Bioaccumulation of metals and PCBs in Raja clavata

The goal of this study was to assess stable isotopes profiles, metals concentration and PCBs in Raja clavata muscle and liver, according to sex and size, and to elucidate its suitability as a Mid-Atlantic biomonitor. The results reflected bioaccumulation and suggested biomagnification processes for As and Hg in muscle tissue. Cd, Cu and Zn were detected in high amounts in liver, Cr, Mn and Rb were relatively stable and low, Pb was not detected and Sr was present in muscle at high levels, decreasing with length. Hg and Se were strongly correlated, suggesting a mitigation role. Both tissues presented low concentrations of PCBs, especially the dioxin-like congeners, although always higher in liver and not correlated with size. None of these contaminants exceed EU legislated limits. However, they need to be monitored given study area's location, volcanic nature and the expected increase of anthropogenic activity related to future prospective mining activities and the establishment of the Transatlantic Trade and Investment Partnership (TTIP) between Europe and the USA. - Highlights: • We analyzed Raja clavata muscle and liver tissue from Mid-Atlantic (Azores). • We determined trophic ecology, stable isotope, trace metal and PCBs content. • Results reflect bioaccumulation and biomagnification for As and Hg. • Low concentrations in PCBs, especially the dioxin-like congeners. • Raja clavata appears to be an effective biomonitor for the Mid-Atlantic.