Spatial Distribution of Plankton in Cikeruh River, Jatinangor District, West Java Province, Indonesia

Cikeruh River is a Citarum tributary that has received a lot of waste inputs, so that will affect the quality of river water and cause differences in aquatic fertility. Aquatic fertility can be determined by calculating plankton abundance and distribution. The purpose of this study was to map the spatial distribution of plankton along the Cikeruh River. The study was conducted in June 2019 to August 2019 at five stations with the purposive sampling method. The parameters observed were physical and chemical parameters of waters, plankton abundance, diversity index, dominance index, species deficit, and Morisita index. The results showed that plankton was identified as many as 33 phytoplankton genera and six zooplankton genera, the spatial distribution of plankton in the Cikeruh River was different at each station, at station 1 consisted of 14 phytoplankton genera, station 2 27 phytoplankton genera, station 3 24 phytoplankton genera, station 4 25 phytoplankton genera, and at station 5 was found 22 phytoplankton genera. The abundance of plankton obtained ranges from 1823-5972 ind/L. Phytoplankton diversity index obtained from ranges 0.71-0.84, while the zooplankton ranges 0.17-0.32 with phytoplankton dominance index 0.16-0.35 and zooplankton 0.68-0.83. Phytoplankton morisita index obtained from ranges 1.37-2.17, while the zooplankton ranges 1.03-2.31. Physical-chemical parameters observed as follows: Temperature 18.58ºC – 27.77ºC, light transparency 16,68 cm -31.92 cm, current 0.17 m/s -0.35 m/s, DO 3.35-8.05 mg/L, CO2 8.36 -37.05 mg/L, pH 7.53 – 8.66, BOD5 10.83 - 25.42 mg/L, Nitrate 0.18-0.26 mg/L, phosphate 0.18-0.26. The physical and chemical parameters qualify for Indonesian Government Regulation No. 82 of 2001 class II and III.