Seasonal influence of physicochemical parameters on phytoplankton diversity and assemblage pattern in Kailash Khal, a tropical wetland, Sundarbans, India

Studies were carried out from April 2016 to March 2017 for effective understanding of diversity combined with environment-influenced spatiotemporal dynamics of microfloral structure in Kailash Khal wetland of Indian Sundarbans. A total of 36 phytoplankton genera were recorded from the study area. Eight major algal groups were in order of: Bacillariophyceae > Cyanophyceae > Chlorophyceae > Coscinodiscophyceae > Xanthophyceae > Euglenophyceae > Conjugatophyceae > Mediophyceae with respect to their quantitative abundance. Mean seasonal abundance was found highest in pre-monsoon (4.32 x 10(3) cells l(-1)) followed by post-monsoon (3.88 x 10(3) cells l(-1)) and monsoon (1.96 x 10(3) cells l(-1)). One-way ANOVA showed that seasonal difference in physicochemical parameters was statistically significant for temperature, DO, specific conductivity, TA, TS, Ca++, nitrate, transparency, salinity, TH, turbidity, Mg++ and phosphate (p < 0.05). pH, temperature, total hardness, TDS nitrate, phosphate and silicate showed a close affinity with the distribution of phytoplankton community as evident from canonical correspondence analysis. Margalef richness index (3.121-3.774) and Shannon-Wiener diversity index (2.730-2.939) indicated moderately rich phytoplankton diversity in the wetland ecosystem.