North Stradbroke Island wetlands date back to last ice age: researchers

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North Stradbroke Island off Brisbane is home to wetlands dating back 200,000 years, researchers find.

north-stradbroke-island-wetlands-date-back-to-last-ice-age-researchers photo 1 Photo: The research involves taking sediment cores from lakes and swamps across 16 wetlands. (Supplied: Dr John Tibby)

North Stradbroke Island off south-east Queensland is home to wetlands dating back 200,000 years and might have been an important refuge during periods of extreme weather, new research has found.

Scientists have discovered important climate and environmental data on the world's second-largest sand island in Brisbane's Moreton Bay.

It is a much-loved holiday destination littered with pristine beaches and home to an abundance of marine life and now North Stradbroke Island is proving even more valuable by offering a window into climate change.

The researchers gathered information about the wetlands on the island at a time when water across Australia was scarce.

The study, led by the University of Adelaide and in collaboration with scientists from the Queensland Government, involved taking sediment cores from lakes and swamps across 16 wetlands on the island.

north-stradbroke-island-wetlands-date-back-to-last-ice-age-researchers photo 2 Photo: Researchers Lydia McKenzie, Jonathan Marshall and Cameron Barr take samples in Duck Lagoon. (Supplied: Dr John Tibby, University of Adelaide)

Lead researcher Dr John Tibby, from the University of Adelaide, said he had found some sediment cores that dated back to 200,000 years and the island has more wetlands dating back to the last ice age than anywhere else in Australia.

"What we found is that on Stradbroke Island we have the largest concentration of wetlands that have existed since the Last Glacial Maximum — the driest and coldest part of the last 100,000 years of Earth's history, about 20,000 years ago," he said.

The research also suggested North Stradbroke Island might have provided a refuge during extreme weather.

"There's always been this sort of mystery about where animals and plants might of gone during the last ice age because we know that there's very little evidence for much of the Australian continent being wet, so Straddie at least becomes a candidate for where plants and animals might of retreated to," he said.

"We're using the chemicals in leaves to determine past rainfall, and fossil algae to tell us how the water in the wetlands has changed."

north-stradbroke-island-wetlands-date-back-to-last-ice-age-researchers photo 3 Photo: Researchers get sediment core samples at Fern Gully. (Supplied: Tim Page)

Dr Tibby said researchers would gain data over the next 12 months as to what the island could reveal about how its climate had changed.

"Having that sort of record of environment and climate change is important, not just to understand how climate varies over time, but particularly to understand debates about whether climate had a role in the extinction of large animals known as mega fauna," Dr Tibby said.

north-stradbroke-island-wetlands-date-back-to-last-ice-age-researchers photo 4 Photo: Researchers John Tibby and Cameron Barr take sediment core samples in Duck Lagoon. (Supplied: Dr John Tibby, University of Adelaide)

Findings confirm island's environmental significance

Queensland's Labor Government will end sand mining on North Stradbroke Island by 2019, reversing a decision by the former LNP government to extend a mining lease to 2035.

Queensland Science Minister Leeanne Enoch, who is also a Quandamooka woman from North Stradbroke Island, said the findings from Dr Tibby and his team confirmed the environmental significance of the area.

"It's very exciting and actually incredibly significant," she said.

"It could have the potential to rewrite what we know about climate change in Australia since the last ice age."

north-stradbroke-island-wetlands-date-back-to-last-ice-age-researchers photo 5 Photo: Researchers gather sediment core samples at Welsby Lagoon on North Stradbroke Island. (Supplied: Dr John Tibby, University of Adelaide)

While the research sheds light on the island's past, Dr Tibby said it was too early to say whether this would help determine how North Stradbroke Island would cope with climate change in the decades ahead.

"The change that's projected to occur over the next 100 years in much greater than the planet's experienced over the last 20, 30, 40,000 years or more."

The research has been published in the Journal of Quaternary Science.

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