Decision support tools (DSTs), like models, GIS-based planning tools and assessment tools, play an important role in incorporating scientific information into decision-making and facilitating policy implementation. In an interdisciplinary Baltic research group, we compiled 43 DSTs developed to support ecosystem-based management of the Baltic Sea and conducted a thorough review. Analyzed DSTs cover a wide variety of policy issues (e.g., eutrophication, biodiversity, human uses) and address environmental as well as socio-economic aspects. In this study, we aim to identify gaps between existing DSTs and end-user needs for DSTs for supporting coastal and marine policy implementation, and to provide recommendations for future DST development. In two online surveys, we assess the awareness and use of DSTs in general, as well as policy implementation challenges and DST needs of representatives of public authorities from all Baltic countries, in particular. Through a policy review we identify major policy issues, policies, and general implementation steps and requirements and develop the synthesis-matrix, which is used to compare DST demand and supply. Our results show that DSTs are predominantly used by researchers. End-users from public authorities use DSTs mostly as background information. Major obstacles for DST use are lacking awareness and experiences. DST demand is strongest for the policy issue eutrophication. Furthermore, DSTs that support the development of plans or programs of measures and assess their impacts and effectiveness are needed. DST supply is low for recently emerging topics, such as non-indigenous species, marine litter, and underwater noise. To overcome existing obstacles, a common database for DSTs available in the BSR is needed. Furthermore, end-users need guidance and training, and cooperation between DST developers and end-users needs to be enhanced to ensure the practical relevance of DSTs for supporting coastal and marine policy implementation. To fill existing gaps, DSTs that address impacts on human welfare and link environmental and socio-economic aspects should be developed. The Baltic Sea Region serves as a best practice case for studying DSTs and their practical use. Hence, our results can provide insights for DST development in other marine regions. Furthermore, our methodological approach is transferable to other areas.

Over 350 European Integrated Coastal Zone Management (ICZM) ‘best practice’ case studies are documented in the OURCOAST online public database, to ensure that lessons learned from experiences and practices are shared and improve coastal management practices. However, concrete criteria for ‘best practice’ are missing and a critical evaluation of the success of these case studies did not take place. We present an indicator-based tool and methodology that allows assessing the progress towards sustainability of ICZM measures. An indicator-based tool was applied to 18 thematically different coastal case studies using two different methods: a fast screening and an analysis in-depth assessment. Both methods used help to identify strengths and weaknesses of ICZM and their contribution to sustainable development. However, indicator scores were highly affected by evaluators’ background and perception. The tool is user-friendly and easy to apply, it indicates what progress has made towards sustainability and to which extent targets have been met.

Spatial assessments of ecosystem services (ES) are needed to fulfil EU policy requirements and to support practical applications of the ES concept in policy implementation. So far, ES assessments have largely focused on terrestrial systems. A joint approach for land and sea is especially lacking. To overcome this gap, we present a novel spatial habitat typology and ES classification for an assessment across the land–sea interface. We build upon existing approaches and common spatial definitions, like CORINE land cover (CLC) types, water bodies of the Water Framework Directive (WFD), and habitat types according to the Habitats Directive (HD). We show applications of the resulting ES matrix for an expert-based assessment of ES potentials in three Baltic study sites (Schlei, Greifswald Bay and Curonian Lagoon). A complementary indicator-based approach to assess ES flows is introduced and applied. It enables a quantification of ES potentials and flows and ensures comparability among case study sites. Comparisons between the results for ES potentials and flows show that development capacities exist in particular for provisioning ES for marine habitats. Our approaches are spatially expandable and transferrable and could be applied to support environmental policy implementation. Further, we discuss their practical relevance, current limitations, and future research perspectives.