FutureMARES sets out to support designing intelligent climate policy by broadening our understanding to what extent climate change (CC) jeopardizes ecosystem functioning and services, and the potential for effective and efficient nature-based solutions (NBSs) to safeguard biodiversity contributions to people. To accomplish this, FutureMARES will develop evidence-based guidance at appropriate spatial and temporal scales for three NBSs (effective habitat restoration, conservation strategies and sustainable harvesting) across a broad range of European and other marine and transitional systems resulting from a guided process leading to in-depth knowledge integrating climate, social, ecological and economic systems (Fig. 1). The overarching goal is to provide socially and economically viable actions, strategies and NBSs for CC adaptation and mitigation to safeguard future biodiversity, and ecosystem functions, maximising natural capital and its delivery of services from marine and transitional ecosystems.

Over the last > 10 years, GEOMAR has conducted a series of in situ pelagic mesocosm studies on ocean acidification (OA) using the KOSMOS experimental system in European waters from the high Arctic off Spitsbergen to temperate waters in the North and Baltic Sea to subtropical oligotrophic waters off Gran Canaria (Fig. 2). The consistent experimental approach of these studies allows for cross-ecosystem comparisons over a wide range of climate zones. Knowledge yield was further amplified by international scientist, who joined via the EU-project AQUACOSM and which is connecting mesocosm facilities all over Europe. Within FutureMARES task 1.4 (Biodiversity Scenarios), GEOMAR project partners are conducting a systematic analysis of the comprehensive data sets collected during these KOSMOS mesocosm studies on OA-induced changes in zooplankton biodiversity and their impacts on ecosystem services, such as trophic transfer and CO₂ sequestration. The projections derived from this analysis shall be compared with published results from smaller-scale approaches obtained from land-based and in-door community level experiments and with ecophysiological responses obtained in lab-based culture experiments.