Occurrence and distribution of metals in mussels from the Cantabrian coast.

From February 2004 to April 2006, the concentrations of more than 10 metals in mussels (Mytilus galloprovincialis) were measured in 10 stations from Galicia to the Basque Country in 8 different times of sampling. The mean highest concentrations are found for Zn [226.8 microg/g, dry weight (d.w.)] followed by Mn, As, Cu, and Co (between 10 and 25 microg/g d.w.). Lower mean concentrations are found for Se, Cr, Pb, V, and Ni (between 2 and 8 microg/g d.w.) and the lowest are for Cd, Sn, Hg, and Sb (between 0.05 and 1 microg/g d.w.). Among the statistical treatments used, the factor analysis showed a clustering of the mussels according to the geographical location. In addition, the temporal trend of the metal concentrations was studied by means of the Mann-Kendall test. In this sense, some stations showed a decreasing trend in the accumulation of the metallic content. However, there were some local pollution events that could be explained as a consequence of anthropogenic activities. Finally, the effects of the oil spill from the Prestige are discussed based on the experimental Ni/V ratio values obtained from this work and those of the original oil.