INTRODUCTION MATERIALS & METHOD RESULTS & DISCUSSION CONCLUSION ASSESSMENT OF WATER QUALITY IN BEN TRE RIVER Mekong Delta, Vietnam Savoeurn Soum1, Tri Truong3 , Thai Tran2, Dang Le2, Ratha Sor3, Long Ho3 , Wout Van Echelpoel3 , Marie Anne Eurie Forio3 , Quang Ngo2 and Peter L. M. Goethals3 sormsavoeurn168@gmail.com 1 Chea Sim University of Kamchaymear, Smong chherng commune, Kamchaymear distric, Prey Veng Province, Cambodia 2 Institute of Tropical Biology, 85 Tran Quoc Toan, District 3, Ho Chi Minh City, Vietnam 3 Department of Animal Sciences and Aquatic Ecology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium INTRODUCTION Ben Tre River is located in the Mekong Delta and impacted by sea level rise during the dry season and human activities (e.g. wastes, chemical fertilizer, pesticide).  Physical-chemical properties are necessary to determine ecosystem health. MATERIALS & METHOD Samples of 50 sites were collected from upstream to downstream during the dry season, 2018 Process of analysis: Water Samples MRC Aquatic life index Full Prati index Physical - chemical water quality analysis Cl- DO NH4+ NO3- PO43- COD BOD pH Ben Tre Province 2,321.6 km2 Population: 1,345,600 Density: 580/km2  Farmland: 137,224 ha 3 main industrial zones NH4+, pH, PO43-,DO, NO3-   NH4+, pH, COD, BOD, DO, NO3-   Source: Mother Nature and a hydropower onslaught aren’t the Mekong Delta’s only problems, 2016  Assess the water quality of rivers in Ben Tre province  Compare two water quality indices used (Full prati and Mekong River Commission) RESULTS & DISCUSSION Overall water quality based on full Prati index Good quality: 1/50 Acceptable: 32/50 Polluted: 16/50 Heavily polluted: 1/50 Centre of Ben Tre Province MRC water quality index for aquatic life Very Good: 3/50 Good: 12/50 Acceptable: 9/50 Polluted: 26/50 Coastal area CONCLUSION ACKNOWLEDGEMENT Water quality in most of sites in Ben Tre, in particular the upstream part, is degraded due to pollution (according to Prati and MRC indices) Due to combined impact of human activities (e.g. high population, agricultural intensity, wastes etc.) and sea water intrusion. Most of sites the coastal area has acceptable quality to good water quality Possibly due to lesser impacts from human activities Probably mainly due to sea water intrusion Coastal area are characterized by higher dissolved oxygen concentration which could be due to the wave action