Participatory systematic mapping as a tool to identify gaps in ecosystem services research: insights from a Baltic Sea case study

•The evidence base on ecosystem service research in the Baltic Sea was mapped systematically.•57 publications on marine and coastal ecosystem services were finally selected for review.•Missing links between science and marine policy making were identified.•Knowledge gaps were indicated to guide future research.•The participatory systematic map method proved to be a valuable tool for ecosystem service research. Evidence-based decision making and policy development rely on the syntheses of available scientific knowledge and the identification of respective knowledge gaps. This article presents a participatory systematic map, which constitutes a relatively new methodological approach in the field of ecosystem services (ES) research. The map identifies, collates, and describes the evidence base on marine and coastal ES research in the Baltic Sea. Key stakeholders were involved throughout the whole mapping process. 1006 publications, identified through searches in eleven databases, were double-screened and 57 publications were found eligible. The results show that research on provisioning, regulating and cultural ES is uniformly distributed in the evidence base while most studies applied bio-physical assessment approaches. The most frequently researched ES are the regulation of nutrients, the provision of fish, and recreation. Only a few studies were conducted in the context of marine policies. While ES research is growing in the Baltic Sea area, this systematic map highlights the plethora of definitions and lack of standardized approaches as an obstacle for policy implementation. The method of participatory systematic mapping was identified as a useful tool for ES research to identify all available knowledge on a specific topic, determine knowledge gaps and inform both researchers and policy makers.