Aboriginal marine subsistence foraging flexibility in a dynamic estuarine environment: The late development of Tin Can Inlet (southeast Queensland) middens revisited

Although the sea arrived in southeast Queensland around 8000 years ago, most estuarine middens date to the past 1000 years. An example is midden deposits dating to the past 400 years forming the upper levels of Sites 62 and 75b from Tin Can Inlet located immediately south of the Fraser Island (K’gari) World Heritage Area. Both sites were excavated and analysed in the 1980s. This paper revisits these results following a detailed re-analysis of midden materials and new insights on regional sea level changes. Taking an historical ecology approach, species-specific habitat requirements and associated substrate sediment dynamics help explain similarities and differences between the two midden shell assemblages. Environmental factors and the location of both sites on landforms that formed following sea level fall over the past 2000 years help explain why the basal levels of both sites are probably <1000–1500 years old. Documenting pre-2000-year-old Aboriginal use of Tin Can Inlet will need to target more elevated inland dune deposits (>5m ASL) fronting the mid-Holocene sea level highstand palaeoshoreline.