Marine Heatwaves Characteristics in Spermonde Islands, West Coast of South Sulawesi, Indonesia

Marine heatwaves (MHWs) have caused devastating impacts on marine communities, especially on coastal ecosystems. A coral reef is a coastal community that is vulnerable to changes in the marine environment, especially sea surface temperature. This study focused on investigating the characteristics of MHWs in the Spermonde Islands (SI), which is home to coral reef communities. The dynamics of MHWs were examined during the cold phase of the Pacific Decadal Oscillation (PDO) in recent years (2008–2021) using satellite-observed sea surface temperature data provided by National Oceanic and Atmospheric Administration (NOAA). Statistical methods calculated the characteristics of MHWs such as frequency, intensity, and duration. The analysis results showed that frequency of occurrence, mean maximum intensity, and mean duration of MHWs in the SI were around three times a year, 0.9–1.5 °C, and 8–12 days, respectively. The linear trend of frequency of occurrence of MHWs in the SI showed a decrease of 1 event per decade. In contrast, the linear trend of maximum intensity and duration of MHWs showed an increasing trend in the SI. In addition, this study also showed that the MHWs characteristics in the SI were controlled remotely by El Niño Southern Oscillation (ENSO) climate phenomena. Towards the end of the strong El Niño periods, notably in 2016, the MHWs occurred longer and more intensely.