A harmonized and integrated approach for monitoring and assessment of contamination, including hydrocarbon exploitation one, is required both by Marine Strategy Framework Directive (MSFD) at EU level and by the Ecosystem Approach (EcAp) program of the Barcelona Convention at Mediterranean level. A broad review of protocols of environmental impact assessment (EIA) procedures, monitoring and decommissioning of offshore platforms adopted by EU and non-EU countries along the Adriatic-Ionian seas was carried out in the framework of the Interreg offshore platforms in Adriatic-Ionian (ADRION) project HarmoNIA (Harmonization and networking for contaminant assessment in the Ionian and Adriatic Seas). The comparison of information provided by six ADRION countries and the application of a harmonized and integrated approach has highlighted specific challenges for managing offshore platform impacts emerged at ADRION level: (i) need of the same legislative level (the Offshore Protocol of Barcelona Convention is not ratified by all countries); (ii) set up of a task force of ADRION experts for discussing critical issues related to impacts of offshore platforms; (iii) harmonization, at the regional level, of EIA procedures, monitoring and decommissioning; (iv) need of an agreed and common list of recommended parameters to monitor in water, sediment and biota for the assessment of impacts due to platform installations and PFW discharges.

During 2006–2008, a pipeline was buried in Vallona lagoon in the Northern Adriatic Sea (Italy). A Before-During-After environmental monitoring programme was scheduled to monitor possible alterations. Bioaccumulation of metal(loid)s, BTs (butyltins) and HMW-PAHs (High Molecular Weight Polycyclic Aromatic Hydrocarbons), and biological responses (Condition index, air Survival—LT_50, Acetylcholinesterase, Micronuclei—MN, acyl-CoA oxidase, catalase, malondialdehyde—MDA, and the total oxyradical scavenging capacity—TOSCA) were investigated in Manila clams (Ruditapes philippinarum) from November 2005 to June 2015. In opera (IO) results showed higher levels of HMW-PAHs (73 ± 13 ng/g), BTs (90 ± 38 ng Sn/g) and increasing levels of Pb (6.7 ± 0.7 mg/kg) and Zn (73.6 ± 6.08 mg/kg) probably linked to works. Other contaminant alterations, especially metal(loid)s, before (AO) and after (PO) the burial, were attributed to a general condition of the area and mostly unrelated to works. In addition, LT₅₀, MN and TOSCA showed alterations, probably due to hotspots occurring in IO. TOSCA and MDA increases, right after the burial, were considered delayed responses of IO, whilst other biological responses detected later were connected to the general condition of the area. Comparisons between results of Principal Component Analyses (PCAs) highlighted partial overlapping of AO and IO, whilst PO differed only for contaminants. Visual correlations between PCAs highlighted the biomarkers’ latter response.

In 2009, the first Italian offshore LNG terminal, located approximately 12 km from the coast of Italy in the Northern Adriatic Sea, started its operation phase. Even if the active chlorine concentration in the discharged seawater is within limits set by Italian regulations (0.2 mg/L), to verify the environmental impact of disinfection by-products (DBPs) on the ecosystem, a specific monitoring program was scheduled from 2010 to 2015. The present study is the first displaying results of DBPs in marine waters of the Adriatic Sea. During the first two years of monitoring activities, DBPs were slightly above limit of quantifications (LOQs) in all investigated matrices and limited to the nearest area around the terminal. In these surveys, bromoform was the most frequently detected compound in seawaters, while haloacetic acid presence, as well as transplanted mussels and fish fauna, mostly characterized sediments. In the following surveys, levels were mostly negligible in all matrices investigated, with values mostly below the specific LOQs of the different compounds.