Leverage points to transform aquatic food systems: insights from Italy, Estonia, Denmark, Greenland, Estonia, and Italy

• Systemic mapping of lock-in and enabling mechanisms in aquatic food systems. • Comparative evidence on cross-cutting and context-specific mechanisms. • Values, policies, collaboration, and funding systems identified as leverage points. • Case-based evidence on interdependencies across leverage points. • Actionable insights to unlock the transformative potential for aquatic food system . Aquatic food systems hold significant potential to address complex social, economic, and environmental challenges, yet their transformative capacity is often constrained by persistent structural, sociopolitical, and institutional lock-ins. Unlocking this potential requires a systems perspective that identifies where change is most constrained and where opportunities for transformation lie. This paper applies a systems-thinking approach to examine transformation mechanisms in aquatic food systems across four coastal communities – Denmark, Greenland, Estonia, and Italy – using qualitative modelling with Causal Loop Diagrams (CLDs). By integrating diverse stakeholders' perspectives, we identify both enabling and lock-in mechanisms for aquatic food systems transformation, bridging context-specific dynamics with cross-cutting patterns to generate actionable insights. Our analysis contributes to the ongoing discussion on leverage points for transformation by providing comparative case study evidence on four interdependent leverage points: (i) values that set the direction for governance and institutional change; (ii) coherent policies; (iii) collaboration networks as the social infrastructure enabling alignment of political, institutional, and research agendas; and (iv) adapted funding mechanisms to ensure the enabling environment translates into the adoption and scaling of innovations along the value chain. Grounded in empirical, cross-case evidence, we show how acting simultaneously across different leverage points can maximize their transformative potential. The findings offer practical guidance for designing integrated, context-sensitive, and systemically informed interventions that foster sustainable and equitable aquatic food systems.