Use of crabs (Carcinus aestuarii) for the biomonitoring of the Lagoon of Venice (Italy)

The integrated use of a battery of biomarkers and chemical analysis of contaminants in sediment, water and biota is becoming of primary interest in environmental monitoring, permitting to enhance the data evaluation. Adult male individuals of the Mediterranean shore crab Carcinus aestuarii, a widespread, easy to sample and abundant benthic organism, were used to evaluate the ecological status of 8 sampling sites located in the Lagoon of Venice (Northern Italy) using a battery of 3 biomarkers and measuring the bioaccumulation of several persistent organic pollutants (POPs) in soft tissues. Vitellogenin (Vg) – like proteins in 3 different tissues (hemolymph, gonads and digestive glands), EROD activity in digestive gland and AChE inhibition hemolymph and gills were used to assess the possible presence of xenoestrogens, planar compounds or neurotoxicants, respectively. Results showed a significant induction in Vg-like proteins in crabs collected in several sampling sites, even if a different induction trend was observed depending on tissue. A significant EROD induction was detected in areas near industrial plants (Fusina) and in sites with intense boat traffic (San Servolo). A widespread AChE inhibition was measured in crab from most sampling sites, probably due to either indirect inhibiting effects caused by several contaminants, or direct anti-AChE activity of neurotoxic agents. An overall decreasing order of chemicals monitored in all sampling sites was PCBs>DDTs>PAHs>HCHs≈HCB. Polychlorinated biphenyls (Σ14PCBs) ranged from 0.7 ;g/g per lipids to 3.3 ;g/g per lipids, measured at the industrial site of Porto Marghera. Surprisingly, moderate to high values of the Σ6 DDTs (0.6-1.8 ;g/g per lipids) were measured in the entire Venice Lagoon, although the current EU limitations of the use and production of this insecticide. By contrast, low levels of the Σ19PAHs (0.06-0.1 ;g/g per lipids) and negligible values of HCB and the Σ4 HCHs were observe