Evaluating Skin Disease in Common Bottlenose Dolphins near Brunswick And Sapelo Island, Georgia
Common bottlenose dolphin (<i>Tursiops truncatus</i>) frequenting the areas of Brunswick and Sapelo Island, Georgia have been monitored via photo-ID, remote biopsy, radio tracking and health assessments since 2004 and have been found to contain high levels of polychlorinated biphenyls (PCBs), with a unique pattern of congeners associated with the PCB mixture Aroclor 1268. Skin lesions have been previously documented in these dolphin populations, but no long-term skin lesion monitoring has taken place. This study examines differences in lesion prevalence between sites, monthly and yearly patterns at both sites, differences in prevalence of major lesion types, correlation with environmental variables (salinity, water temperature, air temperature, and precipitation), correlation with blubber concentration of Aroclor 1268, correlation between lesions associated with the same potential causative agents, and potential spatial patterns. Results of this study show evidence for consistent prevalence and seasonal trends between BRN and SAP, with both exhibiting higher lesion prevalence in spring months, as well as significant changes in variation across years. Monthly mean max precipitation and salinity were both significantly correlated with the presence of skin lesions. Dolphins’ blubber concentration of Aroclor 1268 was not found to significantly correlate with lesion presence in either male or female animals. Finally, current data do not support spatial clustering of dolphins with lesions.