A major scientific discovery off the northwest coast of Australia has revealed the country’s first identified underwater Aboriginal archaeological sites, uncovering artefacts that date back as far as 8,500 years. The findings provide rare insight into ancient coastal life and show that significant parts of Australia’s cultural landscape now lie beneath the sea.
The research was carried out as part of the Deep History of Sea Country Project, a multi-year investigation focused on the submerged landscapes of the Dampier Archipelago in the Pilbara region of Western Australia.
Hidden Heritage Beneath the Ocean
Using advanced marine survey methods, researchers identified more than 200 stone artefacts across multiple underwater locations. Many of these items are believed to have been left on dry land by Aboriginal people thousands of years ago, before rising sea levels submerged the coastline after the last Ice Age.
In total, 269 artefacts were mapped at key sites, some located more than 10 metres below present sea level. Evidence suggests these areas were once part of inhabited coastal environments, including freshwater sources and dry land surfaces.
Advanced Technology Reveals Ancient Landscapes
The discovery was made possible through a combination of aerial scanning, sonar mapping, and underwater archaeological diving. Aircraft equipped with specialised sensors mapped the seabed, while side-scan sonar helped identify potential locations of interest.
Scientific divers then explored these mapped areas, confirming the presence of stone tools and cultural materials preserved beneath layers of marine sediment.
One of the most significant discoveries occurred near a submerged channel close to Gidley Island, where artefacts were found at depths of up to 2.4 metres below sea level.
Evidence of Ancient Coastal Life
Analysis indicates that some of the artefacts date back at least 7,000 to 8,500 years, a time when sea levels were significantly lower and the now-submerged areas were part of a living landscape.
Researchers also identified differences between underwater artefacts and those found on nearby islands, suggesting they represent distinct periods of occupation and activity.
Among the discoveries was evidence of a submerged freshwater environment, including what appears to have been a billabong or spring system that may have supported human activity in the past.
Rewriting Australia’s Coastal History
Experts involved in the project say the findings highlight how much of Australia’s early coastal heritage is now underwater due to post-Ice Age sea level rise. It is estimated that more than 30% of Australia’s landmass was submerged over time, meaning many ancient sites may still remain undiscovered beneath the ocean.
The study demonstrates that these submerged landscapes were not lost, but preserved, offering new opportunities to understand how Aboriginal communities lived along ancient coastlines.
Cultural Significance and Future Protection
For Traditional Owners and researchers, the discovery strengthens understanding of long-standing cultural connections to Sea Country. It also raises important questions about how underwater heritage sites should be protected, as current legislation does not always fully cover submerged archaeological landscapes.
Experts involved in the project emphasise the importance of combining scientific methods with Indigenous knowledge to ensure these underwater heritage sites are properly identified, studied, and preserved for future generations.