'Unshelling the past’ – an archaeological study of shellfish assemblages from Caution Bay, Papua New Guinea

The recent discovery of Lapita pottery at Caution Bay, on the southern coast of Papua New Guinea (PNG) has transformed our understanding of the Lapita culture complex by confirming the migration of Lapita peoples into the southern coast of mainland PNG from around 2900 cal BP where they encountered an extant population who had occupied the Caution Bay area from around 5000 years ago (David et al. completed ms; McNiven et al. 2011). Although Lapita peoples have been traditionally characterised as ‘marine specialists’, relatively little is known about their shellfish subsistence economies in comparison to their distinctive ceramic traditions. This thesis primarily focuses on understanding temporal and spatial changes in how shellfish were exploited throughout the antiquity of human occupation at Caution Bay, especially in relation to before, during and after contact with Lapita peoples. Results have revealed significant changes in distribution, availability and exploitation of shellfish species over time. Trends are particularly prevalent before, during and after periods of ‘contact’ when the established indigenous population met and interacted with Lapita ‘foreigners’. This is supported by the archaeological evidence with an intensification of shellfish resources and site use and extension of human predation pressures coinciding with the introduction of new material culture (i.e. pottery). Subsequent trends also correlate with wider socio-cultural events during post-Lapita occupation with both decreases and increases in site use intensity and shellfish exploitation. In addition, local peoples were most likely also restructuring their subsistence economy with a greater focus on agriculture. While, natural environmental changes have in the past been used to explain shellfish variability in sites, the strong evidence for anthropogenic modifications to the local landscape at Caution Bay suggests that people may have practiced a complex subsistence strategy. This complexity is further evident in the diversity of gathered shellfish from a range of habitats. Certain continuities in shellfish subsistence strategies before and during changes to the local landscape means that natural environmental factors probably did not significantly alter shellfish exploitation. Instead, local occupants at Caution Bay had a complex and diverse shellfish economy, and their activities were mainly dictated by the wider socio-cultural landscape