High resilience of coral communities at Hin Ang Wang, Surat Thani Province and a proposed management strategy

Abstract

The 1998 and 2010 mass coral bleaching events caused coral degradation to be severe and extensive in the Gulf of Thailand, particularly the Western Gulf of Thailand. This study assessed the resilience potential of coral communities at Hin Ang Wang, the Western Gulf of Thailand, by conducting field surveys on benthic components, community structure of scleractinian corals, diversity and density of juvenile corals, composition and abundance of macrobenthic invertebrates and reef fish. The live coral cover was 44.2%, while dead coral cover was 3.7%, indicating that the coral community is very good condition. The dominant coral species were Porites lutea, Pavona decussata and Montipora aequituberculata. The total density of juvenile corals was 1.6 juveniles/m2. The total density of 27 reef fish species was 937. 8±433.6 individuals/100 m2. The most dominant reef fishes were Neopomacentrus anabatoides, Chromis cineracens and Parioglossus philippinnus. There were several target species of macrobenthic invertebrates and reef fish for aquaculture and fishing. Some are attractive to tourists and can be target species for marine ecotourism. Our results show that the coral communities at Hin Ang Wang had high resilience to coral bleaching events and human impacts. It should be established as a marine protected area under the Department of Marine and Coastal Resources. The management plan should be also developed and implemented. The resilience-based management is proposed to support natural processes and maintain coral reef resilience (Yeemin et al. 2012; Sutthacheep et al. 2012). Knowledge concerning the synergistic effects of coral bleaching and anthropogenic impacts on the ecological functions and processes of coral reefs, especially coral recruitment, is very important for establishing a management strategy for enhancing the resilience of coral reefs (Manikandan et al. 2017). High coral recruitment and survivorship of juvenile corals are essential factors in maintaining coral populations after mass mortality from bleaching events (Hughes et al. 2002; Doropoulos et al. 2015; Yucharoen et al. 2015). Therefore, coral recruitment is usually applied as a bioindicator of coral reef recovery and resilience after severe coral bleaching events. Several environmental factors influence coral recruitment, particularly sedimentation, water pollution and overfishing (Yeemin et al. 2013b). The capacity of coral reefs to resist or recover from degradation and to maintain their ecosystem services are defined as coral reef resilience (Mumby et al. 2007). Resilience-based management of coral reefs assesses spatial variation in resilience potential and implementing proper management plans. Several resilience indicators have been developed and used for assessing the ecological resilience of coral reefs, including the assessment of the resilience potential of inshore and offshore coral communities in the Western Gulf of Thailand (Sutthacheep et al. 2019). This study quantitatively assessed the coral reef resilience potential at Hin Ang Wang, Surat Province, the Western Gulf of Thailand, based on scientific surveys in early 2022