MATERNAL TRANSFER OF SELENIUM IN ALLIGATOR MISSISSIPPIENSIS NESTING DOWNSTREAM FROM A COAL-BURNING POWER PLANT
JOHN H. ROE,1 WILLIAMA. HOPKINS,1 JENNIFER A. BAIONNO,1
BRANDON P. STAUB,1 CHRISTOPHER L. ROWE,2
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
(Received 19 September 2003; Accepted 21 January 2004)
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.
