Sharm Obhur: Environmental Consequences of 20 Years ... 129 Sharm Obhur: Environmental Consequences of 20 Years of Uncontrolled Coastal Urbanization A.S. Basaham, A.E., Rifaat, M.A. El-Sayed and N. Rasul * Faculty of Marine Sciences, KAU, and * Saudi Geological Survey, Jeddah, Saudi Arabia Abstract. Sharm Obhur is a coastal creek located about 35 km north of Jeddah City and is an attractive recreational area. Urbanization of its coasts is progressively increasing since the eighties. This manu- script aims at the assessment of the impact of human activities on the natural environment of the Sharm through: 1) observation of the morphological changes of its shore using available aerial and satellite images, 2) carrying out an underwater survey to record the present status of the bottom, 3) using geochemical indicators to assess the possible changes in sediment properties. The present study indicates that the Sharm has suffered considerable changes since the eighties. Between 1986 and 2000 the area of the Sharm has been decreased by about 800,000 m 2 , which represents an average annual loss of about 60,000 m 2 due to filling processes. This loss is actually a loss of coral reef ecosystem and its particular habitat. Physical and chemical char- acteristics of sediments appear to be altered compared with previous observations. Underwater photography showed that the bottom is densely covered with litter composed mainly of plastic bottles, cans and tyres, witnessing the absence of sufficient environmental aware- ness. To stop or slow the degradation of the area, the following meas- ures are suggested: 1) enforcement of legislation related to manage- ment of coastal and marine areas, 2) carrying out studies and programs of coral reefs rehabilitation, 3) enforcement of public aware- ness activities for coral reef conservation, 4) effective control of dredging and filling, and 5) upgrading of wastewater collection and treatment. Keywords: Red Sea, Sharm Obhur, Environmental hazards, Uncon- trolled urbanization. 129 JKAU: Mar. Sci., Vol. 17, pp: 129-152 (2006 A.D. / 1427 A.H.)