The need to assess and address the increasing presence of coexisting environmental threats, that propagate in space and time also across political boundaries, calls for a transactional coordinated actions based on evidence-rooted common understanding.SHAREMED will:- engage stakeholders and authorities, and jointly define state-of-the-art and regional strategies;- collate and harmonise existing info, data and knowledge and contribute to joint production of a database of coherent data;- define common procedures and jointly produce atlas of state and hazard maps;- integrate existing observing infrastructures in a common transnational system of systems and jointly disseminate observations through common portals;- enhance forecast capabilities through development and implementation of coastal high resolution transnational systems;- explore potential of new observing methodologies;- define roadmaps, guidelines, action plans.The actions above will: - increase capability of authorities and scientific community to observe, assess and address environmental threats;- increase coherence and efficacy of assessments;- favour access and use of existing information and project joint products.The project will capitalise on knowledge provided by previous projects and existing EU infrastructures, and will contribute to the definition of long term strategies and action plans for assessing and addressing environmental threats in the Mediterranean.