Integrated ocean governance is needed in the Southwest Atlantic Ocean to foster fisheries, conservation and resilience to climate change.

The Southwest Atlantic Ocean (SWAO) is a globally important region, where diverse water masses converge and mix, regulating the Earth's climate while supporting productive fisheries and high marine biodiversity. Ecological connectivity is also substantial, with multiple species and ecosystems shared across multiple jurisdictions and international borders. However, despite historical efforts and more recent calls for regional management, the SWAO is one of the few large oceanic regions with no dedicated ocean governance body covering all shared resources. This disconnect is particularly alarming in the face of climate change, which is altering the distribution and abundance of fish stocks, shifting species ranges poleward, and intensifying uncertainty in marine resource management. A collaborative regional framework, rooted in ecosystem-based management, is urgently needed to foster sustainable management as well as bolster resilience to the impacts of climate change. As Brazil hosts a series of United Nations meetings on environmental topics, the region faces a decisive moment: either to remain reactive to external governance structures or to proactively design frameworks that reflect regional priorities, balance sovereignty concerns, and better integrate scientific evidence into decision-making. Thus, we invite decision makers, managers and scientists to take advantage of the political momentum in Latin America to advance integrated and multi-scale ocean governance, while strengthening ocean science diplomacy in the SWAO. This is a call to help navigate an uncertain future by addressing shared challenges and prioritizing ocean sustainability in the SWAO.