Abstract:
Vertically sampling technique was employed in the study of genus distribution and abundance of phytoplankton in the Upper Gulf and the west coast of the Lower Gulf of Thailand. Samples were collected from 123 stations (8 cruises) from the Upper Gulf, totaling 142 stations during 1978-1981. These stations were desinges by the subcommittee of the Water Quality and the Quality of Living Resources in Thai Waters. Diversity and similarity indexes were analyzed. Relationship indexes were analyzed. Relationship between some environmental factors and phytoplankton abundance was calculated statistically by Multiple Linear Regression. 45 genus of three phylums were identified: -1 genus of phylum Cyanophyta, (Bluee-green algae), -31 genus of phylum Chrysophyta (Diatom), -13 genus of phylum Pyrrophyta (Dinoflagellate), The diatoms were regularly found to be the most abundant genus. The phytoplankton abundance from the Upper Gulf was greater than those from the west coast of the Lower Gulf. Station nearing the river mouths were densely populated by phytoplankton in comparision to stations on the east, the west, and the middle of the gulf. The least abundance was found in the middle part of the Upper Gulf while the east and west did not differ in their abundance. Statistical tests indicated that there was no general equation for the relationship between phytoplankton abundance and some environmental factors. Because the degree of environmental factors influence varied from station to station and each genus. Thus, the relationship for each conditions was presented by individual equations.