Improving the containment of a freshwater invader using eDNA

Exclusion or containment barriers are often used to prevent the spread of invasive alien species in waterways such as rivers and streams.

Determining appropriate locations for the construction of these barriers relies on precise knowledge of species distributions. eDNA monitoring was shown to improve the distribution data of redfin perch (Perca fluviatilis), a predatory invasive fish in Australia. 

eDNA monitoring has detected the presence of redfin perch further upstream of sites where conventional techniques have detected the fish. This information was used to determine the optimal location for the placement of an exclusion barrier, ensuring that redfin perch are prevented from encroaching into critical breeding grounds of the endangered southern pygmy perch, Nannoperca australis.