|Cycle 2 (2012 Deadline)
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
Dr. Binh (center) and Dr. Carpenter (right) have a discussion at the fish dock (Photo courtesy Dr. Binh).
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 would 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 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 to 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
Since project activities began in September of 2013, the project team made two sampling trips to the Mekong Delta with U.S. partner Kent Carpenter. The first trip, which took place September 22-29, covered seven sites in the south of Vietnam. The target species on this trip were the small-scale croaker (Boesemania microlepis) and the sabertooth thryssa anchovy (Lycothrissa crocodilus). A scarcity of sabretooth thryssa anchovies forced the research team to identify a replacement species. Based on the types of fish available in local markets, the backhand paradise fish (Polynemus melanochir) was chosen. The second sampling trip, in December 2013, focused on three sites located near the Cambodian border. Fish samples were collected at local markets and preserved in alcohol for future DNA work.
Dr. Carpenter and students preparing for an expedition on the water (Photo courtesy Dr. Binh).
Dr. Carpenter at a fish market examining the local catch in search of species (Photo courtesy Dr. Binh).
A third sampling trip is being planned for March 2014. The trip’s main goal is to find samples of redspot emperor snapper (Lethrinus lentjan) at four sites located near the coast of the South China Sea. Dr. Carpenter expects to join the research team for this trip.
The project team was able to obtain QuiaGen DNA extraction kits. The research staff has been learning about the 2b-RAD genotype process. Extractions will be conducted in the first three months of 2014, and the team should get the results by June 2014. Dr. Carpenter is scheduled to travel to the Philippines to teach a training course in bioinformatics to three researchers and PI Dang Thuy Binh. The course will provide technical and analytical guidance for the next phase of the study.
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