Species Composition and Spatial Patterns of Scleractinian Corals on Shallow Reef Flats in Krabi Province, Andaman Sea

Wiphawan Aunkhongthong; Thamasak Yeemin; Laongdow Jungrak; Charernmee Chamchoy; Sittiporn Pengsakun; Wanlaya Klinthong; Kowit Noikotr; Jamrearn Buaruang; Oranong Pengjamrat; Makamas Sutthacheep

Authors

Wiphawan Aunkhongthong Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Thamasak Yeemin Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Laongdow Jungrak Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Charernmee Chamchoy Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Sittiporn Pengsakun Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Wanlaya Klinthong Marine Biodiversity Research Group, Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Kowit Noikotr Department of Biology, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
Jamrearn Buaruang Marine Microbe Environment Research Unit, Division of Environmental Science, Faculty of Science, Ramkhamhaeng University, Huamark, Bangkapi, Bangkok
Oranong Pengjamrat Lower Andaman Sea Marine and Coastal Resources Research Center, Nature Study Center Building, Rajamangala University of Technology Srivijaya, Trang Campus, Mai Fat Subdistrict, Sikao District, Trang Province 92150, Thailand
Makamas Sutthacheep Marine Biodiversity Research Group, Faculty of Science, Department of Biology, Bangkapi, Bangkok, Thailand, 10240

Keywords:

Reef flat, Species composition, Scleractinian coral, Community structure, Andaman Sea

Abstract

Shallow reef flats support diverse coral assemblages but are highly influenced by local environmental conditions and disturbance regimes. This study assessed spatial variation in live coral cover, species composition, and coral community structure at Ko Pu, Ko Ka, and Ko Sriboya in Krabi Province, Andaman Sea, Thailand. Coral communities were surveyed using three replicate 30 × 1 m belt transects at each site. Coral colonies were identified to species level. Live coral cover differed significantly among the three study sites (ANOVA, p < 0.01). Ko Ka exhibited the highest live coral cover (55.1 ± 4.9%), followed by Ko Pu (42.3 ± 3.7%) and Ko Sriboya (33.2 ± 2.9%). Coral species composition and relative density also varied among sites. Porites lutea was consistently the dominant species at all three locations, whereas other prominent taxa differed spatially. Ko Pu was characterized by Galaxea astreata, Dipsastraea favus, Pavona decussata, and Favites abdita, while Turbinaria mesenterina, F. abdita, P. decussata, Diploastrea heliopora, and Montipora aequituberculata were important components at Ko Ka. At Ko Sriboya, Platygyra sinensis, P. decussata, and Lithophyllon undulatum were among the prominent taxa. Several coral species occurred at all sites, whereas others showed site-specific distributions. These findings demonstrate marked spatial variation in live coral cover and coral assemblage composition among shallow reef flats in Krabi Province. The distinct assemblages supported by each site emphasize the importance of incorporating species-level information together with live coral cover in reef assessment and provide essential baseline data for long-term monitoring, site-specific conservation, and management of shallow reef flat ecosystems in the Andaman Sea.

References

Aunkhongthong W, Yeemin T, Rangseethampanya P, Chamchoy C, Ruengthong C, Samsuvan W, Thummasan M, Sutthacheep M (2021) Coral community structures on shallow reef flat, reef slope and underwater pinnacles in Mu Ko Chumphon, the Western Gulf of Thailand. RIST 4(1):1-7

Aunkhongthong W, Yeemina T, Mue-sueaa O, Niyomthaia P, Jungraka L, Ruangthongb L, Sutthacheep M (2019) Assessing population densities of Pocillopora acuta on shallow reef flats in the Western Gulf of Thailand. Ramkhamhaeng Int J Sci Technol 2(1):17-23

Bellwood DR, Tebbett SB, Bellwood O, Mihalitsis M, Morais RA, Streit RP, Fulton CJ (2018) The role of the reef flat in coral reef trophodynamics: past, present, and future. Ecol Evol 8(8):4108-4119

Cacapit AJ, Akiona AK, Alcantar EA, Araújo A, Bersamin I, Betancourt N, et al. (2025) Initial coral assemblage drives benthic community response to different disturbance type events. PLoS One 20(5):e0317515

Cardenas JA, Samadikhoshkho Z, Rehman AU, Valle-Perez AU, de Leon EHP, Hauser CA, et al. (2024) A systematic review of robotic efficacy in coral reef monitoring techniques. Mar Pollut Bull 202:116273

Carlson RR, Crowder LB, Martin RE, Asner GP (2024) The effect of reef morphology on coral recruitment at multiple spatial scales. Proc Natl Acad Sci USA 121(4):e2311661121

Chan WY, Meyers L, Rudd D, Topa SH, van Oppen MJ (2023) Heat-evolved algal symbionts enhance bleaching tolerance of adult corals without trade-off against growth. Glob Change Biol 29(24):6945-6968

Chen T, Roff G, McCook L, Zhao J, Li S (2018) Recolonization of marginal coral reef flats in response to recent sea-level rise. J Geophys Res Oceans 123(10):7618-7628

Comfort CM, Walker GO, McManus MA, Fujimura AG, Ostrander CE, Donaldson TJ (2019) Physical dynamics of the reef flat, channel, and fore reef areas of a fringing reef embayment: an oceanographic study of Pago Bay, Guam. Reg Stud Mar Sci 31:100740

Dumas P, Peignon C, Dumas M, Bourgeois B, Gossuin H, Fiat S (2022) Destructive outbreaks of the corallivorous starfish Acanthaster cf. solaris spare coral assemblages in the shallowest reef flat areas in New Caledonia. ICES J Mar Sci 79(2):350-361

Dunne RP, Brown BE, Phongsuwan N, Putchim L (2021) The Indian Ocean Dipole and El Niño Southern Oscillation as major drivers of coral cover on shallow reefs in the Andaman Sea. Glob Change Biol 27(14):3312-3323

English S, Wilkinson C, Baker V (1997) Survey Manual of Tropical Marine Resources. 2nd Edition. Australian Institute Resources, Townsville, 385 p.

Eddy TD, Lam VW, Reygondeau G, Cisneros-Montemayor AM, Greer K, Palomares MLD, et al. (2021) Global decline in capacity of coral reefs to provide ecosystem services. One Earth 4(9):1278-1285

Fan R, Wei H, Mai Y, Zhang L, Yu J, Wang D (2024) Observations of waves and currents on the fore-reef and reef flat of a coral reef atoll in the South China Sea. Front Mar Sci 11:1460450

Ford HV, Gove JM, Healey JR, Davies AJ, Graham NA, Williams GJ (2024) Recurring bleaching events disrupt the spatial properties of coral reef benthic communities across scales. Remote Sens Ecol Conserv 10(1):39-55

Geldard J, Lowe RJ, Ghisalberti M, Draper S (2025) Wave attenuation by restored coral reef canopies: implications for coastal protection. J Geophys Res Oceans 130(9):e2025JC022854

Girard EB, Pratama AM, del Rio-Hortega L, Volkenandt S, Macher JN, Renema W (2025) Coastal eutrophication transforms shallow micro-benthic reef communities. Sci Total Environ 961:178252

Gouezo M, Olsudong D, Fabricius K, Harrison P, Golbuu Y, Doropoulos C (2020) Relative roles of biological and physical processes influencing coral recruitment during the lag phase of reef community recovery. Sci Rep 10(1):2471

Harmelin-Vivien M, Pichon M, Schohn T (2024) Specific composition and trophic organization of fish assemblages across Yonge Reef, northern Great Barrier Reef, Australia: a 1990 snapshot. Cybium 48(4)

Harris DL, Webster JM, Vila-Concejo A, Duce S, Leon JX, Hacker J (2023) Defining multi-scale surface roughness of a coral reef using a high-resolution LiDAR digital elevation model. Geomorphology 439:108852

Hoarau L, Mouquet P, Ropert M, Cuvillier A, Massé L, Bonhommeau S, et al. (2023) Negative sea level anomalies with extreme low tides in the South-West Indian Ocean shape Reunion Island’s fringing coral reef flats. Ecol Indic 154:110508

Hoegh-Guldberg O, Pendleton L, Kaup A (2019) People and the changing nature of coral reefs. Reg Stud Mar Sci 30:100699

Huang L, Jiang L, Yu X, Yuan X, Yuan T, Zhang Y, et al. (2025) Conservation priorities for reef-building coral biodiversity across multiple dimensions in the South China Sea. Coral Reefs 44(1):113-127

Kenyon T, Eigeland K, Richardson M, Baldock T, Wolfe K, Sjahruddin F, Mumby P (2025) Threshold velocities for coral rubble bind breakage across varying reef environments. Mar Ecol Prog Ser 773:1-16

Klinthong W, Aunkhongthong W, Chamchoy C, Jungrak L, Pengsakun S, Sukkeaw M, et al. (2025) Assessment of coral recruitment on shallow reef flats at Mu Ko Surin, Phang Nga Province, Thailand. Ramkhamhaeng Int J Sci Technol 8(2):76-85

Kusumoto B, Costello MJ, Kubota Y, Shiono T, Wei CL, Yasuhara M, Chao A (2020) Global distribution of coral diversity: biodiversity knowledge gradients related to spatial resolution. Ecol Res 35(2):315-326

Lam VY, Doropoulos C, Bozec YM, Mumby PJ (2020) Resilience concepts and their application to coral reefs. Front Ecol Evol 8:49

Lawrence AK (2025) From global surveys to local dynamics; quantifying ecological variability in tropical coral reef fish and benthic communities. Doctoral dissertation, Bangor University, United Kingdom

Levy N, Simon-Blecher N, Ben-Ezra S, Yuval M, Doniger T, Leray M, et al. (2023) Evaluating biodiversity for coral reef reformation and monitoring on complex 3D structures using environmental DNA (eDNA) metabarcoding. Sci Total Environ 856:159051

Li JY, Duce S, Joyce KE, Xiang W (2021) SeeCucumbers: using deep learning and drone imagery to detect sea cucumbers on coral reef flats. Drones 5(2):28

Liu Y, Li S, Liao Z, Liu Q, Zou Q, Liu W (2023) Explicit wave-runup formula for beaches fronted by coral reefs using tree-based models. Coast Eng 183:104308

Loya Y, Sakai K, Yamazato K, Nakano Y, Sambali H, Van Woesik R (2001) Coral bleaching: the winners and the losers. Ecol Lett 4(2):122-131

Matthews SA, Williamson DH, Beeden R, Emslie MJ, Abom RT, Beard D, et al. (2024) Protecting Great Barrier Reef resilience through effective management of crown-of-thorns starfish outbreaks. PLoS One 19(4):e0298073

Mattos FM, Mulla AJ, Denis V, Lin CH, Lin TH, Nozawa Y (2025) The role of live and dead corals in shaping fish assemblages across life stages. Ecol Evol 15(11):e72443

Peixoto RS, Voolstra CR, Staab S, Ribeiro B, Duarte G, Suggett DJ (2025) Building coral reef resilience through assisted restoration. In: Coral reef microbiome, pp 235-243. Springer Nature Switzerland, Cham

Reid EC, DeCarlo TM, Cohen AL, Wong GT, Lentz SJ, Safaie A, et al. (2019) Internal waves influence the thermal and nutrient environment on a shallow coral reef. Limnol Oceanogr 64(5):1949-1965

Rich WA, Carvalho S, Berumen ML (2022) Coral bleaching due to cold stress on a central Red Sea reef flat. Ecol Evol 12(10):e9450

Richardson LE, Graham NA, Hoey AS (2020) Coral species composition drives key ecosystem function on coral reefs. Proc R Soc B Biol Sci 287(1921):20192214

Sutthacheep M, Chamchoy C, Suebpala W, Wongnutpranont A, Jungrak L, Aunkhongthong W, et al. (2025) Assessment of microplastic pollution in corals, seawater, and marine sediments in the Gulf of Thailand. Front Mar Sci 12:1669901

Sutthacheep M, Jungrak L, Chamchoy C, Aunkhongthong W, Sasithorn N, Suebpala W, et al. (2024) Low impacts of coral bleaching in 2024 on the underwater pinnacles from Krabi Province, the Andaman Sea. Ramkhamhaeng Int J Sci Technol 7(2):1-14

Sutthacheep M, Pengsakun S, Yucharoen M, Klinthong W, Sangmanee K, Yeemin T (2013) Impacts of the mass coral bleaching events in 1998 and 2010 on the western Gulf of Thailand. Deep-Sea Res II 96:25-31

Sutthacheep M, Suebpala W, Banleng W, Aunkhongthong W, Chamchoy C, Jungrak L, et al. (2025) Community structure of scleractinian corals on shallow reef flats at Mu Ko Surin, Phang Nga Province, Thailand. Ramkhamhaeng Int J Sci Technol 8(1):83-93

Tietjen KL, Perks NF, O’Brien NC, Baum JK (2025) Impacts of a prolonged marine heatwave and chronic local human disturbance on juvenile coral assemblages. PLoS One 20(2):e0300084

Timmers MA, Jury CP, Vicente J, Bahr KD, Webb MK, Toonen RJ (2021) Biodiversity of coral reef cryptobiota shuffles but does not decline under the combined stressors of ocean warming and acidification. Proc Natl Acad Sci USA 118(39):e2103275118

Voolstra CR, Peixoto RS, Ferrier-Pagès C (2023) Mitigating the ecological collapse of coral reef ecosystems: effective strategies to preserve coral reef ecosystems. EMBO Rep 24(4):e56826

Webber K, Srinivasan M, Coppock AG, Jones GP (2022) Spatial patterns in the cover and composition of macroalgal assemblages on fringing and nearshore coral reefs. Mar Freshw Res 73(11):1310-1322

Wulandari P, Cholifatullah F, Janwar Z, Setia TM, Soedharma D, Praptiwi RA, Sugardjito J (2022) The health status of coral reef ecosystem in Taka Bonerate, Kepulauan Selayar Biosphere Reserve, Indonesia. Biodiversitas 23(2):721

Xie JJ, Xiong W, Liu HW (2024) Bragg reflection of linear shallow-water waves by an array of widely spaced trapezoidal bars on a fringing reef flat. Ocean Eng 292:116593

Yeemin T, Sudara S, Krairapanond N, Silsoonthorn C, Ruengsawang N, Asa S (2001) International Coral Reef Initiative Country Report: Thailand. Regional ICRI Workshop for East Asia

Zhang T, Chen T, Liu S, Lin X, Li S, Yan W (2023) Coral reef resilience persisted for a millennium but has declined rapidly in recent decades. Front Mar Sci 10:1143728