Scientists studying the response to environmental change over time of Blue Lake, one of the largest lakes on North Stradbroke Island, said analysis of the lake's water discharge and water quality and comparisons of historical photos over the past 117 years shows it has remained relatively stable and resilient for millennia.
Researchers at the University of Adelaide said fossil pollen and algae also allowed them to better understand its history over the past 7,500 years.
"We didn't realize just how unique and unusual this lake is until we started looking at a wide range of environmental markers," study lead author Cameron Barr said in a university release Tuesday.
"We know that there have been variations in climate in the region including North Stradbroke Island over recent decades, but during that time the depth, shoreline and water chemistry of Blue Lake has displayed little variation."
Proposed plans to use the freshwater aquifer of North Stradbroke Island as a source of fresh water for the Australian mainland could affect the lake, researchers said.
"Our study suggests that increased extraction of ground water represents one of the few obvious threats to the stability of Blue Lake," study co-author John Tibbe said.
Barr said he agrees.
"It appears that Blue Lake has been an important climate 'refuge' for the freshwater biota of the region, and is in the same condition now as it was 7,500 years ago," he said. "With appropriate management, the lake could continue relatively unchanged for hundreds, possibly thousands of years to come."