Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication
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,...
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PeerJ Inc.
2021-07-01
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| author | Susana Marcela Simancas-Giraldo Nan Xiang Meghan Moger Kennedy Rassil Nafeh Edoardo Zelli Christian Wild |
| author_facet | Susana Marcela Simancas-Giraldo Nan Xiang Meghan Moger Kennedy Rassil Nafeh Edoardo Zelli Christian Wild |
| author_sort | Susana Marcela Simancas-Giraldo |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-09T06:51:35Z |
| format | Article |
| id | doaj.art-d6eaee5d152d49db8c05c904d28b1a51 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:51:35Z |
| publishDate | 2021-07-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-d6eaee5d152d49db8c05c904d28b1a512023-12-03T10:25:29ZengPeerJ Inc.PeerJ2167-83592021-07-019e1166310.7717/peerj.11663Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophicationSusana Marcela Simancas-Giraldo0Nan Xiang1Meghan Moger Kennedy2Rassil Nafeh3Edoardo Zelli4Christian Wild5Marine Ecology Department, Universität Bremen, Bremen, GermanyMarine Ecology Department, Universität Bremen, Bremen, GermanyMarine Ecology Department, Universität Bremen, Bremen, GermanyMarine Ecology Department, Universität Bremen, Bremen, GermanyMarine Ecology Department, Universität Bremen, Bremen, GermanyMarine Ecology Department, Universität Bremen, Bremen, GermanyEutrophication 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.https://peerj.com/articles/11663.pdfOctocoralPulsating coralStress modulationGlobal stressorLocal stressorDOC |
| spellingShingle | Susana Marcela Simancas-Giraldo Nan Xiang Meghan Moger Kennedy Rassil Nafeh Edoardo Zelli Christian Wild Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication PeerJ Octocoral Pulsating coral Stress modulation Global stressor Local stressor DOC |
| title | Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication |
| title_full | Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication |
| title_fullStr | Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication |
| title_full_unstemmed | Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication |
| title_short | Photosynthesis and respiration of the soft coral Xenia umbellata respond to warming but not to organic carbon eutrophication |
| title_sort | photosynthesis and respiration of the soft coral xenia umbellata respond to warming but not to organic carbon eutrophication |
| topic | Octocoral Pulsating coral Stress modulation Global stressor Local stressor DOC |
| url | https://peerj.com/articles/11663.pdf |
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