SREL Reprint #2616

 

 

 

Using raccoons as an indicator species for metal accumulation across trophic levels: A stable isotope approach

Karen F Gaines1, Christopher S. Romanek1,2, C. Shane Boring1,3, Christine G. Lord3, Michael Gochfeld4,
and Joanna Burger3

1Savannah River Ecology Laboratory, PO. Drawer E, Aiken, SC 29802, USA
2Department of Geology, University of Georgia, Athens, GA 32602, USA
3Nelson Biological Laboratories and Environmental and Occupational Health Sciences Institute,
Rutgers University, Piscataway, NJ 08855, USA
4Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08855, USA

Abstract: The fact that raccoons (Procyon lotor) are an opportunistic omnivore has severly complicated interpretations of contaminant uptake patterns due to the inability to determine the tropic position an individual occupies. Moreover, few studies have examined the relationships between heavy metal bioaccumulation and trophic structure, especially in the terrestrial environment. In this study, the stable isotopes of nitrogren were used to characterize the feeding habits of the raccoon at the population level and to determine whether metal burden was related to trophic feeding structure within a well-defined ecosystem. Raccoon populations were isotopically distinct, and significant positive relationships existed between some trace element contents and of muscle when site was used as a covariable in a statistical model. Although the transfer of metals through terrestrial ecosystems is complex, our study showed that some of the variation in contaminant body burdens in raccoon populations can be attributed to trophic feeding position and the 15N/14N rations of muscle tissue provide a quantitative measure of this process. The potential for using omnivores such as the raccoon, as a sentinel species for contaminant studies, should be explored further since the ambiguity of the relative trophic level an animal occupies can be directly estimated. This provides a more extensive sampling across trophic levels using a single species, which can have a broad consequences for ecological assessments.

Keywords: bioaccumulation, biomagnification, contaminant, metals, nitrogrn isotope, Procyon lotor, raccoon, South Carolina, stable isotope, trophic transfer

SREL Reprint #2616

Gaines, K. F., C. S. Romanek, C. S. Boring, C. G. Lord, M. Gochfeld, and J. Burger. 2002. Using raccoons as an indicator species for metal accumulation across trophic levels: A stable isotope approach. Journal of Wildlife Management 66:811-821.

To request a reprint

 

 
http://srel.uga.edu www.uga.edu