Eastern oyster (Crassostrea virginica) reefs provide valuable ecosystem services such as water filtration and prevention of coastal erosion. Oyster reefs have dramatically declined in recent years due to deteriorating estuarine environments along the Gulf coast. Reef restoration is imperative and therefore studies assessing differing methodologies need to be tested to improve restoration success. Adjunct to a study conducted by the Florida Fish and Wildlife Conservation Commission and The Florida State University Coastal and Marine Lab examining oyster density and growth across five artificial reef substrates (four differing substrates based on “green technology”, and one non-biodegradable substrate), Ohio Northern University students assessed the health of the oysters by means of comparing symbiotic bacterial communities of the oysters across these artificial reef substrates. It was hypothesized that substrate type influences bacterial composition. It was predicted that bacterial community variation is associated with nutrient additives of the artificial reef substrates. Bacterial communities of oysters (N=25) were compared across the substrates using terminal restriction fragment length polymorphism (TRFLP) analysis of polymerase chain reaction (PCR) product amplifying the 16s rRNA gene region of bacterial DNA from emulsified oysters.
Results/Conclusions
Nonmetric multidimensional scaling ordination and permutation-based analysis of variance indicated no significant effects of restoration substrate on oyster bacterial community composition (PERMANOVA: F(4,20)=1.4, P=0.134). Despite potential importance of symbiotic bacterial communities to oyster health, as well as potential concern in regards to food-borne illnesses as a result of oyster consumption, knowledge of these symbiotic bacterial communities is lacking. The finding that substrate type did not influence bacterial community composition of the oysters was a desired result in that substrate choice need not be a limiting factor to restoration efforts. Substrate considerations can instead be focused on rapid oyster recruitment.