Risk Assessment of operational oil releases in the Adriatic Sea, in the Tyrrhenian Sea, Ligurian Sea and in the Sicily Strait

Oil slicks caused by oil tanker accidents compose a major source of hydrocarbon pollution for the marine and coastal environment and can jeopardize its functional integrity. However, the deliberate discharge of oil and oily residues associated with routine tanker operations (bilges residues, tank oil sediments) and from illegal activities, highlights a far-reaching source of pollution perhaps more important than the one caused by accidents (EEA, 2002). The Adriatic Sea with an annual oil transport of 70 MT (million tons) is probably highly affected by operational pollution. Estimates give about 15 000 mt (metric tons) of such residues deliberately discharged every year denoting a major hazard for the marine and coastal environment of Adriatic region (Bilardo et al, 2004)). Risk mapping appears as the most appropriate way to approach the management of oil pollution in marine areas and in order to assess the ecosystem health state. Modern risk mapping should, tackle the intrinsic variability of the marine environment and the lack of knowledge regarding the cause-effects relationships on vulnerability of resources, in other words should consider the inherent uncertainty of the system. Thus risk management requires products that are time-dependent and that allow the continuous assessment of the system space and time variability. Modern operational oceanography gives the appropriate time and space resolution for the ocean hydrodynamics (Pinardi et al., 2003) so that time dependent risk mapping can be developed