Tackling marine pollution in the Mediterranean Sea: needs for harmonized multidisciplinary data

Land and sea-based sources of pollution have long been a threat to the quality of the marine environment in the Mediterranean Sea. Despite long-term monitoring efforts since the 1980s, a coherent and harmonized assessment of pollution at the sub-basin scale remains challenging due to the unknown quality of data in some areas, scarce and limited data, and heterogeneous monitoring programs. Pollution assessment requires information concerning anthropogenic pressures, contaminant concentrations, and environmental characteristics (e.g. sediment granulometry), as well as detailed information on the sampling and analytical methods and quality assurance/quality control protocols. Within the frameworks of European and sub-basin scale initiatives such as the European Marine and Observation Network (EMODnet) and Harmonization and Networking in the Ionian and Adriatic Seas (HarmoNIA), considerable effort is being dedicated to collecting, standardizing, harmonizing, validating, and providing access to data on chemical pollutants according to the ‘FAIR’ principles. In addition, these data have been merged with spatial information on possible pollution sources to help improve the management of maritime activities towards the goals set by several legal obligations (e.g. the Marine Strategy Framework Directive for the achievement of Good Ecological Status, European Zero Pollution Strategy, and Marine Spatial Planning). To promote a coherent assessment of marine pollution, we present the approach adopted to create an integrated and interdisciplinary ocean data system that addresses marine pollution threats and specific requirements for data, metadata, and ancillary information. The adoption of consolidated open standards in terms of metadata profiles, controlled vocabularies, dataset formats, commonly agreed quality control procedures, and quality flagging schema developed in a framework of international cooperation promotes interoperability among different and multidisciplinary data infrastructures (e.g. those of UNEP, ICES and SeaDataNet). In addition, dialogue with major data user communities helps to continuously improve data management to better address societal needs.