Abstract Human activities at sea can produce pressures and cumulative effects in ecosystem components, that need to be monitored and assessed, in a cost-effective manner. Five Horizon European projects have joined forces to collaboratively increase our knowledge and skills to monitor and assess the ocean in an innovative way, assisting managers and policy-makers in taking decisions to maintain sustainable activities at sea. Here we present and discuss the status of some methods revised during a summer school, aiming at a better management of coasts and seas. We include novel methods to monitor the coastal and ocean waters (e.g. environmental DNA, drones, imaging and artificial intelligence, climate modelling and spatial planning) and innovative tools to assess the status (e.g. cumulative impacts assessment, multiple pressures, Nested Environmental status Assessment Tool (NEAT), ecosystem services assessment, or a new unifying approach). As a concluding remark, some of the most important challenges ahead is assessing pros and cons of novel methods, comparing them with benchmark technologies, and integrating these into long standing time series for data continuity. This requires transition periods and careful planning, which can be covered through an intense collaboration of current and future European projects on marine biodiversity and ecosystem health.