Seasonal Variation of Physicochemical Parameters and Fresh Water Algae in Pashan Lake

Abstract

Pashan lake is situated northwest to Pune railway station on NDA road. It is about 3 km from University of Pune Railway Station. The lake was screened for different physicochemical parameters of water and different form of algae during the year 2001-2002. Periodic collections have been made from selecting sampling points of the lake at an interval of a fortnight during January 2001-December 2002. The water samples have been collected in bottles and characterized for different physiochemical parameters the algal forms were observed preserved in 4% formalin and Lugol's solution for detail studies. The live as well as preserved forms were observed under phase contract microscope and identifies with the help of Philipose, Smith, Fritsch and Prescott. Individual algal form or colony was micro photographed in Department of Botany, University of Pune, Pune-411007.
The result revealed that the water temperature varied from 16-36^oC, where as pH ranged from 6.5 to 7.4 . A marked variation in total alkalinity was observed during summer season. The dissolved oxygen content was high during summer season Nitrate level varied from 1.02 2.532 mg /L. Lowest concentration of nitrate, phosphate, chloride, carbonate, sulphate, calcium and magnesium were recorded during the pre-monsoon seasons.
The results on fresh water algae indicated that most of the algae forms were planktonic, free floating and epiphytic. The algae forms belong to different genera of Cyanophyceae, Chlorophyceae, Bacillariophyceae, Dinophyceae, Chrysophyceae and Euglenophyceae. The results on seasonal variations in algal forms revealed that the members of Cyanophyceae were abundant in monsoon while members of Chlorophyceae were increased during the post monsoon to winter season. On the other hand diatoms were found abundant throughout the year except in October-November.
The result of the present investigation revealed that physicochemical parameters of lake water significantly influenced the algae vegetation.