Metal(loid) contamination in tiger sharks (Galeocerdo cuvier) from a remote oceanic island in the Equatorial Atlantic Ocean and potential impacts on physiological parameters

We investigated the relationship between blood metal(loid) concentrations and plasma levels of glucose, proteins, triglycerides, cholesterol, lactate, urea, and polyunsaturated fatty acids in tiger sharks (Galeocerdo cuvier) sampled off the Fernando de Noronha Archipelago, a remote oceanic marine protected area in the Equatorial Atlantic Ocean. Results revealed that Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn were detected in the whole blood of tiger sharks and no sexual differences in blood metal(loid) concentrations were observed. Females had higher concentrations of plasma proteins and docosahexaenoic acid. In females, all analyzed elements were positively correlated with each other, except As. Only As was positively correlated with triglycerides, suggesting a potential impact of As exposure on the nutritional condition of this species. The results presented herein reinforce that sharks, even from remote sites, are exposed to metal(loid)s and that such exposure might elicit physiological responses.