Sarang is the name of a small island in Kelurahan (administrative village) Sekanak Raya, Belakang Padang sub-district, Batam city, administratively. Sarang island is located in the border of international waters, facing Singapore directly. In the 1960–19801, this island along with other area nearby is coastal area with fairly complete ecosystem and in a good natural condition. Mangrove, sea grass, and coral reef create marine ecosystem that are able to support the main livelihood of the local people. Most of the people live as fshermen. The condition of good marine ecosystem is proven to infuence people’s livelihood. They don’t have to...