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Schoepf V, Baumann JH, Barshis DJ, Browne NK, Camp EF, Comeau S, Cornwall CE, Guzmán HM, Riegl B, Rodolfo-Metalpa R, Sommer B. Corals at the edge of environmental limits: A new conceptual framework to re-define marginal and extreme coral communities. Sci Total Environ 2023; 884:163688. [PMID: 37105476 DOI: 10.1016/j.scitotenv.2023.163688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/07/2023]
Abstract
The worldwide decline of coral reefs has renewed interest in coral communities at the edge of environmental limits because they have the potential to serve as resilience hotspots and climate change refugia, and can provide insights into how coral reefs might function in future ocean conditions. These coral communities are often referred to as marginal or extreme but few definitions exist and usage of these terms has therefore been inconsistent. This creates significant challenges for categorising these often poorly studied communities and synthesising data across locations. Furthermore, this impedes our understanding of how coral communities can persist at the edge of their environmental limits and the lessons they provide for future coral reef survival. Here, we propose that marginal and extreme coral communities are related but distinct and provide a novel conceptual framework to redefine them. Specifically, we define coral reef extremeness solely based on environmental conditions (i.e., large deviations from optimal conditions in terms of mean and/or variance) and marginality solely based on ecological criteria (i.e., altered community composition and/or ecosystem functioning). This joint but independent assessment of environmental and ecological criteria is critical to avoid common pitfalls where coral communities existing outside the presumed optimal conditions for coral reef development are automatically considered inferior to coral reefs in more traditional settings. We further evaluate the differential potential of marginal and extreme coral communities to serve as natural laboratories, resilience hotspots and climate change refugia, and discuss strategies for their conservation and management as well as priorities for future research. Our new classification framework provides an important tool to improve our understanding of how corals can persist at the edge of their environmental limits and how we can leverage this knowledge to optimise strategies for coral reef conservation, restoration and management in a rapidly changing ocean.
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Affiliation(s)
- Verena Schoepf
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; UWA Oceans Institute, University of Western Australia, Perth, Western Australia, Australia.
| | - Justin H Baumann
- Department of Biology, Mount Holyoke College, South Hadley, MA, USA
| | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Nicola K Browne
- School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Steeve Comeau
- Sorbonne Université, CNRS-INSU, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-mer, France
| | - Christopher E Cornwall
- School of Biological Sciences and Coastal People: Southern Skies, Victoria University of Wellington, Wellington, New Zealand
| | - Héctor M Guzmán
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Bernhard Riegl
- Department of Marine and Environmental Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Riccardo Rodolfo-Metalpa
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa, New Caledonia; Labex ICONA, International CO(2) Natural Analogues Network, Japan
| | - Brigitte Sommer
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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Baumann JH, Zhao L, Stier AC, Bruno JF. Remoteness does not enhance coral reef resilience. Glob Chang Biol 2022; 28:417-428. [PMID: 34668280 PMCID: PMC8671335 DOI: 10.1111/gcb.15904] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/07/2021] [Accepted: 09/07/2021] [Indexed: 05/02/2023]
Abstract
Remote coral reefs are thought to be more resilient to climate change due to their isolation from local stressors like fishing and pollution. We tested this hypothesis by measuring the relationship between local human influence and coral community resilience. Surprisingly, we found no relationship between human influence and resistance to disturbance and some evidence that areas with greater human development may recover from disturbance faster than their more isolated counterparts. Our results suggest remote coral reefs are imperiled by climate change, like so many other geographically isolated ecosystems, and are unlikely to serve as effective biodiversity arks. Only drastic and rapid cuts in greenhouse gas emissions will ensure coral survival. Our results also indicate that some reefs close to large human populations were relatively resilient. Focusing research and conservation resources on these more accessible locations has the potential to provide new insights and maximize conservation outcomes.
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Affiliation(s)
- Justin H. Baumann
- The Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3280 USA
- Department of Marine Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 USA
- Biology Department, Bowdoin College, Brunswick, Maine, 04011 USA
- Correspondence to: or
| | - Lily Zhao
- Department of Ecology, Evolution, and Marine Biology, The University of California Santa Barbara, Santa Barbara CA, 93106-9620, USA
| | - Adrian C. Stier
- Department of Ecology, Evolution, and Marine Biology, The University of California Santa Barbara, Santa Barbara CA, 93106-9620, USA
| | - John F. Bruno
- The Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3280 USA
- Correspondence to: or
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Oldenburg KS, Urban-Rich J, Castillo KD, Baumann JH. Microfiber abundance associated with coral tissue varies geographically on the Belize Mesoamerican Barrier Reef System. Mar Pollut Bull 2021; 163:111938. [PMID: 33348289 DOI: 10.1016/j.marpolbul.2020.111938] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 05/07/2020] [Revised: 12/03/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Ocean plastic pollution is a global problem that causes ecosystem degradation. Crucial knowledge gaps exist concerning patterns in microfiber abundance across regions and ecosystems, as well as the role of these pollutants within the environment. Here, we quantified the abundance of microfibers in coral samples collected from the Belize Mesoamerican Barrier Reef System (MBRS) using a polarized light microscope and identified a subsample of these to the polymer level using an Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy microscope. Microfibers were found in all coral samples with rayon being identified as the most common microfiber, comprising 85% of quantified pollutants. We found a greater average abundance of microfibers in coral samples from the Sapodilla Cayes (296 ± SE 89) than in samples from the Drowned Cayes (75 ± SE 14), indicating spatial variation in microfiber abundance within coral tissue along the MBRS. These results demonstrate that corals on the Belize MBRS interact with microfibers and that microfiber abundance on reefs varies spatially due to point sources of pollution and local oceanography. As rayon from clothing typically enters the ocean through wastewater effluent, alterations to waste water infrastructure may prove useful in decreasing rayon pollution in coastal waters.
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Affiliation(s)
- Kirsi S Oldenburg
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Juanita Urban-Rich
- Environmental, Coastal and Ocean Sciences, University of Massachusetts-Boston, Boston, USA
| | - Karl D Castillo
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Environment, Ecology, and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Justin H Baumann
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Baumann JH, Ries JB, Rippe JP, Courtney TA, Aichelman HE, Westfield I, Castillo KD. Nearshore coral growth declining on the Mesoamerican Barrier Reef System. Glob Chang Biol 2019; 25:3932-3945. [PMID: 31456305 DOI: 10.1111/gcb.14784] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 02/01/2019] [Revised: 07/23/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
Anthropogenic global change and local stressors are impacting coral growth and survival worldwide, altering the structure and function of coral reef ecosystems. Here, we show that skeletal extension rates of nearshore colonies of two abundant and widespread Caribbean corals (Siderastrea siderea, Pseudodiploria strigosa) declined across the Belize Mesoamerican Barrier Reef System (MBRS) over the past century, while offshore coral conspecifics exhibited relatively stable extension rates over the same temporal interval. This decline has caused nearshore coral extension rates to converge with those of their historically slower growing offshore coral counterparts. For both species, individual mass coral bleaching events were correlated with low rates of skeletal extension within specific reef environments, but no single bleaching event was correlated with low skeletal extension rates across all reef environments. We postulate that the decline in skeletal extension rates for nearshore corals is driven primarily by the combined effects of long-term ocean warming and increasing exposure to higher levels of land-based anthropogenic stressors, with acute thermally induced bleaching events playing a lesser role. If these declining trends in skeletal growth of nearshore S. siderea and P. strigosa continue into the future, the structure and function of these critical nearshore MBRS coral reef systems is likely to be severely impaired.
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Affiliation(s)
- Justin H Baumann
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Justin B Ries
- Department of Marine and Environmental Sciences, Marine Science Center, Northeastern University, Nahant, Massachusetts
| | - John P Rippe
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Travis A Courtney
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Marine and Environmental Sciences, Marine Science Center, Northeastern University, Nahant, Massachusetts
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
| | - Hannah E Aichelman
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Biological Sciences, Boston University, Boston, Massachusetts
| | - Isaac Westfield
- Department of Marine and Environmental Sciences, Marine Science Center, Northeastern University, Nahant, Massachusetts
| | - Karl D Castillo
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Environment, Ecology, and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Rippe JP, Baumann JH, De Leener DN, Aichelman HE, Friedlander EB, Davies SW, Castillo KD. Corals sustain growth but not skeletal density across the Florida Keys Reef Tract despite ongoing warming. Glob Chang Biol 2018; 24:5205-5217. [PMID: 30102827 DOI: 10.1111/gcb.14422] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/11/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Through the continuous growth of their carbonate skeletons, corals record information about past environmental conditions and their effect on colony fitness. Here, we characterize century-scale growth records of inner and outer reef corals across ~200 km of the Florida Keys Reef Tract (FKRT) using skeletal cores extracted from two ubiquitous reef-building species, Siderastrea siderea and Pseudodiploria strigosa. We find that corals across the FKRT have sustained extension and calcification rates over the past century but have experienced a long-term reduction in skeletal density, regardless of reef zone. Notably, P. strigosa colonies exhibit temporary reef zone-dependent reductions in extension rate corresponding to two known extreme temperature events in 1969-1970 and 1997-1998. We propose that the subtropical climate of the FKRT may buffer corals from chronic growth declines associated with climate warming, though the significant reduction in skeletal density may indicate underlying vulnerability to present and future trends in ocean acidification.
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Affiliation(s)
- John P Rippe
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Justin H Baumann
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Daphne N De Leener
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Hannah E Aichelman
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Biology, Boston University, Boston, Massachusetts
| | - Eric B Friedlander
- Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Sarah W Davies
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Biology, Boston University, Boston, Massachusetts
| | - Karl D Castillo
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Curriculum for Environment and Ecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Baumann JH, Davies SW, Aichelman HE, Castillo KD. Correction to: Coral Symbiodinium Community Composition Across the Belize Mesoamerican Barrier Reef System is Influenced by Host Species and Thermal Variability. Microb Ecol 2018; 75:916. [PMID: 29150733 DOI: 10.1007/s00248-017-1112-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The authors regret that acknowledgment for Dr. Adrian Marchetti was omitted from the manuscript. The correct acknowledgment is written below.
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Affiliation(s)
- J H Baumann
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
| | - S W Davies
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - H E Aichelman
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
- Department of Biological Sciences, Old Dominion University, 302 Miles Godwin building, Norfolk, VA, 23529, USA
| | - K D Castillo
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
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Baumann JH, Davies SW, Aichelman HE, Castillo KD. Coral Symbiodinium Community Composition Across the Belize Mesoamerican Barrier Reef System is Influenced by Host Species and Thermal Variability. Microb Ecol 2018; 75:903-915. [PMID: 29098358 DOI: 10.1007/s00248-017-1096-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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: 06/22/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
Reef-building corals maintain a symbiotic relationship with dinoflagellate algae of the genus Symbiodinium, and this symbiosis is vital for the survival of the coral holobiont. Symbiodinium community composition within the coral host has been shown to influence a coral's ability to resist and recover from stress. A multitude of stressors including ocean warming, ocean acidification, and eutrophication have been linked to global scale decline in coral health and cover in recent decades. Three distinct thermal regimes (highTP, modTP, and lowTP) following an inshore-offshore gradient of declining average temperatures and thermal variation were identified on the Belize Mesoamerican Barrier Reef System (MBRS). Quantitative metabarcoding of the ITS-2 locus was employed to investigate differences and similarities in Symbiodinium genetic diversity of the Caribbean corals Siderastrea siderea, S. radians, and Pseudodiploria strigosa between the three thermal regimes. A total of ten Symbiodinium lineages were identified across the three coral host species. S. siderea was associated with distinct Symbiodinium communities; however, Symbiodinium communities of its congener, S. radians and P. strigosa, were more similar to one another. Thermal regime played a role in defining Symbiodinium communities in S. siderea but not S. radians or P. strigosa. Against expectations, Symbiodinium trenchii, a symbiont known to confer thermal tolerance, was dominant only in S. siderea at one sampled offshore site and was rare inshore, suggesting that coral thermal tolerance in more thermally variable inshore habitats is achieved through alternative mechanisms. Overall, thermal parameters alone were likely not the only primary drivers of Symbiodinium community composition, suggesting that environmental variables unrelated to temperature (i.e., light availability or nutrients) may play key roles in structuring coral-algal communities in Belize and that the relative importance of these environmental variables may vary by coral host species.
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Affiliation(s)
- J H Baumann
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
| | - S W Davies
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - H E Aichelman
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
- Department of Biological Sciences, Old Dominion University, 302 Miles Godwin building, Norfolk, VA, 23529, USA
| | - K D Castillo
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA
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Baumann JH, Townsend JE, Courtney TA, Aichelman HE, Davies SW, Lima FP, Castillo KD. Temperature Regimes Impact Coral Assemblages along Environmental Gradients on Lagoonal Reefs in Belize. PLoS One 2016; 11:e0162098. [PMID: 27606598 PMCID: PMC5015988 DOI: 10.1371/journal.pone.0162098] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 08/17/2016] [Indexed: 12/24/2022] Open
Abstract
Coral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress-tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003-2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing these two life history strategies may be better suited to cope with warmer oceans and thus may warrant protective status under climate change.
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Affiliation(s)
- Justin H. Baumann
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
| | - Joseph E. Townsend
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
| | - Travis A. Courtney
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
- Northeastern University, Department of Marine and Environmental Sciences; 430 Nahant Rd, Nahant, MA, United States of America
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Dr., La Jolla, CA, 92093–0202, United States of America
| | - Hannah E. Aichelman
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
| | - Sarah W. Davies
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
- Northeastern University, Department of Marine and Environmental Sciences; 430 Nahant Rd, Nahant, MA, United States of America
| | - Fernando P. Lima
- CIBIO/InBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, Universitdade do Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - Karl D. Castillo
- University of North Carolina at Chapel Hill, Department of Marine Sciences, 3202 Murray and Venable Halls, Chapel Hill, NC, 27599–3300, United States of America
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Schoepf V, Grottoli AG, Levas SJ, Aschaffenburg MD, Baumann JH, Matsui Y, Warner ME. Annual coral bleaching and the long-term recovery capacity of coral. Proc Biol Sci 2016; 282:rspb.2015.1887. [PMID: 26582020 DOI: 10.1098/rspb.2015.1887] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [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: 11/12/2022] Open
Abstract
Mass bleaching events are predicted to occur annually later this century. Nevertheless, it remains unknown whether corals will be able to recover between annual bleaching events. Using a combined tank and field experiment, we simulated annual bleaching by exposing three Caribbean coral species (Porites divaricata, Porites astreoides and Orbicella faveolata) to elevated temperatures for 2.5 weeks in 2 consecutive years. The impact of annual bleaching stress on chlorophyll a, energy reserves, calcification, and tissue C and N isotopes was assessed immediately after the second bleaching and after both short- and long-term recovery on the reef (1.5 and 11 months, respectively). While P. divaricata and O. faveolata were able to recover from repeat bleaching within 1 year, P. astreoides experienced cumulative damage that prevented full recovery within this time frame, suggesting that repeat bleaching had diminished its recovery capacity. Specifically, P. astreoides was not able to recover protein and carbohydrate concentrations. As energy reserves promote bleaching resistance, failure to recover from annual bleaching within 1 year will likely result in the future demise of heat-sensitive coral species.
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Affiliation(s)
- Verena Schoepf
- School of Earth Sciences, The Ohio State University, Columbus, OH, USA Australian Research Council Centre of Excellence for Coral Reef Studies, School of Earth and Environment, and UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia
| | - Andréa G Grottoli
- School of Earth Sciences, The Ohio State University, Columbus, OH, USA
| | - Stephen J Levas
- School of Earth Sciences, The Ohio State University, Columbus, OH, USA Department of Geography and the Environment, Villanova University, Villanova, PA, USA
| | | | - Justin H Baumann
- School of Earth Sciences, The Ohio State University, Columbus, OH, USA Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yohei Matsui
- School of Earth Sciences, The Ohio State University, Columbus, OH, USA
| | - Mark E Warner
- School of Marine Science and Policy, University of Delaware, Lewes, DE, USA
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Aichelman HE, Townsend JE, Courtney TA, Baumann JH, Davies SW, Castillo KD. Heterotrophy mitigates the response of the temperate coral Oculina arbuscula to temperature stress. Ecol Evol 2016; 6:6758-6769. [PMID: 27777745 PMCID: PMC5058543 DOI: 10.1002/ece3.2399] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 01/18/2016] [Revised: 07/19/2016] [Accepted: 08/04/2016] [Indexed: 11/29/2022] Open
Abstract
Anthropogenic increases in atmospheric carbon dioxide concentration have caused global average sea surface temperature (SST) to increase by approximately 0.11°C per decade between 1971 and 2010 – a trend that is projected to continue through the 21st century. A multitude of research studies have demonstrated that increased SSTs compromise the coral holobiont (cnidarian host and its symbiotic algae) by reducing both host calcification and symbiont density, among other variables. However, we still do not fully understand the role of heterotrophy in the response of the coral holobiont to elevated temperature, particularly for temperate corals. Here, we conducted a pair of independent experiments to investigate the influence of heterotrophy on the response of the temperate scleractinian coral Oculina arbuscula to thermal stress. Colonies of O. arbuscula from Radio Island, North Carolina, were exposed to four feeding treatments (zero, low, moderate, and high concentrations of newly hatched Artemia sp. nauplii) across two independent temperature experiments (average annual SST (20°C) and average summer temperature (28°C) for the interval 2005–2012) to quantify the effects of heterotrophy on coral skeletal growth and symbiont density. Results suggest that heterotrophy mitigated both reduced skeletal growth and decreased symbiont density observed for unfed corals reared at 28°C. This study highlights the importance of heterotrophy in maintaining coral holobiont fitness under thermal stress and has important implications for the interpretation of coral response to climate change.
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Affiliation(s)
- Hannah E Aichelman
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina
| | - Joseph E Townsend
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina
| | - Travis A Courtney
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina; Department of Marine and Environmental Sciences Northeastern University Nahant Massachusetts; Present address: Scripps Institution of Oceanography University of California San Diego La Jolla California
| | - Justin H Baumann
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina
| | - Sarah W Davies
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina; Department of Marine and Environmental Sciences Northeastern University Nahant Massachusetts
| | - Karl D Castillo
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina
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Schoepf V, Grottoli AG, Warner ME, Cai WJ, Melman TF, Hoadley KD, Pettay DT, Hu X, Li Q, Xu H, Wang Y, Matsui Y, Baumann JH. Coral energy reserves and calcification in a high-CO2 world at two temperatures. PLoS One 2013; 8:e75049. [PMID: 24146747 PMCID: PMC3795744 DOI: 10.1371/journal.pone.0075049] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [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: 06/02/2013] [Accepted: 08/08/2013] [Indexed: 11/30/2022] Open
Abstract
Rising atmospheric CO2 concentrations threaten coral reefs globally by causing ocean acidification (OA) and warming. Yet, the combined effects of elevated pCO2 and temperature on coral physiology and resilience remain poorly understood. While coral calcification and energy reserves are important health indicators, no studies to date have measured energy reserve pools (i.e., lipid, protein, and carbohydrate) together with calcification under OA conditions under different temperature scenarios. Four coral species, Acropora millepora, Montipora monasteriata, Pocillopora damicornis, Turbinaria reniformis, were reared under a total of six conditions for 3.5 weeks, representing three pCO2 levels (382, 607, 741 µatm), and two temperature regimes (26.5, 29.0 °C) within each pCO2 level. After one month under experimental conditions, only A. millepora decreased calcification (-53%) in response to seawater pCO2 expected by the end of this century, whereas the other three species maintained calcification rates even when both pCO2 and temperature were elevated. Coral energy reserves showed mixed responses to elevated pCO2 and temperature, and were either unaffected or displayed nonlinear responses with both the lowest and highest concentrations often observed at the mid-pCO2 level of 607 µatm. Biweekly feeding may have helped corals maintain calcification rates and energy reserves under these conditions. Temperature often modulated the response of many aspects of coral physiology to OA, and both mitigated and worsened pCO2 effects. This demonstrates for the first time that coral energy reserves are generally not metabolized to sustain calcification under OA, which has important implications for coral health and bleaching resilience in a high-CO2 world. Overall, these findings suggest that some corals could be more resistant to simultaneously warming and acidifying oceans than previously expected.
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Affiliation(s)
- Verena Schoepf
- School of Earth Sciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Andréa G. Grottoli
- School of Earth Sciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Mark E. Warner
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, United States of America
| | - Wei-Jun Cai
- Department of Marine Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Todd F. Melman
- Reef Systems Coral Farm, New Albany, Ohio, United States of America
| | - Kenneth D. Hoadley
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, United States of America
| | - D. Tye Pettay
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, United States of America
| | - Xinping Hu
- Department of Marine Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Qian Li
- Department of Marine Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Hui Xu
- Department of Marine Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Yongchen Wang
- Department of Marine Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Yohei Matsui
- School of Earth Sciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Justin H. Baumann
- School of Earth Sciences, The Ohio State University, Columbus, Ohio, United States of America
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