SEAwise will address the key challenge preventing implementation of a fully operational European Ecosystem Based Fisheries Management: the need to increase fisheries benefits while reducing ecosystem impact under environmental change and increasing competition for space. The SEAwise network of stakeholders, advisory bodies and scientists will co-design key priorities and approaches to provide an open knowledge base on European Social-Ecological Fisheries Systems. SEAwise will innovate the prediction of social indicators of small-scale fisheries, coastal communities, carbon footprint and human health benefits. Using these indicators in fisheries models will help give advice on economically effective and socially acceptable governance under climate change, productivity changes, and the landing obligation. SEAwise will link the first ecosystem-scale assessment of maritime activities’ impacts on habitats with the fish stocks they support. Using ecosystem effects on fishing, including environmental metrics, density dependence, predation, stock health indicators and habitat extent will improve stock productivity predictions. Estimating effects of fishing on sensitive species, benthic habitats, food webs, biodiversity and litter allows evaluation of the mutual consistency of objectives for ecological and social systems. Multispecies-multifleet models will provide ecosystem forecasts of the effect of fisheries management measures. SEAwise will identify the simplest possible combination of management measures and investigate portfolio diversification as an approach for managing ecosystem resilience and climate adaptation. SEAwise tools and courses for ICES, GFCM, stakeholders and decision makers will ensure that these methods can be used directly in Mediterranean, western European, North Sea and Baltic Sea waters. The predictions will inform an online advice tool highlighting stock- and fisheries-specific social and ecological effects and management trade-offs.