SYDNEY, May 28 (Xinhua) -- Australian researchers have mapped biodiversity across Australia's state of New South Wales' (NSW) estuaries using cutting-edge environmental DNA (eDNA) technology.
The project, led by Southern Cross University and supported by the NSW and Australian governments through the Estuary Asset Protection Program, spans 1,000 km of coastline and more than 33 estuaries, a press release from the university in northern NSW said on Wednesday.
The technique, known as eDNA metabarcoding, detects traces of genetic material, from scales to faeces, left behind in water or sediment. It allows scientists to identify hundreds of species at once, including fish, birds, plants, and invasive pests, the release said.
As the first statewide snapshot of estuary biodiversity in NSW, the project provides a vital baseline for managing these dynamic ecosystems, particularly in the wake of floods, bushfires or cyclones, said lead researcher Maarten De Brauwer of Southern Cross University.
"The data revealed the location of 68 invasive pest species in various rivers, including aquatic weeds, algae and even cane toads further south than previously thought," De Brauwer said.
Samples were collected at 234 sites during both summer and winter, researchers said, adding the data helps monitor changes after natural disasters, such as the 2022 floods or Cyclone Alfred in March 2025.
Estuaries, the middle ground between the ocean and rivers, are key habitats for wildlife and are widely used by communities for fishing, boating, and recreation. Yet until now, there was no comprehensive biodiversity record to guide sustainable management, according to the study.
The results, covering more than 7,000 species, are publicly available via an interactive map online, it said. ■
