SREL Reprint #2599

Effects of chronic dietary exposure to trace elements on banded water snakes (Nerodia fasciata)

William A. Hopkins1,2, John H. Roe3, Joel W. Snodgrass4, Brandon P. Staub1, Brian P. Jackson1,
and Justin D.Congdon1

1Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina 29801, USA
2Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
3Department of Biological Sciences, Purdue University, Indiana 46805, USA
4Department of Biology, Towson University, Towson, Maryland 21252, USA

Abstract: Little currently is known about the accumulation or effects of contaminants on reptiles. To date, most studies examining reptile exposure to trace elements report tissue burdens of field-captured animals, but seldom provide insight into the dose, duration, or mode of exposure involved. For two years, we fed juvenile banded water snakes (Nerodia fasciata) prey items collected from a coal ash-contaminated site that contained elevated levels of As, Cd, Cu, Se, Sr, and V. With the exception of Cu, snakes accumulated significant concentrations of elements, usually in a dose-dependent manner. Accumulation varied significantly among liver, kidney, and gonads, and in most cases between sexes. Selenium accumulation was most notable, greatly exceeding established toxicity thresholds for other vertebrates. Despite the high concentrations of pollutants accumulated, snakes exposed to the contaminated diet survived through the study and exhibited normal food consumption, growth, condition factor, overwinter survival and mass loss, metabolic rate, and gonadosomatic index. The results of this study confirm that diet can be a significant route of exposure to trace elements in snakes and indicate that further studies on snakes are warranted to better understand their responses to contaminants.

Keywords: Reptiles, Snakes, Trophic transfer, Coal combustion, Selenium

SREL Reprint #2599

Hopkins, W. A., J. H. Roe, J. W. Snodgrass, B. P. Staub, B. P. Jackson, and J. D. Congdon. 2002. Effects of chronic dietary exposure to trace elements on banded water snakes (Nerodia fasciata). Environmental Toxicology and Chemistry. 21:906-913.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).