Marine heatwaves threaten cryptic coral diversity and erode associations among coevolving partners

Science Advances, Journal Year: 2023, Volume and Issue: 9(32)

Published: Aug. 11, 2023

Climate change–amplified marine heatwaves can drive extensive mortality in foundation species. However, a paucity of longitudinal genomic datasets has impeded understanding how these rapid selection events alter cryptic genetic structure. Heatwave impacts may be exacerbated species that engage obligate symbioses, where the genetics multiple coevolving taxa affected. Here, we tracked symbiotic associations reef-building corals for 6 years through prolonged heatwave, including known survivorship 79 315 colonies. Coral strongly predicted survival ubiquitous coral, Porites (massive growth form), with variable (15 to 61%) across three morphologically indistinguishable—but genetically distinct—lineages. The heatwave also disrupted strong between coral lineages and their algal symbionts (family Symbiodiniaceae), turnover some colonies, resulting reduced specificity lineages. These results highlight threaten genotypes decouple otherwise tightly coevolved relationships hosts symbionts.

Language: Английский

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Microbiome Stability Is Linked to Acropora Coral Thermotolerance in Northwestern Philippines

Environmental Microbiology, Journal Year: 2025, Volume and Issue: 27(2)

Published: Jan. 31, 2025

Corals associate with a diverse community of prokaryotic symbionts that provide nutrition, antioxidants and other protective compounds to their host. However, the influence microbes on coral thermotolerance remains understudied. Here, we examined microbial communities associated colonies Acropora cf. tenuis exhibit high or low upon exposure 33°C (heated) relative 29°C (control). Using 16S rRNA sequencing, show structure all A. was similar each at control temperature. Thermotolerant colonies, however, had relatively greater abundance Endozoicomonas, Arcobacter, Bifidobacterium Lactobacillus. At elevated temperature, only thermosensitive showed distinct shift in microbiome, an increase Flavobacteriales, Rhodobacteraceae Vibrio, accompanying marked bleaching response. Functional prediction indicated thermotolerant corals were enriched for genes related metabolism, while microbiomes cell motility antibiotic compound synthesis. These differences may contribute variable performance under thermal stress. Identification taxa correlated provides insights into beneficial bacterial groups could be used microbiome engineering support reef health changing climate.

Language: Английский

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Management approaches to conserve Australia’s marine ecosystem under climate change

Science, Journal Year: 2023, Volume and Issue: 381(6658), P. 631 - 636

Published: Aug. 10, 2023

Australia's coastal marine ecosystems have a deep cultural significance to Indigenous Australians, include multiple World Heritage sites, and support the nation's rapidly growing blue economy. Yet, increasing local pressures global climate change are expected undermine biological, social, cultural, economic value of these within human generation. Mitigating causes is most urgent action secure their future; however, conventional new management actions will play roles in preserving ecosystem function until that achieved. This includes strategies codeveloped with Australians guided by traditional ecological knowledge modeling decision framework. We provide examples developments at one iconic ecosystems, Great Barrier Reef, where recent, large block funding supports research, governance, engagement accelerate development tools for under change.

Language: Английский

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Divergent bleaching and recovery trajectories in reef-building corals following a decade of successive marine heatwaves

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(52)

Published: Dec. 19, 2023

Increasingly frequent marine heatwaves are devastating coral reefs. Corals that survive these extreme events must rapidly recover if they to withstand subsequent events, and long-term survival in the face of rising ocean temperatures may hinge on recovery capacity acclimatory gains heat tolerance over an individual’s lifespan. To better understand trajectories successive heatwaves, we monitored responses bleaching-susceptible bleaching-resistant individuals two dominant species Hawai’i, Montipora capitata Porites compressa , a decade included three heatwaves. Bleaching-susceptible colonies P. exhibited beneficial acclimatization stress (i.e., less bleaching) following repeat becoming indistinguishable from conspecifics during third heatwave. In contrast, M. repeatedly bleached all seasonal bleaching substantial mortality for up 3 y Encouragingly, both remained pigmented across entire time series; however, pigmentation did not necessarily indicate physiological resilience. Specifically, displayed incremental yet only partial symbiont density tissue biomass phenotypes 35 mo heatwave as well considerable mortality. Conversely, appeared most metrics within 2 experienced little no Ultimately, results even some visually robust, corals can carry cost recurring multiple years, leading divergent erode reef resilience Anthropocene.

Language: Английский

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Symbiodiniaceae diversity varies by host and environment across thermally distinct reefs

Molecular Ecology, Journal Year: 2024, Volume and Issue: 33(9)

Published: April 7, 2024

Abstract Endosymbiotic dinoflagellates (Symbiodiniaceae) influence coral thermal tolerance at both local and regional scales. In isolation, the effects of host genetics, environment, disturbances on symbiont communities are well understood, yet their combined remain poorly resolved. Here, we investigate Symbiodiniaceae across 1300 km in Australia's Coral Sea Marine Park to disentangle these interactive effects. We identified species‐level resolution for three species ( Acropora cf humilis, Pocillopora verrucosa , meandrina ) by sequencing two genetic markers (ITS2 psbA ncr ), paired with genotype‐by‐sequencing (DArT‐seq). Our samples predominantly returned sequences from genus Cladocopium where humilis affiliated C3k, C. pacificum latusorum . Multivariate analyses revealed that symbionts were driven strongly environment disturbances. contrast, partitioned 2.5‐fold more structure than environmental structure. Among species, genetics explained four times variation P. verrucosa. The concurrent bleaching event 2020 had variable impacts communities, consistent patterns A. but not findings demonstrate how macroscale community responses gradients depend respective population Integrating host, symbiont, data will help forecast adaptive potential corals amidst a rapidly changing environment.

Language: Английский

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Heat‐evolved algal symbionts enhance bleaching tolerance of adult corals without trade‐off against growth

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(24), P. 6945 - 6968

Published: Nov. 1, 2023

Ocean warming has caused coral mass bleaching and mortality worldwide the persistence of symbiotic reef-building corals requires rapid acclimation or adaptation. Experimental evolution coral's microalgal symbionts followed by their introduction into is one potential method to enhance thermotolerance. Heat-evolved generalist species, Cladocopium proliferum (strain SS8), were exposed elevated temperature (31°C) for ~10 years, introduced four genotypes chemically bleached adult fragments scleractinian coral, Galaxea fascicularis. Two acquired SS8. The new persisted 5 months experiment enhanced thermotolerance, compared with that inoculated wild-type C. strain. Thermotolerance SS8-corals was similar from same colony hosting homologous symbiont, Durusdinium sp., which naturally heat tolerant. However, SS8-coral exhibited faster growth recovered cell density photochemical efficiency more quickly following chemical inoculation under ambient relative Durusdinium-corals. Mass spectrometry imaging suggests algal pigments involved in photobiology oxidative stress greatest contributors thermotolerance differences between heat-evolved versus proliferum. These may have increased photoprotection symbionts. This first laboratory study show (G. fascicularis) can be via uptake exogenously supplied, symbionts, without a trade-off against temperature. Importantly, remained moderate abundance 2 years after inoculation, suggesting long-term stability this novel symbiosis benefits

Language: Английский

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Cryptic species and hybridisation in corals: challenges and opportunities for conservation and restoration

Published: Feb. 14, 2024

Conservation and management of coral reef ecosystems will depend on accurate assessments reef-building species diversity. However, the true diversity corals may be obfuscated by presence cryptic species, which are likely much more pervasive than is currently recognised. Additionally, sometimes hybridize, resulting in gene introgression between species. Here, we investigate prevalence via a structured literature review find that over 50% population genomic studies show evidence for divisions within taxonomically recognised such closely-related taxa often linked flow. We frequently segregate environment, especially depth, differ phenotypic characteristics including resilience to heat stress. This hidden biodiversity creates challenges conservation restoration planning not well appreciated, hiding declines, biasing estimates species’ breadth, overestimating stressors, yielding uncertainty evolutionary dynamics inferred from past studies, creating reproductive barriers limit mating local translocated corals. Increasing awareness with incomplete boundaries common building this expectation into plans an important pathway forward. Rich opportunities interdisciplinary collaboration among speciation biologists could fill key knowledge gaps relevant conservation. detail recommendations best practice strategies identifying hybrids urge their consideration all future

Language: Английский

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Environmental, host, and symbiont drivers of heat tolerance in a species complex of reef-building corals

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 1, 2024

Abstract Reef-building coral populations are under unprecedented threat from climate warming. Yet, variation in heat tolerance exists whereby some colonies can cope with higher sea temperatures than others and thus may hold unique value for conservation restoration. Here, we quantify of an ecologically important tabular species complex across the Great Barrier Reef (GBR) while also measuring genomic host symbiont partners. Coral bleaching photochemical traits were measured 569 within Acropora hyacinthus 17 reefs following exposure to standardized acute stress assays. We detected substantial tolerance, where individual colony thermal thresholds differed by up 7.3°C 5.7°C among reefs, respectively. Sea surface temperature climatology was strongest predictor warmer northern inshore typically exhibited highest thresholds, cooler southern able tolerate greater increases relative their local summer temperatures. Heat positively associated weeks preceding measurements. Assignment clusters revealed four putative A. that did not vary responses experimental stress. Symbiodiniaceae communities comprised primarily Cladocopium ITS2 variants spatially but had minimal effect on tolerance. Between 36 - 80% explained environmental, host, predictors, leaving 20 64% be additional underlying drivers such as functional here. These results used inform restoration actions, including targeting tolerant individuals selective breeding, will provide a foundation evaluating basis

Language: Английский

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Should I stay or should I go? Coral bleaching from the symbionts' perspective

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(5)

Published: May 1, 2024

Abstract Coral bleaching, the stress‐induced breakdown of coral‐algal symbiosis, threatens reefs globally. Paradoxically, despite adverse fitness effects, corals bleach annually, even outside abnormal temperatures. This generally occurs shortly after once‐per‐year mass coral spawning. Here, we propose a hypothesis linking annual bleaching and transmission symbionts to next generation hosts. We developed dynamic model with two symbiont growth strategies, found that high sexual recruitment low adult survivorship favour susceptibility, while reverse promotes resilience. Otherwise, unexplained trends in Indo‐Pacific align our hypothesis, where taxa exhibiting higher are more susceptible. The results from caution against interpreting potential shifts towards bleaching‐resistant as evidence climate adaptation—we predict such shift could also occur declining systems experiencing rates, common scenario on today's reefs.

Language: Английский

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Highly Diverse Symbiodiniaceae Types Hosted by Corals in a Global Hotspot of Marine Biodiversity

Microbial Ecology, Journal Year: 2024, Volume and Issue: 87(1)

Published: July 10, 2024

Abstract Symbiotic dinoflagellates in the genus Symbiodiniaceae play vital roles promoting resilience and increasing stress tolerance their coral hosts. While much of world’s succumb to stresses associated with increasingly severe frequent thermal bleaching events, live cover Papua New Guinea (PNG) remains some highest reported globally despite historically warm waters surrounding country. Yet, spite high PNG acknowledged within hosts, these communities have not been characterized this global biodiversity hotspot. Using high-throughput sequencing ITS2 rDNA gene, we profiled endosymbionts four species, Diploastrea heliopora , Pachyseris speciosa Pocillopora acuta Porites lutea across six sites PNG. Our findings reveal patterns Cladocopium Durusdinium dominance similar other reefs Coral Triangle, albeit greater intra- intergenomic variation. Host- site-specific variations type profiles were observed collection sites, appearing be driven by environmental conditions. Notably, extensive variation, coupled many previously unreported sequences, highlight as a potential hotspot symbiont diversity. This work represents first characterization coral-symbiont community structure marine hotspot, serving baseline for future studies.

Language: Английский

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