Phytoplankton composition and biomass and its fluorescence parameters in waters of the Nha Trang Bay, South China Sea

B and Chl in the bottom layer exceeded ones in the upper layer. Diatoms dominated in species diversity and abundance. Diatom Guinardia striata made the main contribution to phytoplankton biomass.

Similarity of phytoplankton was high. In the upper layer phytoplankton was photoinhibited during the most part of the light period, but at the bottom photosynthetic activity was high. Water column B varied in an order of magnitude during the daily cycle mainly because of B variations in the bottom layer due to tide flow.