Is the polychaete, Perinereis rullieri (Pilato 1974), a reliable indicator of PCB and PAH contaminants in coastal sediments?

A field survey in a transitional environment (lagoon of Venice, Italy) and a laboratory exposure experiment were carried out to validate the use of polychaetes, Perinereis rullieri, as indicators of PCB and PAH contaminants in the sediments. Results from the field study showed that PCBs, predominantly the hexa- and hepta-chlorinated biphenyls, were promptly bioaccumulated in the tissues of P. rullieri, whereas PAH levels were generally low and fluctuating among seasons. Organisms experimentally exposed to natural polluted sediments bioaccumulated all the examined PCB congeners, whereas those exposed to the reference sediments were able to reduce them, at least to some extent. A PAH depletion was always observed, although the time variations for the single compounds differed from each other. The biomarker malondialdehyde (MDA), evaluated both in native and in treated organisms, was helpful as a supporting parameter in elucidating their oxidative stress condition, although depending on numerous natural confounding factors.