Sustainable development has become the catchcry for environmental protection. However, whilst sustainability goals of social, economic and environmental improvement can be easily identified, appropriate methods to resolve the often conflicting issues remain elusive. In particular, achieving positive outcomes in relation to biodiversity conservation is presenting a challenge for small island states, many of which suffer from similar problems: population pressures, cultural conflicts, economic constraints and environmental threats. Top down legal approaches have been imposed with limited success and it has now been recognised that bottom up, community based, participatory mechanisms are preferable. Much work has been done in the South Pacific to support and enhance community based conservation and management of marine areas, notably the Locally Managed Marine Area (LMMA) Network. However, it has been recognised that legal underpinning is necessary to ensure the sustainability and long term success of such projects. A range of different approaches to marine conservation have been taken in the South Pacific. In Samoa basic provisions in the national environmental legislation have been utilised to support community based projects. However, the linchpin of the success of the system is the empowerment of the village Fono and formal legal recognition of traditional customs and practices under the Fono Act. An alternative approach has been taken in Vanuatu where customary laws have been successfully incorporated into a western legislation model to provide an environmental protection regime, which meets the needs of its people by providing both sustainable livelihoods and conservation of biological diversity. The achievement of triple bottom line goals is problematic the world over, but particularly keenly felt in small island states with large indigenous populations and strong customary laws and practices. However, the experiences of Samoa and Vanuatu have shown that, if the political will to do so is present, there is no impediment to synthesising customary law and the western common law system to achieve improved outcomes in biodiversity conservation.