The Abu Dhabi Coastal Sabkha: A Literature Review on Its Scientific Value, Environmental Vulnerability, and Sustainable Conservation as a UNESCO Tentative List Geoheritage Site

Abu Dhabi Sabkha, located along the southern margin of the Arabian Gulf, is among the most scientifically significant arid coastal systems on Earth. Submitted by the United Arab Emirates to the UNESCO World Heritage Tentative List in 2018 under natural heritage criterion (viii), the site is currently the only documented coastal sabkha where all four diagnostic sedimentary layers, lagoon mud, microbial mat, gypsum mud, and anhydrite nodules, co-occur within a single coastal setting, south of Al Dhabaya and Abu Al Abyadh Islands. This review evaluates Abu Dhabi Sabkha as a geological heritage system by synthesizing its formation processes, UNESCO significance, complete sabkha sequence, microbial and evaporite processes, climatic setting, environmental sensitivity, and conservation requirements. The site operates under a hyper-arid climatic regime with a documented warming trend of +0.43 °C per decade over 1981–2025 (NASA POWER MERRA-2), confirming that the evaporative processes sustaining its geological record are intensifying. Microbial mats facilitate dolomite mineralization via Extracellular Polymeric Substances at a scale unmatched elsewhere in the Arabian Gulf, while gypsum mud and anhydrite nodules record advanced supratidal evaporitic development. Comparative analysis with sabkha systems in Qatar, Kuwait, Saudi Arabia, and Oman confirms that no other regional coastal sabkha preserves equivalent stratigraphic completeness within a single, actively forming setting. The site faces mounting pressures from urban expansion, coastal reclamation, off-road vehicle movement, groundwater modification, and the increasing frequency of extreme rainfall events, all of which can permanently damage fragile surface structures and microbial systems. Sustainable conservation requires protection zoning, controlled access, multi-scale satellite and drone monitoring, groundwater tracking, and integration into coastal planning frameworks. Abu Dhabi Sabkha should be recognized not as marginal saline terrain, but as a globally important geoheritage system whose scientific value depends on the active preservation of biological, chemical, and physical processes operating together within an irreplaceable coastal setting.