Rissoʹs dolphin (Grampus griseus) stranding on the coast of Israel (eastern Mediterranean). Autopsy results and trace metal concentrations

The stranding of Rissoʹs dolphin (Grampus griseus) on the Mediterranean coast of Israel is reported in this study. High concentrations of trace metals (Hg, Cd, Zn, Fe and Se) were found in the various tissues analyzed, while Cu and Mn concentrations were naturally low. The specimen was found alive, but died a day later. The cause of death was attributed to bacterial bronchopneumonia in combination with endotoxemia, resulting in disseminated intravascular coagulation. Plastic bags found in its stomach contributed to the dolphinʹs poor physical condition. No connection was found between the high concentrations of trace metals in the internal organs and the cause of death. It is assumed that the high concentrations were a result of the high trophic level of this species, its diet and its advanced age. Anthropogenic influence could not be assessed due to the sparse database of trace metals for this species, in particular knowledge of the natural levels.