Examining the role of taxonomic diversity of oyster reefs in response to oiling, dispersant, and salinity – a mesocosm study in May 2017

Oyster reefs in the Gulf of Mexico were likely subjected to multiple stressors as a result of the Deepwater Horizon Oil Spill – those directly from the spill and those indirectly from the spill in the form of clean-up/response activities. The resilience of oyster reefs in the Gulf of Mexico in response to oiling may have been influenced by the taxonomic diversity of suspension feeders on oyster reefs. The data here are from a laboratory experiment assessing the effects of oil, dispersants, and salinity on oysters and associated epibionts. Groups of larger oysters (seed and market class), which were cemented together, and there associated epibionts; which included smaller oyster size classes (small seed and spat), barnacles, bryozoan, and polychaete worms; were used in the experiment. Oyster groups came from oyster seed raised by the Auburn Shellfish Lab that were raised from small seed size classes in containers in Portersville Bay, Mississippi Sound, AL from September 2016 to April 2017 and were allowed to obtain an invertebrate fouling community. Fouled oysters were assigned to treatment replicates at random. In addition, supplemental oyster shells from Mississippi sound that were fouled with barnacles were added at random to experimental tank replicates. Survival, growth and condition of juvenile oysters were assessed after 16-19 days of exposure.