Essential and trace metals in a post-nesting olive ridley turtles (Lepidochelys olivacea) in Ceuta beach, Sinaloa, Mexico.

Trace metals have been found in sea turtle blood and tissues and may represent a threat to these endangered species. Essential trace metal (Cu, Zn Cd, Pb, As, and Hg) concentrations were determined in blood of adult female, post-nesting olive ridley turtles Lepidochelys olivacea (n = 35) on Ceuta beach, Sinaloa, Mexico. Essential metals (Zn and Cu) analyzed were found in higher concentrations than toxic metals (Cd and Pb), while As and Hg concentrations were below the limits of detection (0.01 µg g-1). Low Pb concentrations (0.09 µg g-1) were previously observed in sea turtles in the Gulf of California. There were no significant correlations found between curved carapace length (61.00-71.00 ± 2.29) vs metal concentrations (p > 0.05). Cd levels were relatively high when compared to other species and populations of sea turtles worldwide and Cd may represent the greatest risk for sea turtles in the Mexican Pacific. Such concentrations of Cd may pose a further risk to sea turtles through bioaccumulation from the nesting female to offspring which may affect embryo development.

Associations between trace elements and clinical health parameters in the North Pacific loggerhead sea turtle (Caretta caretta) from Baja California Sur, Mexico.

This study investigated selected trace elements toxicity in sea turtles Caretta caretta population from Baja California Sur (BCS), Mexico, by analyzing associations among Zn, Se, Cu, As, Cd, Ni, Mn, Pb, and Hg with various biochemical parameters (packed cell volume, leukocytes, and selected blood parameters), and whether their concentrations could have an impact on the health status of sea turtles. Blood samples from 22 loggerhead (C. caretta) sea turtles from BCS, Mexico, were collected for trace elements on biochemistry parameter analyses. Significant associations among trace element levels and the biochemistry parameters were found: Cd vs ALP (R 2 = 0.874, p Ë‚ 0.001), As vs ALP (R 2 = 0.656, p Ë‚ 0.001), Mn vs ALP (R 2 = 0.834, p Ë‚ 0.001), and Ni vs LDH (R 2 = 0.587, p Ë‚ 0.001). This study is the first report of the biochemical parameters of the North Pacific loggerhead sea turtle (C. caretta) from Baja California Sur, Mexico, and it is the first to observe several associations with toxic and essential trace elements. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and the results suggest that, based on the associations with health clinical parameters, high levels of Cd and As could be representing a risk to the North Pacific loggerhead population health.