
A study on biodiversity of phytoplankton in Fort Lake revealed a total of 35 species belonging to five classes in which Chlorophyceae-19 species, Bacillariophyceae-10 species, Cyanophyceae-3 species, Dinophyceae-2 species and 1 species of Euglenophyceae. Species of Bacillariophyceae were abundant and dominated by Nitzschia sp., Navicula sp., and Synedra sp., which are considered as indicators of organic pollution and bad quality of water. Algal pollution index revealed a score of 28 indicating that Fort Lake is organically polluted. Physico- chemical parameters of Fort Lake revealed that the pH ranges from 7.8 to 9.2, electrical conductivity ranges from 395 µS/cm to 570 μS/cm, dissolved oxygen 2.9 to 6.9 mg/L, total hardness 149 mg/L to 200 mg/L, calcium hardness 69 mg/L to 90 mg/L, Temperature 210C to 250C, Iron 0.1 mg/L to 0.3 mg/L, phosphate 0.0 mg/L to 0.5 mg/L, nitrite 0.0 mg/L, nitrate 0.1 mg/L to 5 mg/L, chloride 60 mg/L to 120 mg/L, residual chlorine 0.0 mg/L to 0.2 mg/L ,ammonium 0.1 mg/L to 5 mg/L, fluoride 0.0 mg/L, turbidity 24.00 cm to 38.100 cm and total alkalinity 105 mg/L to155 mg/L. Based on the investigation we conclude that Fort Lake is polluted by organic waste and is unfit for drinking but can be utilized for fish rearing and recreational activities.