Abstract

The potential relationship between enviranmental pollutants and increasing reports of amphibian deformities is a topic of recent concern. Furthermore, the importance of amphibians as indicators of environmental health in general makes research on how environmental stressors affect them especially pertinent in light of the growing concerns about pollution. Previous studies on bullfrog tadpoles (Rana catesbeiana) have linked a high incidence of oral deformities with the wastes produced from a coal-burning power plant at the Savannah River Site in Aiken County, South Carolina. In the current study, we document significantly higher frequencies of axial tail deformities and elevated whole body concentrations of trace elements (As, Se, Cd, and Cr) when compared to bullfrog tadpoles from two reference sites. Approximately 37 and 18% of the tadpoles from the contaminated habitats exhibited lateral curvatures of the spine, whereas deformities only occurred in 4 and 0% of the tadpoles collected from the reference sites. The results from this study also demonstrate that responsiveness to external stimuli was reduced in tadpoles collected from the ash basin when compared to those from a reference site, and that tadpoles from the ash basin with severe tail deformities exhibited decreased swimming speed when compared to conspecifics from the same site. We hypothesize that conditions in the contaminated habitat caused the observed deformities and that modifications in swimming performance could decrease the ability of bullfrog tadpoles in the ash settling basins to avoid predation.