The Chesapeake Bay has witnessed staggering losses to oyster populations over the past century, reported to be down by 97% when likened to early records (Chesapeake Bay Foundation 2016). Atrazine is commonly used in and around agricultural fields in the Chesapeake Bay watershed (USDA). For this reason, it was chosen to be the focus in this study examining the effects of herbicide-induced bacterial composition changes by running 16S sequencing in hatchery-reared spat. This study hopes to further our understanding of both oyster-prokaryote symbiosis and  herbicide-prokaryote effects.