High macroalgal cover and low coral recruitment undermines the potential resilience of the world's southernmost coral reef assemblages

Handle URI:
http://hdl.handle.net/10754/325295
Title:
High macroalgal cover and low coral recruitment undermines the potential resilience of the world's southernmost coral reef assemblages
Authors:
Hoey, Andrew; Pratchett, Morgan S.; Cvitanovic, Christopher
Abstract:
Coral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience) is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32?S, 159°04?E), the worlds' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment), and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4%) and fleshy macroalgae (20.9%). Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m -2), however, were 5-200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha -1), and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1%) with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances. © 2011 Hoey et al.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Hoey AS, Pratchett MS, Cvitanovic C (2011) High Macroalgal Cover and Low Coral Recruitment Undermines the Potential Resilience of the World-s Southernmost Coral Reef Assemblages. PLoS ONE 6: e25824. doi:10.1371/journal.pone.0025824.
Publisher:
Public Library of Science
Journal:
PLoS ONE
Issue Date:
3-Oct-2011
DOI:
10.1371/journal.pone.0025824
PubMed ID:
21991366
PubMed Central ID:
PMC3185058
Type:
Article
ISSN:
19326203
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorHoey, Andrewen
dc.contributor.authorPratchett, Morgan S.en
dc.contributor.authorCvitanovic, Christopheren
dc.date.accessioned2014-08-27T09:45:31Z-
dc.date.available2014-08-27T09:45:31Z-
dc.date.issued2011-10-03en
dc.identifier.citationHoey AS, Pratchett MS, Cvitanovic C (2011) High Macroalgal Cover and Low Coral Recruitment Undermines the Potential Resilience of the World-s Southernmost Coral Reef Assemblages. PLoS ONE 6: e25824. doi:10.1371/journal.pone.0025824.en
dc.identifier.issn19326203en
dc.identifier.pmid21991366en
dc.identifier.doi10.1371/journal.pone.0025824en
dc.identifier.urihttp://hdl.handle.net/10754/325295en
dc.description.abstractCoral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience) is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32?S, 159°04?E), the worlds' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment), and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4%) and fleshy macroalgae (20.9%). Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m -2), however, were 5-200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha -1), and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1%) with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances. © 2011 Hoey et al.en
dc.language.isoenen
dc.publisherPublic Library of Scienceen
dc.rightsHoey et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en
dc.rightsArchived with thanks to PLoS ONEen
dc.subjectbenthosen
dc.subjectbiomassen
dc.subjectcontrolled studyen
dc.subjectcoralen
dc.subjectcoral reefen
dc.subjectfishen
dc.subjectgrazingen
dc.subjecthabitaten
dc.subjectherbivoreen
dc.subjectlatitudeen
dc.subjectmacroalgaen
dc.subjectAnthozoaen
dc.subjectaquatic speciesen
dc.subjectAustraliaen
dc.subjectgeographyen
dc.subjectgrowth, development and agingen
dc.subjectherbivoryen
dc.subjectphysiologyen
dc.subjectprincipal component analysisen
dc.subjectseaweeden
dc.subjectAnthozoaen
dc.subjectPiscesen
dc.subjectScleractiniaen
dc.subjectAnthozoaen
dc.subjectAquatic Organismsen
dc.subjectAustraliaen
dc.subjectBiomassen
dc.subjectCoral Reefsen
dc.subjectFishesen
dc.subjectGeographyen
dc.subjectHerbivoryen
dc.subjectPrincipal Component Analysisen
dc.subjectSeaweeden
dc.titleHigh macroalgal cover and low coral recruitment undermines the potential resilience of the world's southernmost coral reef assemblagesen
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalPLoS ONEen
dc.identifier.pmcidPMC3185058en
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australiaen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorHoey, Andrewen

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