What's at risk

Coral reefs
Mangroves
Seagrasses
Turtles
Dugongs
Fisheries

The Red Sea and Gulf of Aden constitute a unique ecosystem with high biological diversity. Their natural resources provide a substantial economic support for the region: in addition to the fishery industry, which has ensured food security to many people of the region and created jobs for others, tourism is an ever growing and increasingly important industry for commerce and other economic activities.

Coral reefs

Coral reefs provide habitats for a wide variety of marine species and protect coastal lands from erosion and storm damage. In the Red Sea, coral-reef communities generally form extensive and productive reef flats which create protected habitat for many juvenile species as well as lagoons which also serve this purpose.
There are 194 species of corals recorded along the Saudi Arabian coast. About 30 coral species have been recognized in the Gulf of Aqaba, about 80 near Jeddah, less than 50 near Al Birk, and less than 10 on the southernmost Saudi inshore reefs.
Five areas along the Saudi coast are noted for their extensive coral reefs: the Tiran islands area, Wejh bank, the area north of Yanbu, the coastline between Obhur and Thuwal, north of Jeddah; and the outer Farasan bank.
The number of coral-reef species in the southern Red Sea and the Gulf of Aden is estimated to be around 130 species.
Coral reef development on the Gulf of Aden coast is severely constrained by the low temperature caused by seasonal upwelling resulting in the domination of hard substrates by brown algae, and soft substrates by seagrass.

Read more about coral reefs from Al Sanbouk No. 12:
Coral bleaching
Paradise in Peril
Corals and Human Disturbance

Mangroves

Mangroves generally grow in waterlogged and saline soils of the intertidal zone and are often associated with areas of run-off. Only two species have been recorded along the Saudi Arabian Red Sea coast, Avicennia marina, which is widespread, and Rhizophora mucronata, found at only six sites. They are found in such areas as broad coastal plains, protected shores, over shoals and spits, and in lagoons.
While mangroves are found scattered along much of the Red Sea coast, the main concentration is in the southern Red Sea where factors such as increased sediment creates an environment more conducive to their development. This increased development in the soil also coincides with areas of greatest agricultural potential.
Mangroves have a variety of values: they provide food in the form of detritus, shelter for numerous organisms (such as molluscs, crabs, shrimp, and fish), fodder for camels and goats, and fuel for human use. Mangroves are also important nesting sites for several species of birds.
Development of coastal recreation facilities and coastal villages in the Ras Hatiba area north of Jeddah, shrimp aquaculture along the southern Red Sea coast and extensive landfill operations in Tarut Bay and Qatif Island and the Gulf War oil spill in Mardumah Island and Tanajib in the Eastern Province have all contributed to decline of the region's coastal mangroves.
Mangrove systems are a valuable and ecologically significant habitat with many uses to humans. The high productivity sustained through detrital food chains contributes to resident and migratory animals and birds and to trophic balances in associated ecosystems.

Seagrasses

Seagrasses are fairly widespread along the Red Sea coast although they are more common in the southern Red Sea. They tend to be concentrated in shallow water areas such as lagoons, sharms (drowned wadi mouths), and mersas (shallow embayments) because of the soft-bottom sediments found in these areas. Of the 11 seagrass species in the entire Red Sea, ten have been recorded along the Saudi Arabian coast. As seagrasses are one of the most productive habitats in the coastal environment, their abundance along the Red Sea is indicative of a highly productive ecosystem.
Only two species are found in the Gulf of Aqaba, where temperatures are cooler. In the north, restricted intertidal and sublittoral areas, limited soft substrate environments, and seasonal extremes in temperature and salinity, restrict seagrass beds to shallow, soft-bottom areas of sharms and mersas, or to intertidal and submarine wadi outwash plains.
Nine species of seagrass have been reported from Yemeni Red Sea coast, only three of these species were recorded from the Gulf of Aden coast.
Approximately 42% of the Yemeni Red Sea coastline supports seagrass communities where they form extensive seagrass beds in Khawba, Mukha, Luhayyah, Midi and As Salif, while in the Gulf of Aden, they occur mainly in Khor Umaira. In Socotra Island, seagrass beds are not common although a significant coverage of Halodule spp. and Cymodocea serrulata are found.

Turtles

Five species of marine turtles have been recorded from Arabian waters, of which the green turtle Chelonia mydas and the hawksbill Eretmochelys imbricata are the most important. The MEPA study estimated the Red Sea population of both species at around 3500 individuals. All marine turtles, except for the loggerhead turtle, are on the list of endangered species of the IUCN - World Conservation Union.
The hawksbill is evidently the most abundant of the Red Sea turtles, with records from every country but Jordan. Nesting is also widely reported but most commonly from islands. The Dehlak Archipelago, in Eritrea, was found to have nesting. The Sudan's Suakin Archipelago may have some of the most concentrated nesting anywhere. Nesting along the Egyptian coast from RAS Banas to islands at the mouths of the Gulfs of Suez and Aqaba, such as Gubal el Kebir and Tiran Nesting spoor, probably of this species, has been seen on islands along the coast of Saudi Arabia, and there is likely to be nesting on Yemeni islands, for the species is common there each year.
Thousands of green turtles nest in South Yemen along the shores of the Gulf of Aden; and some tagged females from there have been recaptured in Somalia, more than 2000 km away. Some of these turtles may move between the Gulf of Aden and the Red Sea.

Dugongs

The only sea-cow occurring in the Red Sea and Gulf of Aden region is the dugong, Dugong dugon. It is a quiet, harmless animal found in sheltered, isolated, shallow bays and lagoons with seagrass beds on which it feeds. Dugong distribution in the Red Sea is not continuous; populations are found in isolated channels and bays. They are rare but occasionally reported from the Gulf of Aqaba, scarce in the Gulf of Suez, reported regularly but are not common in the Sudanese Red Sea, and are very rare along the Eritrean coast. In Saudi Arabia the distribution of dugongs is concentrated in three locations: the Wejjh Bank, the Al-Lith area, and the Gizan area. Read more.

Fisheries

Studies on fisheries have indicated that there is a general trend for increased productivity from the north, in the Gulf of Aqaba, south towards the border with Yemen. Over 74% of the annual Red Sea landings come from the southern section between Al Lith and the Yemeni border. Most species of butterfly fish and damsel fish are abundant in the central Red Sea; some Red Sea/Indo-Pacific species are rare in the southern region; e.g., Chaetodon trifascialls, Pomacanthus imperator, Pygoplites diacanthus. These species are either coral or springe-feeders, and rely on well-developed coral reefs common in the central and northern Red Sea and the Gulf of Aqaba.
Special protective measures are necessary for reefs of the central Red Sea and the Gulf of Aqaba, where the butterfly fish are most common, and for Aynunah Bay, home for many damsel fish and the only recorded northern locality for Pristotis cyanostigma, an endemic damsel fish.
Until 1981, Saudi Arabia's fishery was exploited almost exclusively by artisanal fishermen from small boats and larger (up to 20 m) sambouks.
After 1991, an industrial fishery began, which has grown to a point where the largest company, Saudi Fisheries, currently lands around 1500mt of shrimp and a similar amount of fin fish.
Productivity of the shelf adjacent to Tuwwal along the Saudi coast was estimated to be about 0.38 and 0.41 t/sq km in 1982 an d 1983 respectively.
Many shallow water species (typically found between depths of 10 and 50 m) occur closer to the surface in the Gulf of Aqaba than further south in the Red Sea. For example, the butterfly fish Chaelodon paucifasciatus is usually found deeper than 15 m in the central Red Sea, but occurs right up to the surface in the Gulf of Aqaba. The fishing industry in Aqaba is small and artisanal, consisting in 1995 of approximately 85 fishermen and 40 boats.
The total saleable catch in 1995 was an estimated 15 tonnes, with a value of 45,000 Jordanian dinars. This represented a significant drop from the 1993 catch of 105 tonnes, and was well below the largest registered catch of 194 tons in 1966.
Sites in Djibouti were classified as a subcluster of the southern Red Sea for butterfly fish.
The generally turbid conditions of Djibouti reefs are very similar to those prevailing in the southern Red Sea. On the south coast of Djibouti, close to the border with Somalia, the effects of upwelling nutrient-rich water begin to be discernible in fish assemblages. Water there is very turbid and reefs poorly developed. They support fewer species and lower abundances of reef-associated fish than reefs further north. Non-reef species are more productive, however, and this area represents the main artisanal fishing ground in Djibouti.
In Yemen, the main exports of the fisheries sector include the crustacean shrimps from the Red Sea, mainly Penaeus semisulcatus and P. indicus, and from the Gulf of Aden the rock lobsters Panulirus homarus and P. versiclour, and the deep sea lobster Periulus semelli. Among the molluscs, the main export was the cuttlefish Sepia pharaonis from the Gulf of Aden and dried sea cucumber from mainly the western part of the Gulf of Aden and the northern part of the Yemeni Red Sea waters.

Sources:

Assessment of Land-based Sources and Activities Affecting the Marine Environment in the Red Sea and Gulf of Aden. UNEP Regional Seas Reports and Studies No. 166 (UNEP 1997). Available in PDF format on the GPA website.

Dugongs in the Red Sea and Gulf of Aden by Dirar Nasr. Al-Sambouk No. 10, October 1999. Al-Sambouk is available on this site in PDF format; visit the Library.