The Kingdom of Tonga comprises 170 islands of volcanic and coral origin spread over a sea area of 360,000 sqaure km. There are four main islands groups: Tongatapu and „Eua, Vava‟u, Ha‟apai and the remote Niuas. Tonga has a population of 101,134 persons living on 36 islands. Land resources are limited, and only 24% of the country‟s 747 km² is arable. Tonga is experiencing a number of socio-economic and environmental challenges.