• Organochlorines;
  • Early life stages;
  • Turtles


To assess intra-clutch variation in contaminant concentrations in eggs, and to investigate the dynamics of chlorinated hydrocarbon accumulation in embryos of the common snapping turtle (Chelydra serpentina), concentrations of p,p DDE, hexachlorobenzene, trans nonachlor, cis-chlordane, and six PCB congeners were measured in eggs, embryos, and hatchhngs Samples were collected from Cootes Paradise, a wetland at the western end of Lake Ontario, Ontario, Canada The intra-clutch variation in chlorinated hydrocarbon concentrations within four snapping turtle clutches was determined by analyzing the first, last, and middle five eggs oviposited in the nest The first five eggs had the highest mean concentrations of all chlorinated hydrocarbons (wet weight basis), wet weight, and egg diameter On a lipid weight basis, the first five eggs contained the highest concentration of all compounds except total PCBs and cis chlordane The concentration of as chlordane (lipid weight basis) was the only parameter measured that was significantly different among the three sets of eggs At hatching, snapping turtles without yolk sacs contained from 55 2 to 90 5% of the absolute amount of organochlorine compounds measured in the egg at oviposition Eighteen days after hatching, the body burden of PCBs and pesticides decreased to 45 3 to 62 2% of that in the fresh egg The accumulation of organochlorine chemicals in embryonic turtles peaked at or just before hatching and then declined thereafter, which is consistent with trends reported in developing sea turtles, fish, and birds