Abstract:
A study aims to understand the abundance and diversity of phytoplankton in the Tanjung Putus Lake was conducted from Desember 2012 to February 2013. There were three stations with 3 sampling points in each station. Samples were taken 3 times, once/week and they were analyzed in the Aquatic Ecology and Environmental Management Laboratory of the Fisheries and Marine Science Faculty, Riau University.
Result shown that the phytoplankton obtained were consist of 20 species, they were belonged to of 6 classes, namely Bacillariophyceae (4 species), Chlorophyceae (7 species), Cryptophyceae (2 species), Cyanophyceae (4 species), Euglenophyceae (1 species) and Xanthophyceae (2 species). The average of phytoplankton abundance was around 482 – 640 cells/l. The most common phytoplankton was Dactyloccocopsis sp. (263 cells/l, Cyanophyceae). Diversity index (H') was 2.55 – 2.66, equitabity index (E) was 0.89 – 0.90 and dominancy index (C) was 0.09 – 0.10. General water quality parameters are as follow: temperature: 29 – 31 0C, pH: 6, brightness: 194.67 – 243.33 cm, DO: 6.81 – 8.68 mg/l, CO2: 9.86 – 12.38 mg/l, Nitrate: 0.007 – 0.010 mg/l and Phosphate 0.043 – 0.046 mg/l. Based on phytoplankton abundance, the Tanjung Putus lake can be categorized as oligotrophic lake.
