Abstract
Several investigations including nature and geochemistry of surface sediments were carried out on forty-two sediment samples collected from Abu-Shaar, Abu-Galwa, Umm al-Huwayatat and Marsa Shuni lagoons located along with the Egyptian Red Sea coast. The sediments of Abu-Galawa and Abu-Shaar lagoons had highest carbonate content due to dominance of biogenic sediments from the surrounding coral reefs and very little of terrigenious influx. The mud content recorded high values in Umm al-Huwaytat and Marsa Shuni lagoons as compared with other two lagoons due to high contribution of terrigenous influx, especially near Umm al-Huwaytat lagoon. The sediments of Marsa Shuni lagoon had highest total organic matter content as compared to other three lagoons resulting from high contribution of terrestrial input by Wadi El-Shuni. Phosphorus content in sdiments samples from Umm al-Huwaytat lagoon recorded highest values. The investigation of distribution of heavy metals (Fe, Zn, Cu, Pb and Cd) in surficial sediments of the coastal lagoons indicated that the degree of metal pollution was caused by anthropogenic activities or by natural impact by wadies. The present study provides information about nature and geochemistry of sediments and the extent of pollution that represents primary data base for managers to assess anthropogenic impacts, and better for detecting remedial meseaurs in future.