with very little sign of coral bleaching, with only 9% infected by Thalassomonas loyana, the 'white plague' agent. Favia favus coral there harbours a virus, BA3, which kills T. loyana. Scientists are investigating the unique properties of these coral and their commensal algae to see if they can be used to salvage bleached coral elsewhere. Salinity The Red Sea is one of the saltiest bodies of water in the world, owing to high evaporation and low precipitation; no significant rivers or streams drain into the sea, and its southern connection to the Gulf of Aden, an arm of the Indian Ocean, is narrow. Its salinity ranges from between ~36 ‰ in the southern part and 41 ‰ in the northern part around the Gulf of Suez, with an average of 40 ‰. (Average salinity for the world's seawater is ~35 ‰ on the Practical Salinity Scale, or PSU; that translates to 3.5% of actual dissolved salts). Tidal range In general, tide ranges between in the north, near the mouth of the Gulf of Suez and in the south near the Gulf of Aden, but it fluctuates between and away from the nodal point. The central Red Sea (Jeddah area) is therefore almost tideless, and as such the annual water level changes are more significant. Because of the small tidal range the water during high tide inundates the coastal sabkhas as a thin sheet of water up to a few hundred metres rather than flooding the sabkhas through a network of channels. However, south of Jeddah in the Shoiaba area, the water from the lagoon may cover the adjoining sabkhas as far as , whereas north of Jeddah in the Al-Kharrar area the sabkhas are covered by a thin sheet of water as far as . The prevailing north and northeast winds influence the movement of water in the coastal inlets to the adjacent sabkhas, especially during storms. Winter mean sea level is higher than in summer. Tidal velocities passing through constrictions caused by reefs, sand bars and low islands commonly exceed . Coral reefs in the Red Sea are near Egypt, Eritrea, Israel, Saudi Arabia, and Sudan. Current Detailed information regarding current data is lacking, partially because the currents are weak and both spatially and temporally variable. The variation of temporal and spatial currents is as low as and are governed all by wind. During the summer, NW winds drive