Funding source: ARC Discovery

On a chain of ‘naïve islands’ in the Southern Gulf of Carpentaria, North Queensland, UQ scientists are comparing the ‘before and after’ impacts of human settlement and major climatic events on the physical environment.

The southern Wellesley Archipelago was first inhabited by the Kaidalt people some 2000 years ago.  When a severe cyclone caused a massive storm surge in 1948, food and fresh water became scarce on Bentinck Island, and the Kaidalt people were relocated to nearby Mornington Island.

Nearly 40 years later, the Kaidalt people returned to a very different Bentinck Island. Palaeoecological analysis revealed evidence of the cyclone’s direct impact, including an abundance of shell hash and a change in wetland composition from mangrove to freshwater swamp. The resettlement has caused the environment to adapt again to altered vegetation and fire regimes.

Drawing on its archaeological, palaeoecological and geomorphological expertise, a team led by UQ’s Associate Professor  Patrick Moss is analysing the pollen and charcoal content of the sediment cores from across the archipelago, to determine the environmental impacts of human interaction and late Holocene climate change.

The team is also examining climate alterations in the Wellesley Archipelago over the last 3000 years. Changes in cyclone intensity, drought events and their relationship to the El Niño Southern Oscillation, the Pacific Decadal Oscillation and the movement of the Inter Tropical Convergence Zone are of particular interest.

“We are fortunate to have access to extensive ethnographic evidence from local Indigenous people to compare the differences between when the islands were populated and when they were not,” said Dr Moss.

“It’s helping us with key information for modelling future climate change concepts and how both natural and human environments might respond to them.

“For example, this research may identify the key signatures of human presence in palaeoecological records, which we believe is crucial for our understanding of how climatic phenomena may operate under future climate change.”

The research is also informing Indigenous landscape and fire management planning for future conservation of the archipelago, and more broadly, for the northern Australian savannah.