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

Abstract

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.

Keywords:

• Port Phillip Bay
• Mornington Peninsula
• Bunurong
• Victoria
• radiocarbon dating
• sea levels
• shell middens
• archaeology
• submerged landscapes

Acknowledgements

We acknowledge that Bunurong Traditional Custodians have cared for the study area for this research since time immemorial.

This research was conducted under a Cultural Heritage Permit (CHP_0797 RAP BLCAC 041) issued by the Bunurong Land Council Aboriginal Corporation.

We would like to thank all those involved in the Radiocarbon Dating Visualisation Project, including Harry Webber [First Peoples–State Relations (FP-SR)] and Prof. Andy Herries (La Trobe University) for arranging funding support for the verification stage of the project, and Pen Lynch for ACHRIS GIS assistance. Rachel Wood (ANU), Fiona Petchey (University of Waikato), Ron Hatfield (Beta Analytic), Anita Barker, Caroline Bird, Jim Bowler, Vincent Clark, Joanna Fresløv, Michael Godfrey, Daniel James (FP-SR), Roger Luebbers, Susan Pfeffer (FP-SR), Paula Reimer, Alan Williams and Chris Williamson provided support and technical advice, and/or spent time tracking down laboratory reports for the RDVP. Peter Mitchell initially suggested researching this topic; we are grateful to Guy Holdgate for his comments and advice, and to Sean Ulm for providing information on a new ΔR value for Port Phillip Bay ahead of publication.

We are grateful to the three anonymous referees for their prompt and pertinent comments on this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The dataset of the Radiocarbon Dating Visualisation Project for the State of Victoria, Australia <https://doi.org/10.26181/5f41f7247da76> that supports the findings of this study is not publicly available, as it contains sensitive information. It is, however, possible to apply for access to the dataset via the VAHR. More information is available from First Peoples–State Relations at https://www.aboriginalvictoria.vic.gov.au/.