central island has already partially subsided, so that ancient parts of the crater rim still protrude from the water as islands of igneous rocks. The long-sunken caldera can still be noted by the position of the islands in the lagoon. The entire group sits on an underwater rise that sinks relatively rapidly in the south and east, so that the 65 km long fringing reef only rises above the water surface on three sides. From there, numerous low motus, composed of coral sand and rubble, rise just above the sea surface. Economy Today, pearl farming is practiced in the numerous pearl farms in the Gambier lagoons, whose relatively cold waters allow the production of quality pearls. There are 129 farms, including fourteen companies. In recent years, although far from the large population centers of French Polynesia, the archipelago has seen its population increase thanks to pearl farming and the exploitation of mother-of-pearl.In terms of tourism, the Gambier archipelago is one of the least visited in French Polynesia. The remoteness of Tahiti and the price of airfare to get there are largely responsible for this, but the islands have potential because of their climate, environment and unique historical past. A few sailboats call at Rikitea Bay and tourists wishing to visit the British Pitcairn Islands pass through Mangareva as a base. Local production in the Gambier Islands is limited to a few productive sectors, such as subsistence farming and fishing, and most consumer goods are transported by a cargo service operated by two schooners, which rotate every three weeks. The inhabitants are self-sufficient. They grow yams, taro and breadfruit, as well as all kinds of tropical fruits and, to a lesser extent, coffee for export. Politics and government Politically, the Gambier Islands belong to French Polynesia. They form one of 17 municipalities () administered by a subdivision () of the High Commissariat of French Polynesia () in Papeete, Tahiti. In addition to the Gambier Islands in the geographical sense (i.e. including the atolls of Gambier and Temoe), the following atolls in the southeast of the Tuamotu archipelago belong to the municipality of Gambier: Maturei Vavao Atoll Tenararo Atoll Tenarunga (or Tenania) Atoll Vahanga Atoll Maria Atoll Marutea Sud Atoll Morane Atoll The municipality of Gambier had a total population of 1,421 inhabitants according to 2012 data, with a population density of 43 p.e./km. The official language is French. The currency is