Organohalogen contaminants in blood of Kemp’s ridley (Lepidochelys kempii) and green sea turtles (Chelonia mydas) from the Gulf of Mexico

The threat that exposure to organohalogen (OH) contaminants poses to endangered populations of Kemp’s ridley (Lepidochelys kempii) and green sea turtles (Chelonia mydas) is not well understood, partly because few OH data are available. Blood samples from live juvenile and sub-adult L. kempii (n = 46) and C. mydas (n = 9) from the Gulf of Mexico and from L. kempii from the southeastern US coast (n = 3) were extracted using microwave-assisted extraction, and analyzed by large volume injection gas chromatography–mass spectrometry for 85 polychlorinated biphenyls (PCBs), 25 organochlorine pesticides (OCPs) and 27 polybrominated diphenyl ethers (PBDEs). Plasma chemistries, hematology and immune responses were also assessed. Concentrations of ΣPCBs (geometric mean, range: 3190 pg g−1, 227–21 590 pg g−1 blood), ΣDDTs (geometric mean, range: 541 pg g−1, 161–4310 pg g−1 blood) and OCPs in L. kempii from the Gulf were comparable to those reported in L. kempii from the Atlantic. ΣPBDEs were detected in all samples (geometric mean, range: 146 pg g−1, 19.5–1450 pg g−1 blood), with PBDE 47, 99, 100, 153 and 154 being the predominant congeners. ΣPCBs, ΣDDTs and Σchlordanes were one order of magnitude lower in green turtles, and ΣPBDE concentrations were lower by half due to trophic level differences. L. kempii from the southeast USA had higher percentages of highly chlorinated PCBs indicating exposure to Aroclor 1268. Blood urea nitrogen was positively correlated to Σchlordanes, and ΣPCBs were inversely correlated to creatine phosphokinase in L. kempii. These data help establish baseline contaminant concentrations in live L. kempii and C. mydas.