The fact that islands are isolated leads to very high endemism rates (i.e., the percentage of animal or plant species that don’t exist anywhere else), up to 9.5 times higher than that of continental areas. This remarkable biodiversity, whose future is intimately tied to that of human communities, is nevertheless fragile. Islands could shelter up to 40 percent of threatened and particularly endangered species. Biodiversity loss on Islands is linked to several phenomena, firstly to biological invasions, reinforced by the absence of predators or parasites for some species, the reduction of the size and distribution area of some specie populations and the low connectivity with nearby ecosystems, but also to the destruction and fragmentation of habitats, the overexploitation of certain resources (including fisheries), and pollution.
Climate change is aggravating these phenomena and impacting the resilience of islands and island communities (that is, their ability to recover from external disruptions): as they are geographically isolated, islands are more frequently exposed to extreme climatic conditions that are likely to degrade ecosystems which are extremely important to local species.
Island inhabitants are also very dependent on local natural resources and their unique biodiversity, which is both valuable and particularly fragile. The sustainable management of islands should therefor rely on methods which enable human activities to coexist with the protection of nature.