Pb Isotopic Compositions of Fin Whale Baleen Plates – A Clue to Unravel Individual Migrations between the Atlantic Ocean and the Mediterranean Sea?

To assess Mediterranean fin whale ecology and impacts of environmental changes, Pb content and isotopic composition were measured on baleen plates of fin whales stranded on Mediterranean and Bay of Biscay coasts. Pb contents of fin whale baleen plate reflect that of their diet and thus of the dissolved Pb content of the upper 200 meters of the surface ocean. Using Pb isotopes, baleen plates allow reconstituting the evolution of anthropogenic Pb pollution and showing that stranded Mediterranean fin whales constitute a specific population that is resident of the Mediterranean Sea with occasional migrations to the Atlantic Ocean.