APPRAISAL OF CYCLIC DISSIMILARITY AND SEASONAL CHANGES OF THE PHYTOPLANKTON IN TUNGABHADRA RIVER NEAR HARIHAR – KARNATAKA

The present paper deals with the study of the cyclic dissimilarity and seasonal changes in phytoplankton population in Tungabhadra River from Harihar, Karnataka. The river located in the district Davangere is located in the central part of Karnataka state (India) between latitude 14°17ʹ to 14°35ʹ N and longitude 75°50ʹ - 76°05ʹ E covering an area of 6500 sq. km at an average altitude of 540 m above Mean Sea Level (MSL). From the selected 3 stations of Tungabhadra river water, samples were collected at monthly intervals. Qualitative and quantitative analysis of phytoplankton were carried out during the year 2018 – 2019. Seventy-one (71) species of phytoplankton were found comprising Chlorophyceae 35.47%, Bacillariophyceae 18.11%, Cyanophyceae 37.48% and Euglenophyceae 8.93%. Phytoplankton communities had the highest and lowest Shannon-Weaver diversity indices in the winter and summer, respectively. The highest Evenness index occurred in both the winter and rainy seasons, whereas the minimum was in winter. Sequential seasonal phytoplankton succession in Tungabhadra river was divisions Cyanophyceae a followed by Chlorophyceae. The diversity and distribution patterns of certain species were related to water quality as evident from the present study.