PHYTOPLANKTON COMMUNITY ORGANIZATION AND SPECIES-DIVERSITY IN THE HUGLI ESTUARY, NORTHEAST COAST OF INDIA

Phytoplankton were collected from March 1988 to February, 1990 from fo ur different stations in the Hugli estuary. Analyses such as relative abundance, dominance, richness, evenness indices and species diversity were made to detail the community organisation of the available phyto plankton. Maximum numbers of phytoplankton cells were observed between postmonsoon (SW) and early premonsoon months. Only two species, Cosci nodiscus radiatus and Coscinodiscus excentricus out of 29 species domi nated and they contributed > 50% to the total population. A significan t negative correlation was observed between species diversity (HOBAR) and pollution index (R/Chl-a).