From cumulative impacts to informed decisions: an operational ecosystem-based framework for sustainable ocean management

Abstract

There is an increasing need to carry out cumulative effects assessment (CEA) in marine environments to support ecosystem-based management (EBM) and achieve Good Environmental Status (GES) under European and global policy frameworks. This need has been addressed by the 4 year major European project GES4SEAS, which has developed and operationalized an innovative, science-based toolbox to assess and predict the impacts of multiple human pressures, including climate change, on marine ecosystems, their functioning, and the delivery of ecosystem services and societal benefits. To achieve this objective, during the project, we proposed a framework which overcame major challenges, as shown in this review, through progress in recent years. For that, GES4SEAS implemented a co-creation approach involving a high-level Practitioners Advisory Board, ensuring alignment with policy needs and enhancing the uptake of results. This enabled developing a comprehensive conceptual and analytical framework linking EBM principles with key management elements and appropriate methodological tools, thereby bridging the gap between theory and implementation. Significant progress has been made in understanding cumulative effects by integrating statistical, empirical and mechanistic models, which increased identifying non-linear responses, tipping points and ecological feedbacks. In parallel, the project delivered a suite of interoperable tools, centered on the Tikta software and supported by other tools, enabling holistic assessments of pressures, ecosystem components and services. These tools were rigorously tested across multiple European and international case studies (“Learning Sites”), demonstrating their robustness, transferability and applicability across diverse ecological and data contexts. As such, GES4SEAS represents a major step forward in the state-of-the-art of CEA by transforming fragmented approaches into an integrated, operational workflow to inform marine governance. The project provides practical decision-support systems that enhance transparency, address uncertainties and facilitate adaptive management. By strengthening the science–policy interface and enabling informed decision-making, GES4SEAS has contributed directly to sustainable ocean governance and the achieving environmental and socio-economic objectives under global change.