Assemblages of phytoplankton diversity in different zonation of Muthupet mangroves

•Map-out the diversity pattern in different zonation of Muthupet mangroves.•The limiting factor for phytoplankton growth was identified.•In PCA, the hydrological parameters were enhancing the growth of phytoplankton.

The aim of this paper is to determine the seasonal successions, diversity and assemblages of phytoplankton population in different zones of Muthupet mangroves. The phytoplankton characteristics were studied at four different mangroves zones during 12 months of sampling period with monthly intervals. Species diversity, richness and evenness were calculated. Altogether, 72 species of phytoplankton were identified. The species belonging to four groups namely diatoms, dinoflagellates, blue greens and greens were recorded. Among these groups, diatom showed the highest contribution of the total abundance (Up to 70% in the different zone of Muthupet mangroves) and found to be more dominant in marine and Avicennia zone whereas blue greens and greens were found to be meagre in all the zones.