DNA found 22km downstream reveals hidden populations of threatened frogs

In the cool, wet upland streams of Queensland’s Wet Tropics, several species of rainforest frog were pushed to the brink in the 1980s and 1990s by chytrid fungus, an aquatic pathogen that attacks frog skin and has driven extinctions worldwide. For decades, researchers lacked clear data on whether some of these species still persisted in remote creeks or had vanished entirely. Now, a team from James Cook University (JCU) has used environmental DNA (eDNA) to detect threatened frogs without ever seeing or hearing them, analysing tiny water samples collected up to 22 km downstream from where the animals live. As reported by JCU, the study confirms that some populations are more widespread and, in some cases, recovering than previously thought.A deadly fungus reshaped Australia’s frog communitiesThe chytrid fungus arrived in Australia through the international trade in frogs, with outbreaks first recorded in the late 1970s.