Phytoplankton composition of the mangrove ecosystem in Khanh Hoa province, Vietnam

Abstract

The objective of this study was to clarify the structureof phytoplankton in the natural mangroves of Nha Phu lagoon in Khanh Hoa province, Vietnam, and their correlation with other environmental factors. The outcome of the surveys in the area showed that there was a high diversity of phytoplankton species with about 139 ones, particularly Silic algae dominance. The biomass of phytoplankton here is not high, ranging from 25 260 to 58686 cells/liter. The environmental parameters show that the area has a favorable environment for the growth of phytoplankton. The salinity of water was from 18 %o to 35 %o the temperature was between 29.4 °C and 30.1 °C, and the pH index varied from 7.03 to 7.98. Analysis of the relationship between the abundance of phytoplankton species and environmental factors pointed out that the number of phytoplankton species has an inverse linear proportion to the content of Chlorophyll-a but a direct one to the salinity and the total content of Phosphorus in seawater. Also, the biomass of phytoplankton has an inverse linear proportion to salinity and pH but follows the opposite one to the environmental temperature and the content of Chlorophyll-a.