The Red Sea (alternatively Arabian Gulf or Gulf of Arabia) is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez (leading to the Suez Canal). The Red Sea is a Global 200 ecoregion. The sea is underlain by the Red Sea Rift which is part of the Great Rift Valley.
The Red Sea has a surface area of roughly 438,000 km² (169,100 mi²). It is about 2250 km (1398 mi) long and, at its widest point, 355 km (220.6 mi) wide. It has a maximum depth of 2211 m (7254 ft) in the central median trench, and an average depth of 490 m (1,608 ft). However, there are also extensive shallow shelves, noted for their marine life and corals. The sea is the habitat of over 1,000 invertebrate species, and 200 soft and hard corals. It is the world's northernmost tropical sea.
Characteristics of Red Sea Coral Reefs
Red Sea coral reefs have developed an unusually high tolerance to the extreme temperatures, salinity, and occasional turbidity (caused by huge seasonal dust storms) that occur in the region. Such conditions that would be lethal or highly damaging to most hard corals found in other parts of the the Indo-Pacific region or in the Caribbean.
Water clarity is exceptional because the lack of river discharge and low rainfall do not lead to the suspension and dissipation of fine sediments as found in many other parts of the tropical oceans that border large land masses.
Red Sea coral reefs are particularly well developed in the north and central portions (off the coasts of Egypt, Saudi Arabia, Sudan), with large sizable offshore reef complexes containing many islands, fringing reefs, and other coral reef habitats (see photo, above).
Further south, coral growth is somewhat inhibited by the influx of nutrient laden water where the Indian Ocean enters the Red Sea. This surface waters of the more southerly areas are also subject to far greater mixing with deeper water caused by strong winds coming off a high mountainous coast.
In general, the marine biota of Red Sea coral reefs is characterized by high endemism. For example, of the 1200 or so coral reef fish species recorded, about 10% are endemic (found nowhere else).
About 300 hard coral species have been recorded from the Red Sea as a whole. The Egyptian coast alone supports about 200 species of reef building corals belonging to almost 50 genera. This represents about four times the hard coral diversity found on Caribbean reefs, and is comparable to the coral diversity found in the Maldives and Seychelles in the Indian Ocean.
Nonetheless, the biodiversity of Red Sea reefs does not rival that of reefs of the richest parts of the Indo-Pacific region.
Status Of Red Sea Reefs
Despite the extreme conditions characteristic of the region, Red Sea coral reefs are generally healthy. Coral reefs range widely in condition and cover, with up to 85% living coral cover at the best sites and over 50% live coral cover at many other locations. There is usually minimal coral bleaching evident, although some localized outbreaks are reported from time to time.
Still, many Red Sea coral reefs situated near urban centers and other developed parts of the coast have been heavily damaged or lost due to the predicatable effects of poorly planned or regulated population expansions and coastal development, along with associated declines in water quality.
In some of the once most pristine reef areas, insufficiently managed dive tourism (damage from anchors and recreational scuba divers) has also taken its predictable toll on the reefs.
A growing number of marine number of protected areas (MPAs) have been established in the Red Sea to help alleviate some of these problems.
Ras Mohammed National Park was established by Egypt in 1983 and includes miles of healthy fringing reefs (see photo, left: Copyright Fotolia). The Red Sea Marine Peace Park in the Gulf of Aqaba was founded in 1994 by the governments of Jordan and Israel to preserve and protect the area's coral reefs.