Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs.
Many reefs have shifted from coral and fish dominated habitats to less productive macroalgal dominated habitats, and current research is investigating means of reversing this phase shift. In the tropical Pacific, overfished reefs with inadequate herbivory can become dominated by the brown alga Sarga...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2016-01-01
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| Series: | PLoS ONE |
| Online Access: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0155049&type=printable |
| _version_ | 1826583974436143104 |
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| author | Claire L A Dell Guilherme O Longo Mark E Hay |
| author_facet | Claire L A Dell Guilherme O Longo Mark E Hay |
| author_sort | Claire L A Dell |
| collection | DOAJ |
| description | Many reefs have shifted from coral and fish dominated habitats to less productive macroalgal dominated habitats, and current research is investigating means of reversing this phase shift. In the tropical Pacific, overfished reefs with inadequate herbivory can become dominated by the brown alga Sargassum polycystum. This alga suppresses recruitment and survival of corals and fishes, thus limiting the potential for reef recovery. Here we investigate the mechanisms that reinforce S. polycystum dominance and show that in addition to negatively affecting other species, this species acts in a self-reinforcing manner, positively promoting survival and growth of conspecifics. We found that survival and growth of both recruit-sized and mature S. polycystum fronds were higher within Sargassum beds than outside the beds and these results were found in both protected and fished reefs. Much of this benefit resulted from reduced herbivory within the Sargassum beds, but adult fronds also grew ~50% more within the beds even when herbivory did not appear to be occurring, suggesting some physiological advantage despite the intraspecific crowding. Thus via positive feedbacks, S. polycystum enhances its own growth and resistance to herbivores, facilitating its dominance (perhaps also expansion) and thus its resilience on degraded reefs. This may be a key feedback mechanism suppressing the recovery of coral communities in reefs dominated by macroalgal beds. |
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| format | Article |
| id | doaj.art-020e241d8d6948c1a8e0f864346695bc |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2025-03-14T15:30:23Z |
| publishDate | 2016-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-020e241d8d6948c1a8e0f864346695bc2025-02-25T05:36:16ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01115e015504910.1371/journal.pone.0155049Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs.Claire L A DellGuilherme O LongoMark E HayMany reefs have shifted from coral and fish dominated habitats to less productive macroalgal dominated habitats, and current research is investigating means of reversing this phase shift. In the tropical Pacific, overfished reefs with inadequate herbivory can become dominated by the brown alga Sargassum polycystum. This alga suppresses recruitment and survival of corals and fishes, thus limiting the potential for reef recovery. Here we investigate the mechanisms that reinforce S. polycystum dominance and show that in addition to negatively affecting other species, this species acts in a self-reinforcing manner, positively promoting survival and growth of conspecifics. We found that survival and growth of both recruit-sized and mature S. polycystum fronds were higher within Sargassum beds than outside the beds and these results were found in both protected and fished reefs. Much of this benefit resulted from reduced herbivory within the Sargassum beds, but adult fronds also grew ~50% more within the beds even when herbivory did not appear to be occurring, suggesting some physiological advantage despite the intraspecific crowding. Thus via positive feedbacks, S. polycystum enhances its own growth and resistance to herbivores, facilitating its dominance (perhaps also expansion) and thus its resilience on degraded reefs. This may be a key feedback mechanism suppressing the recovery of coral communities in reefs dominated by macroalgal beds.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0155049&type=printable |
| spellingShingle | Claire L A Dell Guilherme O Longo Mark E Hay Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. PLoS ONE |
| title | Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. |
| title_full | Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. |
| title_fullStr | Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. |
| title_full_unstemmed | Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. |
| title_short | Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs. |
| title_sort | positive feedbacks enhance macroalgal resilience on degraded coral reefs |
| url | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0155049&type=printable |
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