Abstract

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 are 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.

摘要

红海是一个重要的水域，拥有重要的珊瑚礁生态系统。由于气候变化或人为压力源的作用，这个半封闭的海洋容易变暖。沙特阿拉伯红海沿岸的海水淡化厂会排放来自冷却系统的大量热水，这将影响附近的珊瑚礁斑块。这项研究的主要目的是通过地理空间分析来描述红海中海表温度（SST）的空间变化和时间趋势，重点是海水淡化厂附近的水温异常。通过中等分辨率成像光谱仪（MODIS）Aqua卫星获取了2003-2019年期间的每月海面温度数据。分别从插值分析和稳健的统计指标获得了年度SST变化和年代际趋势。结果表明，红海具有三个明显的温度带，北部最冷，南部最暖。此外，在红海北部（0.8摄氏度/十年），全球变暖现象明显。大约三分之一的沙特珊瑚产于北部，而其余的珊瑚斑块则定居在海温相对较低的中部和南部。但是，由于海水淡化厂（特别是吉达南部）的热水排放，红海中部的一些珊瑚紧邻海表温度突然升高的区域。