The decline of Eastern Oyster (Crassostrea virginica) populations during the 1900s has negatively impacted coastal ecosystems and economies. In Georgia, as much as 85% of the native C. virginica population has been lost due to overharvesting. Oyster reef restoration projects have been effective at re-establishing these ecosystem engineers in select locations. However, few studies have focused on prioritizing restoration sites using physicochemical conditions conducive for C. virginica recruitment, growth, and reproduction. Our objectives were: 1) identify critical physicochemical parameters as well as optimal ranges for C. virginica establishment and success; 2) create a GIS index that maps low, medium, and high habitat quality for C. virginica; and 3) modify this index by incorporating anthropogenic stressors and bathymetric data along the Georgia coast. Parameter suitability rasters were created through reclassification of interpolated point water quality data. These data layers were then summed and normalized to create a habitat suitability index. Areas in close proximity to anthropogenic stressors were excluded from the suitability index. The suitability index was modified further by the addition of bathymetric data.
Results/Conclusions
The salinity suitability map showed 20% and 10% of the Georgia coast as medium and high quality respectively. The water temperature suitability map showed 20% and 70% of the Georgia coast as medium and high quality respectively. The pH suitability map showed 85% and 10% of the Georgia coast as medium and high quality respectively. The integrated suitability index mapped 80% and 10% of the Georgia coast as medium and high quality respectively. The incorporation of anthropogenic stressors and bathymetric data excluded roughly 30% of the coast from the habitat suitability index. The efficient management of restoration funds is integral to the re-establishment of C. virginica populations. Models, such as this one, could be used as a tool to more effectively target restoration sites in Georgia and throughout the U.S. Future research should target biological monitoring of oyster reefs located in each of the index ranges to determine if this model is applicable for biodiversity indicators.