Coastal corals during heat stress and eutrophication: A case study in Northwest Hainan coastal areas

The impact of coastal upwelling on coral reef ecosystem under anthropogenic influence: Coral reef community and its response to environmental factors

“…Unfortunately, human activities including overfishing, land reclamation, coral mining, and aquaculture expansion contributed to the long-term coral degradation in Hainan Island [Figure 1C; (Huang et al, 2021)]. In the year of 2020, there was few coral bleaching events (1.26%) in the QDU zone, whereas average bleaching percentage was 58.4% for the coastal waters of the northwestern Hainan Island [Figure 1D; (Zhu et al, 2021;Lyu et al, 2022)]. In this work, we surveyed the coral reefs in 2021 from July to September at 20 representative sampling stations (Supplementary Table 1).…”

“…Live reef coral coverage at fixed stations in the west (non-upwelling stations) and east (upwelling stations) of Hainan Academy of Ocean and Fisheries Sciences (C), and data was described in a previous study by Huang et al (2021). The bleaching percentage of northwest coastal areas compared with that of eastern Hainan Island in 2020 (D), and the results were from Zhu et al (2021) and Lyu et al (2022).…”

“…Based on highresolution SST, we uncovered a pronounced temperature disparity between the eastern and western coast of Hainan Island. For comparison, a large-scale coral bleaching incident occurred in the northwestern zone of the Hainan Island but little in a coastal upwelling zone at the eastern coast where cool water may alleviate heating in 2020 (Zhu et al, 2021;Lyu et al, 2022). Frequency and intensity of coral bleaching events that was associated with anthropogenic global warming have significantly increased (Hughes et al, 2017), but fringing reefs at the east coast whereas they are located in within the reach of summer upwelling benefited from colder waters than northwest reefs in the non-upwelling zone.…”

“…The upwelling zone is mainly off the east coast of the Hainan Island and is generally centered in the nearby coastal waters at 18.5°-20.5°N and 110.0°-111.5°E from June to September (Lu et al, 2021). Large-scale coral bleaching in summer of 2020 is the most severe bleaching event reported in China within recent years, western Hainan Island incurred more severe bleaching than QDU (Zhu et al, 2021;Lyu et al, 2022). The QDU zone has the potential to mitigate the effects of harmful heat stress and may serve as a potential thermal refugia for climate change.…”

Hypothetical effects assessment of tourism on coastal water quality in the Marine Tourism Park of the Gili Matra Islands, Indonesia

“…The increasing human population is responsible for a significant increase in water-polluting nutrients, contributing to escalating pressure of human stressors, adversely affecting some existing aquatic ecosystems (such as coral reefs and seagrass) through the direct and indirect mechanisms. In a long time, these conditions with low flushing could also promote eutrophication (Kelly et al, 2021 ; Kermagoret et al, 2019 ; Vigouroux et al, 2021 ; Zhang et al, 2020 ), the decline in the quality of coastal ecosystems and the environment (D'Angelo & Wiedenmann, 2013 ; Devlin et al, 2015 ; Jiang et al, 2013 ; Kermagoret et al, 2019 ; Redding et al, 2013 ; Zhu et al, 2021 ), and reduce the value of the water utilization, including for water-based tourism activities such as swimming, snorkeling, diving, surfing and canoeing (WHO, 2003 ; Pharino, 2007 ; Ngah et al, 2012 ; Cheung et al, 2015 ). Moreover, poor water quality also induces deleterious effects on human health due to bacterial infection (Cheung et al, 2015 ; Thoe et al, 2012 ).…”