Cumulative effects of large-scale desalination on the salinity of semi-enclosed seas

Abstract

Global desalination capacity is set to increase substantially due to growing water demands globally. The impact of desalination plant discharges on local marine environments is a concern but can be partially mitigated by good plant design to rapidly dilute released brine. For some water bodies with restricted connections to the ocean further concerns have been raised as to whether large-scale desalination risks raising salinity levels of the water body as a whole. Here we assess whether the maximum likely desalination growth by 2050 around the Rea Sea and Gulf of Aqaba could raise salinity levels in these restricted water bodies. The cumulative effect of desalination on salinity levels in the Red Sea will be insignificant compared to natural evaporation. The cumulative effect of desalination on salinity levels in the Gulf of Aqaba may be detectable but within the bounds of natural variability. Careful design and management of the desalination plant outfalls will still be required if the ecological impacts of large-scale desalination are to be manageable.