Chapter 4 - Biodiversity of Polynesian Islands: Distribution and Threat From Climate Change

Abstract

Polynesia comprises over 1000 islands scattered over the central and southern Pacific Ocean. Fishing, tourism followed by agriculture are the major economic activities of these islands all of which are dependent on biodiversity. Polynesia is one of the global biodiversity hotspots having high endemism and more number of species per 100 km2. Polynesian islands are home to 6557 vascular plants of which 3334 are endemic and 342 vertebrate species of which 223 are endemic. This region has very high diversity and density of corals, which is known as coral triangle (CT) with 66% of all CT species common to all ecoregions. The CT harbours 37% (2228) of the world’s coral reef fish species and has several unique mangrove species as well. The major agricultural crops are coconut, tubers and roots with good diversity and endemism while other crops currently cultivated are introduced at various time of human settlement. The biodiversity of these islands is threatened by climate change and anthropogenic activities. The projected climate change and its impact on the biodiversity are discussed in details. Several conservation measures are suggested in this chapter for proper maintenance and monitoring of this global biodiversity hotspot.