Australian scientists and Indigenous leaders have mapped ancient landscapes beneath the Great Barrier Reef, revealing submerged rivers, lakes, and forests that once supported First Nations communities 65,000 years ago, as part of a 24-day research voyage led by the University of Queensland.
The research, conducted aboard CSIRO’s RV Investigator, combined advanced sonar technology with Indigenous knowledge to uncover a vast coastal plain
that existed when sea levels were 80 meters lower than today. This discovery, described as in stunning detail
by UQ Professor Helen Bostock, offers a window into the lives of Australia’s First Nations people and the geological evolution of the reef.
Ancient Landscapes Revealed Beneath the Reef
The expedition, which lasted 24 days, used multibeam echosounders to create intricate maps of the seafloor and sub-seafloor, exposing submerged rivers, lakes, estuaries, and beaches. These features were part of a coastal plain that existed before rising sea levels 7,000 years ago submerged the area. First Nations people arrived in Australia over 65,000 years ago when sea levels were 80 meters below present day,
said Bostock, who led the voyage. At that time, the Great Barrier Reef area was a vast coastal plain bordered by towering forests that stretched inland.
The team collected over 20 sediment cores from the seabed, which will help reconstruct past climates, sea levels, and vegetation. These cores act as “time capsules,” allowing scientists to trace the region’s transformation from a terrestrial landscape to the modern reef. The findings align with cultural knowledge from the Darumbal and Woppaburra Traditional Owners, whose songlines and stories connect to the submerged terrain.
Indigenous Collaboration Shapes Scientific Discovery
The research was co-designed with the Darumbal and Woppaburra Traditional Owners, whose ancestral knowledge of the region played a critical role in interpreting the data. Land and Sea Country Ranger Nataliah Backo from the Darumbal people described the project as a deeper connection to our history, ancestors, and the stories held beneath the ocean.
The collaboration also involved Indigenous rangers who worked alongside scientists to link modern findings with cultural narratives.
Reef Management Evolves with Indigenous Leadership
Traditional Owners now manage 43% of the reef’s coastline through Traditional Use of Marine Resources Agreements (TUMRAs), a shift described as a great increase in the governing capability
of Indigenous groups by James Cook University professor Allan Dale.
The World Heritage Committee recently reaffirmed the reef’s status as a natural wonder, citing increased Indigenous involvement in management. However, gaps remain in fully integrating Traditional Owners into decision-making, according to Indigenous governance organizations. There are still gaps in the full inclusion of Indigenous communities in the stewardship of their traditional waters,
said Lyndal Singleton, a Yirrganydji TUMRA holder.
Ocean Dynamics and Climate Resilience
The expedition also studied the East Australian Current (EAC), which interacts with the reef to sustain marine life. CSIRO’s research vessel Investigator used advanced sonar systems and the voyage examined ocean dynamics, including investigating how the powerful East Australian Current interacts with the reef. This research will feed into the CSIRO eReefs model, helping researchers understand past and present ocean conditions, predict how future changes may affect the reef, and identify potential refuges for reef species from climate-driven heat.
The findings also underscore the need for adaptive management strategies as the reef faces threats from rising temperatures and poor water quality.
What Comes Next for the Great Barrier Reef?
The research marks a turning point in understanding the reef’s past and its future. However, challenges remain in balancing conservation with climate change pressures. While the World Heritage Committee has not listed the reef as “in danger,” ongoing threats like coral bleaching and invasive species necessitate continued collaboration between scientists, Indigenous leaders, and policymakers.
The sediment cores and bathymetric maps will be analyzed in the coming years, with results expected to inform new conservation strategies. For Indigenous communities, the project represents not only a scientific milestone but also a step toward reclaiming and protecting their ancestral lands. We hope this journey makes our families, ancestors, and the Darumbal people proud,
said Backo, while creating stronger pathways for our younger generations to continue caring for and protecting our Land and Sea Country.
