Distribution and Abundance of Intertidal Sponge (Porifera) Communities in Coral Reefs of Singapore

Given the important functional roles of sponges in the coral reef community, few studies have looked at sponge community assemblages in Singapore. This study was conducted to assess the sponge diversity, species richness, and species abundance of intertidal sponge communities in Singapore's coral reefs, including Pulau Hantu, P. Subar Laut, Tanjong Rimau, and Labrador Park. Belt transects measuring 10 m by 1 m were established to survey the sponge communities at these reef sites. Based on sponge morphology, a total of 28 morphospecies were identified, belonging to eight different sponge orders, namely Chondrillida, Clionaida, Dictyoceratida, Haplosclerida, Poecilosclerida, Suberitida, Tetractinellida, and Verongiida. Univariate statistical analyses revealed that sponge diversity, species richness, and abundance at P. Hantu site 2 were significantly higher than that in Labrador Park. In addition, multivariate statistical analyses showed that in terms of community structure, there were three distinct clusters found at P. Hantu site 2, Labrador Park, and P. Subar Laut. The formation of these distinct clusters was sponge species specific and shaped by environmental factors and anthropogenic stresses. Preliminary sponge data presented in this study contribute to the regional biogeography of sponges and could serve as baseline data for future studies, including ecological research and biomonitoring of marine invertebrates, and support marine conservation efforts in Singapore.