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).

本环境DNA（environmental DNA, eDNA）采样项目于2024年4月实施，在湄公河干流的老挝段8个采样点与泰国段6个采样点完成样本采集。本次采样采用一次性样本采集套件，沿河道横断面方向采集4组平行重复样本，并在每个采样点设置1组阴性对照。
本次eDNA采样工作的核心目标为评估世界自然基金会（World Wide Fund for Nature, WWF）老挝-泰国渔业项目（Lao-Thai Fisheries Project, LTF）所设立的新增鱼类保护带（Fish Conservation Zones, FCZs）内的鱼类多样性。
除评估研究区域内的鱼类群落结构外，本次采样还旨在检测12种优先保护物种的存在情况，具体包括：亚洲物种行动伙伴关系（Asian Species Action Partnership, ASAP）认定的6个优先物种：查氏魾（Bagarius yarrelli）、贝氏鲃（Bangana behri）、戈氏四须鲃（Barbonymus goniotomus，原文拼写疑似笔误）、巨无齿䰶（Pangasianodon gigas）、桑氏巨鲶（Pangasius sanitwongsei）、朱氏拟四须鲃（Probarbus jullieni）；1种LTF项目指示物种：湄公河半鲇（Hemisilurus mekongensis）；4种被列入国际自然保护联盟（International Union for Conservation of Nature, IUCN）红色名录的濒危物种：老挝窄尾魟（Hemitrygon laosensis）、大鳍拟四须鲃（Probarbus labeamajor）、多鳞粒唇魟（Urogymnus polylepis）、叉尾鲶（Wallago attu）；以及1种外来入侵物种：湄公河鳠（Hemibagrus nemurus）。