Effects of habitat on reef fishes biodiversity and composition in rocky reefs

Reef fish are highly valuable to human society-socially, nutritionally and economically. However, they are vulnerable to both overfishing and habitat degradation. Understanding the community structure and habitat associations of reef fish is important for their management and conservation. Using a gillnet survey conducted in a subtropical rocky reef area of Ma'an Archipelago, China, we developed habitat models linking reef fish diversity and community composition with habitat factors. The parsimonious generalized additive model results showed that higher reef fish diversity was associated with southern shallower water, temperature of 25 degrees C, lower levels of dissolved oxygen and chlorophyll a, and rock bottom type. The multivariate generalized linear model identified that month, depth, bottom type, and location significantly influenced the local reef fish; these habitat variables explained 18% of the variation in reef fish community composition. However, the lack of strong patterns and correlations between species derived from the joint species distribution model revealed that reefs within our study area are difficult to classify based on habitat-driven patterns in their associated reef fish assemblages. These findings enhance our understanding of the habitat effects on reef fish diversity and community composition and have relevance for the management of reef fish, including habitat zonation and deployment of artificial reefs.