Distribution of cadmium and lead in Posidonia oceanica (L.) Delile from the middle Adriatic

Abstract

Concentrations of Cd and Pb were determined in the various tissues of Posidonia oceanica, epibiota, and adhering sediments collected at two locations that represent distinct degrees of anthropogenic influence. The distribution of metals in the components of the sea grass meadow depended on the specific component and the metal species analysed. Cadmium concentrations in the tissues of Posidonia were similar or higher in comparison to the adhering sediment. In contrast, a greater fraction of Pb was bound to the bottom sediment. Photosynthetic parts of leaves accumulated more cadmium than other tissues, while lead concentrations in the underground parts on both stations were higher in comparison to the aboveground parts. The results suggested that Posidonia accumulates lead mainly from the sediment, while cadmium is accumulated mainly from the surrounding water. Lead concentration in the tissues of Posidonia was higher at the more contaminated site, thus confirming the validity of this plant as a biological indicator of lead.