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Zelli E, Simancas-Giraldo SM, Xiang N, Dessì C, Katzer ND, Tilstra A, Wild C. Individual and combined effect of organic eutrophication (DOC) and ocean warming on the ecophysiology of the Octocoral Pinnigorgia flava. PeerJ 2023; 11:e14812. [PMID: 36814959 PMCID: PMC9940650 DOI: 10.7717/peerj.14812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 01/06/2023] [Indexed: 02/19/2023] Open
Abstract
Dissolved organic carbon (DOC) enrichment and ocean warming both negatively affect hard corals, but studies on their combined effects on other reef organisms are scarce. Octocorals are likely to become key players in future reef communities, but they are still highly under-investigated with regard to their responses to global and local environmental changes. Thus, we evaluated the individual and combined effects of DOC enrichment (10, 20 and 40 mg L-1 DOC, added as glucose) and warming (stepwise from 26 to 32 °C) on the widespread Indo-Pacific gorgonian Pinnigorgia flava in a 45-day laboratory experiment. Oxygen fluxes (net photosynthesis and respiration), as well as Symbiodiniaceae cell density and coral growth were assessed. Our results highlight a differential ecophysiological response to DOC enrichment and warming as well as their combination. Individual DOC addition did not significantly affect oxygen fluxes nor Symbiodiniaceae cell density and growth, while warming significantly decreased photosynthesis rates and Symbiodiniaceae cell density. When DOC enrichment and warming were combined, no effect on P. flava oxygen fluxes was observed while growth responded to certain DOC conditions depending on the temperature. Our findings indicate that P. flava is insensitive to the individual effect of DOC enrichment, but not to warming and the two stressors combined. This suggests that, if temperature remains below certain thresholds, this gorgonian species may gain a competitive advantage over coral species that are reportedly more affected by DOC eutrophication. However, under the expected increasing temperature scenarios, it is also likely that this octocoral species will be negatively affected, with potential consequences on community structure. This study contributes to our understanding of the conditions that drive phase shift dynamics in coastal coral reef ecosystemds.
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Affiliation(s)
- Edoardo Zelli
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany,School of Science, University of Waikato, Tauranga, New Zealand
| | | | - Nan Xiang
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany,Helmholtz Centre for Polar and Marine Research, Alfred Wegener Institute, Bremerhaven, Germany
| | - Claudia Dessì
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany,Dipartimento di Scienze della Vita e dell’Ambiente, University of Cagliari, Cagliari, Italy
| | - Nadim Daniel Katzer
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany
| | - Arjen Tilstra
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany
| | - Christian Wild
- Marine Ecology Department, Faculty of Biology & Chemistry (FB 2), University of Bremen, Bremen, Germany
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Voolstra CR, Valenzuela JJ, Turkarslan S, Cárdenas A, Hume BCC, Perna G, Buitrago-López C, Rowe K, Orellana MV, Baliga NS, Paranjape S, Banc-Prandi G, Bellworthy J, Fine M, Frias-Torres S, Barshis DJ. Contrasting heat stress response patterns of coral holobionts across the Red Sea suggest distinct mechanisms of thermal tolerance. Mol Ecol 2021; 30:4466-4480. [PMID: 34342082 DOI: 10.1111/mec.16064] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/04/2021] [Accepted: 06/30/2021] [Indexed: 12/18/2022]
Abstract
Corals from the northern Red Sea, in particular the Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5℃ above their maximum monthly mean (MMM) temperatures. These elevated thresholds are thought to be due to historical selection, as corals passed through the warmer Southern Red Sea during recolonization from the Arabian Sea. To test this hypothesis, we determined thermal tolerance thresholds of GoA versus central Red Sea (CRS) Stylophora pistillata corals using multi-temperature acute thermal stress assays to determine thermal thresholds. Relative thermal thresholds of GoA and CRS corals were indeed similar and exceptionally high (~7℃ above MMM). However, absolute thermal thresholds of CRS corals were on average 3℃ above those of GoA corals. To explore the molecular underpinnings, we determined gene expression and microbiome response of the coral holobiont. Transcriptomic responses differed markedly, with a strong response to the thermal stress in GoA corals and their symbiotic algae versus a remarkably muted response in CRS colonies. Concomitant to this, coral and algal genes showed temperature-induced expression in GoA corals, while exhibiting fixed high expression (front-loading) in CRS corals. Bacterial community composition of GoA corals changed dramatically under heat stress, whereas CRS corals displayed stable assemblages. We interpret the response of GoA corals as that of a resilient population approaching a tipping point in contrast to a pattern of consistently elevated thermal resistance in CRS corals that cannot further attune. Such response differences suggest distinct thermal tolerance mechanisms that may affect the response of coral populations to ocean warming.
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Affiliation(s)
| | | | | | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Gabriela Perna
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Katherine Rowe
- School of Science, The University of Waikato, Hamilton, New Zealand
| | - Monica V Orellana
- Institute for Systems Biology, Seattle, USA.,Polar Science Center, University of Washington, Seattle, USA
| | - Nitin S Baliga
- Institute for Systems Biology, Seattle, USA.,Departments of Biology and Microbiology, University of Washington, Seattle, USA.,Molecular and Cellular Biology Program, University of Washington, Seattle, USA.,Lawrence Berkeley National Laboratory, Berkeley, USA
| | | | - Guilhem Banc-Prandi
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Jessica Bellworthy
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Maoz Fine
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | | | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, USA
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Simancas-Giraldo SM, Xiang N, Kennedy MM, Nafeh R, Zelli E, Wild C. Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication. PeerJ 2021; 9:e11663. [PMID: 34395065 PMCID: PMC8323596 DOI: 10.7717/peerj.11663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 06/01/2021] [Indexed: 11/20/2022] Open
Abstract
Eutrophication with dissolved organic carbon (DOC) as a far under-investigated stressor, and ocean warming, can strongly affect coral reefs and hard corals as major reefs ecosystem engineers. However, no previous studies have investigated the metabolic responses of soft corals to DOC eutrophication, or its interaction with ocean warming. Thus, we investigated respiration and photosynthesis response of Xenia umbellata, a common mixotrophic soft coral from the Indo-pacific, to (1) three levels of DOC eutrophication simulated by glucose addition over the first 21 days of experiment and (2) ocean warming scenarios where the temperature was gradually increased from 26 °C (control condition) to 32 °C over another 24 days in an aquarium experiment. We found no significant difference in response to DOC treatments and all corals survived regardless of the DOC concentrations, whilst subsequent exposure to simulated ocean warming significantly decreased gross photosynthesis by approximately 50% at 30 °C, and 65% at 32 °C, net photosynthesis by 75% at 30 °C and 79% at 32 °C, and respiration by a maximum of 75% at 30 °C; with a slight increase at 32 °C of 25%. The ratio between gross photosynthesis and respiration decreased by the end of the warming period but remained similar between controls and colonies previously exposed to DOC. Our findings suggest that soft corals may be more resistant than hard corals to DOC eutrophication and in consequence, may potentially experiment in less magnitude the negative effects of increased temperature or subsequently both stressors. The results of this study may contribute to explain the successful role of soft corals in phase shifts as reported from many coral reefs. Where predicted declines in reef ecosystems health due to increased eutrophication levels can be exacerbated by future warming.
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Affiliation(s)
| | - Nan Xiang
- Marine Ecology Department, Universität Bremen, Bremen, Germany
- Helmholtz Centre for Polar and Marine Research, Alfred Wegener Institute, Bremerhaven, Germany
| | | | - Rassil Nafeh
- Marine Ecology Department, Universität Bremen, Bremen, Germany
| | - Edoardo Zelli
- Marine Ecology Department, Universität Bremen, Bremen, Germany
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA) & Centro Interdipartimentale di Ricerca per le Scienze Ambientali (CIRSA), University of Bologna, Italy
| | - Christian Wild
- Marine Ecology Department, Universität Bremen, Bremen, Germany
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Bouwmeester J, Coker DJ, Sinclair‐Taylor TH, Berumen ML. Broadcast spawning of
Pocillopora verrucosa
across the eastern and western coast of the central Red Sea. Ecosphere 2021. [DOI: 10.1002/ecs2.3340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jessica Bouwmeester
- Smithsonian Conservation Biology Institute Front Royal Virginia22630USA
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering King Abdullah University of Science and Technology Thuwal23955Saudi Arabia
| | - Darren J. Coker
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering King Abdullah University of Science and Technology Thuwal23955Saudi Arabia
| | - Tane H. Sinclair‐Taylor
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering King Abdullah University of Science and Technology Thuwal23955Saudi Arabia
- Australian Institute of Marine Science Townsville Queensland4810Australia
| | - Michael L. Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering King Abdullah University of Science and Technology Thuwal23955Saudi Arabia
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