Bioindicators in monitoring long term genotoxic impact of oil spill: Haven case study

The evaluation of long term impact and risk of oil spill is a complex process involving chemical analyses and development of the ecosystem-based toxicology. An integrated biomarker approach using different bioindicators, mussels, oysters and fish with different feeding habits was applied to evaluate the long term risk from Haven oil spill along the Ligurian coast (Italy). Mussels were caged for a period of 4 weeks and fish were caught in the impacted and reference area. Caged oysters were also analyzed in different area of the wreck. DNA damage and micronuclei (MN) frequency were evaluated in gill cells of bivalves. DNA single strand breaks were measured in hepatocytes and MN were measured in fish erythrocytes. The results revealed an increase in MN frequency (more than 10 times the level at the reference site) in caged mussels from Arenzano compared to the reference area after an interval of 4 months from the accident. No increase in DNA damage and a significant increase in MN frequency were recorded in caged mussels (mean value 10.15 vs 5.3) and in benthic fish Mullus barbatus (2.5 vs 0.7) in a further sampling in 1998. Statistically significant increase of DNA damage and MN frequency was observed in caged oysters in different areas of the wreck in a biomonitoring carried out in 2001.