A juvenile smalltooth sawfish is pictured in the Charlotte Harbor estuarine system in Florida in this undated handout photo obtained by Reuters June 1, 2015. Reuters/Jamie Mae Darrow/Florida Fish and Wildlife Conservation Commission

Australian scientists have developed a highly-advanced test, known as eDNA, that may save the endangered largetooth sawfish. The researchers of Australia’s four extremely rare sawfish developed the test for an easier way to find estuaries the fish exist in. The new way will be able to successfully test large bodies of water for DNA of the sawfish and that will make key habitats easier to find.

Up to now, researchers had to rely on expensive fish surveys and knowledge of locals to understand the habitat of the species. The new test promises to change that. Researchers from Charles Darwin and James Cook University, led by professor Colin Simpfendorfer from James Cook University, explained how the test works in the study.

The technique has proven to be very accurate at remote water holes in the Northern Territory. Even though it is less effective in flowing water now, it will become better after refining the technology. The test is still in its trial stage. The test is a major breakthrough as largetooth sawfish population has become extinct in 50 countries though is still found in Northern Australia.

“We don't even know if they still exist in many countries. Applying this approach globally will enable us to rapidly find threatened populations and prioritise their protection,” Simpfendorfer told

The eDNA or Environmental DNA test applications are not just limited to freshwater or conservation applications. It has numerous other applications including “detecting invasive pest species at ports.” The test is expected to be in high demand globally.

In total, there are five sawfish species around the world and four are found in Australian waters. They grow to over six metres in length and spotting them is a very labour-intensive process and expensive. With the help of the test, researchers can sample the water, bring it back to the lab and look for presence of DNA.

“At the moment we're only able to detect whether they are present or not present. There is work underway to help us understand about how many sawfish may be present. That's for the future, but we think we will be able to get there at some point,” Simpfendorfer told the ABC.