Saudi Arabia boasts the most coral reefs of any Middle Eastern country, as it includes coastline along both the Red Sea and the Persian Gulf. This high-resolution astronaut photograph shows part of the Al Wadj Bank, located along the northern Red Sea coast. Despite the relatively high salinity of Red Sea water (compared to other oceans), approximately 260 species of coral have been documented in the region. Large tracts of the Saudi Arabian coastline are undeveloped, and reefs in these areas are in generally good ecological health. However, reefs located near large urban centers such as Jeddeh have suffered degradation due to land reclamation (dredging and filling), pollution, and increased sediment runoff from land.
The Al Wadj Bank (a bank is an underwater hill) includes a healthy and diverse reef system, extensive seagrass beds, and perhaps the largest population of dugong—a marine mammal similar to the North American manatee—in the eastern Red Sea. The portion of the Bank in this image illustrates the complex form and topography of the reef system. Several emergent islands (tan) are visible, surrounded primarily by dark green seagrass; the largest is at top left. Only the islands are above the waterline; over the reefs, the water color ranges from light teal (shallow) to turquoise (increasing depth). The southern edge of the reef is well defined by the deep, dark blue water of the Red Sea (top).
In recent years, countries that border the Red Sea have cooperated to form a regional conservation plan for reef ecosystems. The plan includes the designation of several Marine Protected Areas (MPAs), integrated coastal management plans, improved pollution controls, reef health monitoring, and public education efforts. The Al Wadj Bank is one of the areas designated as a MPA.
Astronaut photograph ISS016-E-19394 was acquired on December 30, 2007, with a Kodak 760C digital camera fitted with an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment. The image was taken by the Expedition 16 crew, and is provided by the Image Science & Analysis Laboratory, Johnson Space Center. The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, NASA-JSC.
Saudi Arabia boasts the most coral reefs of any Middle Eastern country, as it includes coastline along both the Red Sea and the Persian Gulf. This high-resolution astronaut photograph shows part of the Al Wadj Bank, located along the northern Red Sea coast. Despite the relatively high salinity of Red Sea water (compared to other oceans), approximately 260 species of coral have been documented in the region.
The Sudanese coast of the Red Sea is a well-known destination for diving due to clear water and abundance of coral reefs (or shia’ab in Arabic). Reefs are formed primarily from precipitation of calcium carbonate by corals. (In addition to its commonly used meaning, precipitation can also describe how something dissolved in a solution becomes “undissolved” through chemical or biological processes.) Massive reef structures are built over thousands of years of succeeding generations of coral. In the Red Sea, fringing reefs form on shallow shelves of less than 50 meters depth along the coastline. This astronaut photograph illustrates the intricate morphology of the reef system located along the coast between Port Sudan to the northwest and the Tokar River delta to the southeast.
This unique photograph of shallow Red Sea waters off the coast of Saudi Arabia gives us a glimpse of both the coral reefs under the surface, and the texture and movements of surface waters. On the left side of the image we see through the water column to the reefs below the surface. On the right side of the image, the sun reflects off of microscopic oily films formed by a combination of natural biological sources and human activities on the sea surface. The films are concentrated by surface water movements and variably dampen surface capillary waves, which effect how the sun’s light is reflected. This creates patterns of brighter and darker reflections when viewed from orbit. These patterns trace the complex surface water dynamics along the coast.