Bioaccumulation patterns of hydrocarbons and polychlorinated biphenyls in bivalves, crustaceans, and fishes.

Abstract

Hydrocarbons and polychlorinated biphenyls (PCBs) were determined in tissues of marine organisms (mussels, crabs, benthic, and pelagic fishes) from six sites along the Catalan Coast (Western Mediterranean). Both aliphatic and aromatic hydrocarbons as well as seven PCB congeners (PCB-28, 52, 101, 118, 138, 153, 180) were quantified and differences in concentrations interpreted in terms of geographical distribution, trophic level, and biological cycle of the organisms. The bioaccumulation patterns of the different chemicals varied substantially. Hydrocarbons were metabolized along the food web, contrarily to PCBs, which exhibited a higher bioaccumulation in fishes. Considering 36 peaks of the GC-ECD profiles, encompassing 40 PCB congeners, from tri- to octa-chlorinated isomers, a relative enrichment was observed in the higher chlorinated ones from: mussels < mullets < tuna < crabs. The slopes of the correlation plots between the bioconcentration factor (log BCF) and the octanol-water partition coefficient (log K(ow)) for the different PCB congeners reflected the feeding behavior of the organisms, mussels exhibiting a preferential uptake by direct partitioning from water, and mullets and crabs with a certain uptake from sediments. Increasing metabolic degradation following a similar trend among species was also observed for aromatic hydrocarbons and PCB congeners containing meta and para vicinal H-atoms. Accordingly, mussels and benthic fishes were the best indicators of coastal pollution in the water column and sediments, respectively, although the above features should not be overlooked in the interpretation of biomonitoring data.