Beneath the waters of the southern Great Barrier Reef lies a drowned world — ancient rivers, lakes, and coastal plains where First Nations people lived before the sea rose some seven thousand years ago. Australian researchers, sailing aboard the CSIRO vessel Investigator, have now mapped that submerged terrain in extraordinary detail, weaving together sediment science and Indigenous songlines in a collaboration co-designed with Darumbal and Woppaburra Traditional Owners. The work reminds us that the ocean does not erase history — it only submerges it, waiting for those with the right tools and
Bathymetry maps reveal ancient landscapes where First Nations lived before Great Barrier Reef submersion
Stories held beneath the ocean, now mapped in stunning detail
Mark
Why does it matter that we can now see these ancient landscapes? They're underwater. They're gone.
Mimi
They're not gone—they're preserved. The sediments on the seafloor hold the record of what happened. When we read that record carefully, we can understand how the climate changed, how the sea rose, and how people adapted. That knowledge helps us understand what might happen next.
Mark
So this is about predicting the future?
Mimi
Partly. But it's also about honoring the people who lived there. The Darumbal and Woppaburra have stories about this land—songlines that encode knowledge passed down for thousands of years. Science can now show what those stories describe. That's a kind of validation.
Mark
The rangers were on the ship. What did they contribute that the scientists couldn't have done alone?
Mimi
They brought cultural knowledge—understanding of the land and sea that goes deeper than any map. They knew what questions to ask, what mattered. They made sure the research was asking the right questions, not just the questions scientists thought were important.
Mark
And what happens now with all this data?
Mimi
The sediment cores will be analyzed. The maps will be studied. The findings will inform how the reef is managed going forward. But more than that—it gives the younger generation of Darumbal and Woppaburra people a tangible connection to their ancestors' world. That's not a small thing.
Le Pouls
- A landscape that sustained human life for tens of thousands of years vanished beneath rising seas 7,000 years ago, leaving an 80-metre-deep silence that science is only now beginning to read.
- Twenty sediment cores pulled from the ocean floor hold geological time capsules — physical records of climate, vegetation, and coastline that could rewrite understanding of the region's deep past.
- The research risks becoming just another technical survey unless Indigenous voices shape it, which is why Darumbal and Woppaburra Land and Sea Country Rangers sailed alongside scientists, anchoring the data to living cultural memory.
- Songlines — the encoded narratives of connection to country — are being woven directly into the scientific reconstruction, bridging tens of thousands of years of knowledge across two very different ways of knowing.
- The findings are already being directed toward real governance gaps, feeding into the Reef 2050 Plan and the Great Barrier Reef Marine Park Authority's management framework at a moment when the reef's future is under acute pressure.
Beneath the waters of the southern Great Barrier Reef lies a drowned world — ancient rivers, lakes, and coastal plains where First Nations people lived before the sea rose some seven thousand years ago. Australian researchers, sailing aboard the CSIRO vessel Investigator, have now mapped that submerged terrain in extraordinary detail, weaving together sediment science and Indigenous songlines in a collaboration co-designed with Darumbal and Woppaburra Traditional Owners. The work reminds us that the ocean does not erase history — it only submerges it, waiting for those with the right tools and the right relationships to bring it back to light.
Seven thousand years ago, the southern Great Barrier Reef was dry land — a wide coastal plain of rivers, lakes, and forests where First Nations people hunted, gathered, and built their lives. Then the ocean rose, and that world disappeared. Now, Australian researchers have brought it back into view.
Aboard CSIRO's research vessel Investigator, a team led by The University of Queensland spent 24 days mapping the seafloor and the sediment layers beneath it, revealing submerged rivers, estuaries, and beaches in what chief scientist Helen Bostock described as stunning detail. More than 20 sediment cores were collected — geological time capsules that will allow scientists to reconstruct the region's ancient climate, vegetation, and coastline from a time when sea levels sat 80 metres below where they stand today.
What sets this project apart is how it was built. Darumbal and Woppaburra Traditional Owners were partners from the beginning, not consultants brought in afterward. Land and Sea Country Rangers from both groups sailed with the research team, connecting technical findings to their own cultural knowledge and songlines — the narrative routes that encode their people's deep relationship to land and sea across generations. Darumbal ranger Nataliah Backo spoke of the work deepening her connection to ancestors and stories held beneath the ocean. Woppaburra ranger Tshinta Barney described learning about mapping and the evolution of Sea Country as a gift, and both women expressed hope that the research would open pathways for younger generations to continue caring for their country.
Beyond its cultural significance, the research addresses gaps identified in the Great Barrier Reef Marine Park Authority's 2024 Outlook Report and contributes to the long-term Reef 2050 Plan. It is, at once, a scientific achievement, an act of cultural restoration, and a reminder that the ocean floor holds histories far older than any written record.
Seven thousand years ago, the southern Great Barrier Reef was not a reef at all. It was dry land—a vast coastal plain where rivers ran, lakes held water, and forests stretched toward the horizon. First Nations people walked across this landscape, hunted, gathered, and built their lives there. Then the ocean rose, and all of it disappeared beneath the waves.
Now, Australian researchers have brought that lost world back into view. Using advanced mapping technology aboard CSIRO's research vessel Investigator, a team led by The University of Queensland has created detailed maps of the seafloor and the layers beneath it, revealing the submerged rivers, lakes, estuaries, and beaches that once formed the southern Great Barrier Reef region. The work represents more than a technical achievement—it is a collaboration between Western science and Indigenous knowledge, designed from the start with the Darumbal Traditional Owners of Sea Country and their neighbors, the Woppaburra people.
The voyage lasted 24 days. During that time, the research team collected more than 20 sediment cores from the ocean floor. These cores are like geological time capsules, holding within them the physical record of what the region was like thousands of years ago. When scientists examine the sediments and fossils they contain, they will be able to reconstruct the climate, vegetation, sea levels, and the very shape of the landscape as it existed in the deep past. "First Nations people arrived in Australia over 65,000 years ago when sea levels were 80 metres below present day," explained Helen Bostock, the voyage's chief scientist. At that time, the Great Barrier Reef area was bordered by towering forests and stretched inland as a wide, habitable plain. The research has now mapped that terrain in what Bostock called "stunning detail."
What makes this work distinctive is how it was conceived and carried out. Land and Sea Country Rangers from both the Darumbal and Woppaburra groups sailed with the research team, working alongside scientists to connect the technical findings with their own cultural knowledge and the songlines—the narratives and routes that encode their people's deep connection to the land and sea. Nataliah Backo, a Darumbal ranger, spoke of the research giving her people a deeper connection to their history and ancestors, to the stories held beneath the ocean. Tshinta Barney, a Woppaburra ranger, described feeling blessed to have learned about the different aspects of mapping and understanding the evolution of Sea Country. Both women expressed hope that the work would make their families and ancestors proud, and that it would create pathways for younger generations to continue caring for and protecting their country.
The research addresses specific gaps identified in the Great Barrier Reef Marine Park Authority's 2024 Outlook Report and contributes to the Reef 2050 Plan, a long-term strategy for managing the reef's future. But beyond the policy implications, the work tells a story that reaches back tens of thousands of years—a story of a landscape transformed by forces larger than any single human life, and of the people who lived there before the water came.
Citations marquantes
Seafloor sediments act like time capsules and allow us to reconstruct the history of the region, from its past as a wide coastal plain to the development of the modern Great Barrier Reef— Professor Helen Bostock, The University of Queensland
We hope this journey makes our families, ancestors and the Darumbal people proud, while creating stronger pathways for our younger generations to continue caring for and protecting our Land and Sea Country— Nataliah Backo, Darumbal Land and Sea Country Ranger
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