Distribution, Abundance and Species Composition of Phytoplankton in the South China Sea, Area II: Sabah, Sarawak and Brunei Darussalam

Abstract

Four hundred and four samples of phytoplankton were collected from 79 stations in Sabah, Sarawak and Brunei Darussalam waters, during 2 cruises of M.V. SEAFDEC, 10 July - 2 August 1996 and 1 – 24 May 1997. The Samples were collected from surface, seasonal thermocline and chlorophyll maximum depth. Three hundred and ten taxa, composed of 2 species of blue green alga, 139 species of diatoms and 150 species of dinoflagellates, were identified. The occurrence of phytoplankton species in each layer were recorded. The species frequently found predominant in the surface layer were Oscillatoria erythraea, Thalassionema frauenfeldii and Pseudosolenia calcaravis, and in the chlorophyll maximum layer were Oscillatoria erythraea, Thalassionema frauenfeldii, Chaetoceros affinis, C. messanensis and Fragilariopsis doliolus. Small numbers of toxic dinoflagelates were observed. Quantity of phytoplankton in the chlorophyll maximum layer was most abundant among the three layers observed. Diversity and evenness indices of phytoplankton in this layer were high during both sampling periods.