Diversity and Abundance of Phytoplankton in the Ports of Chonburi and Rayong Provinces, the Eastern Gulf of Thailand

Abstract

Phytoplankton is the main component of food webs in marine and coastal ecosystems and can be used as a bioindicator to investigate water quality, ecosystem fertility, and ocean circulation, which are also crucial for the fisheries in Thailand. Phytoplankton communities reflect climate variability and changes that occur in coastal and marine ecosystems. Here, we aimed to study the diversity and density of phytoplankton in the Chonburi and Rayong ports. Phytoplanktons were collected by using a 20-micron mesh size plankton net with horizontal hauling from the Ao Udom, Laem Chabang Port, and Ao Bang La Mung in Chonburi Province and the Hin Khong, Hat Nong Fab, and Ko Saket in Rayong Province. The results showed that a total of 68 taxa were found in this study. The highest abundance of phytoplankton was found in Bang Lamung in the summer season (39,400.23±773.31 ind./L), while the lowest one was also found at Bang Lamung (3288.35±16.38 ind./L) in the rainy season. The total abundance of phytoplankton at the vicinity of Chonburi port in the summer season was significantly higher than those rainy seasons and both seasons at the vicinity of Rayong port (p=0.05). The species composition at the vicinity of Chonburi port was dominated by diatoms, while at the vicinity of Rayong port was dominated by diatoms and dinoflagellates. Our study provides baseline data of phytoplankton communities in the vicinity of Chonburi and Rayong port.