Assessing freshwater biodiversity through environmental DNA (eDNA) along the Mekong River in Ubon Ratchathani Province, Thailand and from Bolikhamxai to Savannakhet Provinces in Lao P.D.R.

This environmental DNA sampling project took place in April of 2024, and involved the collection of samples in the mainstem Mekong River across eight sites in Laos and six sites in Thailand. Single-use sample collection kits were used to collect four replicates spanning the width of the river, as well as a single negative control at each site. This eDNA sampling effort was focused on evaluating fish diversity in new Fish Conservation Zones (FCZs) established by the World Wide Fund for Nature's Lao-Thai Fisheries (LTF) Project. In addition to evaluating the fish community, sampling was intended to the detect the presence of 12 priority species, including six identified by the Asian Species Action Partnership (ASAP species; Bagarius yarrelli, Bangana behri, Barbonymous goniotnotus, Pangasianodon gigas, Pangasius sanitwongsei, and Probarbus jullieni), one LTF indicator species (Hemisilurus mekongensis), four species listed as endangered on the IUCN Red List (Hemitrygon laosensis, Probarbus labeamajor, Urogymnus Polylepis, and Wallago attu), and a single non-native invasive species (Hemibagrus nemurus).