This side event will highlight three CMS proposals that demonstrate the urgent need for international cooperation to conserve highly threatened shark species across regional and global scales. In the Southwest Atlantic, the Patagonian narrownose smoothhound (Mustelus schmitti) and the angular angel shark (Squatina guggenheim) face severe population declines due to intensive fishing pressure, bycatch, and habitat degradation. Both species are transboundary or regionally endemic, with life histories that require coordinated management among Brazil, Uruguay, and Argentina, making Appendix II listings under CMS essential. At a global level, the bigeye, common, and pelagic threshers (Alopias superciliosus, A. vulpinus, A. pelagicus) are among the most extinction-prone pelagic sharks. Despite existing international measures, unmanaged fishing mortality and trade continue to drive declines. An Appendix I listing is now necessary to ensure strict protection across all Range States. The event will present scientific evidence underpinning these proposals and highlight CMS as a critical framework for preventing shark extinctions through coordinated international action.