Metal contamination in Portman Bay (Murcia, SE Spain) 15 years after the cessation of mining activities

To evaluate the state and temporal trends of the residual metal contamination caused by the dumping of mine tailings into Portman Bay (SE Spain) during the 20th century, concentrations of Hg, Cd, Pb, Cu, Zn, and As in wild mussels (Mytilus galloprovincialis) were studied over the period 1991-2005. The results show significant downward trends (P < 0.05) in the concentrations of Hg, Cu, Pb, and Zn. Nevertheless, trace metal concentrations in mussels from Portman in 2005 were higher than the reference concentrations established for the coast of Murcia and the Spanish Mediterranean littoral, the only exceptions being Cu and As. Red mullets (Mullus barbatus) caught at Portman in 1990 and 2004 presented higher levels of Hg, Cd, and Pb, in comparison with other areas of the south and southeastern coast of Spain. The results indicate that Portman Bay is still one of the areas most heavily contaminated by Pb and Cd along the Mediterranean coast of Spain 15 years after the cessation of mining activities.