1
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Starko S, Fifer JE, Claar DC, Davies SW, Cunning R, Baker AC, Baum JK. Marine heatwaves threaten cryptic coral diversity and erode associations among coevolving partners. Sci Adv 2023; 9:eadf0954. [PMID: 37566650 PMCID: PMC10421036 DOI: 10.1126/sciadv.adf0954] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 07/12/2023] [Indexed: 08/13/2023]
Abstract
Climate change-amplified marine heatwaves can drive extensive mortality in foundation species. However, a paucity of longitudinal genomic datasets has impeded understanding of how these rapid selection events alter cryptic genetic structure. Heatwave impacts may be exacerbated in species that engage in obligate symbioses, where the genetics of multiple coevolving taxa may be affected. Here, we tracked the symbiotic associations of reef-building corals for 6 years through a prolonged heatwave, including known survivorship for 79 of 315 colonies. Coral genetics strongly predicted survival of the ubiquitous coral, Porites (massive growth form), with variable survival (15 to 61%) across three morphologically indistinguishable-but genetically distinct-lineages. The heatwave also disrupted strong associations between these coral lineages and their algal symbionts (family Symbiodiniaceae), with symbiotic turnover in some colonies, resulting in reduced specificity across lineages. These results highlight how heatwaves can threaten cryptic genotypes and decouple otherwise tightly coevolved relationships between hosts and symbionts.
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Affiliation(s)
- Samuel Starko
- Department of Biology, University of Victoria, PO Box 1700 Station CSC, Victoria, British Columbia V8W 2Y2, Canada
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - James E. Fifer
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Danielle C. Claar
- Department of Biology, University of Victoria, PO Box 1700 Station CSC, Victoria, British Columbia V8W 2Y2, Canada
- Washington Department of Natural Resources, Olympia, WA 98504, USA
| | - Sarah W. Davies
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL 60605, USA
| | - Andrew C. Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
| | - Julia K. Baum
- Department of Biology, University of Victoria, PO Box 1700 Station CSC, Victoria, British Columbia V8W 2Y2, Canada
- Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI 96744, USA
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2
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Núñez-Pons L, Cunning R, Nelson C, Amend A, Sogin EM, Gates R, Ritson-Williams R. Hawai'ian coral holobionts reveal algal and prokaryotic host specificity, intraspecific variability in bleaching resistance, and common interspecific microbial consortia modulating thermal stress responses. Sci Total Environ 2023; 889:164040. [PMID: 37209745 DOI: 10.1016/j.scitotenv.2023.164040] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/18/2023] [Accepted: 05/06/2023] [Indexed: 05/22/2023]
Abstract
Historically, Hawai'i had few massive coral bleaching events, until two consecutive heatwaves in 2014-2015. Consequent mortality and thermal stress were observed in Kane'ohe Bay (O'ahu). The two most dominant local species exhibited a phenotypic dichotomy of either bleaching resistance or susceptibility (Montipora capitata and Porites compressa), while the third predominant species (Pocillopora acuta) was broadly susceptible to bleaching. In order to survey shifts in coral microbiomes during bleaching and recovery, 50 colonies were tagged and periodically monitored. Metabarcoding of three genetic markers (16S rRNA gene ITS1 and ITS2) followed by compositional approaches for community structure analysis, differential abundance and correlations for longitudinal data were used to temporally compare Bacteria/Archaea, Fungi and Symbiodiniaceae dynamics. P. compressa corals recovered faster than P. acuta and Montipora capitata. Prokaryotic and algal communities were majorly shaped by host species, and had no apparent pattern of temporal acclimatization. Symbiodiniaceae signatures were identified at the colony scale, and were often related to bleaching susceptibility. Bacterial compositions were practically constant between bleaching phenotypes, and more diverse in P. acuta and M. capitata. P. compressa's prokaryotic community was dominated by a single bacterium. Compositional approaches (via microbial balances) allowed the identification of fine-scale differences in the abundance of a consortium of microbes, driving changes by bleaching susceptibility and time across all hosts. The three major coral reef founder-species in Kane'ohe Bay revealed different phenotypic and microbiome responses after 2014-2015 heatwaves. It is difficult to forecast, a more successful strategy towards future scenarios of global warming. Differentially abundant microbial taxa across time and/or bleaching susceptibility were broadly shared among all hosts, suggesting that locally, the same microbes may modulate stress responses in sympatric coral species. Our study highlights the potential of investigating microbial balances to identify fine-scale microbiome changes, serving as local diagnostic tools of coral reef fitness.
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Affiliation(s)
- Laura Núñez-Pons
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy; NBFC, National Biodiversity Future Center, Palermo 90133, Italy.
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL 60605, USA.
| | - Craig Nelson
- Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA.
| | - Anthony Amend
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Emilia M Sogin
- Molecular and Cell Biology, University of California Merced, Merced, CA, USA.
| | - Ruth Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA.
| | - Raphael Ritson-Williams
- College of Arts and Sciences, The Heart of Santa Clara University, Vari Hall 500 El Camino Real Santa Clara, CA 95053, USA.
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Davies SW, Gamache MH, Howe-Kerr LI, Kriefall NG, Baker AC, Banaszak AT, Bay LK, Bellantuono AJ, Bhattacharya D, Chan CX, Claar DC, Coffroth MA, Cunning R, Davy SK, del Campo J, Díaz-Almeyda EM, Frommlet JC, Fuess LE, González-Pech RA, Goulet TL, Hoadley KD, Howells EJ, Hume BCC, Kemp DW, Kenkel CD, Kitchen SA, LaJeunesse TC, Lin S, McIlroy SE, McMinds R, Nitschke MR, Oakley CA, Peixoto RS, Prada C, Putnam HM, Quigley K, Reich HG, Reimer JD, Rodriguez-Lanetty M, Rosales SM, Saad OS, Sampayo EM, Santos SR, Shoguchi E, Smith EG, Stat M, Stephens TG, Strader ME, Suggett DJ, Swain TD, Tran C, Traylor-Knowles N, Voolstra CR, Warner ME, Weis VM, Wright RM, Xiang T, Yamashita H, Ziegler M, Correa AMS, Parkinson JE. Building consensus around the assessment and interpretation of Symbiodiniaceae diversity. PeerJ 2023; 11:e15023. [PMID: 37151292 PMCID: PMC10162043 DOI: 10.7717/peerj.15023] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/17/2023] [Indexed: 05/09/2023] Open
Abstract
Within microeukaryotes, genetic variation and functional variation sometimes accumulate more quickly than morphological differences. To understand the evolutionary history and ecology of such lineages, it is key to examine diversity at multiple levels of organization. In the dinoflagellate family Symbiodiniaceae, which can form endosymbioses with cnidarians (e.g., corals, octocorals, sea anemones, jellyfish), other marine invertebrates (e.g., sponges, molluscs, flatworms), and protists (e.g., foraminifera), molecular data have been used extensively over the past three decades to describe phenotypes and to make evolutionary and ecological inferences. Despite advances in Symbiodiniaceae genomics, a lack of consensus among researchers with respect to interpreting genetic data has slowed progress in the field and acted as a barrier to reconciling observations. Here, we identify key challenges regarding the assessment and interpretation of Symbiodiniaceae genetic diversity across three levels: species, populations, and communities. We summarize areas of agreement and highlight techniques and approaches that are broadly accepted. In areas where debate remains, we identify unresolved issues and discuss technologies and approaches that can help to fill knowledge gaps related to genetic and phenotypic diversity. We also discuss ways to stimulate progress, in particular by fostering a more inclusive and collaborative research community. We hope that this perspective will inspire and accelerate coral reef science by serving as a resource to those designing experiments, publishing research, and applying for funding related to Symbiodiniaceae and their symbiotic partnerships.
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Affiliation(s)
- Sarah W. Davies
- Department of Biology, Boston University, Boston, MA, United States
| | - Matthew H. Gamache
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
| | | | | | - Andrew C. Baker
- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, United States
| | - Anastazia T. Banaszak
- Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, Mexico
| | - Line Kolind Bay
- Australian Institute of Marine Science, Townsville, Australia
| | - Anthony J. Bellantuono
- Department of Biological Sciences, Florida International University, Miami, FL, United States
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Danielle C. Claar
- Nearshore Habitat Program, Washington State Department of Natural Resources, Olympia, WA, USA
| | | | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL, United States
| | - Simon K. Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Javier del Campo
- Institut de Biologia Evolutiva (CSIC - Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | | | - Jörg C. Frommlet
- Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Lauren E. Fuess
- Department of Biology, Texas State University, San Marcos, TX, United States
| | - Raúl A. González-Pech
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
- Department of Biology, Pennsylvania State University, State College, PA, United States
| | - Tamar L. Goulet
- Department of Biology, University of Mississippi, University, MS, United States
| | - Kenneth D. Hoadley
- Department of Biological Sciences, University of Alabama—Tuscaloosa, Tuscaloosa, AL, United States
| | - Emily J. Howells
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | | | - Dustin W. Kemp
- Department of Biology, University of Alabama—Birmingham, Birmingham, Al, United States
| | - Carly D. Kenkel
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Sheila A. Kitchen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Todd C. LaJeunesse
- Department of Biology, Pennsylvania State University, University Park, PA, United States
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Mansfield, CT, United States
| | - Shelby E. McIlroy
- Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Ryan McMinds
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, United States
| | | | - Clinton A. Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Raquel S. Peixoto
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Carlos Prada
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | - Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | | | - Hannah G. Reich
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | - James Davis Reimer
- Department of Biology, Chemistry and Marine Sciences, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | | | - Stephanie M. Rosales
- The Cooperative Institute For Marine and Atmospheric Studies, Miami, FL, United States
| | - Osama S. Saad
- Department of Biological Oceanography, Red Sea University, Port-Sudan, Sudan
| | - Eugenia M. Sampayo
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Scott R. Santos
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Edward G. Smith
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Michael Stat
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Timothy G. Stephens
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
| | - Marie E. Strader
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - David J. Suggett
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Timothy D. Swain
- Department of Marine and Environmental Science, Nova Southeastern University, Dania Beach, FL, United States
| | - Cawa Tran
- Department of Biology, University of San Diego, San Diego, CA, United States
| | - Nikki Traylor-Knowles
- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, United States
| | | | - Mark E. Warner
- School of Marine Science and Policy, University of Delaware, Lewes, DE, United States
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States
| | - Rachel M. Wright
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, United States
| | - Tingting Xiang
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Hiroshi Yamashita
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Ishigaki, Okinawa, Japan
| | - Maren Ziegler
- Department of Animal Ecology & Systematics, Justus Liebig University Giessen (Germany), Giessen, Germany
| | | | - John Everett Parkinson
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
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4
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Brown AL, Pfab F, Baxter EC, Detmer AR, Moeller HV, Nisbet RM, Cunning R. Analysis of a mechanistic model of corals in association with multiple symbionts: within-host competition and recovery from bleaching. Conserv Physiol 2022; 10:coac066. [PMID: 36247693 PMCID: PMC9558299 DOI: 10.1093/conphys/coac066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 07/25/2022] [Accepted: 09/09/2022] [Indexed: 06/14/2023]
Abstract
Coral reefs are increasingly experiencing stressful conditions, such as high temperatures, that cause corals to undergo bleaching, a process where they lose their photosynthetic algal symbionts. Bleaching threatens both corals' survival and the health of the reef ecosystems they create. One possible mechanism for corals to resist bleaching is through association with stress-tolerant symbionts, which are resistant to bleaching but may be worse partners in mild conditions. Some corals have been found to associate with multiple symbiont species simultaneously, which potentially gives them access to the benefits of both stress-sensitive and -tolerant symbionts. However, within-host competition between symbionts may lead to competitive exclusion of one partner, and the consequences of associating with multiple partners simultaneously are not well understood. We modify a mechanistic model of coral-algal symbiosis to investigate the effect of environmental conditions on within-host competitive dynamics between stress-sensitive and -tolerant symbionts and the effect of access to a tolerant symbiont on the dynamics of recovery from bleaching. We found that the addition of a tolerant symbiont can increase host survival and recovery from bleaching in high-light conditions. Competitive exclusion of the tolerant symbiont occurred slowly at intermediate light levels. Interestingly, there were some cases of post-bleaching competitive exclusion after the tolerant symbiont had helped the host recover.
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Affiliation(s)
- Alexandra Lynne Brown
- Corresponding author: Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. E-mail:
| | - Ferdinand Pfab
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ethan C Baxter
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - A Raine Detmer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA
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5
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Johnston EC, Cunning R, Burgess SC. Cophylogeny and specificity between cryptic coral species (Pocillopora spp.) at Mo'orea and their symbionts (Symbiodiniaceae). Mol Ecol 2022; 31:5368-5385. [PMID: 35960256 PMCID: PMC9805206 DOI: 10.1111/mec.16654] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/30/2022] [Accepted: 08/08/2022] [Indexed: 01/09/2023]
Abstract
The congruence between phylogenies of tightly associated groups of organisms (cophylogeny) reflects evolutionary links between ecologically important interactions. However, despite being a classic example of an obligate symbiosis, tests of cophylogeny between scleractinian corals and their photosynthetic algal symbionts have been hampered in the past because both corals and algae contain genetically unresolved and morphologically cryptic species. Here, we studied co-occurring, cryptic Pocillopora species from Mo'orea, French Polynesia, that differ in their relative abundance across depth. We constructed new phylogenies of the host Pocillopora (using complete mitochondrial genomes, genomic loci, and thousands of single nucleotide polymorphisms) and their Symbiodiniaceae symbionts (using ITS2 and psbAncr markers) and tested for cophylogeny. The analysis supported the presence of five Pocillopora species on the fore reef at Mo'orea that mostly hosted either Cladocopium latusorum or C. pacificum. Only Pocillopora species hosting C. latusorum also hosted taxa from Symbiodinium and Durusdinium. In general, the Cladocopium phylogeny mirrored the Pocillopora phylogeny. Within Cladocopium species, lineages also differed in their associations with Pocillopora haplotypes, except those showing evidence of nuclear introgression, and with depth in the two most common Pocillopora species. We also found evidence for a new Pocillopora species (haplotype 10), that has so far only been sampled from French Polynesia, that warrants formal identification. The linked phylogenies of these Pocillopora and Cladocopium species and lineages suggest that symbiont speciation is driven by niche diversification in the host, but there is still evidence for symbiont flexibility in some cases.
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Affiliation(s)
- Erika C. Johnston
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinoisUSA
| | - Scott C. Burgess
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
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6
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Pfab F, Brown AL, Detmer AR, Baxter EC, Moeller HV, Cunning R, Nisbet RM. Timescale separation and models of symbiosis: state space reduction, multiple attractors and initialization. Conserv Physiol 2022; 10:coac026. [PMID: 35539007 PMCID: PMC9073712 DOI: 10.1093/conphys/coac026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/18/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Dynamic Energy Budget models relate whole organism processes such as growth, reproduction and mortality to suborganismal metabolic processes. Much of their potential derives from extensions of the formalism to describe the exchange of metabolic products between organisms or organs within a single organism, for example the mutualism between corals and their symbionts. Without model simplification, such models are at risk of becoming parameter-rich and hence impractical. One natural simplification is to assume that some metabolic processes act on 'fast' timescales relative to others. A common strategy for formulating such models is to assume that 'fast' processes equilibrate immediately, while 'slow' processes are described by ordinary differential equations. This strategy can bring a subtlety with it. What if there are multiple, interdependent fast processes that have multiple equilibria, so that additional information is needed to unambiguously specify the model dynamics? This situation can easily arise in contexts where an organism or community can persist in a 'healthy' or an 'unhealthy' state with abrupt transitions between states possible. To approach this issue, we offer the following: (a) a method to unambiguously complete implicitly defined models by adding hypothetical 'fast' state variables; (b) an approach for minimizing the number of additional state variables in such models, which can simplify the numerical analysis and give insights into the model dynamics; and (c) some implications of the new approach that are of practical importance for model dynamics, e.g. on the bistability of flux dynamics and the effect of different initialization choices on model outcomes. To demonstrate those principles, we use a simplified model for root-shoot dynamics of plants and a related model for the interactions between corals and endosymbiotic algae that describes coral bleaching and recovery.
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Affiliation(s)
- Ferdinand Pfab
- Corresponding author: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, USA.
| | - Alexandra Lynne Brown
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - A Raine Detmer
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Ethan C Baxter
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, G. Shedd Aquarium, 1200 S. DuSable Lake Shore Drive, Chicago, IL 60605, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
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7
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Detmer AR, Cunning R, Pfab F, Brown AL, Stier AC, Nisbet RM, Moeller HV. Fertilization by coral-dwelling fish promotes coral growth but can exacerbate bleaching response. J Theor Biol 2022; 541:111087. [PMID: 35276225 DOI: 10.1016/j.jtbi.2022.111087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
Abstract
Many corals form close associations with a diverse assortment of coral-dwelling fishes and other fauna. As coral reefs around the world are increasingly threatened by mass bleaching events, it is important to understand how these biotic interactions influence corals' susceptibility to bleaching. We used dynamic energy budget modeling to explore how nitrogen excreted by coral-dwelling fish affects the physiological performance of host corals. In our model, fish presence influenced the functioning of the coral-Symbiodiniaceae symbiosis by altering nitrogen availability, and the magnitude and sign of these effects depended on environmental conditions. Although our model predicted that fish-derived nitrogen can promote coral growth, the relationship between fish presence and coral tolerance of photo-oxidative stress was non-linear. Fish excretions supported denser symbiont populations that provided protection from incident light through self-shading. However, these symbionts also used more of their photosynthetic products for their own growth, rather than sharing with the coral host, putting the coral holobiont at a higher risk of becoming carbon-limited and bleaching. The balance between the benefits of increased symbiont shading and costs of reduced carbon sharing depended on environmental conditions. Thus, while there were some scenarios under which fish presence increased corals' tolerance of light stress, fish could also exacerbate bleaching and slow or prevent subsequent recovery. We discuss how the contrast between the potentially harmful effects of fish predicted by our model and results of empirical studies may relate to key model assumptions that warrant further investigation. Overall, this study provides a foundation for future work on how coral-associated fauna influence the bioenergetics of their host corals, which in turn has implications for how these corals respond to bleaching-inducing stressors.
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Affiliation(s)
- A Raine Detmer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium Chicago, IL 60605, USA
| | - Ferdinand Pfab
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Alexandra L Brown
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Adrian C Stier
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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8
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Matsuda SB, Chakravarti LJ, Cunning R, Huffmyer AS, Nelson CE, Gates RD, van Oppen MJH. Temperature-mediated acquisition of rare heterologous symbionts promotes survival of coral larvae under ocean warming. Glob Chang Biol 2022; 28:2006-2025. [PMID: 34957651 PMCID: PMC9303745 DOI: 10.1111/gcb.16057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Reef-building corals form nutritional symbioses with endosymbiotic dinoflagellates (Symbiodiniaceae), a relationship that facilitates the ecological success of coral reefs. These symbionts are mostly acquired anew each generation from the environment during early life stages ("horizontal transmission"). Symbiodiniaceae species exhibit trait variation that directly impacts the health and performance of the coral host under ocean warming. Here, we test the capacity for larvae of a horizontally transmitting coral, Acropora tenuis, to establish symbioses with Symbiodiniaceae species in four genera that have varying thermal thresholds (the common symbiont genera, Cladocopium and Durusdinium, and the less common Fugacium and Gerakladium). Over a 2-week period in January 2018, a series of both no-choice and four-way choice experiments were conducted at three temperatures (27, 30, and 31°C). Symbiont acquisition success and cell proliferation were measured in individual larvae. Larvae successfully acquired and maintained symbionts of all four genera in no-choice experiments, and >80% of larvae were infected with at least three genera when offered a four-way choice. Unexpectedly, Gerakladium symbionts increased in dominance over time, and at high temperatures outcompeted Durusdinium, which is regarded as thermally tolerant. Although Fugacium displayed the highest thermal tolerance in culture and reached similar cell densities to the other three symbionts at 31°C, it remained a background symbiont in choice experiments, suggesting host preference for other symbiont species. Larval survivorship at 1 week was highest in larvae associated with Gerakladium and Fugacium symbionts at 27 and 30°C, however at 31°C, mortality was similar for all treatments. We hypothesize that symbionts that are currently rare in corals (e.g., Gerakladium) may become more common and widespread in early life stages under climate warming. Uptake of such symbionts may function as a survival strategy in the wild, and has implications for reef restoration practices that use sexually produced coral stock.
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Affiliation(s)
- Shayle B. Matsuda
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | | | - Ross Cunning
- Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinoisUSA
| | - Ariana S. Huffmyer
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Craig E. Nelson
- Daniel K. Inouye Center for Microbial Oceanography: Research and EducationDepartment of Oceanography and Sea Grant College ProgramUniversity of Hawai‘i at MānoaHonoluluHawai‘iUSA
| | - Ruth D. Gates
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
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9
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Cunning R, Parker KE, Johnson-Sapp K, Karp RF, Wen AD, Williamson OM, Bartels E, D'Alessandro M, Gilliam DS, Hanson G, Levy J, Lirman D, Maxwell K, Million WC, Moulding AL, Moura A, Muller EM, Nedimyer K, Reckenbeil B, van Hooidonk R, Dahlgren C, Kenkel C, Parkinson JE, Baker AC. Census of heat tolerance among Florida's threatened staghorn corals finds resilient individuals throughout existing nursery populations. Proc Biol Sci 2021; 288:20211613. [PMID: 34666521 DOI: 10.1098/rspb.2021.1613] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The rapid loss of reef-building corals owing to ocean warming is driving the development of interventions such as coral propagation and restoration, selective breeding and assisted gene flow. Many of these interventions target naturally heat-tolerant individuals to boost climate resilience, but the challenges of quickly and reliably quantifying heat tolerance and identifying thermotolerant individuals have hampered implementation. Here, we used coral bleaching automated stress systems to perform rapid, standardized heat tolerance assays on 229 colonies of Acropora cervicornis across six coral nurseries spanning Florida's Coral Reef, USA. Analysis of heat stress dose-response curves for each colony revealed a broad range in thermal tolerance among individuals (approx. 2.5°C range in Fv/Fm ED50), with highly reproducible rankings across independent tests (r = 0.76). Most phenotypic variation occurred within nurseries rather than between them, pointing to a potentially dominant role of fixed genetic effects in setting thermal tolerance and widespread distribution of tolerant individuals throughout the population. The identification of tolerant individuals provides immediately actionable information to optimize nursery and restoration programmes for Florida's threatened staghorn corals. This work further provides a blueprint for future efforts to identify and source thermally tolerant corals for conservation interventions worldwide.
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Affiliation(s)
- Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL, USA
| | - Katherine E Parker
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL, USA
| | - Kelsey Johnson-Sapp
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
| | - Richard F Karp
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
| | - Alexandra D Wen
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
| | - Olivia M Williamson
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
| | - Erich Bartels
- Elizabeth Moore International Center for Coral Reef Research and Restoration, Mote Marine Laboratory, Summerland Key, FL, USA
| | | | - David S Gilliam
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Grace Hanson
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Jessica Levy
- Coral Restoration Foundation, Key Largo, FL, USA
| | - Diego Lirman
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
| | - Kerry Maxwell
- Florida Fish and Wildlife Conservation, Marathon, FL, USA
| | - Wyatt C Million
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Alison L Moulding
- Protected Resources Division, NOAA Fisheries Southeast Regional Office, St Petersburg, FL, USA
| | - Amelia Moura
- Coral Restoration Foundation, Key Largo, FL, USA
| | - Erinn M Muller
- Coral Health and Disease Program, Mote Marine Laboratory, Sarasota, FL, USA
| | | | | | - Ruben van Hooidonk
- Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA.,Ocean Chemistry and Ecosystems Division, NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, FL, USA
| | | | - Carly Kenkel
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - John E Parkinson
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, USA
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10
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Rodriguez-Casariego JA, Cunning R, Baker AC, Eirin-Lopez JM. Symbiont shuffling induces differential DNA methylation responses to thermal stress in the coral Montastraea cavernosa. Mol Ecol 2021; 31:588-602. [PMID: 34689363 DOI: 10.1111/mec.16246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/11/2022]
Abstract
Algal symbiont shuffling in favour of more thermotolerant species has been shown to enhance coral resistance to heat-stress. Yet, the mechanistic underpinnings and long-term implications of these changes are poorly understood. This work studied the modifications in coral DNA methylation, an epigenetic mechanism involved in coral acclimatization, in response to symbiont manipulation and subsequent heat stress exposure. Symbiont composition was manipulated in the great star coral Montastraea cavernosa through controlled thermal bleaching and recovery, producing paired ramets of three genets dominated by either their native symbionts (genus Cladocopium) or the thermotolerant species (Durusdinium trenchi). Single-base genome-wide analyses showed significant modifications in DNA methylation concentrated in intergenic regions, introns and transposable elements. Remarkably, DNA methylation changes in response to heat stress were dependent on the dominant symbiont, with twice as many differentially methylated regions found in heat-stressed corals hosting different symbionts (Cladocopium vs. D. trenchii) compared to all other comparisons. Interestingly, while differential gene body methylation was not correlated with gene expression, an enrichment in differentially methylated regions was evident in repetitive genome regions. Overall, these results suggest that changes in algal symbionts favouring heat tolerant associations are accompanied by changes in DNA methylation in the coral host. The implications of these results for coral adaptation, along with future avenues of research based on current knowledge gaps, are discussed in the present work.
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Affiliation(s)
- Javier A Rodriguez-Casariego
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, Illinois, USA.,Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
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11
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Grottoli AG, Toonen RJ, Woesik R, Vega Thurber R, Warner ME, McLachlan RH, Price JT, Bahr KD, Baums IB, Castillo KD, Coffroth MA, Cunning R, Dobson KL, Donahue MJ, Hench JL, Iglesias‐Prieto R, Kemp DW, Kenkel CD, Kline DI, Kuffner IB, Matthews JL, Mayfield AB, Padilla‐Gamiño JL, Palumbi S, Voolstra CR, Weis VM, Wu HC. Increasing comparability among coral bleaching experiments. Ecol Appl 2021; 31:e02262. [PMID: 33222325 PMCID: PMC8243963 DOI: 10.1002/eap.2262] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 09/09/2020] [Indexed: 05/14/2023]
Affiliation(s)
- A. G. Grottoli
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - R. J. Toonen
- Hawaiʻi Institute of Marine Biology University of Hawaiʻi at Mānoa Kāneʻohe Hawaii96744USA
| | - R. Woesik
- Department of Ocean Engineering and Marine Sciences Florida Institute of Technology Melbourne Florida32901USA
| | - R. Vega Thurber
- Department of Microbiology Oregon State University Corvallis Oregon97331USA
| | - M. E. Warner
- School of Marine Science and Policy University of Delaware Lewes Delaware19958USA
| | - R. H. McLachlan
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - J. T. Price
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - K. D. Bahr
- Department of Life Sciences Texas A&M University–Corpus Christi Corpus Christi Texas78412USA
| | - I. B. Baums
- Department of Biology Pennsylvania State University University Park Pennsylvania16802USA
| | - K. D. Castillo
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina27599USA
| | - M. A. Coffroth
- Department of Geology State University of New York at Buffalo Buffalo New York14260USA
| | - R. Cunning
- Daniel P. Hearther Center for Conservation and Research John G. Shedd Aquarium Chicago Illinois60605USA
| | - K. L. Dobson
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - M. J. Donahue
- Hawaiʻi Institute of Marine Biology University of Hawaiʻi at Mānoa Kāneʻohe Hawaii96744USA
| | - J. L. Hench
- Nicholas School of the Environment Duke University Beaufort North Carolina28516USA
| | - R. Iglesias‐Prieto
- Department of Biology Pennsylvania State University University Park Pennsylvania16802USA
| | - D. W. Kemp
- Department of Biology University of Alabama at Birmingham Birmingham Alabama35233USA
| | - C. D. Kenkel
- Department of Biological Sciences University of Southern California Los Angeles California90089USA
| | - D. I. Kline
- Smithsonian Tropical Research Institute Washington D.C.20013USA
| | - I. B. Kuffner
- St Petersburg Coastal & Marine Science Center United States Geological Survey St Petersburg Florida33701USA
| | - J. L. Matthews
- Faculty of Science Climate Change Cluster University of Technology Sydney Broadway, Sydney New South Wales2007Australia
| | - A. B. Mayfield
- Oceanographic and Meteorological Laboratory Atlantic National Oceanic and Atmospheric Administration Miami Florida33149USA
- Cooperative Institute for Marine & Atmospheric Studies University of Miami Miami Florida33149USA
| | - J. L. Padilla‐Gamiño
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington98117USA
| | - S. Palumbi
- Hopkins Marine Station Stanford University Pacific Grove California93950USA
| | - C. R. Voolstra
- Department of Biology University of Konstanz Konstanz78457Germany
| | - V. M. Weis
- Department of Integrative Biology Oregon State University Corvallis Oregon97331USA
| | - H. C. Wu
- Leibniz Centre for Tropical Marine Research Bremen28359Germany
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12
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Mason RAB, Wall CB, Cunning R, Dove S, Gates RD. High light alongside elevated P CO2 alleviates thermal depression of photosynthesis in a hard coral ( Pocillopora acuta). ACTA ACUST UNITED AC 2020; 223:223/20/jeb223198. [PMID: 33087470 DOI: 10.1242/jeb.223198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 08/12/2020] [Indexed: 11/20/2022]
Abstract
The absorbtion of human-emitted CO2 by the oceans (elevated P CO2 ) is projected to alter the physiological performance of coral reef organisms by perturbing seawater chemistry (i.e. ocean acidification). Simultaneously, greenhouse gas emissions are driving ocean warming and changes in irradiance (through turbidity and cloud cover), which have the potential to influence the effects of ocean acidification on coral reefs. Here, we explored whether physiological impacts of elevated P CO2 on a coral-algal symbiosis (Pocillopora acuta-Symbiodiniaceae) are mediated by light and/or temperature levels. In a 39 day experiment, elevated P CO2 (962 versus 431 µatm P CO2 ) had an interactive effect with midday light availability (400 versus 800 µmol photons m-2 s-1) and temperature (25 versus 29°C) on areal gross and net photosynthesis, for which a decline at 29°C was ameliorated under simultaneous high-P CO2 and high-light conditions. Light-enhanced dark respiration increased under elevated P CO2 and/or elevated temperature. Symbiont to host cell ratio and chlorophyll a per symbiont increased at elevated temperature, whilst symbiont areal density decreased. The ability of moderately strong light in the presence of elevated P CO2 to alleviate the temperature-induced decrease in photosynthesis suggests that higher substrate availability facilitates a greater ability for photochemical quenching, partially offsetting the impacts of high temperature on the photosynthetic apparatus. Future environmental changes that result in moderate increases in light levels could therefore assist the P. acuta holobiont to cope with the 'one-two punch' of rising temperatures in the presence of an acidifying ocean.
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Affiliation(s)
- Robert A B Mason
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, PO Box 1346, Kāne'ohe, HI 96744, USA .,ARC Centre of Excellence for Coral Reef Studies, and Centre for Marine Science, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Christopher B Wall
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, PO Box 1346, Kāne'ohe, HI 96744, USA.,Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Ross Cunning
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, PO Box 1346, Kāne'ohe, HI 96744, USA.,Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA
| | - Sophie Dove
- ARC Centre of Excellence for Coral Reef Studies, and Centre for Marine Science, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, PO Box 1346, Kāne'ohe, HI 96744, USA
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13
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Cunning R, Baker AC. Thermotolerant coral symbionts modulate heat stress‐responsive genes in their hosts. Mol Ecol 2020; 29:2940-2950. [DOI: 10.1111/mec.15526] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/05/2020] [Accepted: 06/15/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA
- Daniel P. Haerther Center for Conservation and Research John G. Shedd Aquarium Chicago IL USA
| | - Andrew C. Baker
- Department of Marine Biology and Ecology Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA
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14
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McIlroy SE, Cunning R, Baker AC, Coffroth MA. Competition and succession among coral endosymbionts. Ecol Evol 2019; 9:12767-12778. [PMID: 31788212 PMCID: PMC6875658 DOI: 10.1002/ece3.5749] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/18/2019] [Accepted: 09/23/2019] [Indexed: 01/03/2023] Open
Abstract
Host species often support a genetically diverse guild of symbionts, the identity and performance of which can determine holobiont fitness under particular environmental conditions. These symbiont communities are structured by a complex set of potential interactions, both positive and negative, between the host and symbionts and among symbionts. In reef-building corals, stable associations with specific symbiont species are common, and we hypothesize that this is partly due to ecological mechanisms, such as succession and competition, which drive patterns of symbiont winnowing in the initial colonization of new generations of coral recruits. We tested this hypothesis using the experimental framework of the de Wit replacement series and found that competitive interactions occurred among symbionts which were characterized by unique ecological strategies. Aposymbiotic octocoral recruits within high- and low-light environments were inoculated with one of three Symbiodiniaceae species as monocultures or with cross-paired mixtures, and we tracked symbiont uptake using quantitative genetic assays. Priority effects, in which early colonizers excluded competitive dominants, were evidenced under low light, but these early opportunistic species were later succeeded by competitive dominants. Under high light, a more consistent competitive hierarchy was established in which competitive dominants outgrew and limited the abundance of others. These findings provide insight into mechanisms of microbial community organization and symbiosis breakdown and recovery. Furthermore, transitions in competitive outcomes across spatial and temporal environmental variation may improve lifetime host fitness.
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Affiliation(s)
- Shelby E. McIlroy
- Graduate Program in Evolution, Ecology and BehaviorState University of New YorkUniversity at BuffaloBuffaloNew York
- Swire Institute of Marine ScienceSchool of Biological ScienceThe University of Hong KongHong Kong
- Present address:
Swire Institute of Marine ScienceSchool of Biological ScienceThe University of Hong KongHong Kong
| | - Ross Cunning
- Department of Marine Biology and EcologyRosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiamiFlorida
- Present address:
Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinois
| | - Andrew C. Baker
- Department of Marine Biology and EcologyRosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiamiFlorida
| | - Mary Alice Coffroth
- Graduate Program in Evolution, Ecology and BehaviorState University of New YorkUniversity at BuffaloBuffaloNew York
- Department of GeologyState University of New YorkUniversity at BuffaloBuffaloNew York
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15
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Cunning R, Silverstein RN, Barnes BB, Baker AC. Extensive coral mortality and critical habitat loss following dredging and their association with remotely-sensed sediment plumes. Mar Pollut Bull 2019; 145:185-199. [PMID: 31590775 DOI: 10.1016/j.marpolbul.2019.05.02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 05/02/2019] [Accepted: 05/12/2019] [Indexed: 05/22/2023]
Abstract
Dredging poses a potential threat to coral reefs, yet quantifying impacts is often difficult due to the large spatial footprint of potential effects and co-occurrence of other disturbances. Here we analyzed in situ monitoring data and remotely-sensed sediment plumes to assess impacts of the 2013-2015 Port of Miami dredging on corals and reef habitat. To control for contemporaneous bleaching and disease, we analyzed the spatial distribution of impacts in relation to the dredged channel. Areas closer to dredging experienced higher sediment trap accumulation, benthic sediment cover, coral burial, and coral mortality, and our spatial analyses indicate that >560,000 corals were killed within 0.5 km, with impacts likely extending over 5-10 km. The occurrence of sediment plumes explained ~60% of spatial variability in measured impacts, suggesting that remotely-sensed plumes, when properly calibrated against in situ monitoring data, can reliably estimate the magnitude and extent of dredging impacts.
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Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA; Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL 60605, USA.
| | | | - Brian B Barnes
- College of Marine Science, University of South Florida, 140 7th Avenue South, MSL119, St. Petersburg, FL 33701, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
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16
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Cunning R, Silverstein RN, Barnes BB, Baker AC. Extensive coral mortality and critical habitat loss following dredging and their association with remotely-sensed sediment plumes. Mar Pollut Bull 2019; 145:185-199. [PMID: 31590775 DOI: 10.1016/j.marpolbul.2019.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 05/02/2019] [Accepted: 05/12/2019] [Indexed: 05/28/2023]
Abstract
Dredging poses a potential threat to coral reefs, yet quantifying impacts is often difficult due to the large spatial footprint of potential effects and co-occurrence of other disturbances. Here we analyzed in situ monitoring data and remotely-sensed sediment plumes to assess impacts of the 2013-2015 Port of Miami dredging on corals and reef habitat. To control for contemporaneous bleaching and disease, we analyzed the spatial distribution of impacts in relation to the dredged channel. Areas closer to dredging experienced higher sediment trap accumulation, benthic sediment cover, coral burial, and coral mortality, and our spatial analyses indicate that >560,000 corals were killed within 0.5 km, with impacts likely extending over 5-10 km. The occurrence of sediment plumes explained ~60% of spatial variability in measured impacts, suggesting that remotely-sensed plumes, when properly calibrated against in situ monitoring data, can reliably estimate the magnitude and extent of dredging impacts.
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Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA; Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL 60605, USA.
| | | | - Brian B Barnes
- College of Marine Science, University of South Florida, 140 7th Avenue South, MSL119, St. Petersburg, FL 33701, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
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17
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Cunning R, Bay RA, Gillette P, Baker AC, Traylor-Knowles N. Comparative analysis of the Pocillopora damicornis genome highlights role of immune system in coral evolution. Sci Rep 2018; 8:16134. [PMID: 30382153 PMCID: PMC6208414 DOI: 10.1038/s41598-018-34459-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/19/2018] [Indexed: 12/22/2022] Open
Abstract
Comparative analysis of the expanding genomic resources for scleractinian corals may provide insights into the evolution of these organisms, with implications for their continued persistence under global climate change. Here, we sequenced and annotated the genome of Pocillopora damicornis, one of the most abundant and widespread corals in the world. We compared this genome, based on protein-coding gene orthology, with other publicly available coral genomes (Cnidaria, Anthozoa, Scleractinia), as well as genomes from other anthozoan groups (Actiniaria, Corallimorpharia), and two basal metazoan outgroup phlya (Porifera, Ctenophora). We found that 46.6% of P. damicornis genes had orthologs in all other scleractinians, defining a coral ‘core’ genome enriched in basic housekeeping functions. Of these core genes, 3.7% were unique to scleractinians and were enriched in immune functionality, suggesting an important role of the immune system in coral evolution. Genes occurring only in P. damicornis were enriched in cellular signaling and stress response pathways, and we found similar immune-related gene family expansions in each coral species, indicating that immune system diversification may be a prominent feature of scleractinian coral evolution at multiple taxonomic levels. Diversification of the immune gene repertoire may underlie scleractinian adaptations to symbiosis, pathogen interactions, and environmental stress.
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Affiliation(s)
- R Cunning
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA. .,Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA.
| | - R A Bay
- Department of Evolution and Ecology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - P Gillette
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA
| | - A C Baker
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA
| | - N Traylor-Knowles
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA.
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18
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Wall CB, Mason RAB, Ellis WR, Cunning R, Gates RD. Elevated pCO 2 affects tissue biomass composition, but not calcification, in a reef coral under two light regimes. R Soc Open Sci 2017; 4:170683. [PMID: 29291059 PMCID: PMC5717633 DOI: 10.1098/rsos.170683] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/28/2017] [Indexed: 06/02/2023]
Abstract
Ocean acidification (OA) is predicted to reduce reef coral calcification rates and threaten the long-term growth of coral reefs under climate change. Reduced coral growth at elevated pCO2 may be buffered by sufficiently high irradiances; however, the interactive effects of OA and irradiance on other fundamental aspects of coral physiology, such as the composition and energetics of coral biomass, remain largely unexplored. This study tested the effects of two light treatments (7.5 versus 15.7 mol photons m-2 d-1) at ambient or elevated pCO2 (435 versus 957 µatm) on calcification, photopigment and symbiont densities, biomass reserves (lipids, carbohydrates, proteins), and biomass energy content (kJ) of the reef coral Pocillopora acuta from Kāne'ohe Bay, Hawai'i. While pCO2 and light had no effect on either area- or biomass-normalized calcification, tissue lipids gdw-1 and kJ gdw-1 were reduced 15% and 14% at high pCO2, and carbohydrate content increased 15% under high light. The combination of high light and high pCO2 reduced protein biomass (per unit area) by approximately 20%. Thus, under ecologically relevant irradiances, P. acuta in Kāne'ohe Bay does not exhibit OA-driven reductions in calcification reported for other corals; however, reductions in tissue lipids, energy content and protein biomass suggest OA induced an energetic deficit and compensatory catabolism of tissue biomass. The null effects of OA on calcification at two irradiances support a growing body of work concluding some reef corals may be able to employ compensatory physiological mechanisms that maintain present-day levels of calcification under OA. However, negative effects of OA on P. acuta biomass composition and energy content may impact the long-term performance and scope for growth of this species in a high pCO2 world.
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Affiliation(s)
- C. B. Wall
- Hawai‘i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, PO Box 1346, Kāne‘ohe, HI 96744, USA
| | - R. A. B. Mason
- Hawai‘i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, PO Box 1346, Kāne‘ohe, HI 96744, USA
| | - W. R. Ellis
- Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - R. Cunning
- Hawai‘i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, PO Box 1346, Kāne‘ohe, HI 96744, USA
| | - R. D. Gates
- Hawai‘i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, PO Box 1346, Kāne‘ohe, HI 96744, USA
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Cunning R, Muller EB, Gates RD, Nisbet RM. A dynamic bioenergetic model for coral- Symbiodinium symbioses and coral bleaching as an alternate stable state. J Theor Biol 2017; 431:49-62. [DOI: 10.1016/j.jtbi.2017.08.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/14/2017] [Accepted: 08/02/2017] [Indexed: 11/26/2022]
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Abstract
Symbiotic microalgae (Symbiodinium spp.) strongly influence the performance and stress-tolerance of their coral hosts, making the analysis of Symbiodinium communities in corals (and metacommunities on reefs) advantageous for many aspects of coral reef research. High-throughput sequencing of ITS2 nrDNA offers unprecedented scale in describing these communities, yet high intragenomic variability at this locus complicates the resolution of biologically meaningful diversity. Here, we demonstrate that generating operational taxonomic units by clustering ITS2 sequences at 97% similarity within, but not across, samples collapses sequence diversity that is more likely to be intragenomic, while preserving diversity that is more likely interspecific. We utilize this ‘within-sample clustering’ to analyze Symbiodinium from ten host taxa on shallow reefs on the north and south shores of St. John, US Virgin Islands. While Symbiodinium communities did not differ between shores, metacommunity network analysis of host-symbiont associations revealed Symbiodinium lineages occupying ‘dominant’ and ‘background’ niches, and coral hosts that are more ‘flexible’ or ‘specific’ in their associations with Symbiodinium. These methods shed new light on important questions in coral symbiosis ecology, and demonstrate how application-specific bioinformatic pipelines can improve the analysis of metabarcoding data in microbial metacommunity studies.
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Affiliation(s)
- Ross Cunning
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Peter J Edmunds
- Department of Biology, California State University, Northridge, CA, United States of America
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21
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Okazaki RR, Towle EK, van Hooidonk R, Mor C, Winter RN, Piggot AM, Cunning R, Baker AC, Klaus JS, Swart PK, Langdon C. Species-specific responses to climate change and community composition determine future calcification rates of Florida Keys reefs. Glob Chang Biol 2017; 23:1023-1035. [PMID: 27561209 DOI: 10.1111/gcb.13481] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 08/15/2016] [Accepted: 08/16/2016] [Indexed: 06/06/2023]
Abstract
Anthropogenic climate change compromises reef growth as a result of increasing temperatures and ocean acidification. Scleractinian corals vary in their sensitivity to these variables, suggesting species composition will influence how reef communities respond to future climate change. Because data are lacking for many species, most studies that model future reef growth rely on uniform scleractinian calcification sensitivities to temperature and ocean acidification. To address this knowledge gap, calcification of twelve common and understudied Caribbean coral species was measured for two months under crossed temperatures (27, 30.3 °C) and CO2 partial pressures (pCO2 ) (400, 900, 1300 μatm). Mixed-effects models of calcification for each species were then used to project community-level scleractinian calcification using Florida Keys reef composition data and IPCC AR5 ensemble climate model data. Three of the four most abundant species, Orbicella faveolata, Montastraea cavernosa, and Porites astreoides, had negative calcification responses to both elevated temperature and pCO2 . In the business-as-usual CO2 emissions scenario, reefs with high abundances of these species had projected end-of-century declines in scleractinian calcification of >50% relative to present-day rates. Siderastrea siderea, the other most common species, was insensitive to both temperature and pCO2 within the levels tested here. Reefs dominated by this species had the most stable end-of-century growth. Under more optimistic scenarios of reduced CO2 emissions, calcification rates throughout the Florida Keys declined <20% by 2100. Under the most extreme emissions scenario, projected declines were highly variable among reefs, ranging 10-100%. Without considering bleaching, reef growth will likely decline on most reefs, especially where resistant species like S. siderea are not already dominant. This study demonstrates how species composition influences reef community responses to climate change and how reduced CO2 emissions can limit future declines in reef calcification.
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Affiliation(s)
- Remy R Okazaki
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
- Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, 3737 Brooklyn Ave NE, Seattle, WA, 98195, USA
- NOAA Pacific Marine Environmental Laboratory, 7600 Sandpoint Way NE, Seattle, WA, 98115, USA
| | - Erica K Towle
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Ruben van Hooidonk
- Ocean Chemistry and Ecosystems Division, NOAA Atlantic Oceanographic and Meteorological Laboratory, 4301 Rickenbacker Cswy, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Carolina Mor
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Rivah N Winter
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Alan M Piggot
- Department of Marine Geosciences, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Ross Cunning
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - James S Klaus
- Department of Geological Sciences, University of Miami, 1320 S. Dixie Hwy, Coral Gables, FL, 33124, USA
| | - Peter K Swart
- Department of Marine Geosciences, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
| | - Chris Langdon
- Department of Marine Biology and Ecology, University of Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
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Silverstein RN, Cunning R, Baker AC. Tenacious D: Symbiodinium in clade D remain in reef corals at both high and low temperature extremes despite impairment. J Exp Biol 2017; 220:1192-1196. [DOI: 10.1242/jeb.148239] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 01/18/2017] [Indexed: 11/20/2022]
Abstract
Reef corals are sensitive to thermal stress, which induces coral bleaching (the loss of algal symbionts), often leading to coral mortality. However, corals hosting certain symbionts (notably Symbiodinium in clade D) resist bleaching when exposed to high temperatures. To determine if these symbionts are also cold tolerant, we exposed corals hosting either Symbiodinium C3 or D1a to incremental warming (+1°C week−1 to 35°C) and cooling (−1°C week−1 to 15°C), and measured photodamage and symbiont loss. During warming to 33°C, C3-corals were photodamaged and lost >99% of symbionts, while D1a-corals experienced photodamage but did not bleach. During cooling, D1a-corals suffered more photodamage than C3-corals but still did not bleach, while C3-corals lost 94% of symbionts. These results indicate that photodamage does not always lead to bleaching, suggesting alternate mechanisms exist by which symbionts resist bleaching, and helping explain the persistence of D1a symbionts on recently-bleached reefs, with implications for the future of these ecosystems.
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Affiliation(s)
- Rachel N. Silverstein
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149, USA
- Miami Waterkeeper, 12568 N. Kendall Dr., Miami, FL 33185, USA
| | - Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149, USA
- Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1346, Kaneohe, HI 96744, USA
| | - Andrew C. Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149, USA
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23
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McIlroy SE, Gillette P, Cunning R, Klueter A, Capo T, Baker AC, Coffroth MA. The effects of Symbiodinium (Pyrrhophyta) identity on growth, survivorship, and thermal tolerance of newly settled coral recruits. J Phycol 2016; 52:1114-1124. [PMID: 27690269 DOI: 10.1111/jpy.12471] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 08/23/2016] [Indexed: 05/23/2023]
Abstract
For many coral species, the obligate association with phylogenetically diverse algal endosymbiont species is dynamic in time and space. Here, we used controlled laboratory inoculations of newly settled, aposymbiotic corals (Orbicella faveolata) with two cultured species of algal symbiont (Symbiodinium microadriaticum and S. minutum) to examine the role of symbiont identity on growth, survivorship, and thermal tolerance of the coral holobiont. We evaluated these data in the context of Symbiodinium photophysiology for 9 months post-settlement and also during a 5-d period of elevated temperatures Our data show that recruits that were inoculated with S. minutum grew significantly slower than those inoculated with S. microadriaticum (occasionally co-occurring with S. minutum), but that there was no difference in survivorship of O. faveolata polyps infected with Symbiodinium. However, photophysiological metrics (∆Fv/F'm, the efficiency with which available light is used to drive photosynthesis and α, the maximum light utilization coefficient) were higher in those slower growing recruits containing S. minutum. These findings suggest that light use (i.e., photophysiology) and carbon acquisition by the coral host (i.e., host growth) are decoupled, but did not distinguish the source of this difference. Neither Symbiodinium treatment demonstrated a significant negative effect of a 5-d exposure to temperatures as high as 32°C under low light conditions similar to those measured at settlement habitats.
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Affiliation(s)
- Shelby E McIlroy
- Graduate Program in Evolution, Ecology, and Behavior, University at Buffalo, 126 Cooke Hall, Buffalo, New York, 14260, USA
| | - Phillip Gillette
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Csy, Miami, Florida, 33149, USA
| | - Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Csy, Miami, Florida, 33149, USA
| | - Anke Klueter
- Department of Geology, University at Buffalo, 126 Cooke Hall, Buffalo, New York, 14260, USA
| | - Tom Capo
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Csy, Miami, Florida, 33149, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Csy, Miami, Florida, 33149, USA
| | - Mary Alice Coffroth
- Graduate Program in Evolution, Ecology, and Behavior, University at Buffalo, 126 Cooke Hall, Buffalo, New York, 14260, USA
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Cunning R, Silverstein RN, Baker AC. Investigating the causes and consequences of symbiont shuffling in a multi-partner reef coral symbiosis under environmental change. Proc Biol Sci 2016; 282:20141725. [PMID: 26041354 DOI: 10.1098/rspb.2014.1725] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Dynamic symbioses may critically mediate impacts of climate change on diverse organisms, with repercussions for ecosystem persistence in some cases. On coral reefs, increases in heat-tolerant symbionts after thermal bleaching can reduce coral susceptibility to future stress. However, the relevance of this adaptive response is equivocal owing to conflicting reports of symbiont stability and change. We help reconcile this conflict by showing that change in symbiont community composition (symbiont shuffling) in Orbicella faveolata depends on the disturbance severity and recovery environment. The proportion of heat-tolerant symbionts dramatically increased following severe experimental bleaching, especially in a warmer recovery environment, but tended to decrease if bleaching was less severe. These patterns can be explained by variation in symbiont performance in the changing microenvironments created by differentially bleached host tissues. Furthermore, higher proportions of heat-tolerant symbionts linearly increased bleaching resistance but reduced photochemical efficiency, suggesting that any change in community structure oppositely impacts performance and stress tolerance. Therefore, even minor symbiont shuffling can adaptively benefit corals, although fitness effects of resulting trade-offs are difficult to predict. This work helps elucidate causes and consequences of dynamism in symbiosis, which is critical to predicting responses of multi-partner symbioses such as O. faveolata to environmental change.
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Affiliation(s)
- R Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
| | - R N Silverstein
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA Miami Waterkeeper, 12568 N. Kendall Dr., Miami, FL 33185, USA
| | - A C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA Wildlife Conservation Society, Marine Program, 2300 Southern Boulevard, Bronx, NY 10460, USA
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Cunning R, Yost DM, Guarinello ML, Putnam HM, Gates RD. Variability of Symbiodinium Communities in Waters, Sediments, and Corals of Thermally Distinct Reef Pools in American Samoa. PLoS One 2015; 10:e0145099. [PMID: 26713847 PMCID: PMC4695085 DOI: 10.1371/journal.pone.0145099] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/28/2015] [Indexed: 11/20/2022] Open
Abstract
Reef-building corals host assemblages of symbiotic algae (Symbiodinium spp.) whose diversity and abundance may fluctuate under different conditions, potentially facilitating acclimatization to environmental change. The composition of free-living Symbiodinium in reef waters and sediments may also be environmentally labile and may influence symbiotic assemblages by mediating supply and dispersal. The magnitude and spatial scales of environmental influence over Symbiodinium composition in different reef habitat compartments are, however, not well understood. We used pyrosequencing to compare Symbiodinium in sediments, water, and ten coral species between two backreef pools in American Samoa with contrasting thermal environments. We found distinct compartmental assemblages of clades A, C, D, F, and/or G Symbiodinium types, with strong differences between pools in water, sediments, and two coral species. In the pool with higher and more variable temperatures, abundance of various clade A and C types differed compared to the other pool, while abundance of D types was lower in sediments but higher in water and in Pavona venosa, revealing an altered habitat distribution and potential linkages among compartments. The lack of between-pool effects in other coral species was due to either low overall variability (in the case of Porites) or high within-pool variability. Symbiodinium communities in water and sediment also showed within-pool structure, indicating that environmental influences may operate over multiple, small spatial scales. This work suggests that Symbiodinium composition is highly labile in reef waters, sediments, and some corals, but the underlying drivers and functional consequences of this plasticity require further testing with high spatial resolution biological and environmental sampling.
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Affiliation(s)
- Ross Cunning
- University of Hawai‘i, Hawai‘i Institute of Marine Biology, PO Box 1346, Kāne‘ohe, Hawaii, 96744, United States of America
- * E-mail:
| | - Denise M. Yost
- University of Hawai‘i, Hawai‘i Institute of Marine Biology, PO Box 1346, Kāne‘ohe, Hawaii, 96744, United States of America
| | - Marisa L. Guarinello
- Northwest Knowledge Network, University of Idaho, 875 Perimeter Dr. MS2358, Moscow, Idaho, 83844, United States of America
| | - Hollie M. Putnam
- University of Hawai‘i, Hawai‘i Institute of Marine Biology, PO Box 1346, Kāne‘ohe, Hawaii, 96744, United States of America
| | - Ruth D. Gates
- University of Hawai‘i, Hawai‘i Institute of Marine Biology, PO Box 1346, Kāne‘ohe, Hawaii, 96744, United States of America
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Cunning R, Vaughan N, Gillette P, Capo TR, Matté JL, Baker AC. Dynamic regulation of partner abundance mediates response of reef coral symbioses to environmental change. Ecology 2015; 96:1411-20. [PMID: 26236853 DOI: 10.1890/14-0449.1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Regulating partner abunclance may allow symmotic organisms to mediate interaction outcomes, facilitating adaptive responses to environmental change. To explore the capacity for-adaptive regulation in an ecologically important endosymbiosis, we studied the population dynamics of symbiotic algae in reef-building corals under different abiotic contexts. We found high natural variability in symbiont abundance in corals across reefs, but this variability converged to different symbiont-specific abundances when colonies were maintained under constant conditions. When conditions changed seasonally, symbiont abundance readjusted to new equilibria. We explain these patterns using an a priori model of symbiotic costs and benefits to the coral host, which shows that the observed changes in symbiont abundance are consistent with the maximization of interaction benefit under different environmental conditions. These results indicate that, while regulating symbiont abundance helps hosts sustain maximum benefit in a dynamic environment, spatiotemporal variation in abiotic factors creates a broad range of symbiont abundances (and interaction outcomes) among corals that may account for observed natural variability in performance (e.g., growth rate) and stress tolerance (e.g., bleaching susceptibility). This cost or benefit framework provides a new perspective on the dynamic regulation of reef coral symbioses and illustrates that the dependence of interaction outcomes on biotic and abiotic contexts may be important in understanding how diverse mutualisms respond to environmental change.
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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. Glob Chang Biol 2015; 21:236-249. [PMID: 25099991 DOI: 10.1111/gcb.12706] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Cunning R, Baker AC. Not just who, but how many: the importance of partner abundance in reef coral symbioses. Front Microbiol 2014; 5:400. [PMID: 25136339 PMCID: PMC4120693 DOI: 10.3389/fmicb.2014.00400] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 07/16/2014] [Indexed: 11/18/2022] Open
Abstract
The performance and function of reef corals depends on the genetic identity of their symbiotic algal partners, with some symbionts providing greater benefits (e.g., photosynthate, thermotolerance) than others. However, these interaction outcomes may also depend on partner abundance, with differences in the total number of symbionts changing the net benefit to the coral host, depending on the particular environmental conditions. We suggest that symbiont abundance is a fundamental aspect of the dynamic interface between reef corals and the abiotic environment that ultimately determines the benefits, costs, and functional responses of these symbioses. This density-dependent framework suggests that corals may regulate the size of their symbiont pool to match microhabitat-specific optima, which may contribute to the high spatiotemporal variability in symbiont abundance observed within and among colonies and reefs. Differences in symbiont standing stock may subsequently explain variation in energetics, growth, reproduction, and stress susceptibility, and may mediate the impacts of environmental change on these outcomes. However, the importance of symbiont abundance has received relatively little recognition, possibly because commonly-used metrics based on surface area (e.g., symbiont cells cm-2) may be only weakly linked to biological phenomena and are difficult to compare across studies. We suggest that normalizing symbionts to biological host parameters, such as units of protein or numbers of host cells, will more clearly elucidate the functional role of symbiont abundance in reef coral symbioses. In this article, we generate testable hypotheses regarding the importance of symbiont abundance by first discussing different metrics and their potential links to symbiosis performance and breakdown, and then describing how natural variability and dynamics of symbiont communities may help explain ecological patterns on coral reefs and predict responses to environmental change.
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Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
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Meron D, Rodolfo-Metalpa R, Cunning R, Baker AC, Fine M, Banin E. Changes in coral microbial communities in response to a natural pH gradient. ISME J 2012; 6:1775-85. [PMID: 22437157 PMCID: PMC3498918 DOI: 10.1038/ismej.2012.19] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 12/21/2011] [Accepted: 02/10/2012] [Indexed: 01/08/2023]
Abstract
Surface seawater pH is currently 0.1 units lower than pre-industrial values and is projected to decrease by up to 0.4 units by the end of the century. This acidification has the potential to cause significant perturbations to the physiology of ocean organisms, particularly those such as corals that build their skeletons/shells from calcium carbonate. Reduced ocean pH could also have an impact on the coral microbial community, and thus may affect coral physiology and health. Most of the studies to date have examined the impact of ocean acidification on corals and/or associated microbiota under controlled laboratory conditions. Here we report the first study that examines the changes in coral microbial communities in response to a natural pH gradient (mean pH(T) 7.3-8.1) caused by volcanic CO(2) vents off Ischia, Gulf of Naples, Italy. Two Mediterranean coral species, Balanophyllia europaea and Cladocora caespitosa, were examined. The microbial community diversity and the physiological parameters of the endosymbiotic dinoflagellates (Symbiodinium spp.) were monitored. We found that pH did not have a significant impact on the composition of associated microbial communities in both coral species. In contrast to some earlier studies, we found that corals present at the lower pH sites exhibited only minor physiological changes and no microbial pathogens were detected. Together, these results provide new insights into the impact of ocean acidification on the coral holobiont.
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Affiliation(s)
- Dalit Meron
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Riccardo Rodolfo-Metalpa
- Marine Institute, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth, UK
| | - Ross Cunning
- Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
| | - Andrew C Baker
- Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
| | - Maoz Fine
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Interuniversity Institute for Marine Science in Eilat, Eilat, Israel
| | - Ehud Banin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
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