The relationship between phytoplankton community structure and water conditions at Margagiri-Grenyang coastal waters, Banten Bay

Margagiri-Grenyang coastal waters are shallow water with substrate generally in the form of sandy mud that is busy with various activities, i.e. fishing, transportation, beach development for settlements, and industry. This can disrupt the stability of water conditions and the structure of the organism community in the bay. This study aimed to analyze the structure of phytoplankton communities, including the composition and abundance of types, diversity, evenness, and dominance indices, as well as their relationship with the water quality in these areas. This study was conducted for five months (July–November 2022) at six stations. The study showed that phytoplankton in these waters consisted of six classes and was dominated by the class Bacillariophyceae. Chaetocheros sp. and Thallasionema sp. were the genera commonly found in the waters. The values of the phytoplankton diversity, evenness, and dominance indices were 1.2733–2.5515, 0.3849–0.8003, and 0.1106-0.4912, respectively. Bacillariophyceae, Euglenophyceae,and Chrysophyceae appeared to be correlated with phosphate and total suspended solids (TSS).