Abstract Tridacna gigas, the world’s largest living bivalve, could once be found on shallow coral reefs across the Indo-Pacific Region where its presence can be traced back to around 10 million years. However, following several local extinctions throughout its geographic range, its SCS population appears to have also been the subject of unprecedented overharvesting. This article discusses the obligations of littoral States of the SCS to protect and preserve this threatened resource and its habitat, to cooperate and consult with each other to that effect and act with due diligence. Given these obligations and the risk of irreversible harm and species’ extinction in the SCS, it proposes that littoral States should proceed to list the SCS population of T. gigas in the CITES Appendix I, impose an immediate ban on further harvesting pending (re-)assessment of the population, and adopt a management plan to ensure its survival and sustainable use.