Geochemical patterns of Scrobicularia plana and host sediment from the Tagus estuary (Portugal)

Moreira, S.; Freitas, M.C.; Munha, J.M.; Tassinari, C.C., Andrade, C. and Cabral, H., 2011. Geochemical patterns of Scrobicularia piano from Tagus estuary (Portugal). Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), 1545 - 1549. Szczecin, Poland, ISBN 0749-0208 Thirty seven elements were analyzed in different tissues (viscera, adductor muscle and foot) of Scrohicularia plana from Sitio das Hortas tidal flat (Tagus estuary, Portugal) in order to assess the geochemical fractionation between different Scrobicularia piano tissues and their host sediment. Overall, higher Bioaccumulation Factors were obtained in the viscera, then adductor muscle and foot. Only seven elements were accumulated in the viscera, with the following pattern: Ag >> Zn>Au similar to Cd>Na similar to Cu similar to Hg; Ag and Zn contents of all tissues are higher than those in their sedimentary substrates. The available data indicate that there is significant geochemical fractionation between Scrobicularia plana's tissues and the sediment. Seawater has an important role on the process; however the main fractionation mechanisms should be related to element bioavailability for specific S. plana metabolic processes.