Species-Specific Distribution of Heavy Metals in Tissues and Organs of Loggerhead Turtle ( Caretta caretta) and Green Turtle ( Chelonia mydas) from Japanese Coastal Waters

Abstract

Concentrations of heavy metals (Fe, Mn, Zn, Cu, Pb, Ni, Cd, Co and Hg) were determined in tissues and organs of loggerhead ( Caretta caretta) and green turtles ( Chelonia mydas) collected from Japanese coastal waters, in order to elucidate body distribution and to develop a non-lethal monitoring technique using the carapace. A majority of the metal burdens was present in the muscle, liver, bone and carapace of sea turtles. High Cu concentrations exceeding 10 μg/g wet wt were observed in the liver of these two turtle species. Mean Zn concentrations in fat tissues of loggerhead and green turtles were 94.6 and 51.3 μg/g wet wt respectively, which were about 10-fold higher than those reported in other marine animals. Concentrations of Mn, Zn and Hg in the carapace were correlated with whole body burdens, indicating that the carapace is a useful non-lethal indicator for monitoring heavy metal levels in the body of the sea turtle.