Environmental DNA (eDNA) survey of Tilapia in northern NSW

Objective: Tilapia (Oreochromis mossambicus) is an invasive species from Africa that is present in 20 catchments in Queensland and a new population was recently found in a coastal waterway in far northern NSW. The objective of this study was to conduct a survey of tilapia presence and distribution in the northern NSW region using environmental DNA (eDNA) as the detection method. [Extract] Discussion and Recommendations: Overall, tilapia DNA was confirmed at sites where tilapia are known to be present, but also at additional sites, though at low detection levels. These detections at new sites could represent significant new infestations or undetected contamination. Given the importance of this work and the high frequency of contamination, it is recommended that many of these sites be resampled.