Influence of watershed lithology on heavy metal levels in estuarine sediments and organisms in Galicia (North-West Spain

The possible influence of watershed lithology on metal levels in estuarine sediments and organisms (macroalgae, phanerogams, molluscs and polychaetes) in Galicia (north-west Spain) was investigated. In sediments, background levels of Fe, Mn, Cu, Cr, Pb and Ni—but not of Co and Zn—are determined by watershed lithology. In contrast, watershed lithology is not a reliable predictor of the metal contents in organisms, although for some metals in some species lithology has a statistically significant influence on metal content.