Phytoplankton Community Dynamics in Sei Gesek Reservoir, Bintan Island

Abstract

Bintan is a small island that has limited fresh water resources. Sei Gesek Reservoir is one of the drinking water sources in there. The aim of this research is to determine the dynamics of diversity and abundance phytoplankton in Sei Gesek Reservoir, Bintan Island, Riau Islands. Sampling was carried out at three area representing inlet, center, and outlet of Sei Gesek reservoir in periods 2016-2018. Phytoplankton samples were collected using plankton net by static method. Phytoplankton group were composed of 3 division: Chlorophyta, Cyanophyta, and Bacillariophyta. Each class of phytoplankton has dynamics of abundance and species each year. The highest average abundance was found in 2016 and then fluctuated to 2018. The highest species and abundance of the division were Chlorophyta, Cyanophyta, and Bacillariophyta, respectively. Phytoplankton community dynamics in Sei Gesek Reservoir is influenced by decreased water volume and acidic pH.