A rapid assessment of Scleractinian and non-Scleractinian coral growth forms along the Saudi Arabian coast, Red Sea

In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands (44.55%±11.10% cover) followed by tabular forms in the Doga Islands (ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area (58.89%±15.11% cover) followed by the Jeddah coast (24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah (10.70%±8.21%) and Al-Wajh (9.81%±6.69%). The live coral cover (including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acroporid corals was greater in the southern region than in the northern and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah (Northern region) and the second one comprised the middle and southern regions (Jeddah to Farassan Islands), and one outlier Rabigh.