Mercury in the sea turtle Chelonia mydas (Linnaeus, 1958) from Ceará coast, NE Brazil

Mercury concentrations in carapace fragments of the green turtle Chelonia mydas from the Ceará coast in NE Brazil are reported. Concentrations varied from <0.34 to 856.6 ng.g -1 d.w., and were highest (average of 154.8 ng.g -1 d.w.) in juveniles (n = 22), whereas lowest concentrations (average of 2.5 ng.g -1 d.w.) were observed in adult/sub-adult animals (n = 3). There was a significant negative correlation between animal size and Hg concentration probably due to different diets between juveniles and sub-adults/adults. Carapace fragments, which are non-invasive, non-lethal substrates, may be of importance for monitoring purposes of these generally endangered species.