Skip to main content
U.S. flag

An official website of the United States government

An epizootic of common loons in coastal waters of North Carolina: Concentrations of elemental contaminants and results of necropsies

January 1, 1998

A 1993 die-off of common loons (Gavia immer) in the coastal waters of North Carolina was investigated with emphasis on comparing mercury, selenium, arsenic, and lead between birds from the epizootic and reference specimens. Die-off specimens were emaciated but contained no ingested foreign bodies and no lesions suggestive of infectious disease. Results of bacteriology, virology, parasitology, and botulism testing were unremarkable. The geometric mean concentrations (wet weight) of liver mercury (10.9 ppm), and arsenic (0.96 ppm) did not differ between specimens from the die-off and reference loons from the same area that died of other causes. The geometric mean liver selenium concentration of die-off specimens (10.4 ppm) was significantly higher than that of reference loons. Liver lead concentrations were < 0.20 ppm in all but one sample (5.83 ppm). The geometric mean mercury concentration in the primary remiges of die-off specimens (5.44 ppm dry weight) was significantly lower than in reference birds. Liver mercury significantly correlated with liver selenium on a molar concentration basis. We interpret the range of liver mercury concentrations in birds from the epizootic, similar liver mercury concentrations in reference loons, and higher mercury concentrations in reference loon feathers as evidence that factors other than mercury were primarily responsible for the emaciation diagnosed as the cause of mortality.

Citation Information

Publication Year 1998
Title An epizootic of common loons in coastal waters of North Carolina: Concentrations of elemental contaminants and results of necropsies
DOI 10.1002/etc.5620170211
Authors Tom Augspurger, J. Christian Franson, Kathryn A. Converse, P. Spitzer, E.A. Miller
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Toxicology and Chemistry
Series Number
Index ID 1003652
Record Source USGS Publications Warehouse
USGS Organization National Wildlife Health Center