PEER 2014 - 2017
Project name; Building a Mekong River Genetic Biodiversity Research Network
The Mekong River Basin (MRB) represents a global hotspot of aquatic biodiversity (Dudgeon et al. 2006, Allen et al. 2012) second only to the Amazon River in terms of total fish species richness (Hortle 2009, Baran et al. 2012). The origins of this diversity are hypothesized to stem from complex biogeographic processes (Woodruff 2010). However, actual tests of these hypotheses are scarce (Lukosheck et al. 2012), and there is continued discovery of the limits and relationships of this biodiversity (Woodruff 2010, Baran et al. 2012).
Population genetic studies have revealed both strong and weak spatial structure in the MRB that have mostly been linked to management implications (So et al. 2006a, 2006b, 2006c, 2006d, Ngamsiri et al. 2007, Hurwood et al. 2008, Adamson et al. 2009, Nguyen & Sunnucks 2012) but that also can be used for scientifichypothesis testing in the MRB (Lukosheck et al. 2012). Comparative phylogeographic studies are being used to test specific hypotheses relative to the origins of the extreme marine species richness in Southeast Asia (Carpenter et al. 2011), and advanced genomic methods expand our capability to test similar hypothesesrelative to the origins of MRB biodiversity (Willette et al. 2014). The purpose of this project will be to initiate
a network of scientists working in the MRB whose coordinated action will lead to a systematic sampling ofpopulations and species to provide a set of robust tests of biogeographic origins of MRB biodiversity through advanced genomics and comparative phylogeography. Specifically, we will aim to examine a set of synchronously diverging co-distributed taxa (Dawson 2014) to examine if genetic connectivity or barriers to gene flow are because of processes relating to ecological (relatively recent) or evolutionary (geological) time scales. Directionality of gene flow will be tested to determine if connectivity is predominantly governed by larval dispersal through prevailing fluvial flow or if fish movement patterns potentially reverses this natural tendency. Shared phylogeographic patterns among taxa will be examined together with both present ecological and geological processes to corroborate likely causality in a natural experimental framework.
Population genetic data used for testing explicit phylogeographic hypotheses serve a dual purpose by supporting biodiversity conservation and management of resources (Allendorf et al 2010, Carpenter et al. UT VU Can Tho University Printed On: 13 January 2014 PEER Science Cycle 3 6 2011, Ovenden et al. 2013). A significant development impact of this project will be the establishment of a network of scientists, managers, and conservationists interested in using genetics to better understand and
manage the biodiversity of the MRB. A primary partner will be the Mekong River Commission who previously initiated population genetic data collection for important species, and an aim will be to strengthen and expand this initiative. The implementation of the project will forge and strengthen long-term collaborative research ties through mutual design and implementation of a comparative population genetic project. Since most of the participants do not have extensive experience in next generation sequencing and advanced genomic analysis, another proximate development impact will be the training of aquatic researchers across the MRB in this methodology. Population genetic data will be systematically collected as a result of the establishment of the network, and these data will be analyzed for information relative to resource management and biodiversity conservation. These data will also be used as the basis for establishing a longterm genetic monitoring system for aquatic resources and integrity of genetic biodiversity. The benefits of these data will include:
1) The ability to estimate and monitor effective population size of exploited stocks.
2) Evaluation of spatial stock structure for fisheries management, for assessment of fragmentation due to
damming, and to enhance adaptive mitigation and management in anticipation of hydrological changes from
climate change and damming.
3) The baseline information on genetic variability collected during this study will allow monitoring of
genetic integrity that may be influenced by fishing, stock enhancement (release of hatchery reared
individuals), and accidental release from aquaculture.
4) The baseline information on genetic variability collected during this study will allow monitoring of
genetic variation as potential for biological adaptation and resilience to changing environmental conditions.
5) Establishment of a genetic data repository in collaboration with the Mekong River Commission for data