Red Sea Reefs
The Red Sea contains arguably the richest, most biologically diverse, and most spectacular coral reefs outside Southeast Asia. The coral reefs in the northern and southern areas of the sea differ considerably. In much of the northern section, the coasts shelve extremely steeply and there are few offshore islands. The coral reefs here are mainly narrow fringing reefs, with reef flats typically only a few yards wide, and slopes that plunge steeply toward the sea floor. In the south, off Eritrea and southwestern Saudi Arabia, is a much wider area of shallow continental shelf. Many of the reefs in this area surround offshore islands, and there are fewer steep dropoffs. The southern Red Sea also receives a continuous inflow of water from the Gulf of Aden to its south that is high in nutrients and plankton, making the waters more turbid, or cloudy, which restricts reef development. Live coral cover throughout the Red Sea reefs is generally high, at about 60–70 percent, as is the diversity of stony and soft corals, fish (including the famous Red Sea lionfish), and other reef organisms. More than 260 different species of stony coral have been identified in the central Red Sea.
Although the Red Sea reefs are mainly healthy, intense diving tourism, especially in parts of Egypt, has caused severe local damage. Coral predation by the crown-of-thorns starfish has also been a problem, and there is a threat of oil spillages from tankers heading toward the Suez Canal.