SUDANESE RED SEA Of the most attractive natural areas of Sudan are its Red Sea coastlines. They are the country's biggest tourist attractions and have gained an excellent reputation throughout the world. Geological Characteristics of the Red Sea: The Red Sea is a long and narrow marine basin, with a total length of about 1,900 km. It extends northwards from the strait of Baab El Mandab in Yemen to the southern tip of the Sinai Peninsula in Egypt. It is 306 km at its widest point. The Red Sea has three distinct zones of depth: the shallow reef-
studded shelves of less than 50 metres, the deep shelves of 500-1,000 metres and the central trench of more than 1,000 metres.
The maximum depth of the Red Sea is 3,040 metres off Port Sudan.
The Red Sea is unique in several aspects, among them is its uniform temperature distribution at the surface and at different depths. At the surface near Port Sudan, the temperature range is 26.2-30.5 degrees Celsius, at a depth of 150 metres, the range is still 23.9-25.9 degrees. Moreover, its high degree of transparency reaches up to 46 metres. These characteristics have made the Red Sea an ideal place for snorkelers, divers and photographers - as it is comfortably warm, one could float nicely and the visibility is better than in most other places.
The Sudanese coast is 650-km-long as the crow flies. Numerous embayments and gulfs make it around 800-km-long. It has two prominent features: coastal lagoons or marsas in local parlance and reefs or Shia'ab in Arabic. The marsas may be protected embayments of the sea, or may have been cut into the coastal plain, well beyond the general coastline.
In marsas, despite the heavy fresh water influx during the short rainy season, corals grow and build coral knobs (tens of centimeters to meters in size) and the patch reefs (meters to tens of meters in size). As for the reefs, they are distinguished according to their shapes and positioning. There are the fringing reefs, which are immediately at the coast. They line the entire Sudanese coast, with the exception of the marsas and the Tokar Delta in the south. The fringing reefs are usually 1000 meters wide and could extend up to 3,000 meters. Then there are the barrier reefs, which are generally separated from the coast and the fringing reefs by a ship channel. The barriers range from narrow discontinuous reef walls, only several tens to a few hundred meters wide, to platforms of up to 14 km in width. Finally, there are the atolls, which are reef platforms located farthest offshore, several hundreds of meters to a few kilometers in width and surrounded by waters. Examples of these are the Senganeeb Island and Shia'ab Rumi. All these types of reef provide shelter to a diversity of marine life. They also offer protected areas for snorkelers and shallow-water divers.
One of the most magnificent features of the Red Sea are its beautiful coral reefs. Corals, or more precisely, their skeletons, are the main components of which reefs are built. Coral is an animal, individually called a polyp, which is generally one to a few millimeters in diameter. It looks like a bag with six arms (or multiples of six) and for its protection and support it forms a skeleton of a kind of limestone. These individual skeletons, or corallites, as they are called, are cub or tube shaped. Usually, they live in coral colonies, which may be centimeters to several meters in size. Different kinds of corals occur in different areas of the reef; factors such as waves and light determine the nature of the coral, whether of delicate or solid structure. Thus, the distribution of corals reflects their respective adaptation to the prevailing environmental conditions in various parts of the reef. Aside from corals, other elements are also instrumental in the structure of reefs; for example, worms and calcareous red algae, a form of marine plants.
Surrounding the reefs and complementing them in creating a breath-taking sight, is the wide spectrum of marine life. The Red Sea is famous for its plants and animals, many of which are related to those of the Indian Ocean, but some of which are exclusively found in the Red Sea.
Among the common fish in the Red Sea are the tarpon, giant herring, salmon herring or milkfish, soldier fish, goggle eye and rock cod. There are also more than 320 species of sharks, among them such voracious predators as the tiger shark and hammer shark. It should be noted, however, that unless irritated or attracted by blood, sharks are peaceful animals and, generally speaking, shark attacks along the Red Sea coast are very rare. In addition, several species of whales also find home in the Red Sea, namely the blue whale, a 15-meter-long giant which feeds on plankton, and the killer whale, which poses no threat to humans but scares off sharks. The whale shark, 8 to l0 meters in length, is a jolly, plankton-eating giant that befriends fishermen.
All these characteristics and many others make the Red Sea an attractive location for vacations and relaxation. This is especially true for those who love the sea and enjoy its offerings. Scuba divers, snorkelers, yachting and various water sport enthusiasts will find the Sudanese Red Sea an ideal place for recreation.