Deterioration in Coastal Biodiversity Associated to Degradation Submarine Springs in the Peninsula of Qatar

The Persian Gulf is a semi-enclosed, sub-tropical marginal sea, subjected to several natural and anthropogenic drivers that play a primordial role in shaping its biodiversity and shoreline equilibrium. Its shallow topography in arid climatic conditions as well as low water exchange and limited freshwater inputs challenge its marine inhabitants to one of the most extreme thermal and saline conditions in the world. In addition, several point source and non-point sources pollutions have also been putting further stress on the biodiversity of the Gulf, notably in coastal and urbanized areas. Moreover, the Western coasts of the Persian Gulf are characterized by an important artesian discharge of groundwater through a system of coastal and off-shore aquifers. These systems release artesian submarine freshwater springs arising from the sea-floor through a well-defined network of faults and fractures. The increase in salinity of these submarine springs is adding an additional stress to the spatial distribution of coastal biodiversity and in turns shoreline dynamics. In particular, the spatial distributions of two important coastal ecosystems, coral reefs and mangroves, are investigated over the period from 1956 to 2019, using photogrammetric coregistered airborne and orbital scenes of the peninsula of Qatar and in-situ validation. The coral reef and the mangrove play an important role in reducing shoreline erosion and seawater intrusion in coastal aquifers. Our results suggest massive retreats of both coral reefs and mangroves associated to both natural and anthropogenic drivers. The retreat is unevenly distributed along the coasts of the peninsula with its Northern and Eastern parts suffering the most degradation. The origins and the quantitative analysis of the degradation of both the coral reef and mangrove will be presented as well as the consequences on coastal aquifers salinity, and increased risks from storm surges and tsunamis.