Prokaryotic diversity varied most between oysters treated with 3 μg/L atrazine without rest and the non-exposed control groups (Fig.4 ). Notably, Vibrio was found to be absent in all but one of the atrazine treated groups (P21D, 10μg/L) (Fig 3.).  Arcobacter was present in all non-exposed control groups, but not present in the experimental groups exposed to only to acetone.