Phytoplankton communities in Rudrasagar Lake, Tripura (North-East India) – A Ramsar site.

Abstract

Phytoplankton is the integral link of food webs in the transfer of energy to higher aquatic communities that can also act as biologic indicators for evaluation of trophic status of an aquatic ecosystem. The present study was carried out during October (2017) to May (2019) to assess the phytoplankton diversity and abundance of Rudrassagar lake. the largest freshwter wetland of Tripura. A total phytoplankton genera belonging to four main groups viz., Chlorophyceae (18 genera). Bacillariophyceae (9 genera), Cyanophyce. (Genera) and Euglenophyceae (1 genus) were observed during the study. Chlorophyceae dominated the phytoplankton quantitativ followed by Cyanophyceae, Bacillariophyceae and Euglenophyceae. The phytoplankton consituted 82.21-88.05 percent of the palnkton population during the study period. The average montly phytoplankton abundance varied between 14229-25970 cells way ANOVA revealed significant seasonal variation in the abundance of the phytoplankton groups. Maximum species richness was observed in pre-monsoon season. The phytoplankton communities of Rudrasagar lake showed high Shannon Weiner index (3.00-3.996) and high Pielou's evenness index (0.939-0.986). High Shannon Weiner and Pielou's indices indicated high phytoplankton and even distribution of phytoplankton communities respectively. Abundance of different phytolankton groups shwoed significant correlation with temperature. depth. transprency. pH, alkalinity and nutrient concentrations (nitrite, nitrate and phosphate). Know about the phytoplankton communities of Rudrasagar lake in relation to its water quality parameters will hlep in planning possible c for management and optimum utilization of the lake's resources.