How's the water? Ask a turtle

If you want to know what’s really going on in our rivers and streams, you might want to check on the turtles.

The reptiles feed on a wide range of prey, and pollutants build up in their bodies over their long lives. It makes them excellent subjects of study for scientists trying to understand how the chemicals in our environment affect the animals that live in it.

Which is why EPA scientists have joined researchers from CSIRO, the Arthur Rylah Institute and other agencies in a next-generation project measuring PFAS levels in Victorian turtles.

Phoebe Lewis, EPA Victoria senior scientist in emerging contaminants, said the study would use advanced techniques known as “omics”. These assess thousands of molecular markers in the animal to detect changes to vital processes such as metabolism, reproduction and the immune system.

“So instead of just testing for PFAS in the water, we are testing how those levels have affected the turtles,” Dr Lewis said. “It means the animal becomes a living indicator of ecological health, and it helps us as a regulator to trial new tools that can help us to protect environmental values in future.”

The team has tested turtles in the Murray River, Jacksons Creek, and most recently at Darebin Parklands, where they weighed and carefully took tiny blood samples from 94 turtles before releasing them back into their habitat. Dr Lewis emphasised that samples were collected ethically and did not harm the turtles.

Along with PFAS, CSIRO will analyse the fats, proteins and metabolites in the samples. These biological “fingerprints” can reveal disruptions to vital processes and provide early warnings of harm – long before visible damage or population decline.

Dr Lewis said the project had given EPA researchers the opportunity to work in a team on the cutting edge of environmental science, and was a great example of inter-agency collaboration.

“There are global concerns about the long-term impacts of chemical pollution, and we know we need new ways to measure and understand those impacts,” Dr Lewis said.

“This research has the potential to transform the way we protect our waterways and the biodiversity they support.”