The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba
IntroductionSeagrasses form oxidizing microenvironments around their roots, creating complex and strong redox gradients, thus affecting the rates of microbial carbon mineralization in their surrounding sediments. Since seagrasses are continuously being lost worldwide, a deeper understanding of the c...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-11-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1250931/full |
| _version_ | 1797643250216992768 |
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| author | Neta Soto Neta Soto Gidon Winters Gidon Winters Gilad Antler Gilad Antler |
| author_facet | Neta Soto Neta Soto Gidon Winters Gidon Winters Gilad Antler Gilad Antler |
| author_sort | Neta Soto |
| collection | DOAJ |
| description | IntroductionSeagrasses form oxidizing microenvironments around their roots, creating complex and strong redox gradients, thus affecting the rates of microbial carbon mineralization in their surrounding sediments. Since seagrasses are continuously being lost worldwide, a deeper understanding of the changes that occur within different seagrass sediments following the disappearance of the plants is of ecological and global importance.MethodsWe conducted a slurry experiment with sediments that have different characteristics from the northern tip of Gulf of Aqaba; the different sediments included different compartments of the tropical seagrass Halophila stipulacea (old and young leaves, rhizomes, or roots). We measured the changes over time in dissolved inorganic carbon (DIC), alkalinity, ferrous iron (Fe2+), hydrogen sulfide (H2S), sulfate (SO42-), and sulphur isotope ratios in sulfate within water. These measurements were used to calculate the rate of remineralization of each seagrass compartment, allowing us to predict the potential effects of the disappearance of different H. stipulacea compartments on key microbial processes in the surrounding environment.ResultsWe show that H. stipulacea’s rhizomes had the fastest decomposition rates, followed by the young leaves, roots, and old leaves (which also indicates the preservation potential of old leaves).DiscussionHigh concentrations of hydrogen sulfide were detected only in the slurries containing rhizomes and young leaves. High sulfide concentrations can lead to seagrass mortality and cause a positive feedback loop where the loss of seagrass due to sulfide generates further sulfide accumulation. This positive feedback loop can also be further reinforced by the loss of burrowing fauna in the sediment. This emphasizes the importance of understanding the extent of different pathways of seagrass disappearance on the surrounding environment and other geochemical feedbacks. |
| first_indexed | 2024-03-11T14:12:00Z |
| format | Article |
| id | doaj.art-2f0398e9cd8b4720ad0edb1bff2e4591 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-03-11T14:12:00Z |
| publishDate | 2023-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-2f0398e9cd8b4720ad0edb1bff2e45912023-11-01T17:37:15ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-11-011010.3389/fmars.2023.12509311250931The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of AqabaNeta Soto0Neta Soto1Gidon Winters2Gidon Winters3Gilad Antler4Gilad Antler5Department of Geological and Environmental Sciences, Ben-Gurion University of the Negev, Be'er Sheva, IsraelThe Interuniversity Institute for Marine Sciences, Eilat, IsraelDead Sea and Arava Science Center (DSASC), Masada National Park, Mount Masada, IsraelBen-Gurion University of the Negev, Eilat, IsraelDepartment of Geological and Environmental Sciences, Ben-Gurion University of the Negev, Be'er Sheva, IsraelThe Interuniversity Institute for Marine Sciences, Eilat, IsraelIntroductionSeagrasses form oxidizing microenvironments around their roots, creating complex and strong redox gradients, thus affecting the rates of microbial carbon mineralization in their surrounding sediments. Since seagrasses are continuously being lost worldwide, a deeper understanding of the changes that occur within different seagrass sediments following the disappearance of the plants is of ecological and global importance.MethodsWe conducted a slurry experiment with sediments that have different characteristics from the northern tip of Gulf of Aqaba; the different sediments included different compartments of the tropical seagrass Halophila stipulacea (old and young leaves, rhizomes, or roots). We measured the changes over time in dissolved inorganic carbon (DIC), alkalinity, ferrous iron (Fe2+), hydrogen sulfide (H2S), sulfate (SO42-), and sulphur isotope ratios in sulfate within water. These measurements were used to calculate the rate of remineralization of each seagrass compartment, allowing us to predict the potential effects of the disappearance of different H. stipulacea compartments on key microbial processes in the surrounding environment.ResultsWe show that H. stipulacea’s rhizomes had the fastest decomposition rates, followed by the young leaves, roots, and old leaves (which also indicates the preservation potential of old leaves).DiscussionHigh concentrations of hydrogen sulfide were detected only in the slurries containing rhizomes and young leaves. High sulfide concentrations can lead to seagrass mortality and cause a positive feedback loop where the loss of seagrass due to sulfide generates further sulfide accumulation. This positive feedback loop can also be further reinforced by the loss of burrowing fauna in the sediment. This emphasizes the importance of understanding the extent of different pathways of seagrass disappearance on the surrounding environment and other geochemical feedbacks.https://www.frontiersin.org/articles/10.3389/fmars.2023.1250931/fullHalophila stipulaceaGulf of Aqaba (Eilat)sulfurseagrassblue carbonsediments |
| spellingShingle | Neta Soto Neta Soto Gidon Winters Gidon Winters Gilad Antler Gilad Antler The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba Frontiers in Marine Science Halophila stipulacea Gulf of Aqaba (Eilat) sulfur seagrass blue carbon sediments |
| title | The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba |
| title_full | The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba |
| title_fullStr | The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba |
| title_full_unstemmed | The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba |
| title_short | The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba |
| title_sort | effect of anaerobic remineralization of the seagrass halophila stipulacea on porewater biogeochemistry in the gulf of aqaba |
| topic | Halophila stipulacea Gulf of Aqaba (Eilat) sulfur seagrass blue carbon sediments |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1250931/full |
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