Mercury, zinc and selenium bioaccumulation in tissues and organs of Mediterranean striped dolphins Stenella coeruleoalba meyen. Toxicological result of their interaction.

Neutron activation analysis of 13 Mediterranean striped dolphins Stenella coeruleoalba showed high mercury and selenium contaminations of main tissues and organs of these cetaceans. The mercuric contents were excessive, particularly in liver (from 68 to 2272 micrograms/g dry wt. basis), then in kidney, lung, muscle, heart and brain. The selenium concentrations were also high in liver (from 45 to 1320 micrograms/g dry wt. basis), then in kidney, lung, muscle, skin and heart. The main way of contamination seems to be the food through trophic network, but skin and lung are also able to play a part which must be elucidated. The average Hg/Se ratios in liver and kidney were respectively 1.82 and 1.59. Linear relationship between mercury and selenium concentrations in tissues and organs, particularly in liver and kidney, were confirmed. The mercury and selenium interaction on a toxicological point of view was established by a statistical approach; in the same way, intervention of zinc, metallothioneins and glutathiones have been discussed.