Scientists mapping the southern Great Barrier Reef have revealed submerged ancient coastal landscapes, river channels, and forests that were inhabited by First Nations people before rising sea levels inundated the region roughly 7,000 years ago, according to a University of Queensland statement released in August.
Mapping Submerged Landscapes on the Great Barrier Reef
Researchers aboard the Commonwealth Scientific and Industrial Research Organization (CSIRO) research vessel RV Investigator used advanced bathymetric systems and multibeam echosounders to map the seafloor and sub-seafloor in high resolution. According to University of Queensland Professor Helen Bostock, chief scientist for the 24-day voyage, First Nations people arrived in Australia over 65,000 years ago when sea levels sat 80 meters below current levels. At that time, the area now covered by the reef was a wide coastal plain featuring towering forests, rivers, lakes, and estuaries.
Sediment Cores Act as Climate Time Capsules
To reconstruct the area’s historical climate, sea level changes, and vegetation, the expedition collected more than 20 sediment cores from the seabed. According to Professor Bostock, cited by Xinhua, these seafloor sediment cores function as time capsules that help scientists trace the region’s transformation from a coastal plain into the modern reef system while linking the findings to the cultural heritage of the Darumbal and Woppaburra Traditional Owner groups.
Did you know?
Seafloor sediment cores preserve microscopic fossils and organic material that allow scientists to reconstruct ecological and climatic shifts over thousands of years.
Integrating Traditional Knowledge with Ocean Models
The voyage integrated modern oceanographic research with Indigenous knowledge systems. Land and Sea Country Rangers Nataliah Backo of the Darumbal people and Tshinta Barney of the Woppaburra people joined the expedition to connect scientific mapping with cultural songlines and historical stewardship. In addition to mapping topography, the science team analyzed ocean dynamics, specifically examining how the East Australian Current interacts with the seafloor to influence local water movement and marine life.
Protecting Reef Ecosystems from Marine Heatwaves
Data gathered during the voyage will feed directly into CSIRO’s eReefs model, a simulation tool used to evaluate past and present ocean conditions. According to University of Queensland statements, this modeling will help researchers project how intensifying marine heatwaves—which have driven mass bleaching events across the Great Barrier Reef—will impact the ecosystem in the future. Furthermore, the data assists researchers in identifying potential thermal refugia, which are areas of the reef that may remain shielded from rising temperatures and provide a lifeline for vulnerable species.
Frequently Asked Questions
When was the ancient coastal plain submerged?
According to research from the University of Queensland, the coastal plain was inundated around 7,000 years ago as global sea levels rose to their present height at the end of the last Ice Age.
What vessel was used for the research voyage?
Scientists conducted the expedition aboard the CSIRO research vessel RV Investigator, which is equipped with advanced multibeam echosounders.
How are Traditional Owners involved in the project?
Land and Sea Country Rangers from the Darumbal and Woppaburra peoples participated in the voyage, helping link scientific data with cultural knowledge, songlines, and ancestral history.
Where will the collected data be applied?
The bathymetric maps and sediment analysis will feed into CSIRO’s eReefs model, fill gaps identified in the Great Barrier Reef Marine Park Authority 2024 Outlook Report, and contribute to the Reef 2050 Plan.
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