SREL Reprint #2539

Annual and regional variation in mercury concentrations in wood stork nestlings

Joan C. Gariboldi, A. Lawrence Bryan, Jr., and Charles H. Jagoe

University of Georgia's Savannah River Ecology Laboratory, PO Drawer E, Aiken, South Carolina 29802, USA

Abstract: Mercury concentrations were measured in blood, down, and feathers from approximately 300 wood stork nestlings in one South Carolina, USA, and four Georgia, USA, colonies from 1996 to 1999. Coastal nestlings generally had lower mercury concentrations than those from inland colonies. Interyear differences were also apparent, particularly for coastal colonies, where nestling mercury concentrations were higher in 1998 than in 1997 or 1999. In 1998, a wet winter followed by a dry spring and summer produced ideal freshwater foraging conditions and mercury concentrations in coastal nestlings were higher than during the two dry years. There was little interyear variation in mercury concentrations in nestlings from inland colonies, as parent storks from these colonies forage exclusively in freshwater habitats regardless of rainfall patterns. These results suggest that greater risk of mercury exposure to nestlings is associated with use of freshwater foraging habitats.

Keywords: Mercury, Mycteria americana, Wood stork, Freshwater, Salt water

SREL Reprint #2539

Gariboldi, J. C., A. L. Bryan, Jr., and C. H. Jagoe. 2001. Annual and regional variation in mercury concentrations in wood stork nestlings. Environmental Toxicology & Chemistry 20:1551-1556.

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