Jiraporn Charoenvattanaporn, Suree Satapoomin, Somkiat Kornkiattiwong, Pornsilp Pholpunthin, and Vararin Vongpanich

DOI: 10.14456/sjst-psu.2018.117

pp. 806 - 818

Abstract

The marine phytoplankton community was studied between October 2007 and March 2008 along a transect across the
Similan Islands in the Andaman Sea during the southwest and northeast monsoon seasons. Seawater was collected from 11
stations on the transect. At least 146 species belonging to 68 genera in 37 families and 11 orders of marine phytoplankton were
identified by microscopic observation. Diatoms were the major group of dominant phytoplankton particularly at depths in the
study. Cyanophyta, particularly Trichodesmium spp., was the dominant group but the species diversity was maximal for
dinophyta and heterokontaphyta from both monsoon sampling periods. The most diverse genera of dinoflagellate were Ceratium,
Dinophysis, and Protoperidinium, while a high variety of diatom genera were Rhizosolenia and Chaetoceros. The relative results
between the phytoplankton group and environmental parameters revealed that phytoplankton was strongly affected by salinity
and silicate concentration during the southwest monsoon, while the availability of photosynthetically active radiation was
significantly correlated with seasonal succession during the northeast monsoon.