Resilience Under Pressure: Application of CRes Index to Monitor Coral Ecosystem Shifts in Jaboi, Aceh Post-Mass Bleaching Events

Nadia Aldyza, Afkar Afkar

Abstract


This study assessed the resilience of coral reef ecosystems in the coastal waters of Jaboi, Sabang City, Weh Island, conducted in August 2025. The study area is an open marine zone that has not yet been designated as a marine protected area, highlighting the urgency of evaluating ecosystem resilience as a scientific basis for future conservation planning. Data collection was conducted using six parallel transects installed along the coastline at depths of 3 m and 7 m. Coral cover, turf algae, Crustose Coralline Algae (CCA), and rubble were recorded using 50 m line transects combined with underwater video analysis, while the density of blue sea stars (Linckia laevigata) and sea urchins was assessed using belt transects (100 m²). The results indicated that shallow waters exhibited higher live coral cover, greater CCA presence, and higher abundance of L. laevigata, reflecting a more stable ecosystem with strong recovery potential. In contrast, deeper waters showed increased dominance of turf algae and higher sea urchin density, suggesting emerging ecological pressures despite remaining within the high-resilience category. Differences in substrate quality between depths were identified as a key factor influencing benthic community structure. Overall, the coral reefs of Jaboi demonstrate relatively high resilience; however, early signs of ecological stress emphasize the need for continuous monitoring and proactive management. The findings support the use of the CRes Index as an effective tool for reef resilience assessment and provide essential baseline data to inform conservation zoning, restoration initiatives, and sustainable coastal management in Indonesia.

Full Text:

Untitled PDF

References


Afkar, Barus, T. A., John, A. H., & Sarong, M. A. 2023. Ecological conditions and coral recovery in Jaboi waters, Weh Island Sabang Indonesia. IOP Conference Series: Earth and Environmental Science, 1221(1), 012070. https://doi.org/10.1088/1755-1315/1221/1/012070

Aldyza, N & Afkar. 2015a. Analisis Genus Dan Penyakit Karang Di Perairan Pulau. Jurnal Biotik, 3(2), 107–115.

Aldyza, N., Afkar, A., Hasanah, M., & Roswita, C. 2024. Coral mortality and fish abundance in the Marine Nature Reserve of the Eastern Coast of Weh Island, Sabang, Aceh. Arwana: Jurnal Ilmiah Program Studi Perairan, 6(2), 131–138. https://doi.org/10.51179/jipsbp.v6i2.2861

Aldyza, N., Barus, T. A., Mulya, M. B., & Sarong, M. A. 2022a. Coral resilience inside and outside of Pesisir Timur Pulau Weh conservation zone, Sabang City, Indonesia. Biodiversitas, 23(11), 5744–5751. https://doi.org/10.13057/biodiv/d231126

Aldyza, N., Barus, T. A., Mulya, M. B., Sarong, M. A., Afkar, A., Andi, F., Rahmad, R., & Yuarza, G. 2022b. Coral Covers and The Abundance of Chaetodontidae in Suaka Alam Perairan of Weh Island Aceh. Jurnal Biodjati, 7(1), 56–65. https://doi.org/10.15575/biodjati.v7i1.17604

Aldyza, N., Sarong, M. A., & Rizal, S. 2015b. Monitoring of hard coral covers and zonation of marine conservation area of Tuan Island, Aceh Besar District, Indonesia. AACL Bioflux, 8(5), 640–647.

Ampou, E. E., Johan, O., Menkes, C. E., Niño, F., Birol, F., Ouillon, S., & Andréfouët, S. 2017. Coral mortality induced by the 2015–2016 El-Niño in Indonesia: the effect of rapid sea level fall. Biogeosciences, 14(4), 817–826. https://doi.org/10.5194/bg-14-817-2017

Ampou, E. E., Rahmania, R., Hanintyo, R., Pradisty, N. A., & Setiyo Pranowo, W. 2024. The Potential Use Of Coral Reef Habitat Mapping In Supporting Ecotourism Development In Lombok, Indonesia. International Journal of Conservation Science, 15(4), 1921–1930. https://doi.org/10.36868/IJCS.2024.04.22

Burt, A. J., Koester, A., Bunbury, N., Haupt, P., Walton, R., Fleischer-Dogley, F., & Chong-Seng, K. M. 2025. Supporting resilience-based coral reef management using broadscale threshold approaches. Scientific Reports, 15(1), 25836. https://doi.org/10.1038/s41598-025-09531-9

Ceccarelli, D. M., McLeod, I. M., Boström-Einarsson, L., Bryan, S. E., Chartrand, K. M., Emslie, M. J., Gibbs, M. T., Gonzalez Rivero, M., Hein, M. Y., Heyward, A., Kenyon, T. M., Lewis, B. M., Mattocks, N., Newlands, M., Schläppy, M.-L., Suggett, D. J., & Bay, L. K. 2020. Substrate stabilisation and small structures in coral restoration: State of knowledge, and considerations for management and implementation. PLOS ONE, 15(10), e0240846. https://doi.org/10.1371/journal.pone.0240846

Chou, L.-M., & Huang, D. 2020. Towards Coral Reef Resilience. Journal of Marine Science and Engineering, 8(8), 563. https://doi.org/10.3390/jmse8080563

Curran, A., & Barnard, S. 2021. What is the role of zooxanthellae during coral bleaching? Review of zooxanthellae and their response to environmental stress. South African Journal of Science, 117(7/8). https://doi.org/10.17159/sajs.2021/8369

de Breuyn, M., van der Last, A. J., Klokman, O. J., & Hylkema, A. 2023. Diurnal predators of restocked lab-reared and wild Diadema antillarum near artificial reefs in Saba. PeerJ, 11, e16189. https://doi.org/10.7717/peerj.16189

Do Hung Dang, V., Fong, C.-L., Shiu, J.-H., & Nozawa, Y. 2020. Grazing effects of sea urchin Diadema savignyi on algal abundance and coral recruitment processes. Scientific Reports, 10(1), 20346. https://doi.org/10.1038/s41598-020-77494-0

Fong, C. R., Smith, N., Catalan, E., Caraveo, B. A., Barber, P. H., & Fong, P. 2024. Herbivorous sea urchins (Echinometra mathaei) support resilience on overfished and sedimented tropical reefs. Scientific Reports, 14(1), 3829. https://doi.org/10.1038/s41598-024-52222-0

Forsblom, L., Azhar, M., Barkved, L. J., Berov, D., Børsen, T., & Cenci, A. 2024. Review of existing and emerging techniques for benthic habitats. https://doi.org/10.5281/zenodo.14099051

Freitas Neto, L., & Espósito, B. 2023. Toxicity Of Zinc Oxide To Scleractinian Corals And Zooxanthellae: A Brief Review. Química Nova. https://doi.org/10.21577/0100-4042.20230003

Gaffar, S., Zamani, N. P., & Purwati, P. 2014. Preferensi mikrohabitat bintang laut perairan Pulau Hari, Sulawesi Tenggara. Jurnal Ilmu Dan Teknologi Kelautan Tropis, 6(1), 1–15.

Hafizt, M., Adi, N. S., Munawaroh, M., Wouthuyzen, S., & Adji, A. S. 2023. Coral Reef Health Index Calculation From Remote Sensing Data: A Review. International Journal of Conservation Science, 14(1), 247–264. https://doi.org/10.36868/IJCS.2023.01.17

Harvey, B. P., Allen, R., Agostini, S., Hoffmann, L. J., Kon, K., Summerfield, T. C., Wada, S., & Hall-Spencer, J. M. 2021. Feedback mechanisms stabilise degraded turf algal systems at a CO2 seep site. Communications Biology, 4(1), 219. https://doi.org/10.1038/s42003-021-01712-2

Hughes, T. P., Kerry, J. T., Álvarez-Noriega, M., Álvarez-Romero, J. G., Anderson, K. D., Baird, A. H., Babcock, R. C., Beger, M., Bellwood, D. R., Berkelmans, R., Bridge, T. C., Butler, I. R., Byrne, M., Cantin, N. E., Comeau, S., Connolly, S. R., Cumming, G. S., Dalton, S. J., Diaz-Pulido, G., … Wilson, S. K. 2017. Global warming and recurrent mass bleaching of corals. Nature, 543(7645), 373–377. https://doi.org/10.1038/nature21707

Isdianto, A., Wibowo, R. A., Kudrati, A. V., Alviyanti, D., Asadi, M. A., Dewi, C. S. U., Setyanto, A., Lelono, T. D., Tumulyadi, A., Hidayah, L. N., Fathah, A. L., Putri, B. M., Wardana, N. K., Supriyadi, S., & Luthfi, O. M. 2024. Assessing the relationship between coral cover and coral recruitment in the degraded ecosystems of Sempu Nature Reserve, East Java, Indonesia. Biodiversitas Journal of Biological Diversity, 25(9). https://doi.org/10.13057/biodiv/d250929

Leung, S. K., Kenyon, T. M., Raymundo, L. J., Fox, H. E., Cook, N., Cook, K., Edwards, A. J., Fisher, E. E., Brival, A. J. T., Nicholson, F. E., Philippo, R. W. L., Taylor, A. C. F., Bryan, S. E., Lewis, B. M., Abdul Adzis, K. A. Bin, Edmondson, J. P., Griffin, S. P., Li, X., Liu, X., … Mumby, P. J. 2025. A decision support tool for rubble stabilization on coral reefs. Journal of Environmental Management, 396, 128154. https://doi.org/10.1016/j.jenvman.2025.128154

McLeod, E., Shaver, E. C., Beger, M., Koss, J., & Grimsditch, G. 2021. Using resilience assessments to inform the management and conservation of coral reef ecosystems. Journal of Environmental Management, 277, 111384. https://doi.org/10.1016/j.jenvman.2020.111384

Mulya, M. B., Aldyza, N., & Afkar, A. 2023. The prevalence of coral health issues in the conservation area of Benteng, Weh Island, Sabang, Indonesia. AACL Bioflux, 16(2), 1166–1176.

Mutaqin, B. W., Yuendini, E. P., Aditya, B., Rachmi, I. N., Fathurrizqi, M. I., Damayanti, S. I., Ahadiah, S. N., & Puspitasari, N. N. A. 2020. Kelimpahan Megabentos Sebagai Indikator Kesehatan Karang Di Perairan Bilik, Taman Nasional Baluran, Indonesia. Jurnal Enggano, 5(2), 181–194. https://doi.org/10.31186/jenggano.5.2.181-194

Muttaqin, E., Kamal, M. M., Hariyadi, S., Pardede, S., Tarigan, S., & Campbell, S. J. 2014. Dampak Pemutihan Karang Terhadap Ekosistem Terumbu Karang Pada Tahun 2010 Di Perairan Utara Aceh. Jurnal Teknologi Perikanan Dan Kelautan, 5(1), 15–21. https://doi.org/10.24319/jtpk.5.15-21

Muzaki, F. K., Setiawan, E., Insany, G. F. A., Dewi, N. K., & Subagio, I. B. 2019. Community structure of Echinoderms in seagrass beds of Pacitan beaches, East Java, Indonesia. Biodiversitas Journal of Biological Diversity, 20(7). https://doi.org/10.13057/biodiv/d200701

Otwoma, L. M., & Kochzius, M. 2016. Genetic Population Structure of the Coral Reef Sea Star Linckia laevigata in the Western Indian Ocean and Indo-West Pacific. PLOS ONE, 11(10), e0165552. https://doi.org/10.1371/journal.pone.0165552

Pakpahan, E. H., Anggraini, R., Rahayu, W., Hafizah, N., & Lubis, M. A. 2023. Kerusakan Terumbu Karang Yang Terjadi Akibat Dari Overloadnya Penggunaan Sumber Daya Alam Laut Di Provinsi Banda Aceh. Eksakta : Jurnal Penelitian Dan Pembelajaran MIPA, Vol 8, No 2 (2023): Eksakta : Jurnal Penelitian dan Pembelajaran MIPA, 211–216. http://jurnal.um-tapsel.ac.id/index.php/eksakta/article/view/11683/pdf

Priest, J., Ferreira, C. M., Munday, P. L., Roberts, A., Rodolfo?Metalpa, R., Rummer, J. L., Schunter, C., Ravasi, T., & Nagelkerken, I. 2024. Out of shape: Ocean acidification simplifies coral reef architecture and reshuffles fish assemblages. Journal of Animal Ecology, 93(8), 1097–1107. https://doi.org/10.1111/1365-2656.14127

Rothstein, A., McCarthy, O. S., Luu, S., Kelly, E. L. A., Heller, P., Sandin, S., Smith, J. E., & deVries, M. S. 2025. High abundances of crustose coralline algae inside cryptic coral habitats linked to coral reef functioning. Royal Society Open Science, 12(8). https://doi.org/10.1098/rsos.241971

Saravanan, R., Ranjith, L., Jasmine, S., & Joshi, K. 2017. Coral bleaching: causes, consequences and mitigation. Marine Fisheries Information Service, Technical and Extension Series, 231, 1–9.

Setiawan, F., Muttaqin, A., Tarigan, S. ., Muhidin, M., Hotmariyah, M., Sabil, A., & Pinkan, J. 2017. Pemutihan Karang Akibat Pemanasan Global Tahun 2016 Terhadap Ekosistem Terumbu Karang: Studi Kasus Di TWP Gili Matra (Gili Air, Gili Meno dan Gili Trawangan) Provinsi NTB. JFMR-Journal of Fisheries and Marine Research, 1(2), 39–54. https://doi.org/10.21776/ub.jfmr.2017.001.02.1

Souter, D., Planes, S., Wicquart, J., Logan, M., Obura, D., & Staub, F. 2021. Status of Coral Reefs of the World: 2020. Global Coral Reef Monitoring Network (GCRMN), International Coral Reef Initiative (ICRI). https://doi.org/10.59387/WOTJ9184

Suprapto, P. K., Husna, I. R., Meylani, V., & Wibowo, A. 2023. Spatial Estimations of Suitable Intertidal Habitats for Conservations of Sea Urchin Community in Sancang Coast, West Java. Journal of Multidisciplinary Applied Natural Science, 3(2), 113–121. https://doi.org/10.47352/jmans.2774-3047.162

Tâmega, F. T. S., & Figueiredo, M. A. O. 2019. Colonization, Growth and Productivity of Crustose Coralline Algae in Sunlit Reefs in the Atlantic Southernmost Coral Reef. Frontiers in Marine Science, 6. https://doi.org/10.3389/fmars.2019.00081

Tebbett, S. B., & Bellwood, D. R. 2020. Sediments ratchet-down coral reef algal turf productivity. Science of The Total Environment, 713, 136709. https://doi.org/10.1016/j.scitotenv.2020.136709

Thirukanthan, C. S., Azra, M. N., Lananan, F., Sara’, G., Grinfelde, I., Rudovica, V., Vincevica-Gaile, Z., & Burlakovs, J. 2023. The Evolution of Coral Reef under Changing Climate: A Scientometric Review. Animals, 13(5), 949. https://doi.org/10.3390/ani13050949

Tsikopoulou, I., Dimitriou, P. D., Karakassis, I., Lampadariou, N., Papadopoulou, N., & Smith, C. J. 2021. Temporal Variation in the Ecological Functioning of Benthic Communities After 20 Years in the Eastern Mediterranean. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.768051

Tuhumena, J., Pangaribuan, R., Pane, L., Merly, S., Parenden, D., & Tuhumena, L. 2024. Coral Recruitment And Transplantation To Support Coral Reef Ecosystem Recovery (Overview). Jurnal Ilmiah PLATAX, 12(1), 388–399. https://doi.org/10.35800/jip.v12i1.55333

Tuohy, E., Wade, C., & Weil, E. 2020. Lack of recovery of the long-spined sea urchin Diadema antillarum Philippi in Puerto Rico 33 years after the Caribbean-wide mass mortality. PeerJ, 8, e8428. https://doi.org/10.7717/peerj.8428

Tuwo, A., & Tresnati, J. 2020. Coral Reef Ecosystem. In D. Y. Singh (Ed.), Advances in Biological Sciences and Biotechnology (Vol. 1, pp. 75–104). Integrated Publications. https://doi.org/10.22271/int.book.11

Vimono, I. B., Borsa, P., Hocdé, R., & Pouyaud, L. 2023. Phylogeography of Long-spined Sea Urchin Diadema setosum Across the Indo-Malay Archipelago. Zoological Studies, 62, e39. https://doi.org/10.6620/ZS.2023.62-39

Voolstra, C. R., Peixoto, R. S., & Ferrier?Pagès, C. 2023. Mitigating the ecological collapse of coral reef ecosystems. EMBO Reports, 24(4), EMBR202356826. https://doi.org/10.15252/embr.202356826

Waheed, Z., Bos, A. R., Kochzius, M., & Hoeksema, B. W. 2023. Genetic population structure of the blue sea star (Linckia laevigata) and the boring giant clam (Tridacna crocea) across Malaysia. Hydrobiologia, 850(1), 81–95. https://doi.org/10.1007/s10750-022-05044-y

Watt-Pringle, R., Smith, D. J., Ambo-Rappe, R., Lamont, T. A. C., & Jompa, J. 2022. Suppressed recovery of functionally important branching Acropora drives coral community composition changes following mass bleaching in Indonesia. Coral Reefs, 41(5), 1337–1350. https://doi.org/10.1007/s00338-022-02275-2

Weiss, A., & Martindale, R. C. 2017. Crustose coralline algae increased framework and diversity on ancient coral reefs. PLOS ONE, 12(8), e0181637. https://doi.org/10.1371/journal.pone.0181637




DOI: http://dx.doi.org/10.20884/1.oa.2026.22.1.1333

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Lisensi Creative Commons

Omni-Akuatika by Fisheries and Marine Science Faculty - Jenderal Soedirman University is licensed under the Creative Commons Attribution 4.0 International License.