Coral‐bleaching responses to climate change across biological scales

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(14), P. 4229 - 4250

Published: April 27, 2022

Abstract The global impacts of climate change are evident in every marine ecosystem. On coral reefs, mass bleaching and mortality have emerged as ubiquitous responses to ocean warming, yet one the greatest challenges this epiphenomenon is linking information across scientific disciplines spatial temporal scales. Here we review some seminal recent coral‐bleaching discoveries from an ecological, physiological, molecular perspective. We also evaluate which data processes can improve predictive models provide a conceptual framework that integrates measurements biological Taking integrative approach scales, using for example hierarchical estimate major coral‐reef processes, will not only rapidly advance science but necessary guide decision‐making conservation efforts. To conserve encourage implementing mesoscale sanctuaries (thousands km 2 ) transcend national boundaries. Such networks protected reefs reef connectivity, through larval dispersal transverse thermal environments, genotypic repositories may become essential units selection environmentally diverse locations. Together, multinational be best chance corals persist change, while humanity struggles reduce emissions greenhouse gases net zero.

Language: Английский

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Increased dominance of heat-tolerant symbionts creates resilient coral reefs in near-term ocean warming

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(8)

Published: Feb. 13, 2023

Climate change is radically altering coral reef ecosystems, mainly through increasingly frequent and severe bleaching events. Yet, some reefs have exhibited higher thermal tolerance after severely the first time. To understand changes in eastern tropical Pacific (ETP), we compiled four decades of temperature, cover, bleaching, mortality data, including three mass events during 1982 to 1983, 1997 1998 2015 2016 El Niño heatwaves. Higher heat resistance later was detected dominant framework-building genus, Pocillopora, while other taxa similar susceptibility across Genetic analyses Pocillopora spp . colonies their algal symbionts (2014 2016) revealed that one two lineages present region ( “ type 1”) increased its association with thermotolerant Durusdinium glynnii ) stress event. This lineage experienced lower compared “type 3”, which did not acquire D. Under projected stress, ETP may be able preserve high cover 2060s or later, composed associate However, although low-diversity, high-cover could illustrate a potential functional state for future reefs, this only temporary unless global greenhouse gas emissions resultant warming are curtailed.

Language: Английский

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Hidden heatwaves and severe coral bleaching linked to mesoscale eddies and thermocline dynamics

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Jan. 6, 2023

Abstract The severity of marine heatwaves (MHWs) that are increasingly impacting ocean ecosystems, including vulnerable coral reefs, has primarily been assessed using remotely sensed sea-surface temperatures (SSTs), without information relevant to heating across ecosystem depths. Here, a rare combination SST, high-resolution in-situ temperatures, and sea level anomalies observed over 15 years near Moorea, French Polynesia, we document subsurface MHWs have paradoxical in comparison SST metrics associated with unexpected bleaching Variations the depth range was driven by mesoscale (10s 100s km) eddies altered levels thermocline depths decreased (2007, 2017 2019) or increased (2012, 2015, 2016) internal-wave cooling. Pronounced eddy-induced reductions internal waves during early 2019 contributed prolonged MHW unexpectedly severe bleaching, subsequent mortality offsetting almost decade recovery. Variability eddy fields, thus depths, is expected increase climate change, which, along strengthening deepening stratification, could occurrence ecosystems historically insulated from surface cooling effects waves.

Language: Английский

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Integrating cryptic diversity into coral evolution, symbiosis and conservation

Nature Ecology & Evolution, Journal Year: 2024, Volume and Issue: 8(4), P. 622 - 636

Published: Feb. 13, 2024

Language: Английский

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Contrasting heat stress response patterns of coral holobionts across the Red Sea suggest distinct mechanisms of thermal tolerance

Molecular Ecology, Journal Year: 2021, Volume and Issue: 30(18), P. 4466 - 4480

Published: Aug. 3, 2021

Corals from the northern Red Sea, in particular Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5℃ above their maximum monthly mean (MMM) temperatures. These elevated are thought to be due historical selection, as corals passed through warmer Southern Sea during recolonization Arabian Sea. To test this hypothesis, we determined thermal tolerance GoA versus central (CRS) Stylophora pistillata using multi-temperature acute stress assays determine thresholds. Relative and CRS were indeed similar (~7℃ MMM). However, absolute on average 3℃ those corals. explore molecular underpinnings, gene expression microbiome response coral holobiont. Transcriptomic responses differed markedly, with a strong symbiotic algae remarkably muted colonies. Concomitant this, algal genes showed temperature-induced corals, while exhibiting fixed (front-loading) Bacterial community composition changed dramatically under heat stress, whereas displayed stable assemblages. We interpret that resilient population tipping point contrast pattern consistently resistance cannot further attune. Such differences suggest distinct mechanisms may affect populations ocean warming.

Language: Английский

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Response diversity in corals: hidden differences in bleaching mortality among cryptic Pocillopora species

Ecology, Journal Year: 2021, Volume and Issue: 102(6)

Published: March 10, 2021

Abstract Variation among functionally similar species in their response to environmental stress buffers ecosystems from changing states. Functionally may often be cryptic representing evolutionarily distinct genetic lineages that are morphologically indistinguishable. However, the extent which differ stress, and could therefore provide a source of diversity, remains unclear because they not identified or assumed ecologically equivalent. Here, we uncover differences bleaching between sympatric common Indo‐Pacific coral, Pocillopora . In April 2019, prolonged ocean heating occurred at Moorea, French Polynesia. 72% pocilloporid colonies bleached after 22 d severe (>8 o C‐days) 10 m depth on north shore fore reef. Colony mortality ranged 11% 42% around island four months subsided. The majority (86%) pocilloporids died belonged single haplotype, despite twelve haplotypes, least five species, being sampled. Mitochondrial (open reading frame) sequence variation was greater haplotypes experienced versus all survived than it nominal survived. Colonies > 30 cm diameter were as haplotype experiencing most mortality, 1125 genetically identified, increased with colony size. Mortality did increase size within suffering highest suggesting size‐dependent genus level caused instead by species. relative abundance shifted February August, driven declines same for estimated directly, sites where heat accumulation greatest, larger sizes occurred. identification indistinguishable thermal but share ecological function terms maintaining coral‐dominated state, has important consequences uncovering diversity drives resilience, especially systems low declining functional diversity.

Language: Английский

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Size‐dependent mortality of corals during marine heatwave erodes recovery capacity of a coral reef

Global Change Biology, Journal Year: 2021, Volume and Issue: 28(4), P. 1342 - 1358

Published: Dec. 15, 2021

For many long-lived taxa, such as trees and corals, older, larger individuals often have the lowest mortality highest fecundity. However, climate change-driven disturbances droughts heatwaves may fundamentally alter typical size-dependent patterns of reproduction in these important foundation taxa. Working Moorea, French Polynesia, we investigated how a marine heatwave 2019, one most intense at our sites over past 30 years, drove coral bleaching mortality. The island-wide mass that killed up to 76% 65% largest two dominant genera, Pocillopora Acropora, respectively. Colonies Acropora ≥30 cm diameter were ~3.5× ~1.3×, respectively, more likely die than colonies <30-cm diameter. Typically, annual corals is concentrated on smallest size classes. Yet, this dramatically reshaped pattern, with heat stress disproportionately killing equalizing rates across spectrum. This shift size-mortality relationship reduced overall fecundity genera by >60% because big are for reefs. Additionally, survivorship microscopic recruits, critical recovery following disturbances, declined 2%, an order magnitude lower compared year without elevated thermal stress, where 33% recruits survived. While other research has shown can bleach frequently smaller show severe impact phenomenon reef-wide scale. As become frequent intense, disproportionate largest, fecund near-complete loss entire cohorts newly-settled will reduce capacity iconic ecosystems.

Language: Английский

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Oceanic differences in coral-bleaching responses to marine heatwaves

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 871, P. 162113 - 162113

Published: Feb. 9, 2023

Anomalously high ocean temperatures have increased in frequency, intensity, and duration over the last several decades because of greenhouse gas emissions that cause global warming marine heatwaves. Reef-building corals are sensitive to such temperature anomalies commonly lead coral bleaching, mortality, changes community structure. Yet, despite these overarching effects, there geographical differences thermal regimes, evolutionary histories, past disturbances may different bleaching responses within among oceans. Here we examined overall Atlantic, Indian, Pacific Oceans, using both a spatially explicit Bayesian mixed-effects model deep-learning neural-network model. We used 40-year dataset encompassing 23,288 coral-reef surveys at 11,058 sites 88 countries, from 1980 2020. Focusing on ocean-wide assessed relationships between percentage bleached temperature-related metrics alongside suite environmental variables. found while sea-surface were consistently, strongly, related all oceans, clear most For instance, was an increase with depth Atlantic Ocean whereas opposite observed Indian Ocean, no trend could be seen Ocean. The standard deviation thermal-stress negatively but not Globally, has progressively occurred higher four although, again, three Together, patterns highlight historical circumstances oceanographic conditions play central role contemporary coral-bleaching responses.

Language: Английский

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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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Exploring coral speciation: Multiple sympatric Stylophora pistillata taxa along a divergence continuum on the Great Barrier Reef

Evolutionary Applications, Journal Year: 2024, Volume and Issue: 17(1)

Published: Jan. 1, 2024

Abstract Understanding how biodiversity originates and is maintained are fundamental challenge in evolutionary biology. Speciation a continuous process progression along this continuum depends on the interplay between forces driving divergence promoting genetic homogenisation. Coral reefs broadly connected yet highly heterogeneous ecosystems, with gene flow at small spatial scales might therefore be common. Genomic studies increasingly revealing existence of closely related sympatric taxa within taxonomic coral species, but extent to which these still exchanging genes sharing environmental niches unclear. In study, we sampled extensively across diverse habitats multiple Great Barrier Reef (GBR) comprehensively examined genome‐wide diversity histories among Stylophora pistillata species complex. S. one most abundant well‐studied discovered five distinct taxa, wide geographic ranges extensive sympatry. Demographic modelling showed that speciation events have occurred different stages continuum. We found significant correlations specific variables, suggesting niche partitioning may played role differentially adapted environments. Conservation actions rely estimates richness, population sizes ranges, biased if divergent lumped together. As rapidly degrading due climate change, our study highlights importance recognising evolutionarily improve conservation restoration efforts aiming protecting diversity.

Language: Английский

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