Assessment of maternal contaminant burden by analysis of snapping turtle eggs

Snapping turtles (Chelydra serpentina serpentina) have been extensively use d as an ecosystem and localized indicator of tissue contaminated bioaccumul ation, and for monitoring the geographic and temporal trends of contaminant s. The purpose of this study was to determine if any relationship exists in the pattern and quality of selected contaminations found in turtle tissues relative to egg contamination. Six gravid snapping turtle females were col lected from within and outside the Great Lakes basin and analyzed for conge ner-specific polychlorinated biphenyls (PCBs), dichlorodiphenyl-dichloroeth ylene (DDE), mirex and hexachlorobenzene (HCB) distributions in the fat, li ver, and eggs. Preliminary data collected fron five sites indicates that th e pattern of congener-specific PCBs and homologs, average chlorine/biphenyl , and total PCBs are significantly correlated among snapping turtle eggs an d tissues. Significant correlations were also observed for DDE, mirex, and HCB. All six turtles in this study revealed a consistent. and enhanced lowe r-chlorinated PCB pattern in the eggs relative to material adipose and live r tissues. Although these preliminary results are based on a relatively sma ll sample size (n = 6), the significance of the relationships observed indi cate found in the highest environmental turtle eggs provides a reliable ind icator of maternal contaminant burdens found in the highest environmental t rophic levels.