Accumulation and tissue distribution of mercury and selenium in striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea (southern Italy)

Tissues and organs from Stenella coeruleoalba stranded along the Apulian coasts (southern Italy) during the period April–July 1991 were analyzed for their mercury and selenium content. Analysis showed considerable variations in the mercury concentration in the examined organs and tissues. The highest concentrations of mercury were found in the liver (from 2.27 to 374.50 μg g−1 wet wt.). After the liver, lung, kidney, muscle and brain were the most contaminated, while the lowest mercury contamination was found in the melon. As mercury, the liver also showed the highest selenium levels. Liver samples were also analyzed for their methyl mercury contents. The role of selenium in detoxification process of methyl mercury has been discussed. Mercury concentrations related to geographic variations and pollution of the marine environment have been examined. The possible implications between mercury accumulation and dolphin death have also been discussed.