DNA clues track critters

IMAGINE a future where a small electronic device could identify every species that’s passed through your local area in recent days.

That future is not far off, thanks to an emerging technique known as environmental DNA or eDNA.

Director of James Cook University’s TropWATER research centre Professor Damien Burrows said the technology was a revolution in biology.

“You can confirm the presence of animals or plants without ever actually seeing them,” he said.

“It’s going to enormously magnify the amount of information we get on the distribution of every organism.

“The amount of data we’re going to be able to collect will simply blow us away.”

Professor Burrows explained that the technology allowed scientists to scan a sample of water, air or soil to trace tiny remnants of DNA that all organisms shed into the environment.

“When organisms die, their bodies decay and leave DNA traces,” he said. “But living animals also shed DNA through their mucus, faeces, urine, and skin cells.”

Deputy director of the Centre for Sustainable Tropical Fisheries and Aquaculture and director of the ARC Research Hub for Advanced Prawn Breeding at JCU Professor Dean Jerry said one of the most important uses for eDNA was for biosecurity.

“( eDNA is) really shaking things up for people who do biological surveys,” he said.

“In 2011, JCU was one of the first institutions in Australia to realise the potential for eDNA in environmental protection.

“The technology will soon be at the point where we’re surveying at ports around the country, and there will be routine testing to see what patho- gens and nasties are in the water.” One of JCU’s long- running eDNA studies is focused on tilapia.

Once a popular aquarium fish, tilapia are taking over many of our tropical waterways, including 21 of the 76 catchments in Queensland, and is now banned in Australia.

Other uses of eDNA include studying migration patterns; sampling flowers to see which pollinators have visited; and analysing the gut contents of an animal to determine its diet.

“It’s also really good when we’re looking for rare animals,” Professor Burrows said.

“We might think they’re rare, but it could just be that we haven’t encountered them much, because they live underground or in a remote area.

“There are a lot of animals in Australia that we just don’t know much about, and eDNA is helping us understand their distribution.”