SREL Reprint #2780

 

 

 

Maternal transfer of selenium in Alligator mississippiensis nesting downstream from a coal-burning power plant

John H. Roe1, William A. Hopkins1, Jennifer A. Baionno1, Brandon P. Staub1, Christopher L. Rowe2, and Brian P. Jackson1

1University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E,
Aiken, South Carolina 29802, USA
2University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory,
P.O. Box 38, Solomons, Maryland 20688, USA

Abstract: Selenium (Se) is embryotoxic in many oviparous vertebrates, but little is known about maternal transfer of Se and its impact in reptiles. Over a four-year period, we collected three clutches of eggs of the American alligator (Alligator mississippiensis) from a single nest at a site contaminated with Se and compared egg and hatchling Se concentrations and clutch viability from this nest to nests downstream from the contaminated site (two clutches from two nests) and at a reference site (two clutches from two nests). Eggs and hatchlings from the nest at the Se-contaminated site and downstream nests had elevated Se concentrations (2.1-7.8 ppm) and lower viability (30-54%) compared to reference nests (1.4-2.3 ppm and 67-74% viability), but Se concentrations did not exceed reproductive toxicity thresholds established for other oviparous vertebrates. Selenium concentrations were higher in chorioallantoic membranes of eggs from Se-contaminated sites, suggesting that this tissue may be useful as a nondestructive index of Se exposure for embryos of A. mississippiensis. Examination of these data suggests that further studies on uptake, accumulation, and reproductive success of crocodilian embryos exposed to excessive Se are warranted.

Keywords: Alligator mississippiensis, Chorioallantoic membrane, Crocodylia, Maternal transfer, Selenium

SREL Reprint #2780

Roe, J. H., W. A. Hopkins, J. A. Baionno, B. P. Staub, C. L. Rowe, and B. P. Jackson. 2004. Maternal transfer of selenium in Alligator mississippiensis nesting downstream from a coal-burning power plant. Environmental Toxicology and Chemistry 23:1969-1972.

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