Diversity and distribution of Porifera Phylum in the coral reefs of South Buru District, Buru Island, Maluku

Buru Island is part of the Wallacea region, known for its high marine biodiversity and relatively unexplored coral reef ecosystems, making it a valuable area for egological research. This study inverstigates the community structure of the Porifera phylum (sponges) in the coral reef ecosystem. Data were collected from 15 observation sites using the Belt Transect method at a depth of 10 meters, with each transect spanning 50 meters and replicated. A total of 2,364 Porifera individuals were recorded, making them the second most abundant phylum after Chordata. Commonly observed spesies included Petrosia nigricans, indicating the ecological significance of sponges in the area. The highest density of Porifera was found at site BPT02 with 200 ind/100m², associated with calm and clear waters. The ecological indices revealed a high species diversity (H’ = 2.585), low dominance (C = 0.768), and low evenness (E = 0.441), suggesting a diverse but uneven distribution of individuals across species. These findings highlight the role of Porifera as key benthic components that contribute to the health and complexity of coral reef ecosystems. The presence of ecologically important sponge species also emphasizes the need for conservation efforts to preserve biodiversity and ecosystem stability in the region.