Imagine a lake that’s never been affected by climate change or any other man-made influences. Australian scientists say they have found just that—a remote lake whose crystal-clear waters seem to be in the same chemical state as they were about 7,500 years ago.
“It’s like God’s bathtub,” Dr. Cameron Barr told the Australian Associated Press of the body of water now named Blue Lake. “It is beautiful. It is absolutely beautiful.”
Barr and his team of researchers from the University of Adelaide say the lake—one of the largest on North Stradbroke Island off the south Queensland coast, according to the AAP—is so pure that you can see more than 30 feet below the surface to its bottom.
“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,” Barr told the Australian Broadcasting Corporation.
Barr, who published his findings in the current issue of Freshwater Biology, said it’s the only such lake of its kind known to be in Australia.
To reach its conclusion, the team studied the lake’s water quality, fossil pollen and algae, which team members then compared with photos taken of nearby areas on the island over the past 117 years.
Several other nearby former lakes have dried up over the past 40 years due to climate change, Barr noted. In fact, Barr’s team was on North Stradbroke to study the effects of those former bodies of water when his team stumbled across the anomaly that is Blue Lake.
The lake’s water has remained unchanged, said Barr, because its waters drain into a nearby swamp and are replaced by an aquifer every 35 days or so.
“Because it’s constantly being updated it doesn’t suffer from the vagaries of the climate in so far as it doesn’t evaporate and become more saline,” Barr told the Australian Broadcasting Corporation. “It doesn’t fill up and become fresher. It just remains constant.”
Barr said something as small as sunscreen samples from tourists could alter the lake’s chemistry.