SREL Reprint #3683

Tissue distribution of mercury in the bodies of wild American alligators (Alligator mississippiensis) from a coastal marsh in Louisiana (USA)

Liberty A. Moore1,2, John W. Finger Jr.3, David L. Haskins4, Ruth M. Elsey5, Steven B. Castleberry2, Travis C. Glenn1,6, Charles H. Jagoe1, and I. Lehr Brisbin Jr.1

1Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29801, USA
2Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
3Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
4Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA
5Louisiana Department of Wildlife and Fisheries, Rockefeller Wildlife Refuge, Grand Chenier, LA 70643, USA
6Department of Environmental Health Science, Institute of Bioinformatics,
University of Georgia, Athens, GA 30602, USA

Abstract: Total mercury (THg) concentrations were measured in wild alligators inhabiting a coastal marsh in southern Louisiana, to determine the tissue distribution of THg among various body organs and tissue compartments. Concentrations of THg in claws and dermal tail scutes were compared to those in blood, brain, gonad, heart, kidney, liver, and skeletal muscle to determine if the former tissues, commonly available by non-lethal sampling, could be used as measures of body burdens in various internal organs. Mercury was found in all body organs and tissue compartments. However, overall, THg concentrations measured in alligators were below the FDA action level for fish consumption and were comparable to previous data reported from southwestern Louisiana. Our results suggest consumption of meat from alligators found in this region may be of little public health concern. However, the extended period of time between sampling (in this study) and the present-day highlight the need for continuous, additional, and more recent sampling to ensure consumer safety. Total mercury concentrations were highest in the kidney (3.18 ± 0.69 mg/kg dw) and liver (3.12 ± 0.76 mg/kg dw). THg levels in non-lethal samples (blood, claws, and dermal tail scutes) were positively correlated with all tissue THg concentrations (blood: R2 = 0.513–0.988; claw: R2 = 0.347–0.637, scutes: R2 = 0.333–0.649). Because THg concentrations from blood, claws, and scutes were correlated with those of the internal organs, non-lethal sampling methods may be a viable method of estimating levels of THg in other body tissues.

SREL Reprint #3683

Moore, L., J. W. Finger Jr., D. L. Haskins, R. M. Elsey, S. B. Castleberry, T. C. Glenn, C. H. Jagoe, and I. L. Brisbin Jr. 2022. Tissue distribution of mercury in the bodies of wild American alligators (Alligator mississippiensis) from a coastal marsh in Louisiana (USA). Archives of Environmental Contamination and Toxicology 83(1): 13-20.

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