The best-developed reefs on the Iranian coasts are found around Khark and Kharku islands in the far north and the southern islands from Lavan to Hormuz islands. Fringing reefs are the predominant reef structure on the Iranian coasts.

The coastline of Iran is approximately 2000 km along The Gulf and the Gulf of Oman. Corals are mostly restricted to the offshore islands on the Gulf coast of Iran that are often protected passively by military bases. This also restricts access to these islands for scientific work, such that many of the important coral areas in Iran remain un-surveyed. Much of the Iranian coast in the Gulf of Oman is sedimentary and exposed, therefore unsuitable for coral growth, although important areas of corals probably exist in the more sheltered bays such as Chah Bahar. There is a need for surveys on this coast to describe coral distribution and composition.

Of the known coral rich areas, Farur (19 ha), Farurgan (2.5 ha), Sirri (16 ha), Lavan (18 ha), Hendourabi (20 ha), Kish (62 ha) and Larak (16 ha) islands have been surveyed in the past 10 years, and Kish Island is now a Reef Check site. Tubastraea spp., Heteropsammia sp., Dendronephthya, Sarcophyton, Antipathes sp. and the gorgonian Subergorgia suberosa have been reported from these islands for the first time. It is likely that more detailed work will reveal some better-developed reefs in the Gulf because of the deeper water, slightly lower temperatures and more stable salinities found nearer the Straits of Hormuz.

Other reef sites are known, but have not been surveyed, e.g. the islands of Khark (181 ha), Kharko (266 ha), Nay Band (181 ha), Shidvar (13 ha), Hormuz (59 ha), Hengam (36 ha), Tonb-e-Bozorg and Tonb-e-Koochak (21 ha), Queshm Island and Aboomusa (11 ha). The bestdeveloped reefs are in Kharg, Farur, Farurgan and Larak Islands. Surveys in the 1970s and 1980s indicated live coral cover ranges from 9% on Kish Island, to 30% on Nay Band Bay, with
hard coral extending from 3 m to 15 m depths.

There are coral reefs around 16 islands from the north-west to the south-east and some limited areas around Nay Band Bay. The highest coral cover occurs around Khark and Kharku islands in the far north, Farsi Island in the middle north, and Larak Island on the Iranian side of the Gulf. About 36 species of hard corals have been documented so far by INCO, with Kish Island showing the highest species diversity. Coral cover in 2006 around Farurgan Island was mostly concentrated in the west and north-west of the island with mean coral cover of 25.9% (± 5.8), whereas around Hengam Island it was mostly concentrated on the eastern side of the Island (48.6% ± 1.4). There was a significant difference (p < 0.01) in hard coral coverage among different reefs in each island. Other benthic life forms showed similar patterns with significant differences (p < 0.01) among reefs. The predominant hard coral forms were massive (Porites) in Farurgan Island whilst those in Hengam Island were mainlybranching corals (Acropora). Non-scleractinian corals included Alcyonaceans, 8 of which are new records for Hengam and one for Farurgan islands. Soft corals showed higher diversity and density in the south and north-eastern parts of Hengam Island, but were sparse and isolated in Farurgan Island. There are low density, patchy populations of octocorals, which have been poorly studied because they occur at greater depths. Studies have identified more than 30 species in 21 genera; much less than the 90 genera of Alcyonacea elsewhere in the tropical Indo-Pacific. Octocorals occur along the Iranian side of the Persian Gulf from the Strait of Hormuz to Khark and Kharku Islands in the western part. Populations and density of octocorals varies considerably between the northern Gulf compared to southern parts. The genera in shallow water to around 10 m depth have symbiotic algae (Sinularia and Sarcophyton) whereas those below 15 m depth do not have photosynthetic symbionts.