Persistent organic pollutants in Kemp's Ridley sea turtle Lepidochelys kempii in Playa Rancho Nuevo Sanctuary, Tamaulipas, Mexico

Abstract

Persistent organic pollutants (POP) are toxic substances for wildlife and people. The Kemp's Ridley sea turtle Lepidochelys kempii is an endangered species with limited distribution in the Gulf of Mexico (GM), a marine ecosystem that has been perturbed by a variety of anthropogenic activities. In this work, the concentrations of ten organochlorine pesticides (OP), eight polychlorinated biphenyls (PCB), and atrazine were determined in the plasma of Kemp's Ridley sea turtles that nest in Playa Rancho Nuevo Sanctuary, Tamaulipas, Mexico. Seventy-nine blood samples were collected from female turtles during the 2015–2016 nesting season. Samples were extracted with a focalized ultrasonic sound technique and analyzed through Gas Chromatography coupled to a Mass Spectrometer. POP with the highest percentage of detection were atrazine > PCB 52 > PCB 153 > DDE > alpha endosulfan > DDD > alpha HCH > DDT. There is no linear correlation between the detected POP levels in the Kemp's Ridley sea turtle plasma and its curve carapace length (CCL). When comparing 2015 and 2016 POP concentrations, there were statistically significant differences in atrazine (p < 0.05, R2 = 0.069), PCB 52 (p < 0.05, R2 = 0.0051) and ∑POP (p < 0.05, R2 = 0.0001) and, no statistically significant differences in alpha endosulfan (p < 0.05, R2 = 0.0294), DDE (p < 0.05, R2 = 0.0315) and PCB 153 (p < 0.05, R2 = 0.0036). The reported POP values of this work are one of the few registered for Kemp's Ridley sea turtle in the GM and the first for atrazine levels. These levels were higher than those reported for other sea turtle species from America, Africa, and Europe, which demonstrates a deteriorated health status of the GM marine ecosystem.