The microbial domes of Wadi Muqshin pools,Sultanate of Oman

The paper reports studies on benthic microbial dome‐shaped mats found in hypersaline desert pools in Wadi Muqshin, southern Oman, and details the hydrogeological conditions of the pools, including water quality and recharge features. The upper 1 cm layers of these microbial mats are dominated by cyanobacteria, a phototrophic purple sulphur bacterium and diatoms. The dominant cyanobacterium is Microcoleus chthonoplastes and the purple layer below the upper layer is dominated by the photosynthetic sulphur bacterium Chromatium okenii. It is unusual to find standing water containing microbial domes in such a hyper‐arid, inland site which borders the Rub’ Al Khali (Empty Quarter). The flooding regime here depends largely on ‘fossil’ groundwater (Zone C, L.UER aquifer) mostly derived from the Pleistocene. Attempts to carry out desert agriculture with abstraction of this ‘fossil’ groundwater might cause the extinction of the Muqshin pools.