Correlation between heavy metals and turtle abundance in ponds near the Paducah Gaseous Diffusion Plant, Kentucky, USA.

Reptiles are declining globally, and environmental contamination has been suggested as a contributing factor; however, few studies have investigated the relationship between contamination and reptile populations. We performed a mark-recapture study at ponds near the Paducah Gaseous Diffusion Plant (PGDP), Kentucky, to determine if heavy metals had an impact on turtle populations. We measured concentrations of cadmium, chromium, copper, lead, and mercury in red-eared slider turtle (Trachemys scripta elegans) tissues and pond sediment and determined the correlation between metal concentrations and red-eared slider density. Metal concentrations measured in the current study were low, and turtle density was not significantly correlated with metal concentrations in tissues or sediment. However, we observed a trend of decreasing turtle density in ponds that had greater metal concentrations. Sex ratio and proportion of juveniles were significantly different among ponds, but it is unclear if these differences are related to contamination associated with the PGDP.