Integrated systematic planning and adaptive stakeholder process support a 10-fold increase in South Africa's Marine Protected Area estate

South Africa sought to implement an ecologically representative Marine Protected Area (MPA) network to achieve biodiversity and fisheries management goals with least impact on offshore stakeholders. The result was the declaration of a spatially efficient network representing 131 of 150 marine ecosystem types (87%) in 5.4% of ocean area. We outline the 15-year process from planning to implementation of 20 new MPAs, including contentious areas recognized as important for conservation decades ago. Systematic Conservation Planning (SCP) supported by 532 data layers and an inclusive stakeholder process identified priority areas, reduced conflict and guided complex trade-offs. Multiple scenarios and iterative improvements increased transparency, supported ocean zonation and achieved balanced compromises while maintaining conservation objectives. Key challenges, enabling factors and lessons are shared. We demonstrate that flexible, evidence-based SCP together with adaptive social processes that are alert to opportunities can support implementation of representative MPA networks aligned to ocean economy goals.