Physiological and immunological effects of coal combustion residues in the yellow-bellied slider

Freshwater turtles are at increased risk for extinction, and although they have been shown to accumulate large amounts of pollutants, little is known how contaminants affect their immune status and overall health. Coal combustion residues (CCRs) contain high amounts of potentially toxic trace elements (i.e. selenium) and are known to cause metabolic aberrations and histopathological abnormalities in some reptilian species. My research sought to ascertain if trace elements associated with CCRs negatively impact the health of the yellow-bellied slider (Trachemys scripta). We performed a field study to examine bioaccumulation of CCRs in wild T. scripta and quantified immune responses across site types. We also acutely exposed T. scripta to Se in a controlled lab study, and we measured Se accumulation, mortality, bactericidal capacity, hematological profiles, and metabolic rates. In the field study we found that wild T. scripta captured in CCR-affected wetlands did accumulate large amounts of CCRs, but did not exhibit diminished immune responses. In the lab study we found that T. scripta exposed to Se exhibit symptoms common in other vertebrates (mortality and altered hematological profiles). Overall, my results further our understanding of contaminant accumulation in a widespread chelonian species, and my results suggest that symptoms associated with Se toxicosis can occur in reptiles