Abstract

• Eutrophication is the most studied form of coastal marine pollution. Eutrophic waters are characterized by excessive algae growth as a consequence of nutrient enrichments of coastal surface waters. In this research, totally 9 brackish water samples were collected from Letkhokkon area, seasonally in 2017. The aim of this research work is to study the water quality criteria of brackish water samples around Letkhokkon area and to identify eutrophication level of the studied area. Physicochemical and microorganisms investigations have been carried out by conventional and modern instrumental techniques and compared with the acceptable levels of ASEAN and EPA standards for human health and aquatic life protection. Sampling sites were recorded with GPS detector. According to the research, the eutrophic level (high nutrient-enrichment) was found in the hot season and the mesotrophic level (medium nutrient-enrichment) was found in the cold and rainy seasons.