Assessing the Resilience Potential of Inshore and Offshore Coral Communities in the Western Gulf of Thailand

Abstract

Coral reefs in the Gulf of Thailand have experienced severe coral bleaching events and anthropogenic disturbances during the last two decades. This study assessed the resilience potential of coral communities at Ko Losin offshore reef sites and Mu Ko Chumphon nearshore coral reefs, in the south of Thailand, by conducting field surveys on the live coral cover, hard substratum composition and diversity and density of juvenile corals. Most study sites had higher percentages of live coral cover compared to dead coral cover. Some inshore and offshore reef sites showed low resilience to coral bleaching events. The total densities of juvenile corals at the study sites were in the range of 0.89–3.73 colonies/m2. The density of the juvenile corals at most reef sites was not dependent on the live coral cover of adult colonies in a reef, particularly for the Acropora communities. We suggest that Ko Losin should be established as a marine protected area, and Mu Ko Chumphon National Park should implement its management plans properly to enhance coral recovery and promote marine ecotourism. Other measures, such as shading, should be also applied at some coral reefs during bleaching periods.

Contrasting coral community structures between natural and artificial substrates at Koh Tao, Gulf of Thailand

“…In contrast, Pavona and Fungiidae corals were found to be represented at 9.1% and 8.7% less than in 2014. Crucially, while the representation of fungiid corals is dominant across artificial substrates in 2018-2019, other corals that have been found to be resilient to environmental stressors in Thailand (Sutthacheep et al, 2018(Sutthacheep et al, , 2019 are almost entirely absent from artificial substrates, thus not supporting the hypothesis.…”

“…Acropora spp.) due to bleaching and localised reductions in coral recruitment (Sutthacheep et al, 2018(Sutthacheep et al, , 2019. Despite these important findings, none of these studies have attempted to provide insights into shifting coral community structure through the lens of ecosystem successional pathways.…”

Diversity and Ecology of Lobophora Species Associated with Coral Reef Systems in the Western Gulf of Thailand, including the Description of Two New Species

“…However, Lobophora overgrowth is most likely caused by a severe event, such as a storm, thermal stress, or mass bleaching [ 8 ]. The high sediment load from the mainland may have caused the overgrowth of Lobophora on Kula Island, as the water was relatively turbid [ 43 ]. Furthermore, because the depth of the study sites is very shallow, studies suggest that the abundance of herbivorous fishes is inversely related to water clarity.…”

Coral Diversity at Losin Pinnacle, an Offshore Reef in the Gulf of Thailand: Toward a Future MPA

“…Highly abundant and diverse Acropora populations are uncommon on most inshore reefs in the Gulf of Thailand, making the coral community at Losin Pinnacle a unique potential reservoir of Acropora diversity. After the 2010 bleaching event, coral communities in the Gulf of Thailand have been dominated by bleaching-resistant taxa, with a lower coral diversity than in previous periods (Sutthacheep et al, 2013(Sutthacheep et al, , 2019. Losin Pinnacle has a much higher species diversity, over 75 species, compared to other Thai reefs; 47 species were recorded from twelve sites in the Andaman Sea (Phongsuwan and Chansang, 2012), and only 44 species were recorded from six sites in the Gulf of Thailand (Yeemin et al, 2009;Sutthacheep et al, 2012Sutthacheep et al, , 2013.…”

“…The offshore reef at Losin Pinnacle appeared to be only minorly impacted by the mass coral bleaching that occurred in 2010, with relatively high live coral cover after the bleaching event. After the third global bleaching event in 2016, Sutthacheep et al (2019) noted a decrease in bleaching relative to past bleaching events, with only 5% of the corals bleached. This mild bleaching could be due to its local conditions: surrounded by open sea, with strong currents and internal waves, which could dampen the impacts of increased temperature (Williams et al, 2010;Schmidt et al, 2016).…”