SREL Reprint #3499

Ecotoxicoparasitology of mercury and trace elements in semi-aquatic mammals and their endoparasite communities

Ernest J. Borchert1,2, James C. Leaphart1,2, Albert L. Bryan Jr1, and James C. Beasley1,2

1University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
2University of Georgia, Warnell School of Forestry and Natural Resources, Athens, GA 30602, USA

Abstract: Many contaminants persist in the environment for decades ormore, influencing ecosystem health. Environmental contaminationwithmercury (Hg) is a particular concern due to its ability to biomagnify in foodwebs and its lethal and sub-lethal effects in exposed organisms. Despite the knownimpacts of anthropogenic contamination, there remains a need for data on wildlife exposure to Hg and other contaminants, and the effects of exposure on wildlife health. The objectives of this study were to: 1) quantify differences in concentrations of mercury and other trace elements among three sympatric semiaquatic mammals of different assumed trophic position: North American river otter (Lontra canadensis), raccoon (Procyon lotor), and North American beaver (Castor canadensis), 2) compare trace element concentrations between animals captured on the Savannah River Site (SRS) in South Carolina, USA, where known inputs of Hg and other trace elements have occurred, and reference sites in South Carolina (SC) and
Georgia (GA), USA, and 3) investigate the relationship between host trace element concentrations and endoparasite communities. River otters, beavers, and raccoons were sampled from the SRS, SC, and GA to quantify trace element concentrations in liver tissue and quantify endoparasite communities. Both species and sampling location were important factors determining hepatic trace element concentration, however, there was no consistent trend of elevated trace element concentrations among animals sampled on the SRS. Only Hg demonstrated biomagnification based on assumed trophic position, with river otters having the highest Hg concentrations among the sampled species. Additionally, the results suggest a possible relationship between host hepaticmercury concentration and endoparasite abundance, while hepatic seleniumconcentrationmay be related to endoparasite diversity. These findings further demonstrate how wildlife can accumulate anthropogenic contamination, although future research is needed to determine themechanisms contributing to patterns observed between endoparasite communities and the contaminant concentrations of their mammalian hosts.

Keywords: Anthropogenic; Bioaccumulate; Bioindicator; Furbearer; Savannah River Site; Trophic

SREL Reprint #3499

Borchert, E. J., J. C. Leaphart, A. L. Bryan Jr., and J. C. Beasley. 2019. Ecotoxicoparasitology of mercury and trace elements in semi-aquatic mammals and their endoparasite communities. Science of the Total Environment 679(2019): 307-316.

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