Notes on soft coral responses during a coral bleaching event in a shallow reef flat in southern Okinawa Island, Japan

Notes on soft coral responses during a coral bleaching event in a shallow reef flat in southern Okinawa Island, Japan | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Notes on soft coral responses during a coral bleaching event in a shallow reef flat in southern Okinawa Island, Japan Jue Alef Lalas, Agus A. Hakim, Chloé Julie Loïs Fourreau, Guillermo M. Castelló, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8349369/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Soft corals (Octocorallia) are major benthic components of Indo-Pacific reefs, yet their responses to thermal stress remain poorly documented compared to those of scleractinian corals. The 2024 Global Coral Bleaching Event provided an opportunity to closely examine soft coral dynamics on a shallow reef flat in the subtropical Okinawa Island, Japan. Permanent quadrats containing colonies of Lobophytum , Sarcophyton , Sclerophytum , and Klyxum were surveyed from August to December 2024, covering the period from just before to immediately after a severe bleaching event. Overall soft coral cover based on the haphazardly selected quadrats declined from 48.5% in August to 12.8% in December. Lobophytum , Sclerophytum , and Klyxum experienced substantial mortality, including the complete loss of some colonies by October. In contrast, Sarcophyton showed no significant decline and exhibited signs of recovery, with some colonies regaining Symbiodiniaceae by December as indicated by colony colors. Colony-level differences in bleaching outcomes suggest possible interspecific and intraspecific variations in heat tolerance. Additional observations including cyanobacterial overgrowth, partial tissue dissolution, and the presence of detached soft coral fragments illustrate the multiple processes by which soft corals degrade during heat stress events. These results show that soft corals can undergo rapid and often cryptic mortality during bleaching, with important implications for reef structure, biodiversity, and ecosystem functioning. Given their ecological importance and distinct degradation processes, long-term and fine-scale monitoring of soft coral communities is essential for understanding their resilience and for predicting potential phase shifts on warming oceans. Heat stress resilience Octocorallia Ryukyu Archipelago Subtropical Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Soft corals (Octocorallia) are major benthic components of coral reefs in the Indo-Pacific (Lau et al., 2020 ), providing structural complexity and habitat for various organisms (Jeng et al., 2011 ; Shoham et al., 2019 ; Epstein and Kingsford, 2019 ). They are soft-bodied colonial anthozoans that lack the massive hard skeleton characteristic of their scleractinian counterparts (Fabricius and Alderslade, 2001 ), making it challenging to monitor soft coral responses during events that cause declines in coral health, such as heat stress events. Unlike hermatypic corals, entire soft coral colonies may disintegrate without leaving any trace of their existence in an area, hindering accurate comparisons of pre- and post-bleaching coverage. Although shown to be affected by heat stress events, detailed descriptions of how soft coral degrades in situ are lacking (Chavanich et al., 2009 ; Maucieri and Baum, 2021 ). To address these, more detailed monitoring at shorter intervals during stress events can be performed. In 2023–2024, record-breaking sea temperatures triggered the Fourth Global Coral Bleaching Event (Reimer et al., 2024 ), resulting in widespread coral mortality across many regions of the world (Duarte et al., 2025 ; Spady et al., 2025 ). During this time, the subtropical reefs of Okinawa in southern Japan experienced high degree heating weeks (> 20°C-weeks), where near complete morality is likely (NOAA, 2024). In our knowledge, different teams that studied bleaching in Okinawa during that event are still finalizing reports for publication, so the extent of the reef degradation is still unknown. So far, little is known about how soft corals are affected by heat stress events (Maucieri and Baum, 2021 ). In some parts of Okinawa Island, shallow fringing reefs that are easily accessible have been recently characterized as being dominated by zooxanthellate soft corals based on data from 2022 and 2023 (Lalas et al., 2024a ; Lalas et al., 2024b ). This provided an opportunity to observe the responses of this understudied taxonomic group in greater detail during the 2024 bleaching event in Okinawa. The main aim of this study was to monitor the responses of selected soft coral colonies from four different genera on a reef flat in Okinawa Island during the 2024 coral bleaching event. This study provides a closer examination of how soft corals respond to heat stress, contributing to a better understanding of the processes that influence coral reef benthic community dynamics, especially on soft coral-dominated areas. Materials and methods Fourteen 0.25 m² permanent quadrats were established on a reef flat in Sunabe, on the west coast of southern Okinawa Island, Japan (26°19′20.83″N, 127°44′44.01″E), at depths of 1–3 m. Each quadrat was haphazardly placed to include soft coral colonies representing the four dominant genera at the site: Lobophytum , Sarcophyton , Sclerophytum , and Klyxum (Lalas et al. 2024a ). Photographs of each quadrat were taken in August, September, and October, and, for some quadrats, also in December 2024. Quadrats that had total mortality of corals by October were not monitored anymore in December, while tags of some quadrats were lost after October. Changes in these quadrats were analyzed by measuring the surface area of all corals within each quadrat using ImageJ, and surface areas were then converted to percentage cover. Notable changes were also described and are presented here. A Kruskal–Wallis test was performed on all datasets to compare the percentage cover of soft corals among months, followed by Dunn’s test with Bonferroni correction to identify pairwise differences between specific months. These analyses were conducted for pooled soft coral cover and for each taxon, except for Klyxum , which had only one representative colony. All statistical analyses were conducted in R (R Core Team, 2024 ). Additionally, photographs of observations of soft coral bleaching from other sites in Okinawa Island were taken and are also presented here. Results and discussion This study highlights the high mortality of soft corals during the 2024 coral bleaching event in Okinawa (Fig. 1 ). The overall mean soft coral cover declined from 48.5% (± 7.7 SE) in August to just 12.8% (± 7.4 SE) in December (Fig. 2 a). The percent cover of Lobophytum decreased from 32.6% (± 8.6 SE) in August to 3.9% (± 3.4 SE) in December (Fig. 2 b). A complete loss of Sclerophytum cover was observed by December (Fig. 2 c), and the Klyxum colony disappeared by October (Fig. 2 d). Interestingly, however, no significant decline was observed for Sarcophyton (Kruskal–Wallis, p > 0.05) (Fig. 2 e). Although the results highlight the overall decline of soft corals during this event, they also reveal intergeneric and potentially interspecific and intraspecific variations in heat tolerance. All Sarcophyton colonies showed slight reductions in colony size throughout the observation period, however mortality was not observed. Signs of recovery were evident, as some colonies regained their Symbiodiniaceae by December (Supplementary Fig. 1). DNA barcoding of the Sarcophyton colonies (Lalas et al., unpublished data) indicated that they belong to the same species, thus, these results may only reflect the responses of this particular species. An example of a Sarcophyton species that adapted in an extreme environment is S . elegans , which dominated an acidified volcanic reef where no hard corals and other soft corals were observed (Inoue et al., 2013). This potentially indicates the resilience of some species in this genus to environmental stress. However, in the study by Baran et al. ( 2023 ) in the Philippines, Sarcophyton exhibited higher bleaching prevalence than Lobophytum and Sclerophytum , which may indicate potential differences in species composition in their study from our study area. For Lobophytum , although an overall decline in cover was recorded, two of the nine colonies did not experience mortality (Supplementary Fig. 2). Although these colonies bleached during summer peak months, they showed no signs of mortality and were observed to be recovering by December 2024 (Fig. 3 ). Preliminary barcoding results suggest that all Lobophytum colonies belong to the same species. However, since only a single genetic marker (mt-MutS) was used for identification, potential interspecific variation cannot be ruled out. In hard corals, restoration ecology studies have shown variations in heat resistance even within the same species (e.g., Humanes et al., 2024 ), and this may also be the case for soft corals. Regardless of the taxonomic level at which bleaching response variation occurs, the colonies that survived the bleaching event demonstrated phenotypic tolerance to heat stress, suggesting that these taxa may be more resilient under future ocean-warming scenarios. However, bleaching may negatively affect the reproductive capabilities of surviving colonies, resulting in weak or non-viable recruits (Michalek-Wagner and Willis, 2001 ). Thus, long-term monitoring is crucial to identify longer-term winners and losers after this extreme heat-stress event (van Woesik et al., 2011 ). The results of this study seem to contrast with previous studies. Baran et al. ( 2023 )’s study in the northern Philippines and Floros et al. ( 2004 )’s study in South Africa showed genus level variation in bleaching susceptibility, where bleaching was observed more for Sarcophyton compared to Lobophytum and Sclerophytum . However, as these studies did not examine post-bleaching status, it is not known if these soft corals survived or died. Although corals that are bleached can recover, this may be affected by their ability to stock energy reserves (Yu et al., 2025 ), or by heterotrophic capacity (Love et al., 2025 ) and thus surviving for longer periods of time even without their Symbiodiniaceae. This shows the importance of conducting more detailed monitoring after bleaching events and not just sampling during a bleaching event. Other interesting observations were also noted during our surveys. Unique to the Sclerophytum colonies monitored, red cyanobacterial mats were observed to overgrow on the colony surfaces (Fig. 4 ). In our knowledge, the presence of such overgrowth on soft coral colonies has not yet been reported in the literature. This may be a process that increases the rate of soft colony mortality, as cyanobacterial mats have been hypothesized to facilitate pathogen transmission in scleractinian corals (Cissell et al., 2022 ). Other unique observations were also noted from other species of soft corals outside the quadrats. During the bleaching event, some colonies of soft corals such as Klyxum colonies were not totally white, which may indicate an incomplete loss of Symbiodiniacae in the tissue, but despite this, parts of the colony started to “dissolve” (Fig. 5 a, b). During the bleaching event, we also observed many loose soft coral fragments (Fig. 5 c), which might be caused by detachment due to the colony becoming brittle from bleaching and were easily detached by physical factors such as wave exposure. During this time, many areas of reef substrate were also observed to have some traces of previously and likely recently present soft corals, indicated by sclerites left in the area (Fig. 5 d), which would likely be carried away by water movement soon after disintegration, leaving no trace of the presence of the soft coral. These observations show the multiple processes through which soft corals degrade and die during a bleaching event. The loss of soft coral communities may have significant consequences for the entire coral reef ecosystem. Soft corals host a variety of organisms, including fishes and a myriad of invertebrates (Epstein and Kingsford, 2019 ). Their decline may lead to a phase shift from soft coral–dominated reefs to algae-dominated systems (Bell et al., 2011). Such changes can affect biodiversity (Burke et al., 2011 ), disrupt ecosystem functioning, and alter the delivery of ecosystem services (Woodhead et al., 2019 ). This underscores the need for monitoring ecosystem functions, as well as long-term monitoring of benthic communities, given the potential for eventual phase shifts. While this study provides further insight into the processes of shaping soft coral and benthic community dynamics, including the notable resistance of some soft coral colonies to bleaching, we emphasize the urgent need for stronger action to mitigate the effects of human-driven climate change. Declarations Conflict of interest The authors declare no conflict of interest Ethical approval Not applicable. Funding JAAL, AAH, and CJLF were funded by the Japan Ministry of Education, Sports, Science, and Technology (MEXT) scholarships, and GMC was funded by the Heiwa Nakajima Foundation Scholarship. This study was supported by general education funds from the University of the Ryukyus to JDR. Author contribution Conceptualization: JAAL; Fieldwork: JAA, AAH, CJLF, GMC, MS; Data analyses: JAAL; Supervision: JDR; Literature review: JAAL, MS; Funding acquisition: JDR; Manuscript writing and editing: JAAL, AAH, CJLF, GMC, MS, JDR. Acknowledgements We thank the members of the Molecular Invertebrate Systematics and Ecology Laboratory for their support. Data availability Data inquiries can be directed to the corresponding author. References Baran CC, Luciano RMA, Segumalian CS, Valino ADAM, Baria-Rodriguez MV (2023) Genus and size-specific susceptibility of soft corals to 2020 bleaching event in the Philippines, Marine Biology Research, DOI: 10.1080/17451000.2023.2198242 Bell JJ, Micaroni V, Strano F (2021) Regime shifts on tropical coral reef ecosystems: future trajectories to animal-dominated states in response to anthropogenic stressors. Emerg Top Life Sci 6(1):95–106. https://doi.org/10.1042/ETLS20210231 Burke L, Reytar K, Spalding M, Perry A (2011) Reefs at risk revisited. World Resources Institute, Washington DC. 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Marine Environmental Research. 204: 106966. Supplementary Files Supplementarymaterial.pdf Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 26 Jan, 2026 Editor invited by journal 09 Jan, 2026 Editor assigned by journal 17 Dec, 2025 First submitted to journal 12 Dec, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8349369","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":580758160,"identity":"ed8cc32a-1ce9-4645-b90e-370cceee1bb8","order_by":0,"name":"Jue Alef Lalas","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAElEQVRIiWNgGAWjYBACxgYGxgMMBQwM/EDOAYgAgwGUjVMLUBaoRrKBWC0MDFAtBgcQZuDXwjwj+cCBHwZ29sbXjj88wNh2R7aBvXmbBOOOO7gdNiMt4WCPQXLitts5BkAtz4wbeI6VSTCeeYZHC1AljwFzgtntHAaglsOJDRI5ZhJABh4t+R8O/jGotzeenf4AokX+DSEtOQyHeQwOM26QTjCA2sJDQEvPM4PDMgbHE2eA/JJw7plxG09asUXiGdxaDNuTHz58U1Ftzz87/fGHD2V3ZPvZD2+88XEHHi0NyLwEYHSwgRiJDdgUQ4A8Gv8A1L14tIyCUTAKRsGIAwAK6GIPh0MhUAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-4254-0569","institution":"University of the Ryukyus Faculty of Science Graduate School of Engineering and Science: Ryukyu Daigaku Rigakubu Daigakuin Rikogaku Kenkyuka","correspondingAuthor":true,"prefix":"","firstName":"Jue","middleName":"Alef","lastName":"Lalas","suffix":""},{"id":580758161,"identity":"ca366112-dca1-44c8-8ccf-c7a8e102f5aa","order_by":1,"name":"Agus A. 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Reimer","email":"","orcid":"","institution":"Ryukyu Daigaku","correspondingAuthor":false,"prefix":"","firstName":"James","middleName":"D.","lastName":"Reimer","suffix":""}],"badges":[],"createdAt":"2025-12-13 00:05:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8349369/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8349369/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101439014,"identity":"c6f92aef-878f-4cb2-a839-a9d8a4d64bfd","added_by":"auto","created_at":"2026-01-29 16:41:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2974422,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative colonies of \u003cem\u003eLobophytum\u003c/em\u003e, \u003cem\u003eSclerophytum\u003c/em\u003e, and \u003cem\u003eSarcophyton\u003c/em\u003e monitored in this study from August to October 2024. Total mortality for \u003cem\u003eLobophytum \u003c/em\u003eand \u003cem\u003eSclerophytum \u003c/em\u003ecolonies in these quadrats was observed, while\u003cem\u003e \u003c/em\u003ethe \u003cem\u003eSarcophyton\u003c/em\u003e colony survived.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/91146d7597e3c124105715f1.png"},{"id":101439017,"identity":"19aa3494-3aec-457c-97cf-52307a1b1518","added_by":"auto","created_at":"2026-01-29 16:41:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":39859,"visible":true,"origin":"","legend":"\u003cp\u003eMean percentage cover (± SE) of (a) pooled soft corals, (b) \u003cem\u003eLobophytum\u003c/em\u003e, (c) \u003cem\u003eSclerophytum\u003c/em\u003e, (d) \u003cem\u003eKlyxum\u003c/em\u003e, (e) and \u003cem\u003eSarcophyton\u003c/em\u003eamong the different survey months.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/7ec6b2c8a1cb38feba42f896.png"},{"id":101439013,"identity":"7caa64dc-10d9-4a16-896a-1cca9c4117eb","added_by":"auto","created_at":"2026-01-29 16:41:47","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1454575,"visible":true,"origin":"","legend":"\u003cp\u003eConditions of one of the \u003cem\u003eLobophytum\u003c/em\u003e colonies at Sunabe, Okinawa, monitored from complete bleaching in September to recovery by December 2024.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/66af95363e48c7a7fdae2f2b.png"},{"id":101439016,"identity":"cf793bc0-73e7-4e9d-8f29-c6a6a21d0d1b","added_by":"auto","created_at":"2026-01-29 16:41:47","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":507774,"visible":true,"origin":"","legend":"\u003cp\u003eOne of the monitored \u003cem\u003eSclerophytum \u003c/em\u003ecolonies where bleaching and overgrowth of cyanobacteria was observed in September and mortality by dissolution was observed in October.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/bf77b671eba9f6cf7ea81641.jpeg"},{"id":101439015,"identity":"ca8418a0-a8b3-4b72-aa66-8385cf808302","added_by":"auto","created_at":"2026-01-29 16:41:47","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":571561,"visible":true,"origin":"","legend":"\u003cp\u003eOther notable observations of the effects of heat stress on soft corals in Okinawa. (a) total bleaching and pronounced softness of a soft coral colony, (b) dissolution of colony tissue despite the colony not being totally bleached, (c) a loose soft coral tissue, mostly likely caused by increased fragility of the colony due to heat stress, and (d) soft coral sclerites which indicates the presence of a soft coral in that specific spot and.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/638027fd0c125968b567064c.jpeg"},{"id":101439021,"identity":"d1219887-c0f4-4566-a652-1f994316f37e","added_by":"auto","created_at":"2026-01-29 16:41:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7954918,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/8d51bd14-f039-4892-a535-a34b0e516b02.pdf"},{"id":101439018,"identity":"10729211-e715-4139-8c1b-b0dcbdebda4e","added_by":"auto","created_at":"2026-01-29 16:41:48","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":1157107,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8349369/v1/b8e945329bff2f99cb3feb35.pdf"}],"financialInterests":"","formattedTitle":"Notes on soft coral responses during a coral bleaching event in a shallow reef flat in southern Okinawa Island, Japan","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSoft corals (Octocorallia) are major benthic components of coral reefs in the Indo-Pacific (Lau et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), providing structural complexity and habitat for various organisms (Jeng et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Shoham et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Epstein and Kingsford, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). They are soft-bodied colonial anthozoans that lack the massive hard skeleton characteristic of their scleractinian counterparts (Fabricius and Alderslade, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2001\u003c/span\u003e), making it challenging to monitor soft coral responses during events that cause declines in coral health, such as heat stress events. Unlike hermatypic corals, entire soft coral colonies may disintegrate without leaving any trace of their existence in an area, hindering accurate comparisons of pre- and post-bleaching coverage. Although shown to be affected by heat stress events, detailed descriptions of how soft coral degrades in situ are lacking (Chavanich et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Maucieri and Baum, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). To address these, more detailed monitoring at shorter intervals during stress events can be performed.\u003c/p\u003e \u003cp\u003eIn 2023\u0026ndash;2024, record-breaking sea temperatures triggered the Fourth Global Coral Bleaching Event (Reimer et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), resulting in widespread coral mortality across many regions of the world (Duarte et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Spady et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). During this time, the subtropical reefs of Okinawa in southern Japan experienced high degree heating weeks (\u0026gt;\u0026thinsp;20\u0026deg;C-weeks), where near complete morality is likely (NOAA, 2024). In our knowledge, different teams that studied bleaching in Okinawa during that event are still finalizing reports for publication, so the extent of the reef degradation is still unknown. So far, little is known about how soft corals are affected by heat stress events (Maucieri and Baum, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In some parts of Okinawa Island, shallow fringing reefs that are easily accessible have been recently characterized as being dominated by zooxanthellate soft corals based on data from 2022 and 2023 (Lalas et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2024a\u003c/span\u003e; Lalas et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2024b\u003c/span\u003e). This provided an opportunity to observe the responses of this understudied taxonomic group in greater detail during the 2024 bleaching event in Okinawa.\u003c/p\u003e \u003cp\u003eThe main aim of this study was to monitor the responses of selected soft coral colonies from four different genera on a reef flat in Okinawa Island during the 2024 coral bleaching event. This study provides a closer examination of how soft corals respond to heat stress, contributing to a better understanding of the processes that influence coral reef benthic community dynamics, especially on soft coral-dominated areas.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eFourteen 0.25 m\u0026sup2; permanent quadrats were established on a reef flat in Sunabe, on the west coast of southern Okinawa Island, Japan (26\u0026deg;19\u0026prime;20.83\u0026Prime;N, 127\u0026deg;44\u0026prime;44.01\u0026Prime;E), at depths of 1\u0026ndash;3 m. Each quadrat was haphazardly placed to include soft coral colonies representing the four dominant genera at the site: \u003cem\u003eLobophytum\u003c/em\u003e, \u003cem\u003eSarcophyton\u003c/em\u003e, \u003cem\u003eSclerophytum\u003c/em\u003e, and \u003cem\u003eKlyxum\u003c/em\u003e (Lalas et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2024a\u003c/span\u003e). Photographs of each quadrat were taken in August, September, and October, and, for some quadrats, also in December 2024. Quadrats that had total mortality of corals by October were not monitored anymore in December, while tags of some quadrats were lost after October. Changes in these quadrats were analyzed by measuring the surface area of all corals within each quadrat using ImageJ, and surface areas were then converted to percentage cover. Notable changes were also described and are presented here. A Kruskal\u0026ndash;Wallis test was performed on all datasets to compare the percentage cover of soft corals among months, followed by Dunn\u0026rsquo;s test with Bonferroni correction to identify pairwise differences between specific months. These analyses were conducted for pooled soft coral cover and for each taxon, except for \u003cem\u003eKlyxum\u003c/em\u003e, which had only one representative colony. All statistical analyses were conducted in R (R Core Team, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Additionally, photographs of observations of soft coral bleaching from other sites in Okinawa Island were taken and are also presented here.\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003eThis study highlights the high mortality of soft corals during the 2024 coral bleaching event in Okinawa (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The overall mean soft coral cover declined from 48.5% (\u0026plusmn;\u0026thinsp;7.7 SE) in August to just 12.8% (\u0026plusmn;\u0026thinsp;7.4 SE) in December (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). The percent cover of \u003cem\u003eLobophytum\u003c/em\u003e decreased from 32.6% (\u0026plusmn;\u0026thinsp;8.6 SE) in August to 3.9% (\u0026plusmn;\u0026thinsp;3.4 SE) in December (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). A complete loss of \u003cem\u003eSclerophytum\u003c/em\u003e cover was observed by December (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec), and the \u003cem\u003eKlyxum\u003c/em\u003e colony disappeared by October (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed). Interestingly, however, no significant decline was observed for \u003cem\u003eSarcophyton\u003c/em\u003e (Kruskal\u0026ndash;Wallis, p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAlthough the results highlight the overall decline of soft corals during this event, they also reveal intergeneric and potentially interspecific and intraspecific variations in heat tolerance. All \u003cem\u003eSarcophyton\u003c/em\u003e colonies showed slight reductions in colony size throughout the observation period, however mortality was not observed. Signs of recovery were evident, as some colonies regained their Symbiodiniaceae by December (Supplementary Fig.\u0026nbsp;1). DNA barcoding of the \u003cem\u003eSarcophyton\u003c/em\u003e colonies (Lalas et al., unpublished data) indicated that they belong to the same species, thus, these results may only reflect the responses of this particular species. An example of a \u003cem\u003eSarcophyton\u003c/em\u003e species that adapted in an extreme environment is \u003cem\u003eS\u003c/em\u003e. \u003cem\u003eelegans\u003c/em\u003e, which dominated an acidified volcanic reef where no hard corals and other soft corals were observed (Inoue et al., 2013). This potentially indicates the resilience of some species in this genus to environmental stress. However, in the study by Baran et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) in the Philippines, \u003cem\u003eSarcophyton\u003c/em\u003e exhibited higher bleaching prevalence than \u003cem\u003eLobophytum\u003c/em\u003e and \u003cem\u003eSclerophytum\u003c/em\u003e, which may indicate potential differences in species composition in their study from our study area. For \u003cem\u003eLobophytum\u003c/em\u003e, although an overall decline in cover was recorded, two of the nine colonies did not experience mortality (Supplementary Fig.\u0026nbsp;2). Although these colonies bleached during summer peak months, they showed no signs of mortality and were observed to be recovering by December 2024 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Preliminary barcoding results suggest that all \u003cem\u003eLobophytum\u003c/em\u003e colonies belong to the same species. However, since only a single genetic marker (mt-MutS) was used for identification, potential interspecific variation cannot be ruled out. In hard corals, restoration ecology studies have shown variations in heat resistance even within the same species (e.g., Humanes et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), and this may also be the case for soft corals. Regardless of the taxonomic level at which bleaching response variation occurs, the colonies that survived the bleaching event demonstrated phenotypic tolerance to heat stress, suggesting that these taxa may be more resilient under future ocean-warming scenarios. However, bleaching may negatively affect the reproductive capabilities of surviving colonies, resulting in weak or non-viable recruits (Michalek-Wagner and Willis, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). Thus, long-term monitoring is crucial to identify longer-term winners and losers after this extreme heat-stress event (van Woesik et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe results of this study seem to contrast with previous studies. Baran et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e)\u0026rsquo;s study in the northern Philippines and Floros et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2004\u003c/span\u003e)\u0026rsquo;s study in South Africa showed genus level variation in bleaching susceptibility, where bleaching was observed more for \u003cem\u003eSarcophyton\u003c/em\u003e compared to \u003cem\u003eLobophytum\u003c/em\u003e and \u003cem\u003eSclerophytum\u003c/em\u003e. However, as these studies did not examine post-bleaching status, it is not known if these soft corals survived or died. Although corals that are bleached can recover, this may be affected by their ability to stock energy reserves (Yu et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2025\u003c/span\u003e), or by heterotrophic capacity (Love et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2025\u003c/span\u003e) and thus surviving for longer periods of time even without their Symbiodiniaceae. This shows the importance of conducting more detailed monitoring after bleaching events and not just sampling during a bleaching event.\u003c/p\u003e \u003cp\u003eOther interesting observations were also noted during our surveys. Unique to the \u003cem\u003eSclerophytum\u003c/em\u003e colonies monitored, red cyanobacterial mats were observed to overgrow on the colony surfaces (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). In our knowledge, the presence of such overgrowth on soft coral colonies has not yet been reported in the literature. This may be a process that increases the rate of soft colony mortality, as cyanobacterial mats have been hypothesized to facilitate pathogen transmission in scleractinian corals (Cissell et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Other unique observations were also noted from other species of soft corals outside the quadrats. During the bleaching event, some colonies of soft corals such as \u003cem\u003eKlyxum\u003c/em\u003e colonies were not totally white, which may indicate an incomplete loss of Symbiodiniacae in the tissue, but despite this, parts of the colony started to \u0026ldquo;dissolve\u0026rdquo; (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea, b). During the bleaching event, we also observed many loose soft coral fragments (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec), which might be caused by detachment due to the colony becoming brittle from bleaching and were easily detached by physical factors such as wave exposure. During this time, many areas of reef substrate were also observed to have some traces of previously and likely recently present soft corals, indicated by sclerites left in the area (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed), which would likely be carried away by water movement soon after disintegration, leaving no trace of the presence of the soft coral. These observations show the multiple processes through which soft corals degrade and die during a bleaching event.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe loss of soft coral communities may have significant consequences for the entire coral reef ecosystem. Soft corals host a variety of organisms, including fishes and a myriad of invertebrates (Epstein and Kingsford, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Their decline may lead to a phase shift from soft coral\u0026ndash;dominated reefs to algae-dominated systems (Bell et al., 2011). Such changes can affect biodiversity (Burke et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), disrupt ecosystem functioning, and alter the delivery of ecosystem services (Woodhead et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This underscores the need for monitoring ecosystem functions, as well as long-term monitoring of benthic communities, given the potential for eventual phase shifts. While this study provides further insight into the processes of shaping soft coral and benthic community dynamics, including the notable resistance of some soft coral colonies to bleaching, we emphasize the urgent need for stronger action to mitigate the effects of human-driven climate change.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eConflict of interest\u003c/h2\u003e\n\u003cp\u003eThe authors declare no conflict of interest\u003c/p\u003e\n\u003ch2\u003eEthical approval\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eJAAL, AAH, and CJLF were funded by the Japan Ministry of Education, Sports, Science, and Technology (MEXT) scholarships, and GMC was funded by the Heiwa Nakajima Foundation Scholarship. This study was supported by general education funds from the University of the Ryukyus to JDR.\u003c/p\u003e\n\u003ch2\u003eAuthor contribution\u003c/h2\u003e\n\u003cp\u003eConceptualization: JAAL; Fieldwork: JAA, AAH, CJLF, GMC, MS; Data analyses: JAAL; Supervision: JDR; Literature review: JAAL, MS; Funding acquisition: JDR; Manuscript writing and editing: JAAL, AAH, CJLF, GMC, MS, JDR.\u003c/p\u003e\n\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eWe thank the members of the Molecular Invertebrate Systematics and Ecology Laboratory for their support.\u003c/p\u003e\n\u003ch2\u003eData availability\u003c/h2\u003e\n\u003cp\u003eData inquiries can be directed to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eBaran CC, Luciano RMA, Segumalian CS, Valino ADAM, Baria-Rodriguez MV (2023) Genus and size-specific susceptibility of soft corals to 2020 bleaching event in the Philippines, Marine Biology Research, DOI: 10.1080/17451000.2023.2198242\u003c/li\u003e\n \u003cli\u003eBell JJ, Micaroni V, Strano F (2021) Regime shifts on tropical coral reef ecosystems: future trajectories to animal-dominated states in response to anthropogenic stressors. Emerg Top Life Sci 6(1):95\u0026ndash;106. https://doi.org/10.1042/ETLS20210231\u003c/li\u003e\n \u003cli\u003eBurke L, Reytar K, Spalding M, Perry A (2011) Reefs at risk revisited. World Resources Institute, Washington DC.\u003c/li\u003e\n \u003cli\u003eChavanich S, Viyakarn V, Loyjiw T, Pattaratamrong P, Chankong A (2009) Mass bleaching of soft coral, \u003cem\u003eSarcophyton\u0026nbsp;\u003c/em\u003espp. in Thailand and the role of temperature and salinity stress. \u0026ndash; ICES Journal of Marine Science, 66: 1515\u0026ndash;1519.\u003c/li\u003e\n \u003cli\u003eCissell EC, Eckrich CE, McCoy SJ (2022) Cyanobacterial mats as benthic reservoirs and vectors for coral black band disease pathogens. Ecological Applications. https://doi.org/10.1002/eap.2692\u003c/li\u003e\n \u003cli\u003eDuarte CM, Blythe J, Devlin MJ, et al.\u003cem\u003e\u0026nbsp;\u003c/em\u003e(2025) Layering solutions to conserve tropical coral reefs in crisis. \u003cem\u003eNat. Rev. Biodivers\u003c/em\u003e. https://doi.org/10.1038/s44358-025-00106-0\u003c/li\u003e\n \u003cli\u003eEpstein HE, Kingsford MJ (2019) Are soft coral habitats unfavourable? A closer look at the association between reef fishes and their habitat. Environ. Biol. Fishes 102: 479\u0026ndash;497. https://doi.org/10.1007/s10641-019-0845-4.\u003c/li\u003e\n \u003cli\u003eFabricius KE, Alderslade P (2001) Soft Corals and Sea Fans: A Comprehensive Guide to the Tropical Shallow-water Genera of the Central-west Pacific, the Indian Ocean and the Red Sea. Australian Institute of Marine Science, Melbourne, Australia.\u003c/li\u003e\n \u003cli\u003eFarag MA, Meyer A, Ali SE (2021) Bleaching effect in \u003cem\u003eSacrophyton\u0026nbsp;\u003c/em\u003espp. soft corals- is there a correlation to their diterpene content? Environmental Science and Pollution Research. https://doi.org/10.1007/s11356-021-12483-y\u003c/li\u003e\n \u003cli\u003eFloros CD, Samways MJ, Armstrong B (2004) Taxonomic patterns of bleaching within a South African coral assemblage. Biodiversity and Conservation 13: 1175-1194. DOI: 10.1023/B:BIOC.0000018151.67412.c7\u003c/li\u003e\n \u003cli\u003eHumanes A, Lachs L, Beauchamp E, et al. (2024) Selective breeding enhances coral heat tolerance to marine heatwaves. Nat Commun 15, 8703. https://doi.org/10.1038/s41467-024-52895-1\u003c/li\u003e\n \u003cli\u003eJeng MS, Huang HD, Dai CF, Hsiao YC, Benayahu Y (2011) Sclerite calcification and reef-building in the fleshy octocoral genus \u003cem\u003eSinularia\u0026nbsp;\u003c/em\u003e(Octocorallia: Alcyonacea). Coral Reefs. 30: 925\u0026ndash;933.\u003c/li\u003e\n \u003cli\u003eLalas JAA, Jamodiong EA, Reimer JD (2024a) Spatial patterns of soft coral (Octocorallia) assemblages in the shallow coral reefs of Okinawa Island, Ryukyu Archipelago, Japan: Dominance on highly disturbed reefs. Regional Studies in Marine Science. 103405. 10.1016/j.rsma.2024.103405\u003c/li\u003e\n \u003cli\u003eLalas JAA, Gomez R, Abram A, Hakim AA, Nakamura T, Reimer JD (2024b) Patterns of fish assemblage structure on reefs with varying degrees of hard coral and soft coral dominance in Okinawa Island, Japan. Marine Biodiversity. 54:82. https://doi.org/10.1007/s12526-024-01480-2\u003c/li\u003e\n \u003cli\u003eLau WY, Poliseno A, Kushida Y, Quere G, Reimer JD (2020) The classification, diversity and ecology of shallow water octocorals. 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Rep. 9, 1241. htt ps://doi.org/10.1038/s41598-018-37696-z.\u003c/li\u003e\n \u003cli\u003eSpady BL, Skirving WJ, Liu G, et al. (2025) the 4th global bleaching event: Unprecedented, unbounded, and unrelenting. Preprint in EarthArXiv. https://doi.org/10.31223/X5DX6Q\u003c/li\u003e\n \u003cli\u003evan Woesik R, Sakai K, Ganase A, Loya Y (2011) Revisiting the winners and the losers a decade after coral bleaching. Marine Ecological Progress Series. 434, 67\u0026ndash;76.\u003c/li\u003e\n \u003cli\u003eWoodhead AJ, Hicks CC, Norstr\u0026ouml;m AV, Williams GJ, Graham NAJ (2019) Coral reef ecosystem services in the Anthropocene. Functional Ecology. 33, 1023\u0026ndash;1034.\u003c/li\u003e\n \u003cli\u003eYu Q, He C, Wang Y, An M, Tang K, Liu Z, Zhou Z (2025) The differential physiological responses to heat stress in the scleractinian coral \u003cem\u003ePocillopora damicornis\u0026nbsp;\u003c/em\u003eare affected by its energy reserve. Marine Environmental Research. 204: 106966.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"marine-biodiversity","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"marb","sideBox":"Learn more about [Marine Biodiversity](http://link.springer.com/journal/12526)","snPcode":"12526","submissionUrl":"https://www.editorialmanager.com/marb/default2.aspx","title":"Marine Biodiversity","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Heat stress resilience, Octocorallia, Ryukyu Archipelago, Subtropical","lastPublishedDoi":"10.21203/rs.3.rs-8349369/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8349369/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSoft corals (Octocorallia) are major benthic components of Indo-Pacific reefs, yet their responses to thermal stress remain poorly documented compared to those of scleractinian corals. The 2024 Global Coral Bleaching Event provided an opportunity to closely examine soft coral dynamics on a shallow reef flat in the subtropical Okinawa Island, Japan. Permanent quadrats containing colonies of \u003cem\u003eLobophytum\u003c/em\u003e, \u003cem\u003eSarcophyton\u003c/em\u003e, \u003cem\u003eSclerophytum\u003c/em\u003e, and \u003cem\u003eKlyxum\u003c/em\u003e were surveyed from August to December 2024, covering the period from just before to immediately after a severe bleaching event. Overall soft coral cover based on the haphazardly selected quadrats declined from 48.5% in August to 12.8% in December. \u003cem\u003eLobophytum\u003c/em\u003e, \u003cem\u003eSclerophytum\u003c/em\u003e, and \u003cem\u003eKlyxum\u003c/em\u003e experienced substantial mortality, including the complete loss of some colonies by October. In contrast, \u003cem\u003eSarcophyton\u003c/em\u003e showed no significant decline and exhibited signs of recovery, with some colonies regaining Symbiodiniaceae by December as indicated by colony colors. Colony-level differences in bleaching outcomes suggest possible interspecific and intraspecific variations in heat tolerance. Additional observations including cyanobacterial overgrowth, partial tissue dissolution, and the presence of detached soft coral fragments illustrate the multiple processes by which soft corals degrade during heat stress events. These results show that soft corals can undergo rapid and often cryptic mortality during bleaching, with important implications for reef structure, biodiversity, and ecosystem functioning. Given their ecological importance and distinct degradation processes, long-term and fine-scale monitoring of soft coral communities is essential for understanding their resilience and for predicting potential phase shifts on warming oceans.\u003c/p\u003e","manuscriptTitle":"Notes on soft coral responses during a coral bleaching event in a shallow reef flat in southern Okinawa Island, Japan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-29 16:41:41","doi":"10.21203/rs.3.rs-8349369/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-01-26T22:05:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Marine Biodiversity","date":"2026-01-09T12:06:05+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-17T08:24:29+00:00","index":"","fulltext":""},{"type":"submitted","content":"Marine Biodiversity","date":"2025-12-12T19:04:30+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"marine-biodiversity","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"marb","sideBox":"Learn more about [Marine Biodiversity](http://link.springer.com/journal/12526)","snPcode":"12526","submissionUrl":"https://www.editorialmanager.com/marb/default2.aspx","title":"Marine Biodiversity","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"1d75f117-2f09-4607-b7c4-19ecf543b735","owner":[],"postedDate":"January 29th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-01-29T16:41:41+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-29 16:41:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8349369","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8349369","identity":"rs-8349369","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}