BaselineOccurrence of organochlorines in the green sea turtle (Chelonia mydas) on the northern coast of the state of São Paulo, Brazil

Organochlorines (OCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent, toxic and widely distributed through atmospheric transport and ocean currents. Few studies have been conducted on OCs in sea turtles, especially on the coast of Brazil. Chelonia mydas is the largest hard-shell sea turtle and is found tropical and subtropical regions in all oceans. The aim of the present study was to determine the occurrence of OCs in the green sea turtle (C. mydas). Fat, liver, kidney and muscle samples were collected from 27 juveniles found on the beach of the city of Ubatuba on the northern coast of the state of São Paulo, Brazil. OCs were extracted with organic solvents and the extract was purified with concentrated acid. Gas chromatography-mass spectrometry and electron capture detection were used for the identification and quantification of PCBs and pesticides, respectively. No organochlorine pesticides were detected in any of the samples. Concentrations of total PCBs in wet weight were < 1.6 to 48.9 ng/g in fat tissue, < 1.6 to 17.4 ng/g in liver tissue and < 1.6 to 37.7 ng/g in kidney tissue. The low levels found are mainly related to diet, as the green sea turtle is basically herbivorous and lower PCB contamination compared to other regions.