The Al Wajh platform - located in the Arabian-African desert belt - is a large land-attached carbonate platform in the Red Sea. In order to analyze total organic carbon (TOC) in Al Wajh lagoon, sediments were dried at 40°C and powdered by hand in a mortar to homogenize the sediment. TOC content (n: 157) was measured using a Leco CS-744 elemental analyzer at the University of Bremen (Germany). Total organic carbon contents range from 0.09 to 0.64% (Fig. 8A and C). Samples with the highest TOC contents are associated with the deepest locations in the lagoon (Fig. 8C).