Conservation genetics for improved biodiversity and resource management in a changing Mekong Delta

PI: Dang Thuy Binh (Nha Trang University)
U.S. Partner: Kent E. Carpenter (Old Dominion University)
Project Dates: August 2013 to August 2015

The study of the genetics of populations is a valuable tool in investigating the origins of the extreme biodiversity of southeast Asia. The National Science Foundation (NSF) Partnerships for International Research and Education (PIRE) project “Origins of high marine biodiversity in the Indo-Malay-Philippine Archipelago” has extended phylogeographic studies to Vietnam and Thailand to better understand mechanisms of speciation in the marine realm of this region. This PEER Science project leverages and extends this investigation into the estuarine and freshwater biomes of the most prominent and extremely biodiverse hydrological feature of southeast Asia, the Mekong Delta. Connectivity of populations across and within the Mekong Delta is shaped by the complex and dynamic physical processes of the Mekong River Basin. The outflow of the basin will potentially serve as a barrier to gene flow of marine populations distributed along the coast of Vietnam similar to what has been observed for the Amazon River (Rocha et al. 2002). Also similar to the Amazon system, the complex branches and hydrography of the Mekong Delta provide both potential barriers and environmental gradients that may influence gene flow and natural selection of vertebrate populations (e.g. Cooke et al. 2012, Hollatz 2011) within the Mekong Delta. This PEER project aims to examine fine-scale population connectivity of three fish species (marine, estuarine, and freshwater) across the Mekong Delta using advanced genomic methodologies. This will initiate a long-term research program to investigate processes that promote lineage diversification across the delta and provide a basis to examine genetic adaptation of populations due to the changing conditions of the delta caused by increasing effects of damming, development, agriculture and climate change.

This PEER Science project should produce valuable information about the connectivity of aquatic populations within and across the mouth of the Mekong Delta that can be used for improved environmental governance, such as delineating management zones and formulating strategies for biodiversity conservation. Furthermore, one species to be studied is considered Near Threatened on the International Union for Conservation of Nature Red List (IUCN 2012), and the population information gained in this study will be applicable to its conservation and biodiversity conservation in general in the Mekong Delta. As for capacity building, the project will provide training for Vietnamese researchers and give them a solid foundation for applying their new methods and skills to most pressing environmental concern in Vietnam: threats to the biodiversity and resources of the Mekong Delta.

Summary of Recent Activities

Key activities on this project during the first quarter of 2014 included engaging local citizens in fish sampling efforts. Approximately 50 samples of blackhand paradise fish (Polynemus melanochir) were collected from twelve sites along the Hau and Tien rivers. In the lab, PI Dr. Dang Thuy Binh and her team began DNA extraction work with guidance from U.S. partner Kent Carpenter. To further the collaboration, Dr. Carpenter sent Ellen Biesack, a graduate student from Old Dominion University, to train team members in the ezRAD technique of genomic genotyping.

Dr. Carpenter and students preparing for an expedition on the water - Dr. Carpenter at a fish market examining the local catch in search of species (Photo courtesy Dr. Binh).

Dr. Binh and her group plan an expedition in 2014 to collect additional fish DNA samples from a site in the Mekong River Delta. Members of the research team have also attended an advanced genomics training course in Manila from June 4-14, 2014, which was led by Dr. Carpenter and another PEER PI, Dr. Carmen Ablan Lagman. In September, Dr. Binh and her students, Vu Dang Ha Quyen, and Nguyen Thi Anh Thu will be traveling to Old Dominion University for a training course in ezRAD and bioinformatics.