Concentration of heavy metals in tissues of green turtles (Chelonia mydas) sampled in the Cananéia estuary, Brazil

Abstract

Thirty specimens (15 adults and 15 juveniles) of Chelonia mydas found in the Cananéia estuary in the state of São Paulo on the southeastern Brazilian coast between January 2005 and September 2006, were analyzed The concentrations of Cd, Cu, Pb, Mn and Ni in liver and kidney samples of adult and juvenile green turtles were determined by Flame Atomic Absorption Spectrophotometry. The average Cd concentration found in adult livers (0.57μg.g-1) was significantly higher than that in juveniles (0.279μg.g-1). Cu concentrations were significantly higher in the liver than in the kidney, and significantly higher in adults (39.9μg.g-1) than in juveniles (20.7μg.g-1). Average Mn concentrations in liver and kidney did not differ between adults (4.32 and 4.17μg.g-1) and juveniles (4.81 and 3.82μg.g-1), whereas Ni concentrations in adults (0.28 and 0.19μg.g-1, respectively) were significantly higher than in juveniles (0.13 and 0.089μg.g-1, respectively). Pb concentrations in liver were significantly higher in adults (0.37μg.g-1) than in juveniles (0.06μg.g-1). The concentrations of essential trace elements in Chelonia mydas were generally comparable to values reported in other, similar studies. With respect to non-essential metals (Cd, Pb and Ni), Chelonia mydas presented lower values than those reported for their northern Atlantic counterparts.