The use of a kinetic biomarker approach for in situ monitoring of littoral sediments using the crab Carcinus maenas.

Caged, transplanted, intermoult, female shore crabs (Carcinus maenas) were exposed to sediments from the Port of Cadiz (SW, Spain); the Port of Huelva (SW, Spain), the Port of Pasajes (NE, Spain) and the Port of Bilbao (NW, Spain) for a period of 28 days. Organisms were sampled on days 0, 7, 14, 21 and 28 allowing examination of different biomarkers to exposure to metals and organic compounds; metallothioneins (MTs), ethoxyresorufin O-deethylase (EROD), glutathione-S-transferase (GST) and glutathione peroxidase (GPX). Sediment samples were also analyzed to determine chemical concentration of metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn), PAHs and PCBs. Metals such as As, Cu and Zn associated with mining activities (Port of Huelva), and contaminants such as Ni, Pb, Hg and PCBs, associated with oil spills and industrial activities (Ports of Cadiz, Pasajes and Bilbao), were found to interfere in detoxification and/or anti-stress oxidative defenses in C. maenas. Positive, significant (p<0.05) induction of MTs concentration was associated with increasing sediment As, Cu, Zn and Hg concentrations. EROD activity was associated with PCBs, GST activity with Hg and GPX activity with As, Cu, Ni, Pb and Zn. The use of the parameter AR, which involves the kinetic patterns of the battery of biomarkers tested, was found to be a powerful and sensitive tool for evaluating the bioavailability and adverse effects of contaminants bound to sediments, enabling polluted and nonpolluted sites to be easily distinguished.