Evidence for contrasting accumulation pattern of cadmium in relation to other elements in Senilia senilis and Tagelus adansoni from the Bijagós archipelago, Guinea-Bissau

Evidence for contrasting accumulation pattern of cadmium in relation to other elements in Senilia senilis and Tagelus adansoni from the Bijagós archipelago, Guinea-Bissau

Environmental Science and Pollution Research, September 2017

28918583

Teresa Catry, Paula Figueira, Lina Carvalho, Rui Monteiro, Pedro Coelho, Pedro Miguel Lourenço, Paulo Catry, Quintino Tchantchalam, Inês Catry, Maria J. Botelho, Eduarda Pereira, José Pedro Granadeiro, Carlos Vale

Shellfish harvesting in intertidal areas is a widespread and economically important activity in many countries across West Africa. However, in some areas, there is virtually no information concerning the levels of contaminants (and other elements related to nutritional aspects) in the harvested species. We collected sediments and several individuals of the West African bloody cockle Senilia senilis and of the razor clam Tagelus adansoni during the dry season of 2015 nearby three islands in the Bijagós archipelago, Guinea-Bissau. Aluminium, Ca, Fe, Mg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined in sediments and whole soft tissues of the two bivalves. Sediments showed uniformly low trace element concentrations, pointing to an ecosystem with low levels of trace element contamination. T. adansoni presented higher concentrations of most elements than S. senilis, with the exception of Cd that showed up to 40 times higher values in S. senilis than in T. adansoni from the same sites. Furthermore, Cd concentrations (25±8.7 mg kg(-1), dw) in S. senilis are clearly above the maximum level established for human consumption. Future studies should clarify whether biological factors are the major responsible for this unusual situation.