LAUSR

Abstract Global threats to ocean biodiversity have driven international targets calling for a worldwide network of marine protected areas (MPAs). In line with these targets, the Commission on the Conservation of Marine Living Resources (CCAMLR) has been working towards adopting MPAs in the Southern Ocean. CCAMLR is considered a leader in science-based management and has been guiding the way on international MPAs. The west Antarctic Peninsula, threatened by climate change and industrial fishing, has been a priority area for MPA planning in CCAMLR. Since 2011, Chile and Argentina have worked to develop an Antarctic Peninsula MPA proposal which they submitted to CCAMLR in 2018. We use the Antarctic Peninsula MPA proposal process as a case study for understanding the science-policy interface in this international conservation regime. Specifically, we use existing frameworks for co-production of actionable science to examine the Antarctic Peninsula MPA process. We show that the Antarctic Peninsula MPA Proponents engaged in a highly collaborative, transparent, and science-based process which exemplified best practices for actionable science and co-production. Despite following best practices for actionable science, the MPA proposal has not yet been adopted, largely due to political barriers. We elaborate on the importance of co-production of actionable science and its effectiveness as well as to limitations in the Southern Ocean and beyond. Finally, we highlight that science-policy best practices may not be sufficient to drive consensus and the ultimate need for political will in the decision-making underpinning MPA designation in the Southern Ocean.