Accumulation and tissue distribution of heavy metals and essential elements in loggerhead turtles (Caretta caretta) from Spanish Mediterranean coastline of Murcia

Sea turtles are of increasing interest as potential bioindicators of the heavy metal pollution in marine ecosystems. In the present work, concentrations of heavy metals and essential elements (As, Cd, Hg, Pb, Se, Zn) in different organs and tissues (liver, kidney, muscle, bone, blood, central nervous system and skin) of loggerhead sea turtles (Caretta caretta) were determined from stranded animals found along the Spanish Mediterranean coastlines of Murcia. Relatively high average levels of As (skin: 52.13 μg g−1 dry weight; muscle: 40.95 μg g−1 dry weight), and especially high individual levels of Zn in muscle tissue (1002.4 μg g−1 dry weight) were detected. Furthermore, a significant degree of organotrophism of Cd was observed in kidney tissue. The concentrations detected, the distribution among the tissues and the differences observed between juvenile and adult specimens are generally compatible with chronic exposure to the elements studied, whilst levels produced by acute exposure were ruled out.