Incidental finding of a novel invasive species, the Oriental Weatherloach <i>Misgurnus anguillicaudatus</i> , in the high conservation value Burragorang Valley of New South Wales, Australia using environmental DNA

Environmental DNA (eDNA) is an emerging tool for wildlife biologists and citizen scientists to build local knowledge about biodiversity and detect invasive species. While single-species eDNA assays are widely used to detect cryptic species, metabarcoding approaches can simultaneously detect a wide range of taxa depending on the chosen genetic target. In a partnership pilot study between Traditional Owners, scientists, and Government, we used a 12S metabarcoding approach to identify the vertebrate prey consumed by predators in the Burragorang Valley on Gundungurra Country (NSW, Australia). Here, we report an incidental but important detection of an invasive fish species, Oriental Weatherloach Misgurnus anguillicaudatus, in multiple Red Fox Vulpes vulpes scats within the high conservation value landscape of the Burragorang Valley (encompassing the WaterNSW Warragamba Special Areas). Our eDNA identification of Oriental Weatherloach was later validated by a physical capture of the species. We reviewed public databases to better understand the distribution of this invasive species in the region and discovered that Oriental Weatherloach had been detected upstream of the Warragamba Special Area on the Wollondilly and Wingecarribee Rivers, expanding its range since the 1990s. However, this was the first detection within the strictly controlled inner conservation zone for Lake Burragorang, Sydney’s drinking water supply. The recent invasion of this exotic fish species was not widely known by Traditional Owners, local community, Government departments or conservation groups and is significant as it is within the Greater Blue Mountains World Heritage Area. Our preliminary study highlights the value of using eDNA metabarcoding on predator scats as a biomonitoring tool for the incidental detection of invasive species and shows that freshwater fish may play a more significant role in the diet of foxes than previously understood.