Jonathan Benjamin

Since the peak of the last glacial maximum, approximately 2.12 million square kilometres of Australia’s continental land mass was inundated by post-glacial sea-level rise. Much of this area would have been inhabited by people. Where cultural material has survived transgression, it has the potential to address significant archaeological questions such as human arrivals and dispersal across the continent, past strategies of occupation, and resource usage. The scientific study of submerged terrestrial landscapes around the Australian coast is at a relatively early stage, with most published research focused in the north and north-west of Australia. There is now a need to undertake baseline studies in different environmental and cultural regions of Australia to further develop a framework for the location and management of submerged archaeological sites and landscapes on the Australian continental shelf. In this article, we use terrestrial analogy as the basis for a regional scale Geographic Information Systems predictive model for the identification of areas with favourable preservation potential on the Rottnest ( Wadjemup ) Shelf, southwestern Australia. The results illustrate how the modern physical environment and regional archaeological record of the Swan Coastal Plain can help to identify areas of higher preservation potential in the search for the submerged cultural heritage of southwestern Australia’s first peoples. This article provides a platform for further archaeological investigation of submerged cultural landscapes in southwestern Australia and the development of submerged landscape studies around the continent.

Recent studies conducted in Murujuga Sea Country have confirmed that Indigenous Australian archaeology does not end at the modern shore. Since the earliest peopling of the Australian continent, sea levels have fluctuated significantly, dropping as much as 130 m below modern mean sea-level during the Last Glacial Maximum (LGM). During this period, the continent (including Australia and New Guinea) represented a landmass one-third larger than present day Australia. As sea levels rose following the LGM, this extensive cultural landscape was inundated. The recent reporting of archaeological remains in a submerged context at Murujuga has enabled an integrated analysis of the archaeological landscape, based on direct evidence from archaeological sites that were originally formed on dry land, but are now located in intertidal and submerged environments. This study applies a landscape analysis centred on the submerged Cape Bruguieres channel site, and the Gidley Islands, where submerged, intertidal and coastal archaeology has been recorded. Aerial, pedestrian, and intertidal archaeological surveys were conducted to investigate the onshore and offshore landscape, providing new evidence with which to place the stone artefacts in the Cape Bruguieres channel into a wider context. Rock art engravings, grinding patches, quarries and upstanding stones – some of which are in the intertidal zone – point to the use of a landscape that is now submerged and to the possibility of discovering new underwater sites. By integrating evidence from subtidal and intertidal contexts with the onshore record, we explore the cultural landscape above and below the ‘waterline’ as a continuum.

Regional-scale assessments have proven to be invaluable frameworks for research, public engagement and management of submerged archaeological landscapes. Regional-scale approaches have been implemented internationally through a variety of academic or strategic studies. Such studies represent a much-needed next step towards subregional and site-level prospection to support management, engagement and mitigation of the impacts of offshore development. However, these regional studies are largely absent in Australia. In this article, we build on the recent discovery of submerged archaeological sites in Western Australia and produce a novel regional-scale assessment of submerged archaeological and cultural landscape potential in the coastal and island regions of the Northern Territory. This area is of special significance in the peopling of Australia, containing some of the oldest dated archaeological evidence. We collate and synthesise regional data related to sea-level change, ethnography (e.g. oral traditions), geomorphology, and archaeology, also taking account of logistics and existing data availability to identify prospective areas for further study. We highlight the need for a coordinated national program of regional baseline studies to address a legacy of under-representation of submerged landscapes and provide vital baseline data for a wide spectrum of stakeholders, including researchers, policy makers, environmental and heritage managers, developers and Traditional Owners.