ENVIRONMENTAL CONTAMINATION AND DEVELOPMENTAL ABNORMALITIES IN EGGS AND HATCHLINGS OF THE COMMON SNAPPING TURTLE (CHELYDRA-SERPENTINA-SERPENTINA) FROM THE GREAT-LAKES ST-LAWRENCE-RIVER BASIN (1989-91)

During 1989-91, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpenti na serpentina). Eggs were collected and artificially incubated from ei ght sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polych lorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 poly chlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans ( PCDFs) and total mercury. We found a significant increase in abnormal development with increasing polychlorinated aromatic hydrocarbon expos ure in eggs, particularly PCDD and PCDF concentrations. In contrast,th e risk of abnormality was not significantly higher as toxic equivalent concentrations increased in eggs. We also found significant 7-ethoxyr esorufin O-deethylase and Cytochrome P4501A responses in livers of hat chling turtles from Lake Ontario relative to hatchlings from a clean, inland site whereas we did not find any evidence of porphyria in the h atchlings from either site. (C) 1998 Elsevier Science Ltd. All rights reserved.