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Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [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: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
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Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
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2
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Strader ME, Wright RM, Pezner AK, Nuttall MF, Aichelman HE, Davies SW. Intersection of coral molecular responses to a localized mortality event and ex situ deoxygenation. Ecol Evol 2024; 14:e11275. [PMID: 38654712 PMCID: PMC11036075 DOI: 10.1002/ece3.11275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 03/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
In July 2016, East Bank of Flower Garden Banks (FGB) National Marine Sanctuary experienced a localized mortality event (LME) of multiple invertebrate species that ultimately led to reductions in coral cover. Abiotic data taken directly after the event suggested that acute deoxygenation contributed to the mortality. Despite the large impact of this event on the coral community, there was no direct evidence that this LME was driven by acute deoxygenation, and thus we explored whether gene expression responses of corals to the LME would indicate what abiotic factors may have contributed to the LME. Gene expression of affected and unaffected corals sampled during the mortality event revealed evidence of the physiological consequences of the LME on coral hosts and their algal symbionts from two congeneric species (Orbicella franksi and Orbicella faveolata). Affected colonies of both species differentially regulated genes involved in mitochondrial regulation and oxidative stress. To further test the hypothesis that deoxygenation led to the LME, we measured coral host and algal symbiont gene expression in response to ex situ experimental deoxygenation (control = 6.9 ± 0.08 mg L-1, anoxic = 0.083 ± 0.017 mg L-1) in healthy O. faveolata colonies from the FGB. However, this deoxygenation experiment revealed divergent gene expression patterns compared to the corals sampled during the LME and was more similar to a generalized coral environmental stress response. It is therefore likely that while the LME was connected to low oxygen, it was a series of interconnected stressors that elicited the unique gene expression responses observed here. These in situ and ex situ data highlight how field responses to stressors are unique from those in controlled laboratory conditions, and that the complexities of deoxygenation events in the field likely arise from interactions between multiple environmental factors simultaneously.
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Affiliation(s)
- Marie E. Strader
- Department of BiologyTexas A&M UniversityCollege StationTexasUSA
| | - Rachel M. Wright
- Department of Biological SciencesSouthern Methodist UniversityDallasTexasUSA
| | | | | | | | - Sarah W. Davies
- Department of BiologyBoston UniversityBostonMassachusettsUSA
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3
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Quigley KM. Breeding and Selecting Corals Resilient to Global Warming. Annu Rev Anim Biosci 2024; 12:209-332. [PMID: 37931139 DOI: 10.1146/annurev-animal-021122-093315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Selective breeding of resilient organisms is an emerging topic in marine conservation. It can help us predict how species will adapt in the future and how we can help restore struggling populations effectively in the present. Scleractinian corals represent a potential tractable model system given their widescale phenotypic plasticity across fitness-related traits and a reproductive life history based on mass synchronized spawning. Here, I explore the justification for breeding in corals, identify underutilized pathways of acclimation, and highlight avenues for quantitative targeted breeding from the coral host and symbiont perspective. Specifically, the facilitation of enhanced heat tolerance by targeted breeding of plasticity mechanisms is underutilized. Evidence from theoretical genetics identifies potential pitfalls, including inattention to physical and genetic characteristics of the receiving environment. Three criteria for breeding emerge from this synthesis: selection from warm, variable reefs that have survived disturbance. This information will be essential to protect what we have and restore what we can.
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Affiliation(s)
- K M Quigley
- The Minderoo Foundation, Perth, Western Australia, Australia;
- James Cook University, Townsville, Queensland, Australia
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4
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Maggioni F, Stenger PL, Letourneur Y, Jourand P, Majorel C. Metallic trace elements in marine sponges living in a semi-enclosed tropical lagoon. Biometals 2024; 37:157-169. [PMID: 37725248 DOI: 10.1007/s10534-023-00536-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/05/2023] [Indexed: 09/21/2023]
Abstract
The ability of marine filter feeders to accumulate metals could help monitor the health of the marine environment. This study examined the concentration of metallic trace elements (MTE) in two marine sponges, Rhabdastrella globostellata and Hyrtios erectus, from three sampling zones of the semi-enclosed Bouraké Lagoon (New Caledonia, South West Pacific). MTE in sponge tissues, seawater, and surrounding sediments was measured using inductively coupled plasma with optical emission spectroscopy. The variability in sponge MTE concentrations between species and sampling zones was visually discriminated using a principal component analysis (PCA). Sponges showed Fe, Mn, Cr, Ni, and Zn concentrations 2 to 10 times higher than in the surrounding sediments and seawater. Hyrtios erectus accumulated 3 to 20 times more MTE than R. globostellata, except for Zn. Average bioconcentration factors in sponge tissues were (in decreasing order) Zn > Ni > Mn > Fe > Cr relate to sediments and Fe > Ni > Mn > Cr > Zn relate to seawater. The PCA confirmed higher MTE concentrations in H. erectus compared to R. globostellata. Our results confirm that marine sponges can accumulate MTE to some extent and could be used as a tool for assessing metals contamination in lagoon ecosystems, particularly in New Caledonia, where 40% of the lagoon is classified as a UNESCO World Heritage Site.
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Affiliation(s)
- Federica Maggioni
- University of New Caledonia, UMR ENTROPIE, Ave James Cook, 98800, Nouméa, New Caledonia, France
- IRD, UMR ENTROPIE, 101 Promenade Roger Laroque, 98848, Nouméa, New Caledonia, France
| | - Pierre-Louis Stenger
- IAC, Institut Agronomique Néo-Calédonien (IAC), Équipe Sol & Végétation (SolVeg), 101 Promenade Roger Laroque, 98848, Nouméa, New Caledonia, France
| | - Yves Letourneur
- University of New Caledonia, UMR ENTROPIE, Ave James Cook, 98800, Nouméa, New Caledonia, France
| | - Philippe Jourand
- IRD, UMR ENTROPIE, Université de La Réunion, 15, Avenue René Cassin - CS 92003, 97744, Saint Denis Cédex 9, La Réunion, France
| | - Clarisse Majorel
- IRD, UMR ENTROPIE, 101 Promenade Roger Laroque, 98848, Nouméa, New Caledonia, France.
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5
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Howard RD, Schul MD, Rodriguez Bravo LM, Altieri AH, Meyer JL. Shifts in the coral microbiome in response to in situ experimental deoxygenation. Appl Environ Microbiol 2023; 89:e0057723. [PMID: 37916820 PMCID: PMC10686059 DOI: 10.1128/aem.00577-23] [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: 04/06/2023] [Accepted: 09/12/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Marine hypoxia is a threat for corals but has remained understudied in tropical regions where coral reefs are abundant. Though microbial symbioses can alleviate the effects of ecological stress, we do not yet understand the taxonomic or functional response of the coral microbiome to hypoxia. In this study, we experimentally lowered oxygen levels around Siderastrea siderea and Agaricia lamarcki colonies in situ to observe changes in the coral microbiome in response to deoxygenation. Our results show that hypoxia triggers a stochastic change of the microbiome overall, with some bacterial families changing deterministically after just 48 hours of exposure. These families represent an increase in anaerobic and opportunistic taxa in the microbiomes of both coral species. Thus, marine deoxygenation destabilizes the coral microbiome and increases bacterial opportunism. This work provides novel and fundamental knowledge of the microbial response in coral during hypoxia and may provide insight into holobiont function during stress.
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Affiliation(s)
- Rachel D. Howard
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
| | - Monica D. Schul
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
| | - Lucia M. Rodriguez Bravo
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Andrew H. Altieri
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
| | - Julie L. Meyer
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
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Scucchia F, Zaslansky P, Boote C, Doheny A, Mass T, Camp EF. The role and risks of selective adaptation in extreme coral habitats. Nat Commun 2023; 14:4475. [PMID: 37507378 PMCID: PMC10382478 DOI: 10.1038/s41467-023-39651-7] [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: 01/25/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
The alarming rate of climate change demands new management strategies to protect coral reefs. Environments such as mangrove lagoons, characterized by extreme variations in multiple abiotic factors, are viewed as potential sources of stress-tolerant corals for strategies such as assisted evolution and coral propagation. However, biological trade-offs for adaptation to such extremes are poorly known. Here, we investigate the reef-building coral Porites lutea thriving in both mangrove and reef sites and show that stress-tolerance comes with compromises in genetic and energetic mechanisms and skeletal characteristics. We observe reduced genetic diversity and gene expression variability in mangrove corals, a disadvantage under future harsher selective pressure. We find reduced density, thickness and higher porosity in coral skeletons from mangroves, symptoms of metabolic energy redirection to stress response functions. These findings demonstrate the need for caution when utilizing stress-tolerant corals in human interventions, as current survival in extremes may compromise future competitive fitness.
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Affiliation(s)
- Federica Scucchia
- Department of Marine Biology, Leon H, Charney school of Marine Sciences, University of Haifa, Haifa, Israel.
| | - Paul Zaslansky
- Department for Operative, Preventive and Pediatric Dentistry, Charité-Universitätsmedizin, Berlin, Germany
| | - Chloë Boote
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Annabelle Doheny
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Tali Mass
- Department of Marine Biology, Leon H, Charney school of Marine Sciences, University of Haifa, Haifa, Israel
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia.
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7
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Zhang K, Wu Z, Liu Z, Tang J, Cai W, An M, Zhou Z. Acute hypoxia induces reduction of algal symbiont density and suppression of energy metabolism in the scleractinian coral Pocillopora damicornis. MARINE POLLUTION BULLETIN 2023; 191:114897. [PMID: 37043929 DOI: 10.1016/j.marpolbul.2023.114897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 02/21/2023] [Accepted: 03/27/2023] [Indexed: 05/13/2023]
Abstract
Loss of oxygen in the ocean is accelerating and threatening the coral reef ecosystem. In this study, the impacts of hypoxia on the scleractinian coral Pocillopora damicornis were explored. The algal symbiont density, chlorophyll a + c2 content, energy consumption of corals, as well as energy available and consumption of their symbionts, decreased significantly post hypoxia stress. Meanwhile, the malondialdehyde contents in corals and symbionts, together with the caspase-3 activation level in corals, increased significantly in response to hypoxia stress. Furthermore, it was revealed that activities such as coral cell division and calcification were inhibited under hypoxia. These results collectively suggest that acute hypoxia stress reduces symbiont density and chlorophyll a + c2 content in the coral P. damicornis by elevating intracellular oxidative pressure and apoptotic level, which further suppresses energy metabolism in the symbiotic association and negatively affects a series of activities such as coral cell division and calcification.
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Affiliation(s)
- Kaidian Zhang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China
| | - Zhongjie Wu
- Hainan Academy of Ocean and Fisheries Sciences, Haikou 571126, China
| | - Zhaoqun Liu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China.
| | - Jia Tang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China
| | - Wenqi Cai
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China; Hainan Academy of Ocean and Fisheries Sciences, Haikou 571126, China
| | - Mingxun An
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China
| | - Zhi Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan University, Haikou 570228, China.
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8
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Maggioni F, Bell JJ, Pujo-Pay M, Shaffer M, Cerrano C, Lemonnier H, Letourneur Y, Rodolfo-Metalpa R. Sponge organic matter recycling: Reduced detritus production under extreme environmental conditions. MARINE POLLUTION BULLETIN 2023; 190:114869. [PMID: 37023545 DOI: 10.1016/j.marpolbul.2023.114869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 03/01/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
Sponges are a key component of coral reef ecosystems and play an important role in carbon and nutrient cycles. Many sponges are known to consume dissolved organic carbon and transform this into detritus, which moves through detrital food chains and eventually to higher trophic levels via what is known as the sponge loop. Despite the importance of this loop, little is known about how these cycles will be impacted by future environmental conditions. During two years (2018 and 2020), we measured the organic carbon, nutrient recycling, and photosynthetic activity of the massive HMA, photosymbiotic sponge Rhabdastrella globostellata at the natural laboratory of Bouraké in New Caledonia, where the physical and chemical composition of seawater regularly change according to the tide. We found that while sponges experienced acidification and low dissolved oxygen at low tide in both sampling years, a change in organic carbon recycling whereby sponges stopped producing detritus (i.e., the sponge loop) was only found when sponges also experienced higher temperature in 2020. Our findings provide new insights into how important trophic pathways may be affected by changing ocean conditions.
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Affiliation(s)
- Federica Maggioni
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa 98800, New Caledonia; Labex ICONA International CO(2) Natural Analogues Network, JSPS, Japan.
| | - James J Bell
- School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand
| | - Mireille Pujo-Pay
- Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne, LOMIC, F-66650 Banyuls-sur-Mer, France
| | - Megan Shaffer
- School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand
| | - Carlo Cerrano
- Department of Life and Environmental Sciences (DiSVA), Polytechnic University of Marche, Ancona, Italy
| | - Hugues Lemonnier
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa 98800, New Caledonia
| | - Yves Letourneur
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa 98800, New Caledonia
| | - Riccardo Rodolfo-Metalpa
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa 98800, New Caledonia; Labex ICONA International CO(2) Natural Analogues Network, JSPS, Japan
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9
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Tanvet C, Camp EF, Sutton J, Houlbrèque F, Thouzeau G, Rodolfo‐Metalpa R. Corals adapted to extreme and fluctuating seawater pH increase calcification rates and have unique symbiont communities. Ecol Evol 2023; 13:e10099. [PMID: 37261315 PMCID: PMC10227177 DOI: 10.1002/ece3.10099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 04/18/2023] [Accepted: 05/03/2023] [Indexed: 06/02/2023] Open
Abstract
Ocean acidification (OA) is a severe threat to coral reefs mainly by reducing their calcification rate. Identifying the resilience factors of corals to decreasing seawater pH is of paramount importance to predict the survivability of coral reefs in the future. This study compared corals adapted to variable pHT (i.e., 7.23-8.06) from the semi-enclosed lagoon of Bouraké, New Caledonia, to corals adapted to more stable seawater pHT (i.e., 7.90-8.18). In a 100-day aquarium experiment, we examined the physiological response and genetic diversity of Symbiodiniaceae from three coral species (Acropora tenuis, Montipora digitata, and Porites sp.) from both sites under three stable pHNBS conditions (8.11, 7.76, 7.54) and one fluctuating pHNBS regime (between 7.56 and 8.07). Bouraké corals consistently exhibited higher growth rates than corals from the stable pH environment. Interestingly, A. tenuis from Bouraké showed the highest growth rate under the 7.76 pHNBS condition, whereas for M. digitata, and Porites sp. from Bouraké, growth was highest under the fluctuating regime and the 8.11 pHNBS conditions, respectively. While OA generally decreased coral calcification by ca. 16%, Bouraké corals showed higher growth rates than corals from the stable pH environment (21% increase for A. tenuis to 93% for M. digitata, with all pH conditions pooled). This superior performance coincided with divergent symbiont communities that were more homogenous for Bouraké corals. Corals adapted to variable pH conditions appear to have a better capacity to calcify under reduced pH compared to corals native to more stable pH condition. This response was not gained by corals from the more stable environment exposed to variable pH during the 100-day experiment, suggesting that long-term exposure to pH fluctuations and/or differences in symbiont communities benefit calcification under OA.
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Affiliation(s)
- Clément Tanvet
- Centre IRD NouméaUMR ENTROPIE (IRD, Université de la Réunion, Université de la Nouvelle‐Calédonie, Ifremer)NouméaNew Caledonia
- Univ Brest, CNRS, IRD, Ifremer, LEMARPlouzanéFrance
- Labex ICONA, International CO2 Natural Analogues NetworkShimodaJapan
| | - Emma F. Camp
- Climate Change ClusterUniversity of Technology SydneyUltimoNew South WalesAustralia
| | - Jill Sutton
- Univ Brest, CNRS, IRD, Ifremer, LEMARPlouzanéFrance
| | - Fanny Houlbrèque
- Centre IRD NouméaUMR ENTROPIE (IRD, Université de la Réunion, Université de la Nouvelle‐Calédonie, Ifremer)NouméaNew Caledonia
- Labex ICONA, International CO2 Natural Analogues NetworkShimodaJapan
| | | | - Riccardo Rodolfo‐Metalpa
- Centre IRD NouméaUMR ENTROPIE (IRD, Université de la Réunion, Université de la Nouvelle‐Calédonie, Ifremer)NouméaNew Caledonia
- Labex ICONA, International CO2 Natural Analogues NetworkShimodaJapan
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10
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Schoepf V, Baumann JH, Barshis DJ, Browne NK, Camp EF, Comeau S, Cornwall CE, Guzmán HM, Riegl B, Rodolfo-Metalpa R, Sommer B. Corals at the edge of environmental limits: A new conceptual framework to re-define marginal and extreme coral communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 884:163688. [PMID: 37105476 DOI: 10.1016/j.scitotenv.2023.163688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/07/2023]
Abstract
The worldwide decline of coral reefs has renewed interest in coral communities at the edge of environmental limits because they have the potential to serve as resilience hotspots and climate change refugia, and can provide insights into how coral reefs might function in future ocean conditions. These coral communities are often referred to as marginal or extreme but few definitions exist and usage of these terms has therefore been inconsistent. This creates significant challenges for categorising these often poorly studied communities and synthesising data across locations. Furthermore, this impedes our understanding of how coral communities can persist at the edge of their environmental limits and the lessons they provide for future coral reef survival. Here, we propose that marginal and extreme coral communities are related but distinct and provide a novel conceptual framework to redefine them. Specifically, we define coral reef extremeness solely based on environmental conditions (i.e., large deviations from optimal conditions in terms of mean and/or variance) and marginality solely based on ecological criteria (i.e., altered community composition and/or ecosystem functioning). This joint but independent assessment of environmental and ecological criteria is critical to avoid common pitfalls where coral communities existing outside the presumed optimal conditions for coral reef development are automatically considered inferior to coral reefs in more traditional settings. We further evaluate the differential potential of marginal and extreme coral communities to serve as natural laboratories, resilience hotspots and climate change refugia, and discuss strategies for their conservation and management as well as priorities for future research. Our new classification framework provides an important tool to improve our understanding of how corals can persist at the edge of their environmental limits and how we can leverage this knowledge to optimise strategies for coral reef conservation, restoration and management in a rapidly changing ocean.
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Affiliation(s)
- Verena Schoepf
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; UWA Oceans Institute, University of Western Australia, Perth, Western Australia, Australia.
| | - Justin H Baumann
- Department of Biology, Mount Holyoke College, South Hadley, MA, USA
| | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Nicola K Browne
- School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Steeve Comeau
- Sorbonne Université, CNRS-INSU, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-mer, France
| | - Christopher E Cornwall
- School of Biological Sciences and Coastal People: Southern Skies, Victoria University of Wellington, Wellington, New Zealand
| | - Héctor M Guzmán
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Bernhard Riegl
- Department of Marine and Environmental Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Riccardo Rodolfo-Metalpa
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa, New Caledonia; Labex ICONA, International CO(2) Natural Analogues Network, Japan
| | - Brigitte Sommer
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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11
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Reich HG, Camp EF, Roger LM, Putnam HM. The trace metal economy of the coral holobiont: supplies, demands and exchanges. Biol Rev Camb Philos Soc 2023; 98:623-642. [PMID: 36897260 DOI: 10.1111/brv.12922] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/23/2022]
Abstract
The juxtaposition of highly productive coral reef ecosystems in oligotrophic waters has spurred substantial interest and progress in our understanding of macronutrient uptake, exchange, and recycling among coral holobiont partners (host coral, dinoflagellate endosymbiont, endolithic algae, fungi, viruses, bacterial communities). By contrast, the contribution of trace metals to the physiological performance of the coral holobiont and, in turn, the functional ecology of reef-building corals remains unclear. The coral holobiont's trace metal economy is a network of supply, demand, and exchanges upheld by cross-kingdom symbiotic partnerships. Each partner has unique trace metal requirements that are central to their biochemical functions and the metabolic stability of the holobiont. Organismal homeostasis and the exchanges among partners determine the ability of the coral holobiont to adjust to fluctuating trace metal supplies in heterogeneous reef environments. This review details the requirements for trace metals in core biological processes and describes how metal exchanges among holobiont partners are key to sustaining complex nutritional symbioses in oligotrophic environments. Specifically, we discuss how trace metals contribute to partner compatibility, ability to cope with stress, and thereby to organismal fitness and distribution. Beyond holobiont trace metal cycling, we outline how the dynamic nature of the availability of environmental trace metal supplies can be influenced by a variability of abiotic factors (e.g. temperature, light, pH, etc.). Climate change will have profound consequences on the availability of trace metals and further intensify the myriad stressors that influence coral survival. Lastly, we suggest future research directions necessary for understanding the impacts of trace metals on the coral holobiont symbioses spanning subcellular to organismal levels, which will inform nutrient cycling in coral ecosystems more broadly. Collectively, this cross-scale elucidation of the role of trace metals for the coral holobiont will allow us to improve forecasts of future coral reef function.
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Affiliation(s)
- Hannah G Reich
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI, 02881, USA
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Liza M Roger
- Chemical & Life Science Engineering, Virginia Commonwealth University, 601 W. Main Street, Richmond, VA, 23284, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI, 02881, USA
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12
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Haydon TD, Matthews JL, Seymour JR, Raina JB, Seymour JE, Chartrand K, Camp EF, Suggett DJ. Metabolomic signatures of corals thriving across extreme reef habitats reveal strategies of heat stress tolerance. Proc Biol Sci 2023; 290:20221877. [PMID: 36750192 PMCID: PMC9904954 DOI: 10.1098/rspb.2022.1877] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/11/2023] [Indexed: 02/09/2023] Open
Abstract
Anthropogenic stressors continue to escalate worldwide, driving unprecedented declines in reef environmental conditions and coral health. One approach to better understand how corals can function in the future is to examine coral populations that thrive within present day naturally extreme habitats. We applied untargeted metabolomics (gas chromatography-mass spectrometry (GC-MS)) to contrast metabolite profiles of Pocillopora acuta colonies from hot, acidic and deoxygenated mangrove environments versus those from adjacent reefs. Under ambient temperatures, P. acuta predominantly associated with endosymbionts of the genera Cladocopium (reef) or Durusdinium (mangrove), exhibiting elevated metabolism in mangrove through energy-generating and biosynthesis pathways compared to reef populations. Under transient heat stress, P. acuta endosymbiont associations were unchanged. Reef corals bleached and exhibited extensive shifts in symbiont metabolic profiles (whereas host metabolite profiles were unchanged). By contrast, mangrove populations did not bleach and solely the host metabolite profiles were altered, including cellular responses in inter-partner signalling, antioxidant capacity and energy storage. Thus mangrove P. acuta populations resist periodically high-temperature exposure via association with thermally tolerant endosymbionts coupled with host metabolic plasticity. Our findings highlight specific metabolites that may be biomarkers of heat tolerance, providing novel insight into adaptive coral resilience to elevated temperatures.
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Affiliation(s)
- Trent D. Haydon
- Center for Genomics and Systems Biology, New York University Abu Dhabi, PO Box 129188, Abu Dhabi, UAE
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Jennifer L. Matthews
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Justin R. Seymour
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Jean-Baptiste Raina
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Jamie E. Seymour
- Division of Tropical Health and Medicine, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4811, Australia
| | - Kathryn Chartrand
- Centre for tropical Water and Aquatic Ecosystem Research, James Cook University, Cairns, QLD 4811, Australia
| | - Emma F. Camp
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - David J. Suggett
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
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13
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Brown KT, Barott KL. The Costs and Benefits of Environmental Memory for Reef-Building Corals Coping with Recurring Marine Heatwaves. Integr Comp Biol 2022; 62:1748-1755. [PMID: 35661887 DOI: 10.1093/icb/icac074] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 01/05/2023] Open
Abstract
Marine heatwaves are occurring more frequently as climate change intensifies, resulting in global mass coral bleaching events several times per decade. Despite the time between marine heatwaves decreasing, there is evidence that reef-building corals can develop increased bleaching resistance across repetitive marine heatwaves. This phenomenon of acclimatization via environmental memory may be an important strategy to ensure coral persistence; however, we still understand very little about the apparent acclimatization or, conversely, sensitization (i.e., stress accumulation or weakening) of reef-building corals to consecutive heatwaves and its implications for the trajectory and resilience of coral reefs. Here, we highlight that not only will some corals become stress hardened via marine heatwaves, but many other individuals will suffer sensitization during repeat heatwaves that further exacerbates their stress response during repeat events and depresses fitness. Under current and predicted climate change, it is necessary to gain a better understanding of the acclimatization vs. sensitization trajectories of different species and individuals on the reef, as well as identify whether changes in bleaching susceptibility relates to physiological acclimatization, trade-offs with other biological processes, and ultimately coral persistence in the Anthropocene.
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Affiliation(s)
- Kristen T Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.,School of Biological Sciences, University of Queensland, St. Lucia , QLD 4072, Australia
| | - Katie L Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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14
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McLeod IM, Hein MY, Babcock R, Bay L, Bourne DG, Cook N, Doropoulos C, Gibbs M, Harrison P, Lockie S, van Oppen MJH, Mattocks N, Page CA, Randall CJ, Smith A, Smith HA, Suggett DJ, Taylor B, Vella KJ, Wachenfeld D, Boström-Einarsson L. Coral restoration and adaptation in Australia: The first five years. PLoS One 2022; 17:e0273325. [PMID: 36449458 PMCID: PMC9710771 DOI: 10.1371/journal.pone.0273325] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
While coral reefs in Australia have historically been a showcase of conventional management informed by research, recent declines in coral cover have triggered efforts to innovate and integrate intervention and restoration actions into management frameworks. Here we outline the multi-faceted intervention approaches that have developed in Australia since 2017, from newly implemented in-water programs, research to enhance coral resilience and investigations into socio-economic perspectives on restoration goals. We describe in-water projects using coral gardening, substrate stabilisation, coral repositioning, macro-algae removal, and larval-based restoration techniques. Three areas of research focus are also presented to illustrate the breadth of Australian research on coral restoration, (1) the transdisciplinary Reef Restoration and Adaptation Program (RRAP), one of the world's largest research and development programs focused on coral reefs, (2) interventions to enhance coral performance under climate change, and (3) research into socio-cultural perspectives. Together, these projects and the recent research focus reflect an increasing urgency for action to confront the coral reef crisis, develop new and additional tools to manage coral reefs, and the consequent increase in funding opportunities and management appetite for implementation. The rapid progress in trialling and deploying coral restoration in Australia builds on decades of overseas experience, and advances in research and development are showing positive signs that coral restoration can be a valuable tool to improve resilience at local scales (i.e., high early survival rates across a variety of methods and coral species, strong community engagement with local stakeholders). RRAP is focused on creating interventions to help coral reefs at multiple scales, from micro scales (i.e., interventions targeting small areas within a specific reef site) to large scales (i.e., interventions targeting core ecosystem function and social-economic values at multiple select sites across the Great Barrier Reef) to resist, adapt to and recover from the impacts of climate change. None of these interventions aim to single-handedly restore the entirety of the Great Barrier Reef, nor do they negate the importance of urgent climate change mitigation action.
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Affiliation(s)
- Ian M. McLeod
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Margaux Y. Hein
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- MER Research and Consulting, The Office, Monaco, Monaco
- * E-mail:
| | - Russ Babcock
- CSIRO Oceans & Atmosphere, St Lucia, Queensland, Australia
| | - Line Bay
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - David G. Bourne
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- College of Science and Engineering, James Cook University, Townsville, Australia
| | - Nathan Cook
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Reef Ecologic, Townsville, Queensland, Australia
| | | | - Mark Gibbs
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Peter Harrison
- Marine Ecology Research Centre, Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Stewart Lockie
- The Cairns Institute, James Cook University, Cairns, Queensland, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Neil Mattocks
- Great Barrier Reef Marine Park Authority, Townsville, Queensland, Australia
| | - Cathie A. Page
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Carly J. Randall
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Adam Smith
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Reef Ecologic, Townsville, Queensland, Australia
| | - Hillary A. Smith
- College of Science and Engineering, James Cook University, Townsville, Australia
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Randwick, New South Wales, Australia
| | - David J. Suggett
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Bruce Taylor
- Land & Water, Commonwealth Scientific and Industrial Research Organisation, Dutton Park, Queensland, Australia
| | - Karen J. Vella
- School of Architecture and Built Environment, Queensland University of Technology, Brisbane, Australia
| | - David Wachenfeld
- Great Barrier Reef Marine Park Authority, Townsville, Queensland, Australia
| | - Lisa Boström-Einarsson
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, United Kingdom
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15
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Alderdice R, Perna G, Cárdenas A, Hume BCC, Wolf M, Kühl M, Pernice M, Suggett DJ, Voolstra CR. Deoxygenation lowers the thermal threshold of coral bleaching. Sci Rep 2022; 12:18273. [PMID: 36316371 PMCID: PMC9622859 DOI: 10.1038/s41598-022-22604-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/17/2022] [Indexed: 12/02/2022] Open
Abstract
Exposure to deoxygenation from climate warming and pollution is emerging as a contributing factor of coral bleaching and mortality. However, the combined effects of heating and deoxygenation on bleaching susceptibility remain unknown. Here, we employed short-term thermal stress assays to show that deoxygenated seawater can lower the thermal limit of an Acropora coral by as much as 1 °C or 0.4 °C based on bleaching index scores or dark-acclimated photosynthetic efficiencies, respectively. Using RNA-Seq, we show similar stress responses to heat with and without deoxygenated seawater, both activating putative key genes of the hypoxia-inducible factor response system indicative of cellular hypoxia. We also detect distinct deoxygenation responses, including a disruption of O2-dependent photo-reception/-protection, redox status, and activation of an immune response prior to the onset of bleaching. Thus, corals are even more vulnerable when faced with heat stress in deoxygenated waters. This highlights the need to integrate dissolved O2 measurements into global monitoring programs of coral reefs.
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Affiliation(s)
- Rachel Alderdice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
| | - Gabriela Perna
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Benjamin C C Hume
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Martin Wolf
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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16
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Nitschke MR, Rosset SL, Oakley CA, Gardner SG, Camp EF, Suggett DJ, Davy SK. The diversity and ecology of Symbiodiniaceae: A traits-based review. ADVANCES IN MARINE BIOLOGY 2022; 92:55-127. [PMID: 36208879 DOI: 10.1016/bs.amb.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.
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Affiliation(s)
- Matthew R Nitschke
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia.
| | - Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Stephanie G Gardner
- Center for Marine Science and Innovation, University of New South Wales Sydney, Kensington, NSW, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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17
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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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18
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Boakes Z, Hall AE, Elvan Ampou E, Jones GC, Gusti Ngurah Agung Suryaputra I, Putu Mahyuni L, Prasetyo R, Stafford R. Coral reef conservation in Bali in light of international best practice, a literature review. J Nat Conserv 2022. [DOI: 10.1016/j.jnc.2022.126190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Comeau S, Cornwall CE, Shlesinger T, Hoogenboom M, Mana R, McCulloch MT, Rodolfo-Metalpa R. pH variability at volcanic CO 2 seeps regulates coral calcifying fluid chemistry. GLOBAL CHANGE BIOLOGY 2022; 28:2751-2763. [PMID: 35119159 DOI: 10.1111/gcb.16093] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Coral reefs are iconic ecosystems with immense ecological, economic and cultural value, but globally their carbonate-based skeletal construction is threatened by ocean acidification (OA). Identifying coral species that have specialised mechanisms to maintain high rates of calcification in the face of declining seawater pH is of paramount importance in predicting future species composition, and growth of coral reefs. Here, we studied multiple coral species from two distinct volcanic CO2 seeps in Papua New Guinea to assess their capacity to control their calcifying fluid (CF) chemistry. Several coral species living under conditions of low mean seawater pH, but with either low or high variability in seawater pH, were examined and compared with those living in 'normal' (non-seep) ambient seawater pH. We show that when mean seawater pH is low but highly variable, corals have a greater ability to maintain constant pHcf in their CF, but this characteristic was not linked with changes in abundance. Within less variable low pH seawater, corals with limited reductions in pHcf at the seep sites compared with controls tended to be more abundant at the seep site than at the control site. However, this finding was strongly influenced by a single species (Montipora foliosa), which was able to maintain complete pHcf homeostasis. Overall, although our findings indicate that there might be an association between ecological success and greater pHcf homeostasis, further research with additional species and at more sites with differing seawater pH regimes is required to solidify inferences regarding coral ecological success under future OA.
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Affiliation(s)
- Steeve Comeau
- CNRS-INSU, Laboratoire d'Océanographie de Villefranche, Sorbonne Université, Villefranche- sur-mer, France
- ARC Centre of Excellence for Coral Reef Studies and Ocean Graduate School, The University of Western Australia, Crawley, Western Australia, Australia
| | - Christopher E Cornwall
- ARC Centre of Excellence for Coral Reef Studies and Ocean Graduate School, The University of Western Australia, Crawley, Western Australia, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Tom Shlesinger
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, USA
| | - Mia Hoogenboom
- ARC Centre of Excellence for Coral Reef Studies and College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Ralph Mana
- School of Natural and Physical Sciences, University of Papua New Guinea, Port Moresby, National Capital District, Papua New Guinea
| | - Malcolm T McCulloch
- ARC Centre of Excellence for Coral Reef Studies and Ocean Graduate School, The University of Western Australia, Crawley, Western Australia, Australia
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20
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Smith EG, Hazzouri KM, Choi JY, Delaney P, Al-Kharafi M, Howells EJ, Aranda M, Burt JA. Signatures of selection underpinning rapid coral adaptation to the world's warmest reefs. SCIENCE ADVANCES 2022; 8:eabl7287. [PMID: 35020424 PMCID: PMC10954036 DOI: 10.1126/sciadv.abl7287] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
Coral populations in the world’s warmest reefs, the Persian/Arabian Gulf (PAG), represent an ideal model system to understand the evolutionary response of coral populations to past and present environmental change and to identify genomic loci that contribute to elevated thermal tolerance. Here, we use population genomics of the brain coral Platygyra daedalea to show that corals in the PAG represent a distinct subpopulation that was established during the Holocene marine transgression, and identify selective sweeps in their genomes associated with thermal adaptation. We demonstrate the presence of positive and disruptive selection and provide evidence for selection of differentially methylated haplotypes. While demographic analyses suggest limited potential for genetic rescue of neighboring Indian Ocean reefs, the presence of putative targets of selection in corals outside of the PAG offers hope that loci associated with thermal tolerance may be present in the standing genetic variation.
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Affiliation(s)
- Edward G. Smith
- Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC, USA
- Water Research Center & Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Khaled M. Hazzouri
- Water Research Center & Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
- Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, Abu Dhabi, UAE
| | - Jae Young Choi
- Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | - Patrice Delaney
- Water Research Center & Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Mohammed Al-Kharafi
- Department of Fisheries Resource Development, Public Authority of Agriculture and Fisheries Resources, Kuwait City, Kuwait
| | - Emily J. Howells
- Water Research Center & Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - Manuel Aranda
- King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - John A. Burt
- Water Research Center & Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
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21
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Johnson MD, Swaminathan SD, Nixon EN, Paul VJ, Altieri AH. Differential susceptibility of reef-building corals to deoxygenation reveals remarkable hypoxia tolerance. Sci Rep 2021; 11:23168. [PMID: 34848743 PMCID: PMC8632909 DOI: 10.1038/s41598-021-01078-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/13/2021] [Indexed: 01/16/2023] Open
Abstract
Ocean deoxygenation threatens the persistence of coastal ecosystems worldwide. Despite an increasing awareness that coastal deoxygenation impacts tropical habitats, there remains a paucity of empirical data on the effects of oxygen limitation on reef-building corals. To address this knowledge gap, we conducted laboratory experiments with ecologically important Caribbean corals Acropora cervicornis and Orbicella faveolata. We tested the effects of continuous exposure to conditions ranging from extreme deoxygenation to normoxia (~ 1.0 to 6.25 mg L-1 dissolved oxygen) on coral bleaching, photophysiology, and survival. Coral species demonstrated markedly different temporal resistance to deoxygenation, and within a species there were minimal genotype-specific treatment effects. Acropora cervicornis suffered tissue loss and mortality within a day of exposure to severe deoxygenation (~ 1.0 mg L-1), whereas O. faveolata remained unaffected after 11 days of continuous exposure to 1.0 mg L-1. Intermediate deoxygenation treatments (~ 2.25 mg L-1, ~ 4.25 mg L-1) elicited minimal responses in both species, indicating a low oxygen threshold for coral mortality and coral resilience to oxygen concentrations that are lethal for other marine organisms. These findings demonstrate the potential for variability in species-specific hypoxia thresholds, which has important implications for our ability to predict how coral reefs may be affected as ocean deoxygenation intensifies. With deoxygenation emerging as a critical threat to tropical habitats, there is an urgent need to incorporate deoxygenation into coral reef research, management, and action plans to facilitate better stewardship of coral reefs in an era of rapid environmental change.
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Affiliation(s)
- Maggie D. Johnson
- grid.452909.30000 0001 0479 0204Smithsonian Marine Station, Fort Pierce, FL USA ,grid.1214.60000 0000 8716 3312Tenenbaum Marine Observatories Network, Smithsonian Institution, Edgewater, MD USA ,grid.56466.370000 0004 0504 7510Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA USA ,grid.45672.320000 0001 1926 5090Present Address: Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Sara D. Swaminathan
- grid.15276.370000 0004 1936 8091Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL USA
| | - Emily N. Nixon
- grid.452909.30000 0001 0479 0204Smithsonian Marine Station, Fort Pierce, FL USA
| | - Valerie J. Paul
- grid.452909.30000 0001 0479 0204Smithsonian Marine Station, Fort Pierce, FL USA
| | - Andrew H. Altieri
- grid.15276.370000 0004 1936 8091Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL USA
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22
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Haydon TD, Seymour JR, Raina JB, Edmondson J, Siboni N, Matthews JL, Camp EF, Suggett DJ. Rapid Shifts in Bacterial Communities and Homogeneity of Symbiodiniaceae in Colonies of Pocillopora acuta Transplanted Between Reef and Mangrove Environments. Front Microbiol 2021; 12:756091. [PMID: 34759906 PMCID: PMC8575411 DOI: 10.3389/fmicb.2021.756091] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/24/2021] [Indexed: 01/04/2023] Open
Abstract
It has been proposed that an effective approach for predicting whether and how reef-forming corals persist under future climate change is to examine populations thriving in present day extreme environments, such as mangrove lagoons, where water temperatures can exceed those of reef environments by more than 3°C, pH levels are more acidic (pH < 7.9, often below 7.6) and O2 concentrations are regularly considered hypoxic (<2 mg/L). Defining the physiological features of these “extreme” corals, as well as their relationships with the, often symbiotic, organisms within their microbiome, could increase our understanding of how corals will persist into the future. To better understand coral-microbe relationships that potentially underpin coral persistence within extreme mangrove environments, we therefore conducted a 9-month reciprocal transplant experiment, whereby specimens of the coral Pocillopora acuta were transplanted between adjacent mangrove and reef sites on the northern Great Barrier Reef. Bacterial communities associated with P. acuta specimens native to the reef environment were dominated by Endozoicomonas, while Symbiodiniaceae communities were dominated by members of the Cladocopium genus. In contrast, P. acuta colonies native to the mangrove site exhibited highly diverse bacterial communities with no dominating members, and Symbiodiniaceae communities dominated by Durusdinium. All corals survived for 9 months after being transplanted from reef-to-mangrove, mangrove-to-reef environments (as well as control within environment transplants), and during this time there were significant changes in the bacterial communities, but not in the Symbiodiniaceae communities or their photo-physiological functioning. In reef-to-mangrove transplanted corals, there were varied, but sometimes rapid shifts in the associated bacterial communities, including a loss of “core” bacterial members after 9 months where coral bacterial communities began to resemble those of the native mangrove corals. Bacterial communities associated with mangrove-to-reef P. acuta colonies also changed from their original composition, but remained different to the native reef corals. Our data demonstrates that P. acuta associated bacterial communities are strongly influenced by changes in environmental conditions, whereas Symbiodiniaceae associated communities remain highly stable.
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Affiliation(s)
- Trent D Haydon
- Climate Change Cluster, University of Technology, Ultimo, NSW, Australia
| | - Justin R Seymour
- Climate Change Cluster, University of Technology, Ultimo, NSW, Australia
| | | | | | - Nachshon Siboni
- Climate Change Cluster, University of Technology, Ultimo, NSW, Australia
| | | | - Emma F Camp
- Climate Change Cluster, University of Technology, Ultimo, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology, Ultimo, NSW, Australia
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23
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Turnham KE, Wham DC, Sampayo E, LaJeunesse TC. Mutualistic microalgae co-diversify with reef corals that acquire symbionts during egg development. THE ISME JOURNAL 2021; 15:3271-3285. [PMID: 34012104 PMCID: PMC8528872 DOI: 10.1038/s41396-021-01007-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 04/23/2021] [Accepted: 05/04/2021] [Indexed: 02/04/2023]
Abstract
The application of molecular genetics has reinvigorated and improved how species are defined and investigated scientifically, especially for morphologically cryptic micro-organisms. Here we show how species recognition improves understanding of the ecology and evolution of mutualisms between reef-building corals and their mutualistic dinoflagellates (i.e. Symbiodiniaceae). A combination of genetic, ecological, and morphological evidence defines two sibling species of Cladocopium (formerly Symbiodinium Clade C), specific only to host corals in the common genus Pocillopora, which transmit their obligate symbionts during oogenesis. Cladocopium latusorum sp. nov. is symbiotic with P. grandis/meandrina while the smaller-celled C. pacificum sp. nov. associates with P. verrucosa. Both symbiont species form mutualisms with Pocillopora that brood their young. Populations of each species, like their hosts, are genetically well connected across the tropical and subtropical Pacific Ocean, indicating a capacity for long-range dispersal. A molecular clock approximates their speciation during the late Pliocene or early Pleistocene as Earth underwent cycles of precipitous cooling and warming; and corresponds to when their hosts were also diversifying. The long temporal and spatial maintenance of high host fidelity, as well as genetic connectivity across thousands of kilometers, indicates that distinct ecological attributes and close evolutionary histories will restrain the adaptive responses of corals and their specialized symbionts to rapid climate warming.
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Affiliation(s)
| | - Drew C Wham
- Penn State University, University Park, PA, USA
| | | | - Todd C LaJeunesse
- Penn State University, University Park, PA, USA.
- Penn State Institutes of Energy and the Environment, University Park, PA, USA.
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24
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Agostini S, Harvey BP, Milazzo M, Wada S, Kon K, Floc'h N, Komatsu K, Kuroyama M, Hall-Spencer JM. Simplification, not "tropicalization", of temperate marine ecosystems under ocean warming and acidification. GLOBAL CHANGE BIOLOGY 2021; 27:4771-4784. [PMID: 34268836 DOI: 10.1111/gcb.15749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/28/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed "tropicalization". A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems. We conducted field surveys and in situ transplants at natural analogues for present and future conditions under (i) ocean warming and (ii) both ocean warming and acidification at a transition zone between kelp and coral-dominated ecosystems. We show that increased herbivory by warm-water fishes exacerbates kelp forest loss and that ocean acidification negates any benefits of warming for range extending tropical corals growth and physiology at temperate latitudes. Our data show that, as the combined effects of ocean acidification and warming ratchet up, marine coastal ecosystems lose kelp forests but do not gain scleractinian corals. Ocean acidification plus warming leads to overall habitat loss and a shift to simple turf-dominated ecosystems, rather than the complex coral-dominated tropicalized systems often seen with warming alone. Simplification of marine habitats by increased CO2 levels cascades through the ecosystem and could have severe consequences for the provision of goods and services.
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Affiliation(s)
- Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Marco Milazzo
- Dipartimento di Scienze della Terra e del Mare, University of Palermo, Palermo, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa, Rome, Italy
| | - Shigeki Wada
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Koetsu Kon
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Nicolas Floc'h
- Ecole Européenne Supérieure d'Art de Bretagne, Rennes, France
| | - Kosei Komatsu
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Mayumi Kuroyama
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Jason M Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
- Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth, UK
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25
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Qin Z, Yu K, Chen S, Chen B, Liang J, Yao Q, Yu X, Liao Z, Deng C, Liang Y. Microbiome of juvenile corals in the outer reef slope and lagoon of the South China Sea: insight into coral acclimatization to extreme thermal environments. Environ Microbiol 2021; 23:4389-4404. [PMID: 34110067 DOI: 10.1111/1462-2920.15624] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 04/18/2021] [Accepted: 06/03/2021] [Indexed: 11/28/2022]
Abstract
Environmental conditions between the outer reef slope (ORS) and lagoon in tropical atolls are significantly different, but the variations of juvenile coral-microbiomes in the two environments and their relationship with coral thermal acclimatization are poorly understood. We explored this issue based on local water conditions and the microbiome of juvenile corals in the ORS and lagoon in the central South China Sea. Coral-symbiotic Symbiodiniaceae showed significant differences among coral species; Pocillopora verrucosa and Pachyseris rugosa in the ORS, and Acropora formosa in the lagoon were dominated by Durusdinium, but other corals were dominated by Cladocopium. Although A. formosa in the ORS were dominated by Cladocopium (C3u), they were dominated by Durusdinium (D1/D1a) and Cladocopium (C50) in the lagoon. Other coral species were both dominated by Cladocopium in the lagoon and ORS. The relative abundance of bacteria in the Deinococcus-Thermus was generally higher in the lagoon corals than in the ORS corals. Our study indicates that P. verrucosa, P. rugosa and Porites lutea may have high thermal tolerance based on the relatively high abundance of heat-tolerant Durusdinium and Thermus scotoductus. Likewise, A. formosa in the lagoon may acclimatize to the thermal environment based on a high relative abundance of heat-tolerant Durusdinium.
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Affiliation(s)
- Zhenjun Qin
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Kefu Yu
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China.,Southern Marine and Engineering Guangdong Laboratory, Zhuhai, China
| | - Shuchang Chen
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Biao Chen
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Jiayuan Liang
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Qiucui Yao
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Xiaopeng Yu
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Zhiheng Liao
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Chuanqi Deng
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Yanting Liang
- Coral Reef Research Center of China, Guangxi University, Nanning, 530004, China.,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, 530004, China.,School of Marine Sciences, Guangxi University, Nanning, 530004, China
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26
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Potential local adaptation of corals at acidified and warmed Nikko Bay, Palau. Sci Rep 2021; 11:11192. [PMID: 34045589 PMCID: PMC8159998 DOI: 10.1038/s41598-021-90614-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/12/2021] [Indexed: 02/04/2023] Open
Abstract
Ocean warming and acidification caused by increases of atmospheric carbon dioxide are now thought to be major threats to coral reefs on a global scale. Here we evaluated the environmental conditions and benthic community structures in semi-closed Nikko Bay at the inner reef area in Palau, which has high pCO2 and seawater temperature conditions with high zooxanthellate coral coverage. Nikko Bay is a highly sheltered system with organisms showing low connectivity with surrounding environments, making this bay a unique site for evaluating adaptation and acclimatization responses of organisms to warmed and acidified environments. Seawater pCO2/Ωarag showed strong gradation ranging from 380 to 982 µatm (Ωarag: 1.79-3.66), and benthic coverage, including soft corals and turf algae, changed along with Ωarag while hard coral coverage did not change. In contrast to previous studies, net calcification was maintained in Nikko Bay even under very low mean Ωarag (2.44). Reciprocal transplantation of the dominant coral Porites cylindrica showed that the calcification rate of corals from Nikko Bay did not change when transplanted to a reference site, while calcification of reference site corals decreased when transplanted to Nikko Bay. Corals transplanted out of their origin sites also showed the highest interactive respiration (R) and lower gross photosynthesis (Pg) to respiration (Pg:R), indicating higher energy acquirement of corals at their origin site. The results of this study give important insights about the potential local acclimatization and adaptation capacity of corals to different environmental conditions including pCO2 and temperature.
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27
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García-Troche EM, Morell JM, Meléndez M, Salisbury JE. Carbonate chemistry seasonality in a tropical mangrove lagoon in La Parguera, Puerto Rico. PLoS One 2021; 16:e0250069. [PMID: 33951056 PMCID: PMC8099052 DOI: 10.1371/journal.pone.0250069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 03/30/2021] [Indexed: 11/18/2022] Open
Abstract
We investigated the seasonal carbonate chemistry variability within a semi-enclosed tropical mangrove lagoon in southwestern Puerto Rico. Biweekly measurements of seawater temperature, salinity, total alkalinity (TA), and dissolved inorganic carbon (DIC) were conducted from 2014 to 2018. We describe the possible mechanisms driving the observed variability by correlating the DIC/TA ratio with pH and Ωarg, suggesting that the mean pH (7.87 ± 0.09) and aragonite saturation state (Ωarg, 2.96 ± 0.47) of the mangrove lagoon negatively affected calcification. The measured pCO2 and DIC/TA ratios indicate that heterotrophic activity was the primary driver for persistent acidification, which reached its maximum expression during the wet season. We conclude that mangrove lagoons with limited seawater exchange and high carbon input will not mitigate ocean acidification.
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Affiliation(s)
- Erick M. García-Troche
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, Mayagüez, Puerto Rico
- Caribbean Coastal Ocean Observing System, NOAA-IOOS, Lajas, Puerto Rico
- * E-mail:
| | - Julio M. Morell
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, Mayagüez, Puerto Rico
- Caribbean Coastal Ocean Observing System, NOAA-IOOS, Lajas, Puerto Rico
| | - Melissa Meléndez
- School of Ocean and Earth Science and Technology (SOEST), University of Hawai’i at Manoa, Honolulu, Hawai’i, United States of America
| | - Joseph E. Salisbury
- Ocean Process Analysis Laboratory, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, United States of America
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28
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Resilience of Tropical Ecosystems to Ocean Deoxygenation. Trends Ecol Evol 2021; 36:227-238. [PMID: 33419595 DOI: 10.1016/j.tree.2020.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 01/18/2023]
Abstract
The impacts of ocean deoxygenation on biodiversity and ecosystem function are well established in temperate regions, and here we illustrate how the study of hypoxia in tropical ecosystems can offer insights of general importance. We first describe how mechanisms of resilience have developed in response to naturally occurring hypoxia across three tropical ecosystems: coral reefs, seagrass beds, and mangrove forests. We then suggest that the vulnerability of these systems to deoxygenation lies in interactions with other stressors that are increasing rapidly in the Anthropocene. Finally, we advocate for the adoption of a broader community- and ecosystem-level perspective that incorporates mutualisms, feedbacks, and mechanisms of self-rescue and recovery to develop a better predictive understanding of the effects of deoxygenation in coastal ecosystems.
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29
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Alderdice R, Suggett DJ, Cárdenas A, Hughes DJ, Kühl M, Pernice M, Voolstra CR. Divergent expression of hypoxia response systems under deoxygenation in reef-forming corals aligns with bleaching susceptibility. GLOBAL CHANGE BIOLOGY 2021; 27:312-326. [PMID: 33197302 DOI: 10.1111/gcb.15436] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/27/2020] [Indexed: 06/11/2023]
Abstract
Exposure of marine life to low oxygen is accelerating worldwide via climate change and localized pollution. Mass coral bleaching and mortality have recently occurred where reefs have experienced chronic low oxygen events. However, the mechanistic basis of tolerance to oxygen levels inadequate to sustain normal functioning (i.e. hypoxia) and whether it contributes to bleaching susceptibility, remain unknown. We therefore experimentally exposed colonies of the environmentally resilient Acropora tenuis, a common reef-building coral from the Great Barrier Reef, to deoxygenation-reoxygenation stress that was aligned to their natural night-day light cycle. Specifically, the treatment involved removing the 'night-time O2 buffer' to challenge the inherent hypoxia thresholds. RNA-Seq analysis revealed that coral possess a complete and active hypoxia-inducible factor (HIF)-mediated hypoxia response system (HRS) homologous to other metazoans. As expected, A. tenuis exhibited bleaching resistance and showed a strong inducibility of HIF target genes in response to deoxygenation stress. We applied this same approach in parallel to a colony of Acropora selago, known to be environmnetally susceptible, which conversely exhibited a bleaching phenotype response. This phenotypic divergence of A. selago was accompanied by contrasting gene expression profiles indicative of varied effectiveness of their HIF-HRS. Based on our RNA-Seq analysis, we propose (a) that the HIF-HRS is central for corals to manage deoxygenation stress and (b) that key genes of this system (and the wider gene network) may contribute to variation in coral bleaching susceptibility. Our analysis suggests that heat shock protein (hsp) 70 and 90 are important for low oxygen stress tolerance and further highlights how hsp90 expression might also affect the inducibility of coral HIF-HRS in overcoming a metabolic crisis under deoxygenation stress. We propose that differences in coral HIF-HRS could be central in regulating sensitivity to other climate change stressors-notably thermal stress-that commonly drive bleaching.
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Affiliation(s)
- Rachel Alderdice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David J Hughes
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Michael Kühl
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
- Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
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30
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Kellogg CA, Moyer RP, Jacobsen M, Yates K. Identifying mangrove-coral habitats in the Florida Keys. PeerJ 2020; 8:e9776. [PMID: 32904138 PMCID: PMC7450997 DOI: 10.7717/peerj.9776] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/30/2020] [Indexed: 11/20/2022] Open
Abstract
Coral reefs are degrading due to many synergistic stressors. Recently there have been a number of global reports of corals occupying mangrove habitats that provide a supportive environment or refugium for corals, sheltering them by reducing stressors such as oxidative light stress and low pH. This study used satellite imagery and manual ground-truthing surveys to search for mangrove-coral habitats in the Florida Keys National Marine Sanctuary and then collected basic environmental parameters (temperature, salinity, dissolved oxygen, pHNBS, turbidity) at identified sites using a multi-parameter water quality sonde. Two kinds of mangrove-coral habitats were found in both the Upper and Lower Florida Keys: (1) prop-root corals, where coral colonies were growing directly on (and around) mangrove prop roots, and (2) channel corals, where coral colonies were growing in mangrove channels under the shade of the mangrove canopy, at deeper depths and not in as close proximity to the mangroves. Coral species found growing on and directly adjacent to prop roots included Porites porites (multiple morphs, including P. divaricata and P. furcata), Siderastrea radians, and Favia fragum. Channel coral habitats predominantly hosted S. radians and a few S. siderea, although single colonies of Solenastrea bournoni and Stephanocoenia intersepta were observed. Although clear, low-turbidity water was a consistent feature of these mangrove-coral habitats, the specific combination of environmental factors that determine which mangrove habitats are favorable for coral recruitment remains to be defined. Circumstantial evidence suggests additional coral communities existed on mangrove shorelines of oceanside and backcountry islands until destroyed, likely by Hurricane Irma. These mangrove-coral habitats may be climate refugia for corals and could be included in ecosystem management plans and considered for their applications in coral restoration.
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Affiliation(s)
- Christina A Kellogg
- St. Petersburg Coastal and Marine Science Center, U.S. Geological Survey, St. Petersburg, FL, USA
| | - Ryan P Moyer
- Florida Fish & Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, USA
| | - Mary Jacobsen
- Florida Fish & Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, USA
| | - Kimberly Yates
- St. Petersburg Coastal and Marine Science Center, U.S. Geological Survey, St. Petersburg, FL, USA
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31
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Behrendt L, Salek MM, Trampe EL, Fernandez VI, Lee KS, Kühl M, Stocker R. PhenoChip: A single-cell phenomic platform for high-throughput photophysiological analyses of microalgae. SCIENCE ADVANCES 2020; 6:6/36/eabb2754. [PMID: 32917592 PMCID: PMC7467707 DOI: 10.1126/sciadv.abb2754] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/17/2020] [Indexed: 05/05/2023]
Abstract
Photosynthetic microorganisms are key players in aquatic ecosystems with strong potential for bioenergy production, yet their systematic selection at the single-cell level for improved productivity or stress resilience ("phenotyping") has remained largely inaccessible. To facilitate the phenotyping of microalgae and cyanobacteria, we developed "PhenoChip," a platform for the multiparametric photophysiological characterization and selection of unicellular phenotypes under user-controlled physicochemical conditions. We used PhenoChip to expose single cells of the coral symbiont Symbiodinium to thermal and chemical treatments and monitor single-cell photophysiology via chlorophyll fluorometry. This revealed strain-specific thermal sensitivity thresholds and distinct pH optima for photosynthetic performance, and permitted the identification of single cells with elevated resilience toward rising temperature. Optical expulsion technology was used to collect single cells from PhenoChip, and their propagation revealed indications of transgenerational preservation of photosynthetic phenotypes. PhenoChip represents a versatile platform for the phenotyping of photosynthetic unicells relevant to biotechnology, ecotoxicology, and assisted evolution.
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Affiliation(s)
- Lars Behrendt
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland.
- Science for Life Laboratory, Department of Environmental Toxicology, Uppsala University, Norbyv. 18A, 75236 Uppsala, Sweden
| | - M Mehdi Salek
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland
- School of Engineering, Massachusetts Institute of Technology, 77 Massachussetts Ave., MA 02139, USA
| | - Erik L Trampe
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Vicente I Fernandez
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland
| | - Kang Soo Lee
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland.
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32
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Klepac CN, Barshis DJ. Reduced thermal tolerance of massive coral species in a highly variable environment. Proc Biol Sci 2020; 287:20201379. [PMID: 32811319 DOI: 10.1098/rspb.2020.1379] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Coral bleaching events are increasing in frequency and severity, resulting in widespread losses in coral cover. However, branching corals native to highly variable (HV) thermal environments can have higher bleaching resistance than corals from more moderate habitats. Here, we investigated the response of two massive corals, Porites lobata and Goniastrea retiformis, from a moderately variable (MV) and a low variability (LV) pool transplanted into a HV pool on Ofu Island in American Samoa. Paired transplant and native ramets were exposed to an acute thermal stress after 6 and 12 months of exposure to the HV pool to evaluate changes in thermal tolerance limits. For both species, photosynthetic efficiency and chlorophyll loss following acute heat stress did not differ between ramets transplanted into the HV pool and respective native pool. Moreover, HV native P. lobata exhibited the greatest bleaching susceptibility compared to MV and LV natives and there was no effect of acute heat stress on MV P. lobata. There was also a thermal anomaly during the study, where Ofu's backreef thermal regime surpassed historical records-2015 had 8 degree heating weeks (DHW) and 2016 had up to 5 DHW (in comparison to less than or equal to 3 over the last 10 years)-which may have exceeded the upper thermal limits of HV native P. lobata. These results strongly contrast with other research on coral tolerance in variable environments, potentially underscoring species-specific mechanisms and regional thermal anomalies that may be equally important in shaping coral responses to extreme temperatures.
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Affiliation(s)
- C N Klepac
- Department of Biology, Old Dominion University, Norfolk, VA 23529, USA
| | - D J Barshis
- Department of Biology, Old Dominion University, Norfolk, VA 23529, USA
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Fujii T, Tanaka Y, Maki K, Saotome N, Morimoto N, Watanabe A, Miyajima T. Organic Carbon and Nitrogen Isoscapes of Reef Corals and Algal Symbionts: Relative Influences of Environmental Gradients and Heterotrophy. Microorganisms 2020; 8:microorganisms8081221. [PMID: 32796689 PMCID: PMC7464353 DOI: 10.3390/microorganisms8081221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/07/2020] [Accepted: 08/09/2020] [Indexed: 11/21/2022] Open
Abstract
The elemental (C/N) and stable isotopic (δ13C, δ15N) compositions and compound-specific δ15N values of amino acids (δ15NAA) were evaluated for coral holobionts as diagnostic tools to detect spatiotemporal environmental heterogeneity and its effects on coral health. Hermatypic coral samples of eight species were collected at 12 reef sites with differing levels of pollution stress. The C/N ratios, δ13C values, and δ15N values of coral tissues and endosymbiotic algae were determined for 193 coral holobionts, and the amino acid composition and δ15NAA values of selected samples were analyzed. δ15N values were influenced most by pollution stress, while C/N ratios and δ13C values depended most strongly on species. The results imply that δ13C and δ15N values are useful indicators for distinguishing the ecological niches of sympatric coral species based on microhabitat preference and resource selectivity. Using δ15NAA values, the trophic level (TL) of the examined coral samples was estimated to be 0.71 to 1.53, i.e., purely autotrophic to partially heterotrophic. Significant portions of the variation in bulk δ15N and δ13C values could be explained by the influence of heterotrophy. The TL of symbionts covaried with that of their hosts, implying that amino acids acquired through host heterotrophy are translocated to symbionts. Dependence on heterotrophy was stronger at polluted sites, indicating that the ecological role of corals changes in response to eutrophication.
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Affiliation(s)
- Takanori Fujii
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
| | - Yasuaki Tanaka
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
| | - Koh Maki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
| | - Nobue Saotome
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
| | - Naoko Morimoto
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
| | - Atsushi Watanabe
- School of Environment and Society, Tokyo Institute of Technology, O-okayama 2-12-1 W8-13, Meguro, Tokyo 152-8552, Japan;
| | - Toshihiro Miyajima
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8564, Japan; (T.F.); (Y.T.); (K.M.); (N.S.); (N.M.)
- Correspondence: ; Tel.: +81-4-7136-6086
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Impact of ocean acidification on the metabolome of the brown macroalgae Lobophora rosacea from New Caledonia. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101783] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Osman EO, Suggett DJ, Voolstra CR, Pettay DT, Clark DR, Pogoreutz C, Sampayo EM, Warner ME, Smith DJ. Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities. MICROBIOME 2020; 8:8. [PMID: 32008576 PMCID: PMC6996193 DOI: 10.1186/s40168-019-0776-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 12/12/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND The capacity of reef-building corals to tolerate (or adapt to) heat stress is a key factor determining their resilience to future climate change. Changes in coral microbiome composition (particularly for microalgal endosymbionts and bacteria) is a potential mechanism that may assist corals to thrive in warm waters. The northern Red Sea experiences extreme temperatures anomalies, yet corals in this area rarely bleach suggesting possible refugia to climate change. However, the coral microbiome composition, and how it relates to the capacity to thrive in warm waters in this region, is entirely unknown. RESULTS We investigated microbiomes for six coral species (Porites nodifera, Favia favus, Pocillopora damicornis, Seriatopora hystrix, Xenia umbellata, and Sarcophyton trocheliophorum) from five sites in the northern Red Sea spanning 4° of latitude and summer mean temperature ranges from 26.6 °C to 29.3 °C. A total of 19 distinct dinoflagellate endosymbionts were identified as belonging to three genera in the family Symbiodiniaceae (Symbiodinium, Cladocopium, and Durusdinium). Of these, 86% belonged to the genus Cladocopium, with notably five novel types (19%). The endosymbiont community showed a high degree of host-specificity despite the latitudinal gradient. In contrast, the diversity and composition of bacterial communities of the surface mucus layer (SML)-a compartment particularly sensitive to environmental change-varied significantly between sites, however for any given coral was species-specific. CONCLUSION The conserved endosymbiotic community suggests high physiological plasticity to support holobiont productivity across the different latitudinal regimes. Further, the presence of five novel algal endosymbionts suggests selection of certain genotypes (or genetic adaptation) within the semi-isolated Red Sea. In contrast, the dynamic composition of bacteria associated with the SML across sites may contribute to holobiont function and broaden the ecological niche. In doing so, SML bacterial communities may aid holobiont local acclimatization (or adaptation) by readily responding to changes in the host environment. Our study provides novel insight about the selective and endemic nature of coral microbiomes along the northern Red Sea refugia.
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Affiliation(s)
- Eslam O Osman
- Coral Reef Research Unit, School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK.
- Marine Biology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, 11448, Egypt.
| | - David J Suggett
- Coral Reef Research Unit, School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, 2007, Australia
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - D Tye Pettay
- School of Marine Science and Policy, College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - Dave R Clark
- Coral Reef Research Unit, School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | - Claudia Pogoreutz
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Eugenia M Sampayo
- ARC Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, St. Lucia, 4072, QLD, Australia
| | - Mark E Warner
- School of Marine Science and Policy, College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - David J Smith
- Coral Reef Research Unit, School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
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Klein SG, Steckbauer A, Duarte CM. Defining CO 2 and O 2 syndromes of marine biomes in the Anthropocene. GLOBAL CHANGE BIOLOGY 2020; 26:355-363. [PMID: 31637801 DOI: 10.1111/gcb.14879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 09/22/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Research efforts have intensified to foresee the prospects for marine biomes under climate change and anthropogenic drivers over varying temporal and spatial scales. Parallel with these efforts is the utilization of terminology, such as 'ocean acidification' (OA) and 'ocean deoxygenation' (OD), that can foster rapid comprehension of complex processes driving carbon dioxide (CO2 ) and oxygen (O2 ) concentrations in the global ocean and thus, are now widely used in discussions within and beyond academia. However, common usage of the terms 'acidification' and 'deoxygenation' alone are subjective and, without adequate contextualization, have the potential to mislead inferences over drivers that may ultimately shape the future state of marine ecosystems. Here we clarify the usage of the terms OA and OD as global, climate change-driven processes and discuss the various attributes of elevated CO2 and reduced O2 syndromes common to coastal ecosystems. We support the use of the existing terms 'coastal acidification' and 'coastal deoxygenation' because they help differentiate the sometimes rapid and extreme nature of CO2 and O2 syndromes in coastal ecosystems from the global, climate change-driven processes of OA and OD. Given the complexity and breadth of the processes involved in altering CO2 and O2 concentrations across marine ecosystems, we provide a workflow to enable contextualization and clarification of the usage of existing terms and highlight the close link between these two gases across spatial and temporal scales in the ocean. These distinctions are crucial to guide effective communication of research within the scientific community and guide policymakers responsible for intervening on the drivers to secure desirable future ocean states.
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Affiliation(s)
- Shannon G Klein
- Red Sea Research Center and Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Alexandra Steckbauer
- Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Carlos M Duarte
- Red Sea Research Center and Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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Byrne M, Foo SA, Ross PM, Putnam HM. Limitations of cross- and multigenerational plasticity for marine invertebrates faced with global climate change. GLOBAL CHANGE BIOLOGY 2020; 26:80-102. [PMID: 31670444 DOI: 10.1111/gcb.14882] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/12/2019] [Indexed: 05/18/2023]
Abstract
Although cross generation (CGP) and multigenerational (MGP) plasticity have been identified as mechanisms of acclimation to global change, the weight of evidence indicates that parental conditioning over generations is not a panacea to rescue stress sensitivity in offspring. For many species, there were no benefits of parental conditioning. Even when improved performance was observed, this waned over time within a generation or across generations and fitness declined. CGP and MGP studies identified resilient species with stress tolerant genotypes in wild populations and selected family lines. Several bivalves possess favourable stress tolerance and phenotypically plastic traits potentially associated with genetic adaptation to life in habitats where they routinely experience temperature and/or acidification stress. These traits will be important to help 'climate proof' shellfish ventures. Species that are naturally stress tolerant and those that naturally experience a broad range of environmental conditions are good candidates to provide insights into the physiological and molecular mechanisms involved in CGP and MGP. It is challenging to conduct ecologically relevant global change experiments over the long times commensurate with the pace of changing climate. As a result, many studies present stressors in a shock-type exposure at rates much faster than projected scenarios. With more gradual stressor introduction over longer experimental durations and in context with conditions species are currently acclimatized and/or adapted to, the outcomes for sensitive species might differ. We highlight the importance to understand primordial germ cell development and the timing of gametogenesis with respect to stressor exposure. Although multigenerational exposure to global change stressors currently appears limited as a universal tool to rescue species in the face of changing climate, natural proxies of future conditions (upwelling zones, CO2 vents, naturally warm habitats) show that phenotypic adjustment and/or beneficial genetic selection is possible for some species, indicating complex plasticity-adaptation interactions.
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Affiliation(s)
- Maria Byrne
- School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Shawna A Foo
- Center for Global Discovery and Conservation Science, Arizona State University, Tempe, AZ, USA
| | - Pauline M Ross
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
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Moura É, Pimentel M, Santos CP, Sampaio E, Pegado MR, Lopes VM, Rosa R. Cuttlefish Early Development and Behavior Under Future High CO 2 Conditions. Front Physiol 2019; 10:975. [PMID: 31404314 PMCID: PMC6676914 DOI: 10.3389/fphys.2019.00975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/11/2019] [Indexed: 02/01/2023] Open
Abstract
The oceanic uptake of carbon dioxide (CO2) is increasing and changing the seawater chemistry, a phenomenon known as ocean acidification (OA). Besides the expected physiological impairments, there is an increasing evidence of detrimental OA effects on the behavioral ecology of certain marine taxa, including cephalopods. Within this context, the main goal of this study was to investigate, for the first time, the OA effects (∼1000 μatm; ΔpH = 0.4) in the development and behavioral ecology (namely shelter-seeking, hunting and response to a visual alarm cue) of the common cuttlefish (Sepia officinalis) early life stages, throughout the entire embryogenesis until 20 days after hatching. There was no evidence that OA conditions compromised the cuttlefish embryogenesis - namely development time, hatching success, survival rate and biometric data (length, weight and Fulton's condition index) of newly hatched cuttlefish were similar between the normocapnic and hypercapnic treatments. The present findings also suggest a certain behavioral resilience of the cuttlefish hatchlings toward near-future OA conditions. Shelter-seeking, hunting and response to a visual alarm cue did not show significant differences between treatments. Thus, we argue that cuttlefishes' nekton-benthic (and active) lifestyle, their adaptability to highly dynamic coastal and estuarine zones, and the already harsh conditions (hypoxia and hypercapnia) inside their eggs provide a degree of phenotypic plasticity that may favor the odds of the recruits in a future acidified ocean. Nonetheless, the interacting effects of multiple stressors should be further addressed, to accurately predict the resilience of this ecologically and economically important species in the oceans of tomorrow.
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Affiliation(s)
- Érica Moura
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Marta Pimentel
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Catarina P. Santos
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Eduardo Sampaio
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
- Department of Collective Behaviour, Max Planck Institute of Animal Behavior, University of Konstanz, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Maria Rita Pegado
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Vanessa Madeira Lopes
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Rui Rosa
- MARE – Centro de Ciências do Mar e do Ambiente, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
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Host-symbiont combinations dictate the photo-physiological response of reef-building corals to thermal stress. Sci Rep 2019; 9:9985. [PMID: 31292499 PMCID: PMC6620294 DOI: 10.1038/s41598-019-46412-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/24/2019] [Indexed: 01/10/2023] Open
Abstract
High sea surface temperatures often lead to coral bleaching wherein reef-building corals lose significant numbers of their endosymbiotic dinoflagellates (Symbiodiniaceae). These increasingly frequent bleaching events often result in large scale coral mortality, thereby devasting reef systems throughout the world. The reef habitats surrounding Palau are ideal for investigating coral responses to climate perturbation, where many inshore bays are subject to higher water temperature as compared with offshore barrier reefs. We examined fourteen physiological traits in response to high temperature across various symbiotic dinoflagellates in four common Pacific coral species, Acropora muricata, Coelastrea aspera, Cyphastrea chalcidicum and Pachyseris rugosa found in both offshore and inshore habitats. Inshore corals were dominated by a single homogenous population of the stress tolerant symbiont Durusdinium trenchii, yet symbiont thermal response and physiology differed significantly across coral species. In contrast, offshore corals harbored specific species of Cladocopium spp. (ITS2 rDNA type-C) yet all experienced similar patterns of photoinactivation and symbiont loss when heated. Additionally, cell volume and light absorption properties increased in heated Cladocopium spp., leading to a greater loss in photo-regulation. While inshore coral temperature response was consistently muted relative to their offshore counterparts, high physiological variability in D. trenchii across inshore corals suggests that bleaching resilience among even the most stress tolerant symbionts is still heavily influenced by their host environment.
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Martinez A, Crook ED, Barshis DJ, Potts DC, Rebolledo-Vieyra M, Hernandez L, Paytan A. Species-specific calcification response of Caribbean corals after 2-year transplantation to a low aragonite saturation submarine spring. Proc Biol Sci 2019; 286:20190572. [PMID: 31238847 DOI: 10.1098/rspb.2019.0572] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Coral calcification is expected to decline as atmospheric carbon dioxide concentration increases. We assessed the potential of Porites astreoides, Siderastrea siderea and Porites porites to survive and calcify under acidified conditions in a 2-year field transplant experiment around low pH, low aragonite saturation (Ωarag) submarine springs. Slow-growing S. siderea had the highest post-transplantation survival and showed increases in concentrations of Symbiodiniaceae, chlorophyll a and protein at the low Ωarag site. Nubbins of P. astreoides had 20% lower survival and higher chlorophyll a concentration at the low Ωarag site. Only 33% of P. porites nubbins survived at low Ωarag and their linear extension and calcification rates were reduced. The density of skeletons deposited after transplantation at the low Ωarag spring was 15-30% lower for all species. These results suggest that corals with slow calcification rates and high Symbiodiniaceae, chlorophyll a and protein concentrations may be less susceptible to ocean acidification, albeit with reduced skeletal density. We postulate that corals in the springs are responding to greater energy demands for overcoming larger differences in carbonate chemistry between the calcifying medium and the external environment. The differential mortality, growth rates and physiological changes may impact future coral species assemblages and the reef framework robustness.
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Affiliation(s)
- Ana Martinez
- 1 Department of Earth and Planetary Science, University of California Santa Cruz , Santa Cruz, CA , USA
| | - Elizabeth D Crook
- 4 Department of Earth System Science, University of California Irvine , Irvine, CA , USA
| | - Daniel J Barshis
- 5 Department of Biological Sciences, Old Dominion University , Norfolk, VA , USA
| | - Donald C Potts
- 2 Department of Ecology and Evolutionary Biology, University of California Santa Cruz , Santa Cruz, CA , USA.,3 Institute of Marine Sciences, University of California Santa Cruz , Santa Cruz, CA , USA
| | | | | | - Adina Paytan
- 3 Institute of Marine Sciences, University of California Santa Cruz , Santa Cruz, CA , USA
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Pichler T, Biscéré T, Kinch J, Zampighi M, Houlbrèque F, Rodolfo-Metalpa R. Suitability of the shallow water hydrothermal system at Ambitle Island (Papua New Guinea) to study the effect of high pCO 2 on coral reefs. MARINE POLLUTION BULLETIN 2019; 138:148-158. [PMID: 30660256 DOI: 10.1016/j.marpolbul.2018.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/02/2018] [Accepted: 11/03/2018] [Indexed: 06/09/2023]
Abstract
Volcanic CO2 seeps were successfully used to predict coral reef response to ocean acidification, although toxic elements, often characteristic of hydrothermal vents were rarely reported. We measured the physicochemical conditions, seawater carbonate chemistry and trace elements in Tutum Bay, Papua New Guinea. There, intense emission of hydrothermal fluids and CO2 expose the coral reef to a seawater pHT between 7.6 and 7.7. Arsenic and silica were enriched by up to six times in surface seawater, while bottom concentrations were lower and thus similar to coral reefs worldwide. Manganese, cesium, iron and zinc concentrations fell into the range of other coastal environments. Our measurements suggest that Tutum Bay is a suitable site to study the response of coral reefs to high pCO2. Considering that arsenic is a common metal in hydrothermal fluids, its characterization should be included in any study that uses volcanic CO2 seeps as natural laboratories for ocean acidification.
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Affiliation(s)
- T Pichler
- Geosciences, University of Bremen, Klagenfurter Str. 2-4, 28359 Bremen, Germany.
| | - T Biscéré
- ENTROPIE IRD - Université de La Réunion - CNRS, Nouméa 98848, New Caledonia
| | - J Kinch
- National Fisheries College, PO Box 239, Kavieng, New Ireland Province 611, Papua New Guinea
| | - M Zampighi
- ENTROPIE IRD - Université de La Réunion - CNRS, Nouméa 98848, New Caledonia
| | - F Houlbrèque
- ENTROPIE IRD - Université de La Réunion - CNRS, Nouméa 98848, New Caledonia
| | - R Rodolfo-Metalpa
- ENTROPIE IRD - Université de La Réunion - CNRS, Nouméa 98848, New Caledonia
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Kornder NA, Riegl BM, Figueiredo J. Thresholds and drivers of coral calcification responses to climate change. GLOBAL CHANGE BIOLOGY 2018; 24:5084-5095. [PMID: 30152194 DOI: 10.1111/gcb.14431] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/15/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Increased temperature and CO2 levels are considered key drivers of coral reef degradation. However, individual assessments of ecological responses (calcification) to these stressors are often contradicting. To detect underlying drivers of heterogeneity in coral calcification responses, we developed a procedure for the inclusion of stress-effect relationships in ecological meta-analyses. We applied this technique to a dataset of 294 empirical observations from 62 peer-reviewed publications testing individual and combined effects of elevated temperature and pCO2 on coral calcification. Our results show an additive interaction between warming and acidification, which reduces coral calcification by 20% when pCO2 levels exceed 700 ppm and temperature increases by 3°C. However, stress levels varied among studies and significantly affected outcomes, with unaffected calcification rates under moderate stresses (pCO2 ≤ 700 ppm, ΔT < 3°C). Future coral reef carbon budgets will therefore depend on the magnitude of pCO2 and temperature elevations and, thus, anthropogenic CO2 emissions. Accounting for stress-effect relationships enabled us to identify additional drivers of heterogeneity including coral taxa, life stage, habitat, food availability, climate, and season. These differences can aid reef management identifying refuges and conservation priorities, but without a global effort to reduce CO2 emissions, coral capacity to build reefs will be at risk.
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Affiliation(s)
- Niklas A Kornder
- Department of Freshwater and Marine Ecology, Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Halmos College of Natural Science and Oceanography, Nova Southeastern University, Dania Beach, Florida
| | - Bernhard M Riegl
- Halmos College of Natural Science and Oceanography, Nova Southeastern University, Dania Beach, Florida
| | - Joana Figueiredo
- Halmos College of Natural Science and Oceanography, Nova Southeastern University, Dania Beach, Florida
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43
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Synthesis: Coral Bleaching: Patterns, Processes, Causes and Consequences. ECOLOGICAL STUDIES 2018. [DOI: 10.1007/978-3-319-75393-5_14] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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