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

Abstract

Margagiri-Grenyang coastal waters are shallow water with substrate generally in the form of sandy mud that is busy with various fishing activities, 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 aims to analyze the structure of phytoplankton communities including the composition and abundance of types, the index of diversity, evenness, and dominance, as well as their relationship with the quality of water in these water areas. This research was conducted from July to November 2022 with six stations. The results of the observations show that phytoplankton in these waters consist of seven classes and are dominated by the class Bacillariophyceae. The most common type of phytoplankton is Chaetocheros sp. The values of the phytoplankton diversity, evenness, and dominance indices were 1,2733-2,5515; 0,3849-0,8003; and 0,1106-0,4912. Based on the structure of the community formed, it can be seen that phytoplankton can still grow and develop. The structure of phytoplankton communities in Margagiri-Grenyang waters reflects stable conditions and no ecological pressure on biota in these habitats.