Assessment of mercury distribution and partitioning in recent sediments of the western Mediterranean basin

Surface sediments collected throughout the Tyrrhenian Sea and the Western Mediterranean basin were analyzed for granulometric and geochemical characteristics and for total mercury content. Sediments of the Southern Tyrrhenian continental shelf and those collected from the Tyrrhenian slope and the Western Mediterranean basin have a total mercury content which is in the same range as that for other marine areas assumed to be background. Based on chemical leaching studies, most of the mercury appears to be fixed in a refractory phase and ∼20% is associated with organic materials. Biogenic carbonates, a large constituent of Mediterranean sediments, contain a very low percentage of the total mercury. On the basis of its content and its geochemistry, mercury in Mediterranean sediments, outside the continental shelf, seems to have little relevance to the high concentrations of the metal in tuna and other pelagic fish. © 1988.