Résumé
Marine social-ecological systems across the Western Indian Ocean (WIO) face unprecedented pressures, demanding interventions and approaches designed to create new and sustainable systems of human-environment interactions. Transformation theory offers frameworks for understanding systemic change, but the empirical testing in marine contexts remains limited, particularly at regional scales. This study addresses this gap by analyzing three marine transformation case studies in the WIO region: seabird bycatch mitigation in South African fisheries, fisheries co-management in Tanzania, and regional tuna fisheries management through the Indian Ocean Tuna Commission. Each case was analyzed through Olsson's three-phase transformation framework (Preparing for change, Navigating transition, and Building resilience) while tracking the evolution of knowledge systems, leadership functions, and transformation attributes including scope, depth, and speed. Our findings reveal contrasting strategies for scaling transformative change and some common patterns. Notably, an inverse relationship between governance scale and transformative depth was found: local and national initiatives achieved deeper transformations through market incentives and community capacity building respectively, while regional governance faced greater barriers due to competing national interests and institutional inertia. All transformations required decades of sustained effort and specific actor functions to guide transformation, such as actors providing information and knowledge, actors leading and guiding action, and those connecting people and coordinating effort. Strong leadership functions were also found to help overcome resistance to change. These case studies emphasize that although some common patterns emerge, unlocking the potential for successful transformation in marine social-ecological systems of the WIO is context-dependent, with no one-size-fits-all solution. Success depends on the alignment of problem framing, institutional capacity, actor interests, and value alignment within specific socio-political contexts.