Fish community structure in the seagrass ecosystem of Tidung Besar Island, Seribu Islands

Seagrass plays an important role as a habitat for spawning, nurturing, protecting, and foraging marine biota such as fish. However, the fish community structure in the seagrass ecosystem of Tidung Besar Island has not been studied. This study aimed to analyze the structure of fish communities in the seagrass ecosystem of Tidung Besar Island during high- and low-tide conditions. Fish sampling was carried out for three months from October to December 2023 using gillnets with four different mesh sizes, lengths, and widths. The fish samples were analyzed in the laboratory. During the study, 1144 individuals were collected, consisting of 12 orders, 30 families, and 70 species. The fish composition was dominated by Dischistodus chrysopoecilus (white-spot damsel) at 612 Ind/m 2 . The abundance and dominance of species were higher at high tide, whereas species richness, diversity, and evenness were higher at low tide. Fish diversity on Tidung Besar Island is included in the medium category, with conditions that tend to be stable.