Project background: Transitional waters (TWs) link adjacent river basins and marine areas and are critically important for the ecological health of the Baltic Sea. Four cross-border TW regions of the South Baltic Area (SBA) – Curonian Lagoon (LT/RU), Vistula Lagoon (RU/PL), Odra Lagoon (PL/DE) and Oresund Sound (DK SE) – are the target areas for the project. The European Water Policy and the EU Water Framework Directive (WFD) set the guidelines for managing river basins, while marine areas are managed within the EU Maritime Spatial Planning (MSP) framework. To implement these policies and to ensure a proper environmental integrity of the TWs, the cross-border cooperation of local and regional interest groups, citizens and politicians is crucial.Project rationale and aims: ARTWEI will be based on existing experiences from the EU and international Baltic Sea cooperation networks and develop local and regional methods for effective management of TWs from two perspectives: first, cross-border cooperation and second, environmental integrity of river basins – TWs – open sea. ARTWEI, hence, is aimed to facilitate coherent spatial planning and Strategic Environmental Assessment (SEA) efforts across administrative borders and the land-sea boundary. It will build relevant capacities among the local and regional interest groups; including political involvement on different levels as a key prerequisite for the maintenance of environmental integrity in the TWs. The content of ARTWEI focuses on the development of an effective South Baltic cross-border cooperation network for the advanced cross-border TW management and for the maintenance of environmental integrity by introducing a cooperation model of the cross-border Transitional Waters Stakeholders Bodies (TWSBs). Four cross-border TWSBs will be established (one in each TW area) which, in close cooperation among all four areas, will develop and launch local programmes of measures with particular focus on the integrated cross-border spatial planning and SEA. All four TWSBs will jointly build a common innovative knowledge pool of the best experience forming the basis of a Good Practice Code of Conduct for reinforcing of the environmental integrity of the South Baltic TWs. The ultimate project result is effective regional co-operation and strong political support for the integrated cross-border management of TWs in connection with river basins and the sea. Concrete conclusions and recommendations for the durable reinforcement of the environmental integrity of the TWs will be developed and politically endorsed in the form of a Good Practice Code of Conduct. A web-based multilingual platform, including webGIS and other ICT tools, will be created facilitating an interactive knowledge exchange within and among the TWSBs. Environmental education will be an additional tool implemented in the form of a transboundary coastal dialogue, a photo competition and a public information system Achievements: The major achievements of the project are:-Project final report compiled with the total spending of 94,80%.-Budget reallocation percentage 9,64 %-Budget changes between partners 1,53 %-Final accomplishing of cross-border photo competitions; -Dissemination of ARTWEI project results to varous international conferences and project meetings, major of it being EMD 2013 in Malta (May 2013 20-23)-Web page visits 8751 as of 2013 end; -3 media coverage and press releases; -Launching of an open source-based knowledge exchange platform that provides links to web-based geographical information delivery systems; -Good Practice Code of Conduct for the reinforcement of the TW environmental integrity based on cross-border solutions translated into Polish; -Improved capacities of the stakeholders in proper management and maintenance of the environmental integrity of the SBTWs in the target areas.