Spatio-temporal variability of sea surface temperatures in the Red Sea and their implications on Saudi Arabia coral reefs

The Red Sea is a conspicuous water body that hosts important coral reef ecosystems. This semi-closed sea is exposed to warming either by climate change or by anthropogenic stressors. The desalination plants along the Red Sea coast of Saudi Arabia dispose tremendous effluents of hot water from cooling systems, which is expected to impact the neighboring coral reef patches. The main objectives of this study were to delineate the spatial variations and the temporal trends of sea surface temperatures (SST) in the Red Sea using geospatial analysis with focusing on water temperature anomalies adjacent to seawater desalination plants. Monthly sea surface temperatures data were acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite for the period 2003-2019. Annual SST changes and decadal trends were obtained from interpolation analysis and robust statistical metrics, respectively. Results showed that the Red Sea has three distinguished temperature zones with the coldest at the north and the warmest at the south. In addition, global warming is remarkably apparent in the northern part of the Red Sea (0.8 °C/decade). About one third of the Saudi corals occur at the northern part, while the remaining coral patches settle in the middle and southern parts of relatively lower SST trends. However, some corals in the middle section of the Red Sea occur proximate to regions of abruptly high SST trends due to the discharge of hot waters from desalination plants, particularly south of Jeddah. The continuous human-induced heating by hot water disposal could be fatal to coral reef ecosystems nearby desalination plants.