Late Holocene drying of Port Phillip Bay: archaeological and cultural perspectives

Evidence from bay floor channelling, seismic surveys and core dating has been used to suggest that Port Phillip Bay dried out for a period between about 2800 and 1000 cal. yr BP as sandbars blocked it off from the sea. This model is now supported by the examination of radiocarbon ages from archaeological excavations of Aboriginal shell middens on the shoreline of the Mornington Peninsula on Bunurong Country. This shows a near-continuous use of marine resources by Bunurong people over the last 6000 years for areas south of Rosebud, while those to the north are only of more recent date, following the refilling of the bay in the last millennium. This study provides an example of the integration of traditional, archaeological and geoscience evidence and the way in which local environmental changes impact on society. KEY POINTS 1. Radiocarbon dates from Aboriginal places support the argument that a sandbar blocked much of Port Phillip Bay from the sea between about 2800 and 1000 cal. yr BP. 2. Dates from Aboriginal places south of the sand bar show continuity since the bay formed following the post-Pleistocene rise in sea-levels. 3. Dates north of the sandbar indicate that Aboriginal people began exploiting marine resources in this area once the bay refilled about 1000 years ago.

Automated summary

Evidence from bay floor channelling, seismic surveys and core dating suggests that Port Phillip Bay experienced a period of drying out between 2800 and 1000 cal. yr BP due to sandbar blockage. The examination of radiocarbon ages from Aboriginal shell middens supports this model, showing continuous marine resource use by Bunurong people for the past 6000 years south of Rosebud. The refilling of the bay in the last millennium led to the exploitation of marine resources in the northern areas.