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, acting as a host for a specific set of core microbiota. The study found that control groups maintained a common community of microbes in their overall body system throughout the experiemnt. Conversely, we observed significant compositional variation between and within experimental groups in the genus PseudoalteromonasVibrio, and Nocardia. The presence of the genus Nocardia is of particular interest as they are known oyster pathogens which cause round yellow-to-green pustules up to 1 cm in diameter to be displayed on the surface of the mantle, gill, adductor muscle, and heart (Friedman 1998). Nocardia were found only within the atrazine treated groups. During the 30-day exposure period no significant relative abundance was observed for Nocardia in all three atrazine exposed treatment groups, however, after the 30-day rest period a significant relative abundance was detected. This suggests that atrazine selected for the survival of Nocardia. Conversely, vibrio species were found to to a lesser degree in the experimental groups when compared to the controls. Both after the 30-day exposure period and the 30-day recovery period. This finding indicates that atrazine exposure may be play a role in facilitating an environment which does not allow for vibrio species to colonize oysters efficiently.  
    Interestingly, populations of bacterial species which decreased in the presence of atrazine continued to sustain low abundance % after a 30-day rest period, indicating that atrazine may have lasting effects (greater than 1 month) in the population dynamics of C. virginica. Bacterial species known to be pathogenic to C. virginia and thus related to immunity and defense were of particular interest in order to uncover how atrazine is affecting the molecular-bacterial basis of oyster tolerance/resistance to the herbicide’s toxic effects. As has been reported in other studies (Westlund et. at., 2017; Romero et. al., 2002; A Arfken et. al., 2017;  Pierce 2016) our results confirm that oysters maintain similar microbial communities over time. The health of C. virginica is impaired by inflowing storm-water runoff from nearby agricultural fields, which carry large amounts of atrazine into estuarine waters, however,  the knowledge of oyster-associated bacterial community response to biocidal runoff is scarce.
The sequence data obtained could be used to compare oyster aquaculture management strategies as well as aquaculture practiced in different regions that may have similar or different climactic conditions. It is also meant to facilitate a greater understanding of how atrazine, as a persistant environmental condition effects oyster-prokayote interactions. Further studies of this nature could reveal important links between oyster farming, environmental factors, husbandry strategies, as well as legal regulations currently governing the surrounding areas of the Chesapeake Bay.