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Radice VZ, Martinez A, Paytan A, Potts DC, Barshis DJ. Complex dynamics of coral gene expression responses to low pH across species. Mol Ecol 2024; 33:e17186. [PMID: 37905582 DOI: 10.1111/mec.17186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/25/2023] [Accepted: 10/17/2023] [Indexed: 11/02/2023]
Abstract
Coral capacity to tolerate low pH affects coral community composition and, ultimately, reef ecosystem function. Low pH submarine discharges ('Ojo'; Yucatán, México) represent a natural laboratory to study plasticity and acclimatization to low pH in relation to ocean acidification. A previous >2-year coral transplant experiment to ambient and low pH common garden sites revealed differential survivorship across species and sites, providing a framework to compare mechanistic responses to differential pH exposures. Here, we examined gene expression responses of transplants of three species of reef-building corals (Porites astreoides, Porites porites and Siderastrea siderea) and their algal endosymbiont communities (Symbiodiniaceae) originating from low pH (Ojo) and ambient pH native origins (Lagoon or Reef). Transplant pH environment had the greatest effect on gene expression of Porites astreoides hosts and symbionts and P. porites hosts. Host P. astreoides Ojo natives transplanted to ambient pH showed a similar gene expression profile to Lagoon natives remaining in ambient pH, providing evidence of plasticity in response to ambient pH conditions. Although origin had a larger effect on host S. siderea gene expression due to differences in symbiont genera within Reef and Lagoon/Ojo natives, subtle effects of low pH on all origins demonstrated acclimatization potential. All corals responded to low pH by differentially expressing genes related to pH regulation, ion transport, calcification, cell adhesion and stress/immune response. This study demonstrates that the magnitude of coral gene expression responses to pH varies considerably among populations, species and holobionts, which could differentially affect acclimatization to and impacts of ocean acidification.
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Affiliation(s)
- Veronica Z Radice
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia, USA
| | - Ana Martinez
- University of California, Santa Cruz, California, USA
| | - Adina Paytan
- University of California, Santa Cruz, California, USA
| | | | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia, USA
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2
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Rogers JGD, Plagányi ÉE, Babcock RC, Fletcher CS, Westcott DA. Improving coral cover using an integrated pest management framework. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2913. [PMID: 37615222 DOI: 10.1002/eap.2913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 06/15/2023] [Accepted: 07/14/2023] [Indexed: 08/25/2023]
Abstract
Integrated pest management (IPM) leverages our understanding of ecological interactions to mitigate the impact of pest species on economically and/or ecologically important assets. It has primarily been applied in terrestrial settings (e.g., agriculture), but has rarely been attempted for marine ecosystems. The crown-of-thorns starfish (CoTS), Acanthaster spp., is a voracious coral predator throughout the Indo-Pacific where it undergoes large population increases (irruptions), termed outbreaks. During outbreaks CoTS act as a pest species and can result in substantial coral loss. Contemporary management of CoTS on the Great Barrier Reef (GBR) adopts facets of the IPM paradigm to manage these outbreaks through strategic use of direct manual control (culling) of individuals in response to ecologically based target thresholds. There has, however, been limited quantitative analysis of how to optimize the implementation of such thresholds. Here we use a multispecies modeling approach to assess the performance of alternative CoTS management scenarios for improving coral cover trajectories. The scenarios examined varied in terms of their ecological threshold target, the sensitivity of the threshold, and the level of management resourcing. Our approach illustrates how to quantify multidimensional trade-offs in resourcing constraints, concurrent CoTS and coral population dynamics, the stringency of target thresholds, and the geographical scale of management outcomes (number of sites). We found strategies with low target density thresholds for CoTS (≤0.03 CoTS min-1 ) could act as "Effort Sinks" and limit the number of sites that could be effectively controlled, particularly under CoTS population outbreaks. This was because a handful of sites took longer to control, which meant other sites were not controlled. Higher density thresholds (e.g., 0.04-0.08 CoTS min-1 ), tuned to levels of coral cover, diluted resources among sites but were more robust to resourcing constraints and pest population dynamics. Our study highlights trade-off decisions when using an IPM framework and informs the implementation of threshold-based strategies on the GBR.
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Affiliation(s)
- Jacob G D Rogers
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland, Australia
- CSIRO Oceans and Atmosphere, Brisbane, Queensland, Australia
| | - Éva E Plagányi
- CSIRO Oceans and Atmosphere, Brisbane, Queensland, Australia
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3
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Cruz AR, Davidowitz G, Moore CM, Bronstein JL. Mutualisms in a warming world. Ecol Lett 2023. [PMID: 37303268 DOI: 10.1111/ele.14264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/16/2023] [Accepted: 05/21/2023] [Indexed: 06/13/2023]
Abstract
Predicting the impacts of global warming on mutualisms poses a significant challenge given the functional and life history differences that usually exist among interacting species. However, this is a critical endeavour since virtually all species on Earth depend on other species for survival and/or reproduction. The field of thermal ecology can provide physiological and mechanistic insights, as well as quantitative tools, for addressing this challenge. Here, we develop a conceptual and quantitative framework that connects thermal physiology to species' traits, species' traits to interacting mutualists' traits and interacting traits to the mutualism. We first identify the functioning of reciprocal mutualism-relevant traits in diverse systems as the key temperature-dependent mechanisms driving the interaction. We then develop metrics that measure the thermal performance of interacting mutualists' traits and that approximate the thermal performance of the mutualism itself. This integrated approach allows us to additionally examine how warming might interact with resource/nutrient availability and affect mutualistic species' associations across space and time. We offer this framework as a synthesis of convergent and critical issues in mutualism science in a changing world, and as a baseline to which other ecological complexities and scales might be added.
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Affiliation(s)
- Austin R Cruz
- Department of Ecology & Evolutionary Biology, The University of Arizona, Tucson, Arizona, USA
| | - Goggy Davidowitz
- Department of Ecology & Evolutionary Biology, The University of Arizona, Tucson, Arizona, USA
- Department of Entomology, The University of Arizona, Tucson, Arizona, USA
| | | | - Judith L Bronstein
- Department of Ecology & Evolutionary Biology, The University of Arizona, Tucson, Arizona, USA
- Department of Entomology, The University of Arizona, Tucson, Arizona, USA
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4
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Coral Gardens Reef, Belize: An Acropora spp. refugium under threat in a warming world. PLoS One 2023; 18:e0280852. [PMID: 36753468 PMCID: PMC9907857 DOI: 10.1371/journal.pone.0280852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 01/09/2023] [Indexed: 02/09/2023] Open
Abstract
Live coral cover has declined precipitously on Caribbean reefs in recent decades. Acropora cervicornis coral has been particularly decimated, and few Western Atlantic Acropora spp. refugia remain. Coral Gardens, Belize, was identified in 2020 as a long-term refugium for this species. This study assesses changes in live A. cervicornis coral abundance over time at Coral Gardens to monitor the stability of A. cervicornis corals, and to explore potential threats to this important refugium. Live coral cover was documented annually from 2012-2019 along five permanent transects. In situ sea-surface temperature data were collected at Coral Gardens throughout the study period and compared with calibrated satellite data to calculate Maximum Monthly Mean (MMM) temperatures and Degree Heating Weeks (DHW). Data on bathymetry, sediment, substrate, herbivore abundance, and macroalgal abundance were collected in 2014 and 2019 to assess potential threats to Coral Gardens. Live coral cover declined at all five transect sites over the study period. The greatest loss of live coral occurred between 2016 and 2017, coincident with the earliest and highest maximum average temperatures recorded at the study site, and the passage of a hurricane in 2016. Structural storm damage was not observed at Coral Gardens, though live coral cover declined after the passage of the storm. Uranium-thorium (230Th) dating of 26 dead in situ fragments of A. cervicornis collected in 2015 from Coral Gardens revealed no correlation between coral mortality and tropical storms and hurricanes in the recent past. Our data suggest that several other common drivers for coral decline (i.e. herbivory, predation, sedimentation, pH) may likely be ruled out for Coral Gardens. At the end of the study period, Coral Gardens satisfied most criteria for refugium status. However, the early onset, higher mean, and longer duration of above-average temperatures, as well as intermittent temperature anomalies likely played a critical role in the stability of this refugium. We suggest that temperature stress in 2016 and perhaps 2015 may have increased coral tissue vulnerability at Coral Gardens to a passing hurricane, threatening the status of this unique refugium.
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Shantz AA, Ladd MC, Ezzat L, Schmitt RJ, Holbrook SJ, Schmeltzer E, Vega Thurber R, Burkepile DE. Positive interactions between corals and damselfish increase coral resistance to temperature stress. GLOBAL CHANGE BIOLOGY 2023; 29:417-431. [PMID: 36315059 DOI: 10.1111/gcb.16480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 08/12/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
By the century's end, many tropical seas will reach temperatures exceeding most coral species' thermal tolerance on an annual basis. The persistence of corals in these regions will, therefore, depend on their abilities to tolerate recurrent thermal stress. Although ecologists have long recognized that positive interspecific interactions can ameliorate environmental stress to expand the realized niche of plants and animals, coral bleaching studies have largely overlooked how interactions with community members outside of the coral holobiont shape the bleaching response. Here, we subjected a common coral, Pocillopora grandis, to 10 days of thermal stress in aquaria with and without the damselfish Dascyllus flavicaudus (yellowtail dascyllus), which commonly shelter within these corals, to examine how interactions with damselfish impacted coral thermal tolerance. Corals often benefit from nutrients excreted by animals they interact with and prior to thermal stress, corals grown with damselfish showed improved photophysiology (Fv /Fm ) and developed larger endosymbiont populations. When exposed to thermal stress, corals with fish performed as well as control corals maintained at ambient temperatures without fish. In contrast, corals exposed to thermal stress without fish experienced photophysiological impairment, a more than 50% decline in endosymbiont density, and a 36% decrease in tissue protein content. At the end of the experiment, thermal stress caused average calcification rates to decrease by over 80% when damselfish were absent but increase nearly 25% when damselfish were present. Our study indicates that damselfish-derived nutrients can increase coral thermal tolerance and are consistent with the Stress Gradient Hypothesis, which predicts that positive interactions become increasingly important for structuring communities as environmental stress increases. Because warming of just a few degrees can exceed corals' temperature tolerance to trigger bleaching and mortality, positive interactions could play a critical role in maintaining some coral species in warming regions until climate change is aggressively addressed.
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Affiliation(s)
- Andrew A Shantz
- Florida State University Coastal and Marine Laboratory, St. Teresa, Florida, USA
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
| | - Mark C Ladd
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
- NOAA-National Marine Fisheries Service, Southeast Fisheries Science Center, Key Biscayne, Florida, USA
| | - Leila Ezzat
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
- School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Russell J Schmitt
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
| | - Sally J Holbrook
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
| | - Emily Schmeltzer
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | | | - Deron E Burkepile
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
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6
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Pacherres CO, Ahmerkamp S, Koren K, Richter C, Holtappels M. Ciliary flows in corals ventilate target areas of high photosynthetic oxygen production. Curr Biol 2022; 32:4150-4158.e3. [PMID: 36002003 DOI: 10.1016/j.cub.2022.07.071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 07/01/2022] [Accepted: 07/26/2022] [Indexed: 12/14/2022]
Abstract
Most tropical corals live in symbiosis with Symbiodiniaceae algae whose photosynthetic production of oxygen (O2) may lead to excess O2 in the diffusive boundary layer (DBL) above the coral surface. When flow is low, cilia-induced mixing of the coral DBL is vital to remove excess O2 and prevent oxidative stress that may lead to coral bleaching and mortality. Here, we combined particle image velocimetry using O2-sensitive nanoparticles (sensPIV) with chlorophyll (Chla)-sensitive hyperspectral imaging to visualize the microscale distribution and dynamics of ciliary flows and O2 in the coral DBL in relation to the distribution of Symbiodiniaceae Chla in the tissue of the reef building coral, Porites lutea. Curiously, we found an inverse relation between O2 in the DBL and Chla in the underlying tissue, with patches of high O2 in the DBL above low Chla in the underlying tissue surrounding the polyp mouth areas and pockets of low O2 concentrations in the DBL above high Chla in the coenosarc tissue connecting neighboring polyps. The spatial segregation of Chla and O2 is related to ciliary-induced flows, causing a lateral redistribution of O2 in the DBL. In a 2D transport-reaction model of the coral DBL, we show that the enhanced O2 transport allocates parts of the O2 surplus to areas containing less chla, which minimizes oxidative stress. Cilary flows thus confer a spatially complex mass transfer in the coral DBL, which may play an important role in mitigating oxidative stress and bleaching in corals.
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Affiliation(s)
- Cesar O Pacherres
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, 27568 Bremerhaven, Germany; Department of Biology and Chemistry, University of Bremen, 28359 Bremen, Germany; Marine Biological Section, Department of Biology, University of Copenhagen, 3000 Helsingør, Denmark.
| | - Soeren Ahmerkamp
- Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany; MARUM - Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany.
| | - Klaus Koren
- Center for Water Technology, Section for Microbiology, Department of Biology, Aarhus University, 8000 Aarhus, Denmark
| | - Claudio Richter
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, 27568 Bremerhaven, Germany; Department of Biology and Chemistry, University of Bremen, 28359 Bremen, Germany
| | - Moritz Holtappels
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, 27568 Bremerhaven, Germany; MARUM - Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
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7
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Adaptive Responses of the Sea Anemone Heteractis crispa to the Interaction of Acidification and Global Warming. Animals (Basel) 2022; 12:ani12172259. [PMID: 36077978 PMCID: PMC9454579 DOI: 10.3390/ani12172259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022] Open
Abstract
Ocean acidification and warming are two of the most important threats to the existence of marine organisms and are predicted to co-occur in oceans. The present work evaluated the effects of acidification (AC: 24 ± 0.1 °C and 900 μatm CO2), warming (WC: 30 ± 0.1 °C and 450 μatm CO2), and their combination (CC: 30 ± 0.1 °C and 900 μatm CO2) on the sea anemone, Heteractis crispa, from the aspects of photosynthetic apparatus (maximum quantum yield of photosystem II (PS II), chlorophyll level, and Symbiodiniaceae density) and sterol metabolism (cholesterol content and total sterol content). In a 15-day experiment, acidification alone had no apparent effect on the photosynthetic apparatus, but did affect sterol levels. Upregulation of their chlorophyll level is an important strategy for symbionts to adapt to high partial pressure of CO2 (pCO2). However, after warming stress, the benefits of high pCO2 had little effect on stress tolerance in H. crispa. Indeed, thermal stress was the dominant driver of the deteriorating health of H. crispa. Cholesterol and total sterol contents were significantly affected by all three stress conditions, although there was no significant change in the AC group on day 3. Thus, cholesterol or sterol levels could be used as important indicators to evaluate the impact of climate change on cnidarians. Our findings suggest that H. crispa might be relatively insensitive to the impact of ocean acidification, whereas increased temperature in the future ocean might impair viability of H. crispa.
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8
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Culling corallivores improves short-term coral recovery under bleaching scenarios. Nat Commun 2022; 13:2520. [PMID: 35534497 PMCID: PMC9085818 DOI: 10.1038/s41467-022-30213-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 04/21/2022] [Indexed: 12/02/2022] Open
Abstract
Management of coral predators, corallivores, is recommended to improve coral cover on tropical coral reefs under projected increasing levels of accumulated thermal stress, but whether corallivore management can improve coral cover, which is necessary for large-scale operationalisation, remains equivocal. Here, using a multispecies ecosystem model, we investigate intensive management of an invertebrate corallivore, the Crown-of-Thorns Starfish (Acanthaster cf. solaris), and show that culling could improve coral cover at sub-reef spatial scales, but efficacy varied substantially within and among reefs. Simulated thermal stress events attenuated management-derived coral cover improvements and was dependent on the level of accumulated thermal stress, the thermal sensitivity of coral communities and the rate of corallivore recruitment at fine spatial scales. Corallivore management was most effective when accumulated thermal stress was low, coral communities were less sensitive to heat stress and in areas of high corallivore recruitment success. Our analysis informs how to manage a pest species to promote coral cover under future thermal stress events. This study uses multispecies modelling to show that the management of a coral predator, the crown-of-thorns starfish, could help corals recover following bleaching events. They show that management was most effective when heat stress severity for corals was low to moderate, when corals had lower heat sensitivity and when the recruitment rate of starfish was high.
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9
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Godefroid M, Dupont S, Metian M, Hédouin L. Two decades of seawater acidification experiments on tropical scleractinian corals: Overview, meta-analysis and perspectives. MARINE POLLUTION BULLETIN 2022; 178:113552. [PMID: 35339865 DOI: 10.1016/j.marpolbul.2022.113552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/03/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Ocean acidification has emerged as a major concern in the last fifteen years and studies on the impacts of seawater acidification on marine organisms have multiplied accordingly. This review aimed at synthesizing the literature on the effects of seawater acidification on tropical scleractinians under laboratory-controlled conditions. We identified 141 articles (published between 1999 and 2021) and separated endpoints into 22 biological categories to identify global trends for mitigation and gaps in knowledge and research priorities for future investigators. The relative number of affected endpoints increased with pH intensity (particularly for endpoints associated to calcification and reproduction). When exposed to pH 7.6-7.8 (compared to higher pH), 49% of endpoints were affected. The diversity in experimental designs prevented deciphering the modulating role of coral life stages, genera or duration of exposure. Finally, important bias in research efforts included most experiments on adult corals (68.5%), in 27 out of 150 (18%) coral ecoregions and exclusively from shallow-waters.
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Affiliation(s)
- Mathilde Godefroid
- PSL Research University: EPHE-CNRS-UPVD, USR 3278 CRIOBE, BP 1013, 98729 Papetoai, Mo'orea, French Polynesia; Laboratoire d'Excellence "CORAIL", Mo'orea, French Polynesia.
| | - Sam Dupont
- Department of Biological and Environmental Sciences, University of Gothenburg, Kristineberg Marine Research Station, Kristineberg 566, 45178 Fiskebäckskil, Sweden; Radioecology Laboratory International Atomic Energy Agency (IAEA), Marine Laboratories, 4 Quai Antoine 1er, 98000, Monaco
| | - Marc Metian
- Radioecology Laboratory International Atomic Energy Agency (IAEA), Marine Laboratories, 4 Quai Antoine 1er, 98000, Monaco
| | - Laetitia Hédouin
- PSL Research University: EPHE-CNRS-UPVD, USR 3278 CRIOBE, BP 1013, 98729 Papetoai, Mo'orea, French Polynesia; Laboratoire d'Excellence "CORAIL", Mo'orea, French Polynesia
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10
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Sun Y, Jiang L, Gong S, Diaz-Pulido G, Yuan X, Tong H, Huang L, Zhou G, Zhang Y, Huang H. Changes in physiological performance and protein expression in the larvae of the coral Pocillopora damicornis and their symbionts in response to elevated temperature and acidification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:151251. [PMID: 34728194 DOI: 10.1016/j.scitotenv.2021.151251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/22/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Climate change causes ocean warming and acidification, which threaten coral reef ecosystems. Ocean warming and acidification cause bleaching and mortality, and decrease calcification in adult corals, leading to changes in the composition of coral communities; however, their interactive effects on coral larvae are not comprehensively understood. To examine the underlying molecular mechanisms of larval responses to elevated temperature and pCO2, we examined the physiological performance and protein expression profiles of Pocillopora damicornis at two temperatures (29 and 33 °C) and pCO2 levels (500 and 1000 μatm) for 5 d. Extensive physiological and proteomic changes were observed in coral larvae. The results indicated a significant decrease in net photosynthesis (PNET) and autotrophic capability (PNET/RD) of larvae exposed to elevated temperature but a marked increase in PNET and PNET/RD of larvae exposed to high pCO2 levels. Elevated temperature significantly reduced endosymbiont densities by 70% and photochemical efficiency, indicating that warming impaired host-symbiont symbiosis. Expression of photosynthesis-related proteins, the photosystem (PS) I reaction center subunits IV and XI as well as oxygen-evolving enhancer 1, was downregulated at higher temperatures in symbionts, whereas expression of the PS I iron‑sulfur center protein was increased under high pCO2 conditions. Furthermore, expression of phosphoribulokinase (involved in the Calvin cycle) and phosphoenolpyruvate carboxylase (related to the C4 pathway) was downregulated in symbionts under thermal stress; this finding suggests reduced carbon fixation at high temperatures. The abundance of carbonic anhydrase-associated proteins, which are predicted to exert biochemical roles in dissolved inorganic carbon transport in larvae, was reduced in coral host and symbionts at high temperatures. These results elucidate potential mechanisms underlying the responses of coral larvae exposed to elevated temperature and acidification and suggest an important role of symbionts in the response to warming and acidification.
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Affiliation(s)
- Youfang Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Department of Ocean Science and Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong University of Science and Technology, Hong Kong 999077, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Department of Ocean Science and Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong University of Science and Technology, Hong Kong 999077, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China
| | - Sanqiang Gong
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Guillermo Diaz-Pulido
- School of Environment and Science, and Australian Rivers Institute - Coast & Estuaries, Nathan Campus, Griffith University, Brisbane, Nathan Campus, Queensland 4111, Australia
| | - Xiangcheng Yuan
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China
| | - Haoya Tong
- Department of Ocean Science and Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong University of Science and Technology, Hong Kong 999077, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China
| | - Lintao Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guowei Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China
| | - Yuyang Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China
| | - Hui Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; Sanya National Marine Ecosystem Research Station; Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya 572000, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya 572000, China.
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11
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Boco SR, Pitt KA, Melvin SD. Ocean acidification impairs the physiology of symbiotic phyllosoma larvae of the lobster Thenus australiensis and their ability to detect cues from jellyfish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 793:148679. [PMID: 34328968 DOI: 10.1016/j.scitotenv.2021.148679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 06/01/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Ocean acidification (OA) can alter the behaviour and physiology of marine fauna and impair their ability to interact with other species, including those in symbiotic and predatory relationships. Phyllosoma larvae of lobsters are symbionts to many invertebrates and often ride and feed on jellyfish, however OA may threaten interactions between phyllosomas and jellyfish. Here, we tested whether OA predicted for surface mid-shelf waters of Great Barrier Reef, Australia, under ∆ pH = -0.1 (pH ~7.9) and ∆pH = -0.3 (pH ~7.7) relative to the present pH (~8.0) (P) impaired the survival, moulting, respiration, and metabolite profiles of phyllosoma larvae of the slipper lobster Thenus australiensis, and the ability of phyllosomas to detect chemical cues of fresh jellyfish tissue. We discovered that OA was detrimental to survival of phyllosomas with only 20% survival under ∆pH = -0.3 compared to 49.2% and 45.3% in the P and ∆pH = -0.1 treatments, respectively. The numbers of phyllosomas that moulted in the P and ∆pH = -0.1 treatments were 40% and 34% higher, respectively, than those in the ∆pH = -0.3 treatment. Respiration rates varied between pH treatments, but were not consistent through time. Respiration rates in the ∆pH = -0.3 and ∆pH = -0.1 treatments were initially 40% and 22% higher, respectively, than in the P treatment on Day 2 and then rates varied to become 26% lower (∆pH = -0.3) and 17% (∆pH = -0.1) higher towards the end of the experiment. Larvae were attracted to jellyfish tissue in treatments P and ∆pH = -0.1 but avoided jellyfish at ∆pH = -0.3. Moreover, OA conditions under ∆pH = -0.1 and ∆pH = -0.3 levels reduced the relative abundances of 22 of the 34 metabolites detected in phyllosomas via Nuclear Magnetic Resonance (NMR) spectroscopy. Our study demonstrates that the physiology and ability to detect jellyfish tissue by phyllosomas of the lobster T. australiensis may be impaired under ∆pH = -0.3 relative to the present conditions, with potential negative consequences for adult populations of this commercially important species.
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Affiliation(s)
- Sheldon Rey Boco
- Australian Rivers Institute, School of Environment and Science, Griffith University, Southport, Queensland 4215, Australia.
| | - Kylie A Pitt
- Australian Rivers Institute, School of Environment and Science, Griffith University, Southport, Queensland 4215, Australia
| | - Steven D Melvin
- Australian Rivers Institute, School of Environment and Science, Griffith University, Southport, Queensland 4215, Australia
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12
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Suárez-Castro AF, Beyer HL, Kuempel CD, Linke S, Borrelli P, Hoegh-Guldberg O. Global forest restoration opportunities to foster coral reef conservation. GLOBAL CHANGE BIOLOGY 2021; 27:5238-5252. [PMID: 34350684 DOI: 10.1111/gcb.15811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
Sediment runoff from disturbed coastal catchments is a major threat to marine ecosystems. Understanding where sediments are produced and where they are delivered enables managers to design more effective strategies for improving water quality. A management strategy is targeted restoration of degraded terrestrial areas, as it provides opportunities to reduce land-based runoff from coastal areas and consequently foster coral reef conservation. To do this strategically, a systematic approach is needed to identify watersheds where restoration actions will provide the highest conservation benefits for coral reefs. Here, we develop a systematic approach for identifying global forest restoration opportunities that would also result in large decreases in the flux of sediments to coral reefs. We estimate how land-use change affects sediment runoff globally using high-resolution spatial data and determine the subsequent risk of sediment exposure on coral reefs using a diffusion-based ocean transport model. Our results reveal that sediment export is a major issue affecting 41% of coral reefs globally. The main coastal watersheds with the highest sediment export are predominantly located in Southeast Asian countries, with Indonesia and the Philippines accounting for 52% of the sediment export in coastal areas near coral reefs. We show how restoring forest across multiple watersheds could help to reduce sediment export to 63,000 km2 of coral reefs. Although reforestation opportunities in areas that discharge onto coral reefs are relatively small across watersheds, it is possible to achieve large sediment reduction benefits by strategically targeting watersheds located in regions with a high density of corals near to the coast. Thus, reforestation benefits on coral reefs do not necessarily come from the watersheds that produce the highest sediment export. These analyses are key for generating informed action to support both international conservation policy and national restoration activities.
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Affiliation(s)
- Andrés F Suárez-Castro
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia
| | - Hawthorne L Beyer
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
| | - Caitlin D Kuempel
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
| | - Simon Linke
- Australian Rivers Institute - Coast and Estuaries, School of Environment and Science, Griffith University, Gold Coast, Qld, Australia
| | - Pasquale Borrelli
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
- Department of Biological Environment, Kangwon National University, Chuncheon, Republic of Korea
| | - Ove Hoegh-Guldberg
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
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13
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van der Zande RM, Mulders YR, Bender-Champ D, Hoegh-Guldberg O, Dove S. Asymmetric physiological response of a reef-building coral to pulsed versus continuous addition of inorganic nutrients. Sci Rep 2021; 11:13165. [PMID: 34162916 PMCID: PMC8222273 DOI: 10.1038/s41598-021-92276-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/18/2021] [Indexed: 02/06/2023] Open
Abstract
Coral reefs, especially those located near-shore, are increasingly exposed to anthropogenic, eutrophic conditions that are often chronic. Yet, corals under unperturbed conditions may frequently receive natural and usually temporary nutrient supplementation through biological sources such as fishes. We compared physiological parameters indicative of long- and short-term coral health (day and night calcification, fragment surface area, productivity, energy reserves, and tissue stoichiometry) under continuous and temporary nutrient enrichment. The symbiotic coral Acropora intermedia was grown for 7 weeks under continuously elevated (press) levels of ammonium (14 µmol L-1) and phosphate (10 µmol L-1) as separate and combined treatments, to discern the individual and interactive nutrient effects. Another treatment exposed A. intermedia twice-daily to an ammonium and phosphate pulse of the same concentrations as the press treatments to simulate natural biotic supplementation. Press exposure to elevated ammonium or phosphate produced mixed effects on physiological responses, with little interaction between the nutrients in the combined treatment. Overall, corals under press exposure transitioned resources away from calcification. However, exposure to nutrient pulses often enhanced physiological responses. Our findings indicate that while continuous nutrient enrichment may pose a threat to coral health, episodic nutrient pulses that resemble natural nutrient supplementation may significantly benefit coral health and physiology.
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Affiliation(s)
- Rene M. van der Zande
- grid.1003.20000 0000 9320 7537Coral Reef Ecosystems Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Global Change Institute, The University of Queensland, St. Lucia, QLD 4072 Australia
| | - Yannick R. Mulders
- grid.1003.20000 0000 9320 7537Coral Reef Ecosystems Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072 Australia
| | - Dorothea Bender-Champ
- grid.1003.20000 0000 9320 7537Coral Reef Ecosystems Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Global Change Institute, The University of Queensland, St. Lucia, QLD 4072 Australia
| | - Ove Hoegh-Guldberg
- grid.1003.20000 0000 9320 7537Coral Reef Ecosystems Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Global Change Institute, The University of Queensland, St. Lucia, QLD 4072 Australia
| | - Sophie Dove
- grid.1003.20000 0000 9320 7537Coral Reef Ecosystems Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, QLD 4072 Australia
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Davis C, Murphy AK, Bambrick H, Devine GJ, Frentiu FD, Yakob L, Huang X, Li Z, Yang W, Williams G, Hu W. A regional suitable conditions index to forecast the impact of climate change on dengue vectorial capacity. ENVIRONMENTAL RESEARCH 2021; 195:110849. [PMID: 33561446 DOI: 10.1016/j.envres.2021.110849] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/22/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The mosquitoes Aedes aegypti and Ae. albopictus are the primary vectors of dengue virus, and their geographic distributions are predicted to expand further with economic development, and in response to climate change. We aimed to estimate the impact of future climate change on dengue transmission through the development of a Suitable Conditions Index (SCI), based on climatic variables known to support vectorial capacity. We calculated the SCI based on various climate change scenarios for six countries in the Asia-Pacific region (Australia, China, Indonesia, The Philippines, Thailand and Vietnam). METHODS Monthly raster climate data (temperature and precipitation) were collected for the period January 2005 to December 2018 along with projected climate estimates for the years 2030, 2050 and 2070 using Representative Concentration Pathway (RCP) 4·5, 6·0 and 8·5 emissions scenarios. We defined suitable temperature ranges for dengue transmission of between 17·05-34·61 °C for Ae. aegypti and 15·84-31·51 °C for Ae. albopictus and then developed a historical and predicted SCI based on weather variability to measure the expected geographic limits of dengue vectorial capacity. Historical and projected SCI values were compared through difference maps for the six countries. FINDINGS Comparing different emission scenarios across all countries, we found that most South East Asian countries showed either a stable pattern of high suitability, or a potential decline in suitability for both vectors from 2030 to 2070, with a declining pattern particularly evident for Ae. albopictus. Temperate areas of both China and Australia showed a less stable pattern, with both moderate increases and decreases in suitability for each vector in different regions between 2030 and 2070. INTERPRETATION The SCI will be a useful index for forecasting potential dengue risk distributions in response to climate change, and independently of the effects of human activity. When considered alongside additional correlates of infection such as human population density and socioeconomic development indicators, the SCI could be used to develop an early warning system for dengue transmission.
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Affiliation(s)
- Callan Davis
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Amanda K Murphy
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia; Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Hilary Bambrick
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Gregor J Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Francesca D Frentiu
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Laith Yakob
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Xiaodong Huang
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Zhongjie Li
- Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Weizhong Yang
- Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; School of Population Medicine & Public Health, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China
| | - Gail Williams
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Wenbiao Hu
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia.
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15
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Keshavmurthy S, Beals M, Hsieh HJ, Choi KS, Chen CA. Physiological plasticity of corals to temperature stress in marginal coral communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143628. [PMID: 33248756 DOI: 10.1016/j.scitotenv.2020.143628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/06/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
Adaptation and/or acclimatization through various mechanisms have been suggested to help some tropical coral species to overcome temperature-induced bleaching that is intensifying with climate change; however, while much research has been done on the physiological responses of tropical and subtropical corals to stress, little is known about these responses in corals in marginal environments-e.g., high-latitude and non-reefal communities. In this study, we examined the thermal-tolerant physiology of the flowerpot coral, Alveopora japonica, endemic to the high-latitude Jeju Island (33.39°N), South Korea and Oulastrea crispata and Coelastrea aspera from the subtropical non-reefal coral community on the Penghu Islands (23.34°N), Taiwan. Analysis of physiological parameters; photochemical efficiency, Chlorophyll pigment, Symbiodiniaceae cell number and host soluble proteins - showed that A. japonica can survive through a wide range of temperature stresses (10-32 °C) over a period of 8 days without showing signs of bleaching. In addition, corals O. crispata and C. aspera withstood temperature stresses of up to 33 °C and repeated temperature fluctuations without bleaching. Our results indicate that, under large seasonal variations and asymmetrical daily fluctuations in temperature, corals currently living in marginal environments could have thermal plasticity, allowing them to survive in the future climate change scenarios. This study reiterates the importance of studying the eco-physiology of corals that are generally ignored because of their neutral or positive responses to stress.
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Affiliation(s)
| | - Morgan Beals
- Biodiversity Research Centre, Academia Sinica, Nangang, Taipei 115, Taiwan; Department of Life Sciences, National Taiwan Normal University, Taipei 106, Taiwan
| | - Hernyi Justin Hsieh
- Penghu Marine Biology Research Center, Fishery Research Institute, Council of Agriculture, Magong, Penghu 880, Taiwan
| | - Kwang-Sik Choi
- School of Marine Biomedical Science (BK 21 PLUS), Jeju National University, 102 Jejudaehakno, Jeju 63243, Republic of Korea
| | - Chaolun Allen Chen
- Biodiversity Research Centre, Academia Sinica, Nangang, Taipei 115, Taiwan; Taiwan International Graduate Program-Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan; Department of Life Sciences, National Taiwan Normal University, Taipei 106, Taiwan; Department of Life Sciences, Tunghai University, Taichung 404, Taiwan.
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16
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Fabricius KE, Neill C, Van Ooijen E, Smith JN, Tilbrook B. Progressive seawater acidification on the Great Barrier Reef continental shelf. Sci Rep 2020; 10:18602. [PMID: 33110129 PMCID: PMC7592051 DOI: 10.1038/s41598-020-75293-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
Coral reefs are highly sensitive to ocean acidification due to rising atmospheric CO2 concentrations. We present 10 years of data (2009-2019) on the long-term trends and sources of variation in the carbon chemistry from two fixed stations in the Australian Great Barrier Reef. Data from the subtropical mid-shelf GBRWIS comprised 3-h instrument records, and those from the tropical coastal NRSYON were monthly seawater samples. Both stations recorded significant variation in seawater CO2 fugacity (fCO2), attributable to seasonal, daytime, temperature and salinity fluctuations. Superimposed over this variation, fCO2 progressively increased by > 2.0 ± 0.3 µatm year-1 at both stations. Seawater temperature and salinity also increased throughout the decade, whereas seawater pH and the saturation state of aragonite declined. The decadal upward fCO2 trend remained significant in temperature- and salinity-normalised data. Indeed, annual fCO2 minima are now higher than estimated fCO2 maxima in the early 1960s, with mean fCO2 now ~ 28% higher than 60 years ago. Our data indicate that carbonate dissolution from the seafloor is currently unable to buffer the Great Barrier Reef against ocean acidification. This is of great concern for the thousands of coral reefs and other diverse marine ecosystems located in this vast continental shelf system.
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Affiliation(s)
| | - Craig Neill
- CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, 7004, Australia
| | - Erik Van Ooijen
- CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, 7004, Australia
| | - Joy N Smith
- Australian Institute of Marine Science, PMB 3, Townsville, QLD, 4810, Australia
| | - Bronte Tilbrook
- CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, 7004, Australia.,Australian Antarctic Program Partnership, University of Tasmania, Hobart, 7001, Australia
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17
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Jackson RL, Gabric AJ, Cropp R. Coral reefs as a source of climate-active aerosols. PeerJ 2020; 8:e10023. [PMID: 33062438 PMCID: PMC7531332 DOI: 10.7717/peerj.10023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 09/02/2020] [Indexed: 01/17/2023] Open
Abstract
We review the evidence for bio-regulation by coral reefs of local climate through stress-induced emissions of aerosol precursors, such as dimethylsulfide. This is an issue that goes to the core of the coral ecosystem’s ability to maintain homeostasis in the face of increasing climate change impacts and other anthropogenic pressures. We examine this through an analysis of data on aerosol emissions by corals of the Great Barrier Reef, Australia. We focus on the relationship with local stressors, such as surface irradiance levels and sea surface temperature, both before and after notable coral bleaching events. We conclude that coral reefs may be able to regulate their exposure to environmental stressors through modification of the optical properties of the atmosphere, however this ability may be impaired as climate change intensifies.
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Affiliation(s)
- Rebecca L Jackson
- School of Environment and Science, Griffith University, Gold Coast, QLD, Australia
| | - Albert J Gabric
- School of Environment and Science, Griffith University, Nathan, QLD, Australia
| | - Roger Cropp
- School of Environment and Science, Griffith University, Gold Coast, QLD, Australia
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18
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Venn AA, Bernardet C, Chabenat A, Tambutté E, Tambutté S. Paracellular transport to the coral calcifying medium: effects of environmental parameters. J Exp Biol 2020; 223:jeb227074. [PMID: 32675232 DOI: 10.1242/jeb.227074] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022]
Abstract
Coral calcification relies on the transport of ions and molecules to the extracellular calcifying medium (ECM). Little is known about paracellular transport (via intercellular junctions) in corals and other marine calcifiers. Here, we investigated whether the permeability of the paracellular pathway varied in different environmental conditions in the coral Stylophora pistillata Using the fluorescent dye calcein, we characterised the dynamics of calcein influx from seawater to the ECM and showed that increases in paracellular permeability (leakiness) induced by hyperosmotic treatment could be detected by changes in calcein influx rates. We then used the calcein-imaging approach to investigate the effects of two environmental stressors on paracellular permeability: seawater acidification and temperature change. Under conditions of seawater acidification (pH 7.2) known to depress pH in the ECM and the calcifying cells of S. pistillata, we observed a decrease in half-times of calcein influx, indicating increased paracellular permeability. By contrast, high temperature (31°C) had no effect, whereas low temperature (20°C) caused decreases in paracellular permeability. Overall, our study establishes an approach to conduct further in vivo investigation of paracellular transport and suggests that changes in paracellular permeability could form an uncharacterised aspect of the physiological response of S. pistillata to seawater acidification.
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Affiliation(s)
- Alexander A Venn
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Coralie Bernardet
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Apolline Chabenat
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Eric Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Sylvie Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
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