THE DIFFERENCE OF PHYTOPLANKTON ABUNDANCE INSIDE AND OUTSIDE OF FLOATING CAGE IN BANDAR KHAYANGAN RESERVOIR PEKANBARU

Abstract

This research has been conducted from September – October 2011 in Bandar Khayangan reservoir. This research aims to understand the difference of phytoplankton abundance inside and outside the floating cage in Bandar Khayangan reservoir. Water samples were collected from 3 stations, namely station 1 (in the upstream of the floating cage area), station 2 (in the floating cage area) and station 3 (downstream of the floating cage area). There were 2 sampling sites in each station, in the surface and in 2.5 secchi depth. Sampling was done three times, once a week. Water quality parameters measured were temperature, transparency, pH, DO, CO2, Nitrate and Phosphate. Method used in this research is a survey method. Phytoplankton were sampled using plankton net no 25 and were preserved using lugol 1% and then identifield based on Davis (1955), Prescot (1972), Yunfang (1989), and Yamaji (1995). Result shown that the abundance of phytoplankton range from 10.534 – 42.297 cell/l. The highest of abundance in station 3 (after floating cage) was 42.297 cell/l and the lowest was in the station 1 (before floating cage area) was 10.534 cell/l. Water quality parameter values were as follow: Nitrate, 0.019 – 0.034 mg/l and Phosphate 0.035 – 0.062 mg/l. Based on phytoplankton data, it can be concluded that Bandar Khayangan water can be categorized as mesotrophic.