Influence of Coral Reef Rugosity on Fish Communities in Marine Reserves Around Lombok Island, Indonesia

Coral reef structural form is widely considered a key factor with respect to the availability of shelter and foraging spaces for fishes and invertebrates. However, anthropogenic stressors are damaging coral reefs and the structural complexity they provide for millions of marine species. It is therefore important to assess the effect of coral reef structural form on fish diversity, especially in the coral reefs within the world's hyper-diverse Coral Triangle region. This study examined the relationship between rugosity (as a proxy for complexity of form in coral reef habitat) and fish communities in three marine reserves around Lombok Island (Gili Matra, Gili Sula, and Gita Nada) in Indonesia. Data on fish (taxonomic identification, trophic guild, and abundance) and habitat rugosity were collected at six stations in each reserve using three 50 m transects at each station. Data were analysed through analysis of variance and non-metric multidimensional scaling. The results showed that species richness and abundance were strongly correlated with coral reef habitat rugosity. There was also a statistically significant relationship between three trophic guilds (corallivores, planktivores, and omnivores) and coral reef habitat rugosity. This study strongly supports the view that the fine-scale rugosity of coral reef habitat is a critical factor in maintaining abundant and diverse reef fish communities. We did not examine the mechanisms by which coral reef habitat rugosity impact fish communities, but others have found that this is likely due to increased nursery and foraging habitat availability.