Global warming impairs stock–recruitment dynamics of corals

Nature, Год журнала: 2019, Номер 568(7752), С. 387 - 390

Опубликована: Апрель 1, 2019

Язык: Английский

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

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Янв. 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.

Язык: Английский

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Experimental support for alternative attractors on coral reefs

Proceedings of the National Academy of Sciences, Год журнала: 2019, Номер 116(10), С. 4372 - 4381

Опубликована: Фев. 11, 2019

Ecological theory predicts that ecosystems with multiple basins of attraction can get locked in an undesired state, which has profound ecological and management implications. Despite their significance, alternative attractors have proven to be challenging detect characterize natural communities. On coral reefs, it been hypothesized persistent coral-to-macroalgae “phase shifts” result from overfishing herbivores and/or nutrient enrichment may reflect a regime shift alternate attractor, but, date, the evidence equivocal. Our field experiments Moorea, French Polynesia, revealed following: ( i ) hysteresis existed herbivory–macroalgae relationship, creating potential for coral–macroalgae bistability at some levels herbivory, ii macroalgae were attractor under prevailing conditions lagoon but not on fore reef, where ambient herbivory fell outside experimentally delineated region hysteresis. These findings help explain different community responses disturbances between reef habitats Moorea over past several decades reinforce idea reversing reefs difficult. experimental framework represents powerful diagnostic tool probe systems and, as such, inform strategies needed maintain critical ecosystem functions face escalating stresses.

Язык: Английский

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Landscape‐scale patterns of nutrient enrichment in a coral reef ecosystem: implications for coral to algae phase shifts

Ecological Applications, Год журнала: 2020, Номер 31(1)

Опубликована: Сен. 24, 2020

Nutrient pollution is altering coastal ecosystems worldwide. On coral reefs, excess nutrients can favor the production of algae at expense reef-building corals, yet role in driving community changes such as shifts from to macroalgae not well understood. Here we investigate potential anthropogenic nutrient loading recent coral-to-macroalgae phase on reefs lagoons surrounding Pacific island Moorea, French Polynesia. We use nitrogen (N) tissue content and stable isotopes (δ15 N) an abundant macroalga (Turbinaria ornata) together with empirical models discharge describe spatial temporal patterns enrichment lagoons. then employ time series data test whether increases are associated nutrients. Our results revealed that N were linked several factors, including rainfall, wave-driven circulation, distance sources, especially human sewage. Reefs near large watersheds, where inputs sewage agriculture high, have been consistently enriched for least last decade. In many these areas, corals decreased increased, while lower levels input maintained high cover low macroalgae. Importantly, patchy occurred despite substantial island-wide density biomass herbivorous fishes over period. Together, indicate may be important driver Moorea even though harbor diverse herbivore assemblage. These emphasize bottom-up factors play underscore critical importance watershed management reducing other land-based pollutants reef ecosystems.

Язык: Английский

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

Ecology, Год журнала: 2021, Номер 102(6)

Опубликована: Март 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.

Язык: Английский

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

Global Change Biology, Год журнала: 2021, Номер 28(4), С. 1342 - 1358

Опубликована: Дек. 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.

Язык: Английский

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Energetic and reproductive costs of coral recovery in divergent bleaching responses

Scientific Reports, Год журнала: 2021, Номер 11(1)

Опубликована: Дек. 7, 2021

Abstract Mass thermal bleaching events are a primary threat to coral reefs, yet the sublethal impacts, particularly on energetics and reproduction, poorly characterized. Given that persistence of populations is contingent upon reproduction individuals survive disturbances, there an urgent need understand effects reproductive output accurately predict recovery rates. In 2019, French Polynesian island Mo’orea experienced severe mass event accompanied by widespread mortality. At most heavily impacted sites, we observed Acropora hyacinthus were resistant bleaching, alongside colonies bleached but showed signs symbiont shortly after event. We collected fragments from A. five months post-bleaching and, using energetic assays histological measurements, examined physiological consequences these two distinct heat stress responses. Despite healthy appearances in both recovered corals, found had significantly reduced energy reserves compared colonies. addition, detected compound reproduction: displayed lower probability containing gametes fecundity per polyp. Our results indicate inflicts constraint concurrent re-accumulation development material, with decreased potential survivors possibly hampering overall reef resilience. These findings highlight presence intraspecific responses importance considering multiple trajectories for individual species when predicting population following disturbance.

Язык: Английский

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Coral restoration for coastal resilience: Integrating ecology, hydrodynamics, and engineering at multiple scales

Ecosphere, Год журнала: 2023, Номер 14(5)

Опубликована: Май 1, 2023

Abstract The loss of functional and accreting coral reefs reduces coastal protection resilience for tropical coastlines. Coral restoration has potential recovering healthy that can mitigate risks from hazards increase sustainability. However, scaling up to the large extent needed requires integrated application principles engineering, hydrodynamics, ecology across multiple spatial scales, as well filling missing knowledge gaps disciplines. This synthesis aims identify how scientific understanding multidisciplinary processes at interconnected scales advance reef restoration. work is placed within context a decision support framework evaluate design effectiveness resilience. Successfully linking science with practice will ensure future large‐scale restorations maximize at‐risk communities.

Язык: Английский

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The effect of reef morphology on coral recruitment at multiple spatial scales

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(4)

Опубликована: Янв. 8, 2024

Coral reefs are in decline worldwide, making it increasingly important to promote coral recruitment new or degraded habitat. reef morphology—the structural form of substrate—affects many aspects function, yet the effect morphology on is not well understood. We used structure-from-motion photogrammetry and airborne remote sensing measure (rugosity, curvature, slope, fractal dimension) across a broad continuum spatial scales evaluated three broadcast-spawning genera. also measured other environmental biotic factors such as fish density, adult cover, hydrodynamic larval import, depth recruitment. All variables combined explained 72% study region. Coarse rugosity curvature mapped at ≥2 m resolution—such large colonies, knolls, boulders—were positively correlated with recruitment, explaining 22% variation Morphology finer (≤32 cm resolution) was significant. Hydrodynamic import related Porites Montipora spp., grazer density linked significantly lower all In addition, morphology, had differential effects genera, reflecting genus-specific life history traits, model performance gonochoric species. Overall, key indicator potential that can be detected by sensing, allowing sinks identified factored into restoration actions.

Язык: Английский

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Increasing disturbance frequency undermines coral reef recovery

Ecological Monographs, Год журнала: 2024, Номер 94(3)

Опубликована: Июнь 24, 2024

Abstract Climate‐driven alterations to disturbance regimes are increasingly disrupting patterns of recovery in many biomes. Here, we examine the impact and subsequent level live hard coral cover on Great Barrier Reef (GBR) across last three decades. We demonstrate that a preexisting pattern infrequent disturbances limited spatial extent has changed larger more frequent disturbances, dominated by marine heatwaves severe tropical cyclones. detected an increase (measured as loss) 265 individual impacts 131 reefs 36‐year dataset (1985–2022). Additionally, number survey impacted increased each decade from 6% 1980s 44% 2010s, frequency mass bleaching GBR, which between 19% 28% per year, cyclones (3%–5% year), resulting less time for recovery. Of recorded, complete highest levels recorded earlier this study (the “historical benchmark”) occurred only 62 (23%) times. 23% resulted historical benchmarks, 34/62 recovered their benchmark 2021 or 2022. Complete was likely when <25% cover. The lack attributed windows becoming shorter due increases thermal stress events result episodes. These results confirm climate change is contributing ecosystem‐wide changes ability recover.

Язык: Английский

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