Small island developing States are renowned for their species diversity and endemism. However, due to the small size, isolation and fragility of island ecosystems, their biological diversity is among the most threatened in the world. Deforestation, coral reef deterioration, habitat degradation and loss, and the introduction of certain non-indigenous species are the most significant causes of the loss of biodiversity in small island developing States. Some of the most precious biological resources for islanders, environmentally, economically and culturally, are marine and coastal rather than terrestrial. This requires a conservation focus that takes into account customary land and reef tenure systems and practices, which may differ from that usually found in larger developed countries. The basic principles and specific actions that are required at the national, regional and international levels to support sustainable development in small island developing states in the area of biodiversity are outlined in Chapters 9 of the BPoA and the MSI.

Thirty eight SIDS are parties to the Convention on Biological Diversity (CBD), and all have produced at least one National Biodiversity Strategy and Action Plan (NBSAP). Twenty nine SIDS are also parties to the Cartagena Protocol on Biosafety of the CBD, which seeks to protect biological diversity from the potential risks posed by living modified organisms resulting from modern biotechnology. Twenty nine SIDS have signed the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and eleven SIDS are also parties to the Convention on the Conservation of Migratory Species of Wild Animals (CMS).