The coastline is divided into north and south sectors, separated by the Horn of Africa. There are flourishing coral reefs along the Gulf of Aden coastline near Raas Khansir, Raas Cuuda Siyara, and off El Girdi and west of Berbera.

Berbera Harbour (10°24.88'N 44°57.55'E): Low-cliffed (2 - 3 m) shore line of fossilized seabed. Subtidally, rock boulders and rubble with scattered coral communities and alga beds at 1 - 4.5 m, sloping gently to sand. Up to 32 species of corals, scattered and mostly dead with a maximum of 5% live cover of small colonies (most being < 20 cm in diameter). Silt conditions favouring Faviids, which were dominant. Coral rubble included Acropora cf. formosa (or A. nobilis). Fish were notably abundant (32 species), mostly Scarus and Epinephelus. Invertebrates: Xestospongia sp., Dysidea cf herbacea, Cryptodendron adhaesivum, Palythoa cf natalensis, Lambis truncata, Pinctada Margaritifera. Turtles: One green Chelonia mydas and hawksbill Ertmochelys imbricata.

Raas Khansir (10°49.01'N 45°44.79'E), approximately 1 km west of Karin village. Scattered Porites bommie field on sand in 2 - 4 m depth, apparently extending westwards from Karin to the next headland and possibly beyond. Corals scattered on a sandy substratum, with a maximum of 8 species representing 5% live cover. Porites solida formed small 'bommies' under silted conditions. Fishes were notably abundant, but low in diversity (17 species).

Raas Cuuda (10°42.98'N 45°33.37'E): Reef comprising a flat and algal covered area interspersed with mats of pale and dark mats of zoanthids (Zoanthus sansibaricus); some appeared a deep blue in the dim light. Corals are very sparse and small, with a few Faviids and Stylophora pistillata. A relatively productive area with regard to fishes. Extremely abundant juvenile Lutjanus sp., two sandbar sharks (Carcharhinus plumbeus) and one guitar shark (Rhynchobates sp.).Other invertebrates: Xestospongia sp., Zoanthus sansibaricus.

1 km west of Raas Cuuda (10°42.21'N 45°31.30'E): Shallow reef composed largely of stands of Millepora squanrosa and Porites lutea bommies ranging from 0.54 m in diameter. Also considerable Pocillopora verrucosa. Most of the coral (27 species) was dead apparently from bleaching, and the mortality ranged from 60 - 100%. Millepora and Porites previously dominant, now 99% dead, apparently from a bleaching event.Evidence of continued bleaching was observed. Two very small Acropora colonies were totally bleached and a colony of Galaxea and a small Montipora were partially bleached. Fish were relatively abundant (35 species)Other invertebrates: Xestospongia sp., Acanthella sp., Dysidea cf herbacea, Panulirus versicolor (4), Palythoa sp. and a single Tridacna sp.

From 10°41.55'N 45°31.46'E to 10°40.63N 45°28.37E, there is sparse rubble (with very corals - only 8 species) interspersed with sand inhabited by numerous holothurians at 4 - 5 m depth. A few alive and dead specimens (40 cm) to of Lobophylliacf. corymbosa were conspicuous. One Acanthaster planci (40 cm) was observed under a small bommie and one (30 cm) was moving rapidly across the sand. A large, almost mono-specific stand 2 - 5 m of Pocillopora verrucosa with some Porites lutea ranging in depth from 2-5 m. Patches of this were dead and overgrown with turf algae; the average cover being +/- 60%. A single A. planci (35 cm) was associated with a dead patch but no feeding scars were to observed. The approximate size of the outcrop was 50 x 50 m. The outcrop was inhabited by a rich fish fauna. The outcrop gave way to a shallower (1-2 m) area of broken reef consisting almost entirely of dead coral with very few faviids, a single Stylophora pistillata, a few specimens of Montipora stellata and sponge (Haliclona sp. ). The dead coral community was mixed but mostly unidentifiable as it was largely encrusted by coralline algae.

In between Raas Cuuda and Raas Xaatib (10°39'91'N 45°25'27'E): Coral and rock rubble, with some bedrock under coarse sand veneer at 6.5 metres depth. Very scattered live corals, including Platygyra daedalea, Favia sp., Porites solida, P. /utea, Coscinarea sp. Fishes were very abundant (particularly Sphyraena sp. ), but low in diversity (7 species). Invertebrates: Dysidea sp., Plakortis sp., Xestospongia sp., Sepia pharaonis.

In between Raas Cuuda and Raas Xaatib (10°39'65'N 45°25'04'E): Coral rock rubble at 2 - 3 metres (14 species). Scattered live corals forming a maximum 1 - 2% live cover in very silted conditions. Abundant fish life (28 species). Invertebrates: Holothuria edulis, Sepia pharacnis, unidentified sponges.

Siyara (10°36.09'N 45°15.85'E): Reef off village at base of cliff. The reef commences with exposed rock immediately offshore off Siyara and slopes to a depth of 10 m where the substratum again becomes sand. The reef covers > 40% of the seafloor and generally consists of boulders overgrown with coral and small bommies. The rocks at a depth of 1-3 m have a few encrusting algae and sponges. Scattered sponges and some Litophyton cf. Iiltveldi were found up to a depth of 6 m with a number of hard corals, the average coral cover being 40%. The extent of the rock cover diminished from 6 - 10 m, averaging 30% of the seafloor, with a coral cover of > 40%. The coral cover is diverse (33 species) and uniformly mixed up to 6 - 7 m, whereafter Astreopora mounds with a few Montipora plates were conspicuous. Many of the former bore old COTS feeding scars; those that had not been entirely eaten were showing good recovery. Fish life was abundant and diverse (70 species). Invertebrates: Xestospongia, Dysidea cf. herbacea, Palythoa cf. natalensis.

El Girdi (10°33.65'N 45°13.1 5'E): Reef adjacent to a narrow dune belt on the shore backed by a steeply sloping mountain. The subtidal sand gradually gives way to broken, submerged rock which develops into reef, approximately 11 km² in extent. In its shallow reaches (1 - 2 m to the reef top), the reef consists of regular spurs, raised up to 2 m above the intervening patches of sand. The rock has been overgrown by coral so that the reef tops are flat and the sides vertical. The deeper margin of the reef (2 - 3 m to the reef top) forms a complete fringing reef which falls away to reef, with Porites and Astreopora bommies ranging in depth from 5 - 10 m, giving way to sand. The shallower regions of the reef were almost entirely dead and encrusted and accreted with coralline algae. There were only very few small fragments of Montipora stellata on the reef and isolated colonies of e.g. Pocillopora and Stylophora. The mortality was uniform and complete, and probably resulted from bleaching at an earlier date. More coral had survived on the outer fringe of the reef and Porites bommies of up to 3 m were conspicuous. These give way to a coral community similar to that found in the deeper water at Siyara. Plates of Montipora were more conspicuous and there were no COTS feeding scars. The reef cover ranged from 40 - 100% and the coral cover on the reef averaged from 0 - 60%. Fish dauna was diverse and abundant (65 spp.), especially surgeonfishes and parrotfishes. Invertebrates: Tridacna sp., Holothuria scabra, grey holothurian, Haliclona cf. tulearensis, several large Lambis truncata.

There is 1,300 km of coastline on the Gulf of Aden from Ras Caseyr to the border of Djibouti, with large shallow sandy areas and a few seagrass beds. Coral growth is limited because of a lack of suitable bottom substrates and unfavourable currents. A seasonal upwelling in the Gulf of Aden encourages the growth of macro-algae on most hard substrates on northern Somalia. Corals grow in sheltered bays, but there are few true reefs. However there are extensive areas of coral-dominated communities. The largest and most diverse communities occur near Saad ad-Din Island, and near Karin, in the Maydh area, between Buruc and Bosaso and west of Xabo. Elsewhere there are isolated coral colonies and small coral patches. Coral species diversity is comparatively low and large areas are covered by one species of coral, sometimes with live coral cover of 80%.

At the Saardin islands 69 species of scleractinian coral, 11 species of alcyonacean coral and 2 fire corals were recorded in 2002, and fish populations contained many large fish. The last survey 6 years ago showed an average of 50% living coral cover (30% hard coral, 20% soft coral) at the survey sites. Butterflyfish were most abundant with 4.1/500 m³, plus grouper (0.6/500 m³), and parrotfish (0.9/500 m³). The area is both productive and relatively pristine, apart from the effects of coral bleaching and some COTS predation. Somali fishermen target a limited number of demersal stocks and a small range of coral reef fish. Fishing is limited and nearly entirely artisanal, however, foreign commercial fishing occurs on the north coast.