Habitat structure determines coral reef fish assemblages at the northern tip of the Red Sea

Coral reefs and reef fish communities at the northern tip of the Gulf of Aqaba (Red Sea) are at the extreme of their distribution range. We investigated the effect of habitat structure on fish community structure in five different habitats and over four seasons (during 1 year) at Eilat. ish assemblages varied between habitats and sites, but not between seasons. The combination of habitat parameters that best explained community structure were average depth, distance from shore, vertical relief, percentage cover by rock and the cover complexity index. Our research indicates a high correlation between fish community structure and habitat and demonstrates the ability of multivariate methods to predict community structure in a particular region, based only on habitat parameters. This may offer an effective tool for monitoring programs to detect changes in community composition. We found that the complex relationship between habitat and community structure cannot be described by single community indices nor by their combination. Therefore, a multivariate approach is needed. It is shown to be sufficient to record only 50 of the most common species in order to obtain a community structure similar to that obtained from all the species. Our findings validate the use of multivariate methods when trying to interpret spatial and temporal patterns in fish communities.