Seasonal variations and biodiversity of phytoplankton in Harsool-Savangi dam, Aurangabad, India.

The present study concerns seasonal variations, correlation coefficient and biodiversity indices of phytoplankton during January to December, 2008 in the Harsool-Savangi dam, Aurangabad, India. A total of 35 genera were recorded out of which 15 were Chlorophyceae, 7 Bacillariophyceae, 7 Cyanophyceae and 6 Euglenophyceae. Present study revealed maximum percentage wise compositions of Chlorophyceae at north site 41.91%, Bacillariophyceae at west site 32.70%, Cyanophyceae at south site 19.50% and Euglenophyceae at west site 11.47%. Minimum percentage wise compositions Chlorophyceae at south site 37.80%, Bacillariophyceae at east site 28.15%, Cyanophyceae at west site 17.47% and Euglenophyceae at north site 10.57%. Margalef's index (R1) and Menhinick index (R2) values (4.12 and 0.56) were found to be highest at south site and lowest values (3.77 and 0.38) were found at north site. Simpson's index (I) values (0.30) were found to be the highest at north site and lowest values (0.29) were found at south, east, and west sites. Shannon-Weiner index (H') values (1.26) were found to be the highest at south, east, and west sites and lowest values (1.24) were found at north site. Maximum species evenness was recorded at south site; minimum at north site. Maximum population density of Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae (1923, 1173, 889 and 541 organisms I(-1)) were recorded at north site in summer and minimum (108,195, 67 and 24 organisms l(-1)) were recorded at south site in monsoon, respectively.