Preliminary assessment of the environmental impact of NEOM coastal developments on the Northern Red Sea coral reefs

In the context of a warming world, annual bleaching events are becoming more likely and threaten coral reefs on a global scale, leading to a growing interest in identifying local-scale thermal refugia. However such shallow reef refugia are predicted to disappear in a +2.0 °C climate world. Yet, hope remains as Northern Red Sea (NRS) corals could act as a thermal refuge until the end of the century. While being virtually immune to climate change, these so-called ‘super-corals’ are not immune to anthropogenic stressors such as the NEOM mega-project. Here, we used the three-dimensional multi-scale ocean model SLIM3D coupled with a Lagrangian Particle Tracker model to simulate sediment dispersal originating from coastal development sites and assess the environmental impact of the NEOM project on NRS corals. We show that fine sediments (<32μm) have a high potential to impact the entire Gulf of Aqaba (GoA) and part of the NRS, as they can remain suspended in the water column for up to one month and can settle 200 km away from their release site. We identified the most exposed reefs located within 10 km of Sindalah and along 45 km of the Oxagon coastline. Furthermore, we highlight that all the most exposed reefs are located in the NRS; none are within the GoA. To our knowledge, this work is the first to quantitatively assess the environmental impact of the NEOM project on NRS and GoA shallow coral reefs. Based on our results, we expose the need for the implementation of mitigation measures to ensure sustainable coastal development. In a broader way, our model could provide further insights into marine pollution (e.g. desalination plants brines, hydrocarbon pollution) and mesophotic-shallow reef interaction.