Taking a regional ocean-based approach - Integrating Ocean Acidification into the European Union's Marine Strategy Framework Directive

This paper examines the integration of ocean acidification (OA) considerations into the European Union's Marine Strategy Framework Directive (MSFD). Ocean acidification, driven by the increase of CO₂ in ocean water, threatens marine biodiversity, fisheries, and economies across European waters, affecting ecosystems in the North-East Atlantic, Baltic, Black, and Mediterranean seas. This study identifies opportunities within MSFD descriptors, particularly Descriptor 5 (eutrophication) and Descriptor 7 (hydrographical conditions), to integrate OA parameters in ways that strengthen the EU’s goal of achieving Good Environmental Status (GES). The study further highlights the role of Regional Seas Conventions, such as OSPAR and HELCOM, as key platforms for coordinating OA monitoring and data-sharing across borders, promoting harmonized efforts to address OA impacts on marine ecosystems. By leveraging these collaborative networks, EU Member States can ensure that OA indicators and best practices are consistently applied, fostering more regionally coordinated responses to the challenges of OA. This paper also demonstrates that scientific data on OA can be effectively translated into policy actions through strategic MSFD integration, providing a valuable model for adapting marine policy to emerging environmental threats. By embedding OA-specific monitoring and mitigation within the MSFD framework, this research underscores how European nations can support ecosystem resilience, advancing sustainable marine management in a changing climate.