Most of the coral reefs occur along the Red Sea coast and the Socotra archipelago, with some sites in the Gulf of Aden. Corals grow on the Red Sea coast as both coral reefs and coral communities on a variety of substrates. Coral reefs in the northern Gulf of Aden are limited by intense cold seasonal upwelling. Extensive coral reefs surround the Socotra archipelago.

The coastline of Yemen is 2,200 km long, with two thirds in the Gulf of Aden. The Red Sea and Gulf of Aden are markedly different environments and the reef types reflect these differences. The Red Sea coral reefs are mainly coastal and island fringing reefs, with some patch reefs and coral pinnacles; the reefs cover approximately 25% of the coastline. Reefs fringe the limestone islands (e.g. the Kamaran group or the southern Farasans), and the volcanic oceanic islands in clearer water (e.g. the Hunaish, Zuqar and Zubairy groups). There are more than 100 islands in the Yemen Red Sea and only a few have been assessed. Coral growth is generally reduced due to the shallow muddy nature of the shelf; unlike the central and northern Red Sea. There are strong seasonal southerly winds, which stir up the sediments, reduce water visibility and stress the corals. In addition, these shallow waters experience comparatively high water temperatures which further stresses the corals. The reefs are more like reef flats without true crests and slopes. The condition of Yemen Red Sea reefs varies widely. Many were badly damaged in the 1990s by bleaching, COTS outbreaks and trawling, with coral cover losses of up to 90%.

The Yemeni Socotra Islands, located at the entrance to the Gulf of Aden, were recognized as a UNESCO Man and Biosphere Reserve in 2003 and have been recommended for inclusion on the World Heritage Register, for which a nomination is currently being prepared. The islands, Socotra, The Brothers (Samha and Darsa) and Abd al Kuri and small islets, host outstanding levels of terrestrial endemism, and are important nesting sites for at least 10 species of seabird. The marine communities are also diverse, with some 250 species of reef-building corals, 730 species of coastal fishes and 120 species of algae, and are characterised by a unique 'cocktail' mix of species representative of several marine biogeographic realms that merge here: the Red Sea and Arabian Sea, East Africa and the western Indian Ocean and the broader Indo-Pacific. For the time being at least, a small number of these species are known only from these islands, like many of their terrestrial counterparts.

Corals are widespread and generally healthy in this area. The Yemen Liquefied Natural Gas (YLNG) project surveyed several sites in 2005 including the Balhaf area; however, Yemen lacks the capacity to design, implement, and support monitoring and management programs in the area. There are extensive and high-cover coral communities in the Gulf of Aden region,especially in sheltered and moderately sheltered areas where coral cover is often well over 50% and up to 100% at the best sites, which may spread for hundreds of metres. In Khor Omera, Aden, Shuqra, Balhaf, Bir Ali and Burum the reefs are dominated by branching, foliose, encrusting and massive coral forms, as well as soft corals. The volcanic headlands and small rocky islands near Aden are covered with highly diverse coral communities, including branching, encrusting, foliose and massive formations which often cover 100% of the rocky surfaces. Balhaf and Bir Ali are the most important coral areas in the eastern Gulf of Aden with extensive fringing coral reefs and important fishing areas.



Recent estimates show that average coral cover is 45% (25% hard coral, 20% soft coral) at the survey sites. The target fish populations are dominated by butterflyfish (5.5/500 m³), while grouper (0.5/500 m³), and parrotfish (0.6/500 m³) are less common.