Distribution, Abundance and Species Composition of Phytoplankton in the South China Sea, Area I: Gulf of Thailand and East Coast of Peninsular Malaysia

Abstract

Phytoplankton samples were collected from 81 stations in the Gulf of Thailand and the east coast of Peninsular Malaysia during pre-northeast monsoon season (4 Sept. - 4 Oct. 1995) and the post-northeast monsoon season (23 Apr. - 23 May 1996). Two hundred and sixty taxa, composed of 2 species of blue green alga, 133 species of diatoms and 107 species of dinoflagellates, were identified. One species of blue green algae and 17 species of diatoms dominated the population in the study area. The dominant species most frequently found were Oscillatoria erythraea, Thalassionema frauenfeldii, Chaetoceros lorenzianus and C. compressus. The greatest phytoplankton bloom occurred by the highest cell density of Skeletonema costatum in the post-monsoon season near the end of Peninsular Malaysia. The toxic dinoflagellates were found with low cell densities. Species diversity indices (richness indices, diversity indices and evenness indices) were high in the coastal areas in the postmonsoon season.