POSTER: Oyster Larval Dispersal and Recruitment in the Caloosahatchee River Estuary, Southwest Florida
Research Mentor: Dr. Felix Jose
Additional Authors: Dr. Melissa May, Dr. Eric Milbrandt, Rachael Waldrop
Abstract:
Eastern oyster (Crassostrea virginica) reefs in Southwest Florida provide numerous benefits such as being critical habitats for juvenile fish and invertebrate species, along with contaminant filtration. In order to provide accurate data for the creation of a baroclinic model that can simulate oyster larval transport and settlement within the Caloosahatchee River Estuary (CRE), a field study was conducted throughout the oyster spawning season (May-Oct) of 2020 and 2021. This model can provide much needed insight into the physical and chemical processes that shape reef recruitment. At ten sites throughout the CRE that were deemed ecologically significant, 10L water samples were filtered biweekly using a 55-um mesh, dyed with the organic dye Rose Bengal, separated using an adapted plankton-splitting technique, and counted using microscopy techniques. All concentrations were converted and reported as bivalve larvae/L. At each site, a PVC t-frame hung three shell stringers to measure oyster spat settlement. Oyster spat that had settled on the stringers were recorded biweekly, averaged, and then the stringers were replaced with clean shells. Preliminary analysis shows that the Pine Island Sound receives the greatest larval supply but has little settlement success until September, while the rest of the CRE has earlier settlement success, albeit reduced. Matlacha Pass has the greatest settlement success relative to larval supply, potentially indicating it would be conducive for restoration efforts. This data is being used to support the creation of a particle (larval) tracking model, which will be conjoined with the 3D baroclinic model and can advise oyster reef restoration projects and water management in SWFL.