at understanding the role gut microbes have in oyster physiology. \(\)