Abstract
The Red Sea hosts a high diversity of modern coral reef morphologies and non-accreting coral communities which exist under a wide range of environmental regimes. The majority of research into the coral reefs in the Red Sea has focused on the steep fringing reefs' characteristic of the northern Red Sea and other reef types along the Arabian coastline. This chapter explores the less well-known coral reefs and other coral communities in the central region and southern region, along the coasts of Sudan, Eritrea, Djibouti, and Yemen. In the central region, the Red Sea widens and fringing reefs diminish in scale, as nearshore water depths shallow on account of the presence of broad shallow shelf platforms. Other more unusual reef types and coral communities occur, growing on carbonate, granitic, and volcanic lava flows. Environmental conditions become progressively more extreme towards the south and exhibit cross-shelf and pronounced seasonal gradients. Corals demonstrate a high degree of local acclimation and adaptation to these shifts in conditions. The central region and southern region are transitional zones between the optimal Red Sea reef conditions and the more marginal conditions characteristic of the Gulf of Aden and Arabian Sea.