Austronesian speakers arrived in New Guinea later than Papuan speakers, bringing with them items such as the domesticated pig, outrigger canoes, and navigational skills. The Proto-Austronesian Lapita culture, centered in the Bismarck Archipelago since at least 1,600 B . C ., is believed to be ancestral to the Manam. The Manam themselves say that they came from the west prior to settling on Manam. Early written references to Manam are found from the sixteenth century on in the ships' logs of Europeans who noted the island's volcano. Regular contact with Europeans began when the Germans claimed sovereignty over northeast New Guinea in 1884. There have never been nonindigenous coconut plantations on Manam; however, over the years many Manam have worked as contract laborers on coastal plantations and in the goldfields of Wau and Bulolo. Since its establishment on the island in 1925, the Society of Divine Word Catholic mission has been the most significant Western influence. During World War II the Japanese occupation of the mainland caused the Manam to abandon their villages to live in the jungle for the duration of the war. The end of the war opened the way to considerable change, including much interest in the cargo cult and protonationalist activities of the Rai Coast leader Yali, native production of copra for sale, and the Development of other commercial activities. These enterprises, combined with increasing educational and job opportunities on the mainland, have led to a continuing dependence on cash and a consumer economy. The Manam have Traditionally maintained exchange relations with hereditary trade partners ( taoa ) on the mainland. There is little or no contact with other Schouten Islanders. Trade most frequently occurs with the Momboan villages on the coast directly across from Manam and with Kaian, Boroi, Watam, and Marangis villages near the Ramu River.