Diversification of farmed fishes in the Mekong Delta through the selection of new euryhaline fish candidates - a multidisciplinary approach for a sustainable aquaculture.

Vietnam, and more particularly the Mekong Delta (MD), has experienced unprecedented aquaculture development, positioning the country in just two decades among the world's aquaculture leading producers. However, this exponential growth of aquaculture in the MD is mainly due to the success of a few species, the main ones being shrimps and striped catfish. Unfortunately, MD is also one of the regions that are already and will be even more in the short and medium term, heavily impacted by climate change and sea level rise, leading to increased salinisation. These environmental changes will negatively impact the production of freshwater species such as striped catfish. Faced with this situation, the overall objective of this project is to contribute to the sustainability of the fish sector in Vietnam through a better adaptation of fish farming. More specifically, the project aims to develop the capacities for the profitable development of euryhaline indigenous fish production in the MD. To achieve this, it will develop husbandry techniques (R1), provide institutional stakeholders with a comprehensive feasibility as a decision-making tool (R2), provide producers with relevant knowledge and know-how (R3) and build research capacities (R4). Activities will include: i) a socio-economic assessment of the demand for euryhaline local fishes and of issues in the value chains, ii) a biological selection of candidate species and the characterization of its genetic diversity, iii) the establishment of optimal husbandry conditions for reproduction, larval rearing and on growing, and iv) a production cost assessment associated to market and sensitivity scenario analyses. These activities will benefit from the contribution of three PhD students and several master and bachelor students, improving the research capacities of Can Tho University. The close collaboration between scientists and stakeholders will be ensured through a participatory Action-Research including tests in farms, regular knowledge exchange and liaison with extension services and specific communication to end-users, capitalization of lessons learnt and preparation of a technical/socio-economical manual.