Seasonal variations of algal diversity in response to water quality at beeshazari lake, tropical lowland, nepal

The algal diversity of an ecotone between land and water is majorly determined by the quality of water. Seasonal fluctuation in water quality due to natural and anthropogenic influence in tropical lowland lakes of Nepal brings variations in algal diversity. The purpose of the study was to assess seasonal variation of the algal diversity in response to physicochemical parameters of lakeshore water. Sampling was performed for algae during monsoon and winter season in the year 2018-2019. The value of pH, dissolved oxygen (DO), total dissolved solute (TDS) and conductivity were recorded highest during winter while highest temperature was recorded during monsoon season. Chlorophyceae was found to be dominant during both seasons. Shannon -Weiner Index was higher during monsoon with more evenly distributed algae species. Closterium sp. and Glaucocystis sp. were more frequent while Gomphonema sp. was highly abundant during monsoon. Dictyosphaerium sp., Anabaena sp., Pinnularia sp. and Closterium sp. showed high abundance with high conductivity during winter but Cymbella sp., Ulnaria sp. and Pleurotaenium sp. seemed concentrated towards high DO during winter.