Maternal transfer of chlorinated contaminants in the leatherback turtles, Dermochelys coriacea, nesting in French Guiana

Abstract

We examined the maternal transfer of organochlorine contaminants (OCs), pesticides (DDTS and HCHs) and polychlorinated biphenyls (PCBs), and the temporal variation of blood and eggs concentrations from 38 leatherback turtles ( Dermochelys coriacea) nesting in French Guiana. PCBs were found to be the dominant OCs with respective mean concentrations of 55.14 ng g −1 lipid-mass for egg and 1.26 ng mL −1 wet-mass for blood. OC concentrations were lower than concentrations measured in other marine turtles which might be due to the lower trophic position (diet based on gelatinous zooplankton) and to the location of their foraging and nesting grounds. All OCs detected in leatherback blood were detected in eggs, suggesting a maternal transfer of OCs. This transfer was shown to depend on female blood concentration for ΣDDTs and for the most prevalent PCB congeners, since significant relationships were found between paired blood–egg concentrations. During the nesting season, OC concentrations in eggs and the percentage of lipid in eggs were found to decline in successive clutches, highlighting a process of offloading from females to their eggs and a decreasing investment of lipid from females into their clutches. OCs in eggs tended to be higher in females spending 3 years in the foraging grounds between two nesting seasons than in those spending 2 years, suggesting an impact of time spacing two breeding seasons, called remigration interval, and of location of the foraging grounds.