in the south and Ivirua and Karanga in the northeast. Mangaia's population was estimated at two to three thousand by John Williams in 1823. Despite an epidemic following European contact, and again in 1844, by 1846 its population had risen to 3567. Emigration and disease had reduced the population to 2237 in 1867, and 1700 in 1892. In the twentieth century its population grew, peaking at 2002 in 1966. The decline of the pineapple industry and subsequent economic collapse has led to further emigration and caused the population to drop by 75% from its peak, to 499 in 2016. Culture Unlike other islands of the Southern Cook Islands, Mangaia has retained its traditional collective land tenure system. Land use is decided by each district's kavana, independently of the Land Court. It has also retained its own dialect of Cook Islands Māori, reo Mangaia. One anthropologist, Donald Marshall, described Mangain residents as "the most sexually active culture on record" prior to European contact, with men "[spending] their late teens and 20s having an average of 21 orgasms a week (more than 1,000 times a year)." Economy Mangaia's economy is heavily government-supported, with 50% of the workforce employed by the public-sector. Historically, its economy was based around agricultural production, which benefited from privileged access to the New Zealand market. The removal of this access combined with shipping interruptions destroyed the industry. Subsequent depopulation has left the island lacking in basic services, with no doctor or dentist. Current exports include eis necklaces made from the shells of the pupu snail. Mangaia is connected to the rest of the Cook Islands by Mangaia Airport. Previously powered by diesel generators, since 2018 it has been powered by a solar-battery power station. Ecology Flora The flora of Mangaia can be divided into five ecological zones. The pa tai, or coast, is dominated by coconuts, Pandanus tectorius, Barringtonia asiatica, and other scrub plants. The Rautuitui, or upland makatea, is native forest, dominated by indigenous species such as Elaeocarpus tonganus, Hernandia moerenhoutiana, and Guettarda speciosa, with coconuts, candlenuts, and Morinda citrifolia in areas near villages and tracks. The harsher parts of the makatea are covered in scrub, including pandanus and the endemic Geniostoma sykesii. The Puna (swampy lowlands) contain the island's most fertile soils, and are dominated by introduced and cultivate species such as taro, coconut, and Hibiscus tiliaceus. The Rautuanue (slopes) and maunga (mountain) are heavily modified,