Biodiversity indices were calculated
following the standard formulae: Biodiversity: H’=-S Pi log Pi; I=1;
richness: D=1-C; C=SPi2; Pi=ni/N and evenness: J’=H’/log2S [13-15]. A
calendar year was divided into four seasons viz., Monsoon (October to
December), Postmonsoon (January to March), summer (April to June)
and Premonsoon (July to September) based on the northeast monsoon
which is prevalent in the study area. Correlation coefficients (r) were
calculated for phytoplankton density and physico-chemical parameters
and the Analysis of Variance (F) tests were made for hydrological
parameters in relation to stations and seasons.