Phytoplankton and Water Quality of Three Small Lakes in Cibinong, West Java, Indonesia

Abstract

In West Java small lakes, known as “Situ”, have many functions including flood control, irrigation, tourism, domestic water and fisheries. Lakes in urban area arevulnerable to anthropogenic impact and typically show elevated level of nitrate and phosphate which support eutrophication. Phytoplankton is sensitive to changes in aquatic ecosystems that arise from excessive eutrophication. This study is to determine the differences of phytoplankton composition and abundance and environmental factors three small lakes in Cibinong City. Two small lakes, Situ Cibuntu and Situ Lotus, receive water source which is coming from the streams flowing through agriculture and human settlement. The other lake, Situ Dora, receive water source coming from the ground water. Phytoplankton was collected weekly in July 2018, while the nutrient (TN and TP) and water quality including temperature, pH, DO, conductivity and TDS were monitored from July to December 2018. There was different phytoplankton composition and abundance and water quality between situ receiving water which flow through agriculture and settlement and groundwater. Phytoplankton composition of Situ Cibuntu and Situ Lotus was dominated by the group of Chlorophyta and Bacillariophyta with the average of phytoplankton abundance were 50967 and 16700 cells. L−1and the chlorophyll-a concentration were 21.451 and 6.591 µg.L−1 respectively. Phytoplankton composition of Situ Dora was dominated by the group of Chlorophyta with the lowest of phytoplankton abundance and chlorophyll-awere5858 cell. L−1 and 4.072 µg.L−1 respectively. The highest nutrient and species number of phytoplankton was recorded in Lake Cibuntu. Water quality of Situ Dora was also characterized by the low value of pH, nutrient (TP and TN). It is highlighted that water source enter into the lake determine status of water quality and characteristic of phytoplankton in urban small lake.