Biodiversity and Distribution Patterns of Clams (Tridacninae) on Coral Reefs in Kayu Angin Bira Island, Indonesia

This research aims to find out the biodiversity and distribution patterns of clams and the relationship between clam abundance and coral reef conditions in the Waters of Kayu Angin Bira Island, Kepulauan Seribu. The research was conducted between April and July 2022, with field data collection taking place in September 2022 at four chosen stations. These stations were selected based on variations in water depth and were situated in the South, West, North, and East regions of the waters surrounding Kayu Angin Bira Island. The data collection was conducted using survey methods. Coral reef data collection using LIT (Line Intercept Transect) method and clam observation using belt transect. The results showed that in the waters of Bira Kayu Angin Island, 25 individuals of 2 species of bivalve class were found, namely Tridacna squamosa, Tridacna crocea. The highest relative abundance of clams is found at the eastern station which is 20% and the lowest relative abundance is found at the southern, western and northern stations which is only 8%. Low diversity index of Tridacninae Clams was discovered at the four stations, which ranged from 0.451 - 0.662 and the uniformity index at the four stations ranged from 0.650 - 0.954, indicates high population uniformity. Based on Morisita distribution index, which ranges from 0.4 - 0.74, the spatial distribution of Tridacninae clams could be assigned as uniform. The relationship between clams and coral reefs is 0.7284, shows that clams have a strong relationship with the condition of coral reefs.