The first significant Neolithic migration of people into the Pacific was the dispersal of Lapita culture at 3200-2850. cal. BP that involved the colonization of previously uninhabited and large island groups. Population expansion was accompanied by the introduction of domesticated plants and animals, but the location and content of Lapita deposits frequently suggests that early subsistence focused on the collection of wild resources. The tension between models that advocate Neolithic migration as sustained by agricultural yields and archaeological data that disclose rapid dispersal and a reliance on indigenous resources is particularly acute in the Kingdom of Tonga. Lapita settlements located on the palaeoshoreline of Tongatapu are associated with extensive shell midden deposits suggesting the establishment of permanent settlements that were located in proximity to marine resources before human predation or a declining sea-level fall led to resource collapse and site abandonment. Analysis of a shell midden sample associated with ancient burials from Talasiu on Tongatapu suggests a small sedentary occupation that lasted a few generations ~ 2700-2650 cal BP. Site abandonment does not appear to have been caused by a decline in marine yields and identified starch from eight food plants is the first direct evidence for a broad-spectrum mixed economy. While human predation of marine resources was substantial, sea-level fall is likely to have led to the closure of the Fanga 'Uta Lagoon at ~ 2500 cal BP resulting in the loss of benthic habitats and the reduction of economically important marine taxa that sustained and structured early sedentism.