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Peixoto RS, Rosado PM, Leite DCDA, Rosado AS, Bourne DG. Beneficial Microorganisms for Corals (BMC): Proposed Mechanisms for Coral Health and Resilience. Front Microbiol 2017; 8:341. [PMID: 28326066 PMCID: PMC5339234 DOI: 10.3389/fmicb.2017.00341] [Citation(s) in RCA: 233] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/17/2017] [Indexed: 12/21/2022] Open
Abstract
The symbiotic association between the coral animal and its endosymbiotic dinoflagellate partner Symbiodinium is central to the success of corals. However, an array of other microorganisms associated with coral (i.e., Bacteria, Archaea, Fungi, and viruses) have a complex and intricate role in maintaining homeostasis between corals and Symbiodinium. Corals are sensitive to shifts in the surrounding environmental conditions. One of the most widely reported responses of coral to stressful environmental conditions is bleaching. During this event, corals expel Symbiodinium cells from their gastrodermal tissues upon experiencing extended seawater temperatures above their thermal threshold. An array of other environmental stressors can also destabilize the coral microbiome, resulting in compromised health of the host, which may include disease and mortality in the worst scenario. However, the exact mechanisms by which the coral microbiome supports coral health and increases resilience are poorly understood. Earlier studies of coral microbiology proposed a coral probiotic hypothesis, wherein a dynamic relationship exists between corals and their symbiotic microorganisms, selecting for the coral holobiont that is best suited for the prevailing environmental conditions. Here, we discuss the microbial-host relationships within the coral holobiont, along with their potential roles in maintaining coral health. We propose the term BMC (Beneficial Microorganisms for Corals) to define (specific) symbionts that promote coral health. This term and concept are analogous to the term Plant Growth Promoting Rhizosphere (PGPR), which has been widely explored and manipulated in the agricultural industry for microorganisms that inhabit the rhizosphere and directly or indirectly promote plant growth and development through the production of regulatory signals, antibiotics and nutrients. Additionally, we propose and discuss the potential mechanisms of the effects of BMC on corals, suggesting strategies for the use of this knowledge to manipulate the microbiome, reversing dysbiosis to restore and protect coral reefs. This may include developing and using BMC consortia as environmental "probiotics" to improve coral resistance after bleaching events and/or the use of BMC with other strategies such as human-assisted acclimation/adaption to shifting environmental conditions.
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Affiliation(s)
- Raquel S. Peixoto
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Museu Aquário Marinho do Rio de Janeiro-AquaRio (IMAM/AquaRio) – Rio de Janeiro Marine Aquarium Research CenterRio de Janeiro, Brazil
| | - Phillipe M. Rosado
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Museu Aquário Marinho do Rio de Janeiro-AquaRio (IMAM/AquaRio) – Rio de Janeiro Marine Aquarium Research CenterRio de Janeiro, Brazil
| | | | - Alexandre S. Rosado
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Museu Aquário Marinho do Rio de Janeiro-AquaRio (IMAM/AquaRio) – Rio de Janeiro Marine Aquarium Research CenterRio de Janeiro, Brazil
| | - David G. Bourne
- College of Science and Engineering, James Cook University, TownsvilleQLD, Australia
- Australian Institute of Marine Science, TownsvilleQLD, Australia
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Reproductive output of a non-zooxanthellate temperate coral is unaffected by temperature along an extended latitudinal gradient. PLoS One 2017; 12:e0171051. [PMID: 28158213 PMCID: PMC5291506 DOI: 10.1371/journal.pone.0171051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/13/2017] [Indexed: 11/19/2022] Open
Abstract
Global environmental change, in marine ecosystems, is associated with concurrent shifts in water temperature, circulation, stratification, and nutrient input, with potentially wide-ranging biological effects. Variations in seawater temperature might alter physiological functioning, reproductive efficiency, and demographic traits of marine organisms, leading to shifts in population size and abundance. Differences in temperature tolerances between organisms can identify individual and ecological characteristics, which make corals able to persist and adapt in a climate change context. Here we investigated the possible effect of temperature on the reproductive output of the solitary non-zooxanthellate temperate coral Leptopsammia pruvoti, along an 8° latitudinal gradient. Samples have been collected in six populations along the gradient and each polyp was examined using histological and cyto-histometric analyses. We coupled our results with previous studies on the growth, demography, and calcification of L. pruvoti along the same temperature gradient, and compared them with those of another sympatric zooxanthellate coral Balanophyllia europaea to understand which trophic strategy makes the coral more tolerant to increasing temperature. The non-zooxanthellate species seemed to be quite tolerant to temperature increases, probably due to the lack of the symbiosis with zooxanthellae. To our knowledge, this is the first field investigation of the relationship between reproductive output and temperature increase of a temperate asymbiotic coral, providing novel insights into the poorly studied non-zooxanthellate scleractinians.
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van de Water JAJM, Lamb JB, Heron SF, van Oppen MJH, Willis BL. Temporal patterns in innate immunity parameters in reef‐building corals and linkages with local climatic conditions. Ecosphere 2016. [DOI: 10.1002/ecs2.1505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Jeroen A. J. M. van de Water
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland 4811 Australia
- College of Marine and Environmental Sciences James Cook University Townsville Queensland 4811 Australia
- AIMS@JCU James Cook University Townsville Queensland 4811 Australia
- Australian Institute of Marine Science PMB 3, Townsville MC Townsville Queensland 4810 Australia
- Centre Scientifique de Monaco MC 98000 Monaco
| | - Joleah B. Lamb
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland 4811 Australia
- College of Marine and Environmental Sciences James Cook University Townsville Queensland 4811 Australia
- AIMS@JCU James Cook University Townsville Queensland 4811 Australia
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14850 USA
| | - Scott F. Heron
- National Oceanic and Atmospheric Administration–Coral Reef Watch James Cook University Townsville Queensland 4811 Australia
- Marine Geophysical Laboratory Physics Department College of Science, Technology and Engineering James Cook University Townsville Queensland 4811 Australia
| | - Madeleine J. H. van Oppen
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland 4811 Australia
- AIMS@JCU James Cook University Townsville Queensland 4811 Australia
- Australian Institute of Marine Science PMB 3, Townsville MC Townsville Queensland 4810 Australia
- School of BioSciences The University of Melbourne Parkville Victoria 3010 Australia
| | - Bette L. Willis
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland 4811 Australia
- College of Marine and Environmental Sciences James Cook University Townsville Queensland 4811 Australia
- AIMS@JCU James Cook University Townsville Queensland 4811 Australia
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Bay LK, Doyle J, Logan M, Berkelmans R. Recovery from bleaching is mediated by threshold densities of background thermo-tolerant symbiont types in a reef-building coral. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160322. [PMID: 27429786 PMCID: PMC4929921 DOI: 10.1098/rsos.160322] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 05/27/2016] [Indexed: 05/24/2023]
Abstract
Sensitive molecular analyses show that most corals host a complement of Symbiodinium genotypes that includes thermo-tolerant types in low abundance. While tolerant symbiont types are hypothesized to facilitate tolerance to temperature and recovery from bleaching, empirical data on their distribution and relative abundance in corals under ambient and stress conditions are still rare. We quantified visual bleaching and mortality of coral hosts, along with relative abundance of C- and D-type Symbiodinium cells in 82 Acropora millepora colonies from three locations on the Great Barrier Reef transplanted to a central inshore site over a 13 month period. Our analyses reveal dynamic change in symbiont associations within colonies and among populations over time. Coral bleaching and declines in C- but not D-type symbionts were observed in transplanted corals. Survival and recovery of 25% of corals from one population was associated with either initial D-dominance or an increase in D-type symbionts that could be predicted by a minimum pre-stress D : C ratio of 0.003. One-third of corals from this population became D dominated at the bleached stage despite no initial detection of this symbiont type, but failed to recover and died in mid to late summer. These results provide a predictive threshold minimum density of background D-type symbionts in A. millepora, above which survival following extreme thermal stress is increased.
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Affiliation(s)
- Line K. Bay
- Adaptation and Resilience of Coral Reefs to Climate Change, Australian Institute of Marine Science, PMB 3 Townsville MC, Townsville, Queensland 4810, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Jason Doyle
- Adaptation and Resilience of Coral Reefs to Climate Change, Australian Institute of Marine Science, PMB 3 Townsville MC, Townsville, Queensland 4810, Australia
| | - Murray Logan
- Adaptation and Resilience of Coral Reefs to Climate Change, Australian Institute of Marine Science, PMB 3 Townsville MC, Townsville, Queensland 4810, Australia
| | - Ray Berkelmans
- Adaptation and Resilience of Coral Reefs to Climate Change, Australian Institute of Marine Science, PMB 3 Townsville MC, Townsville, Queensland 4810, Australia
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55
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Recent Advances in Understanding the Effects of Climate Change on Coral Reefs. DIVERSITY-BASEL 2016. [DOI: 10.3390/d8020012] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Jin YK, Lundgren P, Lutz A, Raina JB, Howells EJ, Paley AS, Willis BL, van Oppen MJH. Genetic markers for antioxidant capacity in a reef-building coral. SCIENCE ADVANCES 2016; 2:e1500842. [PMID: 27386515 PMCID: PMC4928996 DOI: 10.1126/sciadv.1500842] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 04/20/2016] [Indexed: 05/02/2023]
Abstract
The current lack of understanding of the genetic basis underlying environmental stress tolerance in reef-building corals impairs the development of new management approaches to confronting the global demise of coral reefs. On the Great Barrier Reef (GBR), an approximately 51% decline in coral cover occurred over the period 1985-2012. We conducted a gene-by-environment association analysis across 12° latitude on the GBR, as well as both in situ and laboratory genotype-by-phenotype association analyses. These analyses allowed us to identify alleles at two genetic loci that account for differences in environmental stress tolerance and antioxidant capacity in the common coral Acropora millepora. The effect size for antioxidant capacity was considerable and biologically relevant (32.5 and 14.6% for the two loci). Antioxidant capacity is a critical component of stress tolerance because a multitude of environmental stressors cause increased cellular levels of reactive oxygen species. Our findings provide the first step toward the development of novel coral reef management approaches, such as spatial mapping of stress tolerance for use in marine protected area design, identification of stress-tolerant colonies for assisted migration, and marker-assisted selective breeding to create more tolerant genotypes for restoration of denuded reefs.
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Affiliation(s)
- Young K. Jin
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Petra Lundgren
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Adrian Lutz
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Jean-Baptiste Raina
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Emily J. Howells
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- Center for Genomics and Systems Biology, New York University Abu Dhabi, United Arab Emirates
| | - Allison S. Paley
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Bette L. Willis
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science (AIMS), PMB No. 3, Townsville, Queensland 4810, Australia
- AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
- Corresponding author.
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Bennett S, Wernberg T, Arackal Joy B, de Bettignies T, Campbell AH. Central and rear-edge populations can be equally vulnerable to warming. Nat Commun 2015; 6:10280. [PMID: 26691184 PMCID: PMC4703895 DOI: 10.1038/ncomms10280] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/24/2015] [Indexed: 11/13/2022] Open
Abstract
Rear (warm) edge populations are often considered more susceptible to warming than central (cool) populations because of the warmer ambient temperatures they experience, but this overlooks the potential for local variation in thermal tolerances. Here we provide conceptual models illustrating how sensitivity to warming is affected throughout a species' geographical range for locally adapted and non-adapted populations. We test these models for a range-contracting seaweed using observations from a marine heatwave and a 12-month experiment, translocating seaweeds among central, present and historic range edge locations. Growth, reproductive development and survivorship display different temperature thresholds among central and rear-edge populations, but share a 2.5 °C anomaly threshold. Range contraction, therefore, reflects variation in local anomalies rather than differences in absolute temperatures. This demonstrates that warming sensitivity can be similar throughout a species geographical range and highlights the importance of incorporating local adaptation and acclimatization into climate change vulnerability assessments. Low latitude populations are often thought to be more vulnerable to climate change due to warmer ambient conditions. Here, Bennett et al. show that populations of seaweed from different areas of their range have distinct thermal-tolerance thresholds, but share remarkably similar thermal safety margins to warming.
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Affiliation(s)
- Scott Bennett
- UWA Oceans Institute (M470) and School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia.,Department of Environment and Agriculture, Curtin University, Bentley, Western Australia 6102, Australia
| | - Thomas Wernberg
- UWA Oceans Institute (M470) and School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Bijo Arackal Joy
- UWA Oceans Institute (M470) and School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Thibaut de Bettignies
- UWA Oceans Institute (M470) and School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Alexandra H Campbell
- Evolution and Ecology Research Centre, Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.,Sydney Institute of Marine Sciences, Chowder Bay, New South Wales 2088, Australia
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58
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Pandolfi JM. Incorporating Uncertainty in Predicting the Future Response of Coral Reefs to Climate Change. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-120213-091811] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- John M. Pandolfi
- Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia;
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59
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Kenkel CD, Almanza AT, Matz MV. Fine-scale environmental specialization of reef-building corals might be limiting reef recovery in the Florida Keys. Ecology 2015; 96:3197-212. [DOI: 10.1890/14-2297.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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60
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Witman JD, Lamb RW, Byrnes JEK. Towards an integration of scale and complexity in marine ecology. ECOL MONOGR 2015. [DOI: 10.1890/14-2265.1] [Citation(s) in RCA: 18] [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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61
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Koch MS, Coronado C, Miller MW, Rudnick DT, Stabenau E, Halley RB, Sklar FH. Climate change projected effects on coastal foundation communities of the Greater Everglades using a 2060 scenario: need for a new management paradigm. ENVIRONMENTAL MANAGEMENT 2015; 55:857-875. [PMID: 25312295 DOI: 10.1007/s00267-014-0375-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 09/12/2014] [Indexed: 06/04/2023]
Abstract
Rising sea levels and temperature will be dominant drivers of coastal Everglades' foundation communities (i.e., mangrove forests, seagrass/macroalgae, and coral reefs) by 2060 based on a climate change scenario of +1.5 °C temperature, +1.5 foot (46 cm) in sea level, ±10 % in precipitation and 490 ppm CO2. Current mangrove forest soil elevation change in South Florida ranges from 0.9 to 2.5 mm year(-1) and would have to increase twofold to fourfold in order to accommodate a 2060 sea level rise rate. No evidence is available to indicate that coastal mangroves from South Florida and the wider Caribbean can keep pace with a rapid rate of sea level rise. Thus, particles and nutrients from destabilized coastlines could be mobilized and impact benthic habitats of southern Florida. Uncertainties in regional geomorphology and coastal current changes under higher sea levels make this prediction tentative without further research. The 2060 higher temperature scenario would compromise Florida's coral reefs that are already degraded. We suggest that a new paradigm is needed for resource management under climate change that manages coastlines for resilience to marine transgression and promotes active ecosystem management. In the case of the Everglades, greater freshwater flows could maximize mangrove peat accumulation, stabilize coastlines, and limit saltwater intrusion, while specific coral species may require propagation. Further, we suggest that regional climate drivers and oceanographic processes be incorporated into Everglades and South Florida management plans, as they are likely to impact coastal ecosystems, interior freshwater wetlands and urban coastlines over the next few decades.
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Affiliation(s)
- M S Koch
- Biological Sciences Department, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, USA,
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Abstract
The genetic enhancement of wild animals and plants for characteristics that benefit human populations has been practiced for thousands of years, resulting in impressive improvements in commercially valuable species. Despite these benefits, genetic manipulations are rarely considered for noncommercial purposes, such as conservation and restoration initiatives. Over the last century, humans have driven global climate change through industrialization and the release of increasing amounts of CO2, resulting in shifts in ocean temperature, ocean chemistry, and sea level, as well as increasing frequency of storms, all of which can profoundly impact marine ecosystems. Coral reefs are highly diverse ecosystems that have suffered massive declines in health and abundance as a result of these and other direct anthropogenic disturbances. There is great concern that the high rates, magnitudes, and complexity of environmental change are overwhelming the intrinsic capacity of corals to adapt and survive. Although it is important to address the root causes of changing climate, it is also prudent to explore the potential to augment the capacity of reef organisms to tolerate stress and to facilitate recovery after disturbances. Here, we review the risks and benefits of the improvement of natural and commercial stocks in noncoral reef systems and advocate a series of experiments to determine the feasibility of developing coral stocks with enhanced stress tolerance through the acceleration of naturally occurring processes, an approach known as (human)-assisted evolution, while at the same time initiating a public dialogue on the risks and benefits of this approach.
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63
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Silverstein RN, Cunning R, Baker AC. Change in algal symbiont communities after bleaching, not prior heat exposure, increases heat tolerance of reef corals. GLOBAL CHANGE BIOLOGY 2015; 21:236-249. [PMID: 25099991 DOI: 10.1111/gcb.12706] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 06/13/2014] [Indexed: 05/28/2023]
Abstract
Mutualistic organisms can be particularly susceptible to climate change stress, as their survivorship is often limited by the most vulnerable partner. However, symbiotic plasticity can also help organisms in changing environments by expanding their realized niche space. Coral-algal (Symbiodinium spp.) symbiosis exemplifies this dichotomy: the partnership is highly susceptible to 'bleaching' (stress-induced symbiosis breakdown), but stress-tolerant symbionts can also sometimes mitigate bleaching. Here, we investigate the role of diverse and mutable symbiotic partnerships in increasing corals' ability to thrive in high temperature conditions. We conducted repeat bleaching and recovery experiments on the coral Montastraea cavernosa, and used quantitative PCR and chlorophyll fluorometry to assess the structure and function of Symbiodinium communities within coral hosts. During an initial heat exposure (32 °C for 10 days), corals hosting only stress-sensitive symbionts (Symbiodinium C3) bleached, but recovered (at either 24 °C or 29 °C) with predominantly (>90%) stress-tolerant symbionts (Symbiodinium D1a), which were not detected before bleaching (either due to absence or extreme low abundance). When a second heat stress (also 32 °C for 10 days) was applied 3 months later, corals that previously bleached and were now dominated by D1a Symbiodinium experienced less photodamage and symbiont loss compared to control corals that had not been previously bleached, and were therefore still dominated by Symbiodinium C3. Additional corals that were initially bleached without heat by a herbicide (DCMU, at 24 °C) also recovered predominantly with D1a symbionts, and similarly lost fewer symbionts during subsequent thermal stress. Increased thermotolerance was also not observed in C3-dominated corals that were acclimated for 3 months to warmer temperatures (29 °C) before heat stress. These findings indicate that increased thermotolerance post-bleaching resulted from symbiont community composition changes, not prior heat exposure. Moreover, initially undetectable D1a symbionts became dominant only after bleaching, and were critical to corals' resilience after stress and resistance to future stress.
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Affiliation(s)
- Rachel N Silverstein
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
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Coral spawning in the Gulf of Oman and relationship to latitudinal variation in spawning season in the northwest Indian Ocean. Sci Rep 2014; 4:7484. [PMID: 25501043 PMCID: PMC4265778 DOI: 10.1038/srep07484] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 11/26/2014] [Indexed: 11/30/2022] Open
Abstract
Despite a wealth of information on sexual reproduction in scleractinian corals, there are regional gaps in reproductive records. In the Gulf of the Oman in the Arabian Sea, reproductive timing was assessed in four common species of broadcast spawning corals using field surveys of gamete maturity and aquarium observations of spawning activity. The appearance of mature gametes within the same month for Acropora downingi, A. hemprichii, Cyphastrea microphthalma and Platygyra daedalea (≥ 75% of colonies, n = 848) indicated a synchronous and multi-specific spawning season. Based on gamete disappearance and direct observations, spawning predominantly occurred during April in 2013 (75–100% of colonies) and May in 2014 (77–94% of colonies). The difference in spawning months between survey years was most likely explained by sea temperature and the timing of lunar cycles during late-stage gametogenesis. These reproductive records are consistent with a latitudinal gradient in peak broadcast spawning activity at reefs in the northwestern Indian Ocean which occurs early in the year at low latitudes (January to March) and progressively later in the year at mid (March to May) and high (June to September) latitudes.
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Kamya PZ, Dworjanyn SA, Hardy N, Mos B, Uthicke S, Byrne M. Larvae of the coral eating crown-of-thorns starfish, Acanthaster planci in a warmer-high CO2 ocean. GLOBAL CHANGE BIOLOGY 2014; 20:3365-76. [PMID: 24615941 DOI: 10.1111/gcb.12530] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 01/06/2014] [Indexed: 05/14/2023]
Abstract
Outbreaks of crown-of-thorns starfish (COTS), Acanthaster planci, contribute to major declines of coral reef ecosystems throughout the Indo-Pacific. As the oceans warm and decrease in pH due to increased anthropogenic CO2 production, coral reefs are also susceptible to bleaching, disease and reduced calcification. The impacts of ocean acidification and warming may be exacerbated by COTS predation, but it is not known how this major predator will fare in a changing ocean. Because larval success is a key driver of population outbreaks, we investigated the sensitivities of larval A. planci to increased temperature (2-4 °C above ambient) and acidification (0.3-0.5 pH units below ambient) in flow-through cross-factorial experiments (3 temperature × 3 pH/pCO2 levels). There was no effect of increased temperature or acidification on fertilization or very early development. Larvae reared in the optimal temperature (28 °C) were the largest across all pH treatments. Development to advanced larva was negatively affected by the high temperature treatment (30 °C) and by both experimental pH levels (pH 7.6, 7.8). Thus, planktonic life stages of A. planci may be negatively impacted by near-future global change. Increased temperature and reduced pH had an additive negative effect on reducing larval size. The 30 °C treatment exceeded larval tolerance regardless of pH. As 30 °C sea surface temperatures may become the norm in low latitude tropical regions, poleward migration of A. planci may be expected as they follow optimal isotherms. In the absence of acclimation or adaptation, declines in low latitude populations may occur. Poleward migration will be facilitated by strong western boundary currents, with possible negative flow-on effects on high latitude coral reefs. The contrasting responses of the larvae of A. planci and those of its coral prey to ocean acidification and warming are considered in context with potential future change in tropical reef ecosystems.
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Affiliation(s)
- Pamela Z Kamya
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
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Crowder CM, Liang WL, Weis VM, Fan TY. Elevated temperature alters the lunar timing of Planulation in the brooding coral Pocillopora damicornis. PLoS One 2014; 9:e107906. [PMID: 25329546 PMCID: PMC4198079 DOI: 10.1371/journal.pone.0107906] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 08/20/2014] [Indexed: 11/21/2022] Open
Abstract
Reproductive timing in corals is associated with environmental variables including temperature, lunar periodicity, and seasonality. Although it is clear that these variables are interrelated, it remains unknown if one variable in particular acts as the proximate signaler for gamete and or larval release. Furthermore, in an era of global warming, the degree to which increases in ocean temperatures will disrupt normal reproductive patterns in corals remains unknown. Pocillopora damicornis, a brooding coral widely distributed in the Indo-Pacific, has been the subject of multiple reproductive ecology studies that show correlations between temperature, lunar periodicity, and reproductive timing. However, to date, no study has empirically measured changes in reproductive timing associated with increased seawater temperature. In this study, the effect of increased seawater temperature on the timing of planula release was examined during the lunar cycles of March and June 2012. Twelve brooding corals were removed from Hobihu reef in Nanwan Bay, southern Taiwan and placed in 23 and 28°C controlled temperature treatment tanks. For both seasons, the timing of planulation was found to be plastic, with the high temperature treatment resulting in significantly earlier peaks of planula release compared to the low temperature treatment. This suggests that temperature alone can influence the timing of larval release in Pocillopora damicornis in Nanwan Bay. Therefore, it is expected that continued increases in ocean temperature will result in earlier timing of reproductive events in corals, which may lead to either variations in reproductive success or phenotypic acclimatization.
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Affiliation(s)
- Camerron M Crowder
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Wei-Lo Liang
- Institute of Marine Biology, National Dong Hwa University, Pingtung, Taiwan, R.O.C
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Tung-Yung Fan
- Institute of Marine Biology, National Dong Hwa University, Pingtung, Taiwan, R.O.C.; National Museum of Marine Biology and Aquarium, Pingtung, Taiwan, R.O.C
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67
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Doors are closing on early development in corals facing climate change. Sci Rep 2014; 4:5633. [PMID: 25005591 PMCID: PMC5381609 DOI: 10.1038/srep05633] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 06/20/2014] [Indexed: 11/17/2022] Open
Abstract
Marine invertebrates are particularly vulnerable to climatic anomalies in early life history stages because of the time spent in the water column. Studies have focused on the effect of seawater temperature on fertilization, development, and larval stages in corals; however, none of them show comparative results along an environmental gradient. In this study, we show that temperatures in the range of 15–33°C have strong effects on fertilization rates and embryonic stages of two coral species, Acropora muricata in the subtropical environment and Acropora hyacinthus in subtropical and temperate environments. Deformations after the first cleavage stages were observed at low (15°C) and high (33°C) temperatures. Development was delayed by 6–7 h in the slightly non-optimal temperature of 20°C. We found significant differences in fertilization rates and responses of embryos from different latitudes, with temperate corals being more sensitive to extremely hot temperatures and vice versa. We hypothesize that the coral development is restricted to a narrow temperature range and deviation outside this window could inhibit a species' continuance and ecological success. Thus, it would have significant negative effects on adult populations and communities, playing a role in future of coral reef survival.
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68
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Keshavmurthy S, Meng PJ, Wang JT, Kuo CY, Yang SY, Hsu CM, Gan CH, Dai CF, Chen CA. Can resistant coral-Symbiodinium associations enable coral communities to survive climate change? A study of a site exposed to long-term hot water input. PeerJ 2014; 2:e327. [PMID: 24765567 PMCID: PMC3994648 DOI: 10.7717/peerj.327] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 03/11/2014] [Indexed: 11/21/2022] Open
Abstract
Climate change has led to a decline in the health of corals and coral reefs around the world. Studies have shown that, while some corals can cope with natural and anthropogenic stressors either through resistance mechanisms of coral hosts or through sustainable relationships with Symbiodinium clades or types, many coral species cannot. Here, we show that the corals present in a reef in southern Taiwan, and exposed to long-term elevated seawater temperatures due to the presence of a nuclear power plant outlet (NPP OL), are unique in terms of species and associated Symbiodinium types. At shallow depths (<3 m), eleven coral genera elsewhere in Kenting predominantly found with Symbiodinium types C1 and C3 (stress sensitive) were instead hosting Symbiodinium type D1a (stress tolerant) or a mixture of Symbiodinium type C1/C3/C21a/C15 and Symbiodinium type D1a. Of the 16 coral genera that dominate the local reefs, two that are apparently unable to associate with Symbiodinium type D1a are not present at NPP OL at depths of <3 m. Two other genera present at NPP OL and other locations host a specific type of Symbiodinium type C15. These data imply that coral assemblages may have the capacity to maintain their presence at the generic level against long-term disturbances such as elevated seawater temperatures by acclimatization through successful association with a stress-tolerant Symbiodinium over time. However, at the community level it comes at the cost of some coral genera being lost, suggesting that species unable to associate with a stress-tolerant Symbiodinium are likely to become extinct locally and unfavorable shifts in coral communities are likely to occur under the impact of climate change.
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Affiliation(s)
| | - Pei-Jie Meng
- National Museum of Marine Biology/Aquarium , Checheng, Pingtung , Taiwan ; Institute of Marine Biodiversity and Evolution, National Dong Hwa University , Checheng, Pingtung , Taiwan
| | - Jih-Terng Wang
- Institute of Biotechnology, Tajen University of Science and Technology , Pintung , Taiwan
| | - Chao-Yang Kuo
- Biodiversity Research Center, Academia Sinica , Nangang, Taipei , Taiwan ; ARC Centre for Coral Reef Studies, James Cook University , Townsville , Australia
| | - Sung-Yin Yang
- University of Ryukyus, Graduate School of Engineering and Science , Okinawa , Japan
| | - Chia-Min Hsu
- Biodiversity Research Center, Academia Sinica , Nangang, Taipei , Taiwan ; Institute of Oceanography, National Taiwan University , Taipei , Taiwan
| | - Chai-Hsia Gan
- Biodiversity Research Center, Academia Sinica , Nangang, Taipei , Taiwan
| | - Chang-Feng Dai
- Institute of Oceanography, National Taiwan University , Taipei , Taiwan
| | - Chaolun Allen Chen
- Biodiversity Research Center, Academia Sinica , Nangang, Taipei , Taiwan ; Institute of Oceanography, National Taiwan University , Taipei , Taiwan ; Taiwan International Graduate Program (TIGP)-Biodiversity, Academia Sinica , Nankang, Taipei , Taiwan
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69
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Fine M, Gildor H, Genin A. A coral reef refuge in the Red Sea. GLOBAL CHANGE BIOLOGY 2013; 19:3640-7. [PMID: 23959950 DOI: 10.1111/gcb.12356] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 05/18/2023]
Abstract
The stability and persistence of coral reefs in the decades to come is uncertain due to global warming and repeated bleaching events that will lead to reduced resilience of these ecological and socio-economically important ecosystems. Identifying key refugia is potentially important for future conservation actions. We suggest that the Gulf of Aqaba (GoA) (Red Sea) may serve as a reef refugium due to a unique suite of environmental conditions. Our hypothesis is based on experimental detection of an exceptionally high bleaching threshold of northern Red Sea corals and on the potential dispersal of coral planulae larvae through a selective thermal barrier estimated using an ocean model. We propose that millennia of natural selection in the form of a thermal barrier at the southernmost end of the Red Sea have selected coral genotypes that are less susceptible to thermal stress in the northern Red Sea, delaying bleaching events in the GoA by at least a century.
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Affiliation(s)
- Maoz Fine
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel; The Interuniversity Institute for Marine Sciences, P.O.B 469, Eilat, 88103, Israel
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Munday PL, Warner RR, Monro K, Pandolfi JM, Marshall DJ. Predicting evolutionary responses to climate change in the sea. Ecol Lett 2013; 16:1488-500. [PMID: 24119205 DOI: 10.1111/ele.12185] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 08/29/2013] [Indexed: 01/17/2023]
Abstract
An increasing number of short-term experimental studies show significant effects of projected ocean warming and ocean acidification on the performance on marine organisms. Yet, it remains unclear if we can reliably predict the impact of climate change on marine populations and ecosystems, because we lack sufficient understanding of the capacity for marine organisms to adapt to rapid climate change. In this review, we emphasise why an evolutionary perspective is crucial to understanding climate change impacts in the sea and examine the approaches that may be useful for addressing this challenge. We first consider what the geological record and present-day analogues of future climate conditions can tell us about the potential for adaptation to climate change. We also examine evidence that phenotypic plasticity may assist marine species to persist in a rapidly changing climate. We then outline the various experimental approaches that can be used to estimate evolutionary potential, focusing on molecular tools, quantitative genetics, and experimental evolution, and we describe the benefits of combining different approaches to gain a deeper understanding of evolutionary potential. Our goal is to provide a platform for future research addressing the evolutionary potential for marine organisms to cope with climate change.
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Affiliation(s)
- Philip L Munday
- Australian Research Council Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, QLD, 4811, Australia
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