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dc.contributor.authorRoik, Anna
dc.contributor.authorRöthig, Till
dc.contributor.authorPogoreutz, Claudia
dc.contributor.authorSaderne, Vincent
dc.contributor.authorVoolstra, Christian R.
dc.date.accessioned2018-12-18T15:02:34Z
dc.date.available2018-12-18T15:02:34Z
dc.date.issued2018-10-26
dc.identifier.citationRoik, A. et al (2018) ‘Coral reef carbonate budgets and ecological drivers in the central Red Sea: a naturally high temperature and high total alkalinity environment’, Biogeosciences, 15(20), pp. 6277–6296. doi: 10.5194/bg-15-6277-2018en
dc.identifier.issn1726-4170
dc.identifier.doi10.5194/bg-15-6277-2018
dc.identifier.urihttp://hdl.handle.net/10545/623244
dc.description.abstractThe structural framework provided by corals is crucial for reef ecosystem function and services, but high seawater temperatures can be detrimental to the calcification capacity of reef-building organisms. The Red Sea is very warm, but total alkalinity (TA) is naturally high and beneficial for reef accretion. To date, we know little about how such detrimental and beneficial abiotic factors affect each other and the balance between calcification and erosion on Red Sea coral reefs, i.e., overall reef growth, in this unique ocean basin. To provide estimates of present-day reef growth dynamics in the central Red Sea, we measured two metrics of reef growth, i.e., in situ net-accretion/-erosion rates (Gnet) determined by deployment of limestone blocks and ecosystem-scale carbonate budgets (Gbudget), along a crossshelf gradient (25 km, encompassing nearshore, midshore, and offshore reefs). Along this gradient, we assessed multiple abiotic (i.e., temperature, salinity, diurnal pH fluctuation, inorganic nutrients, and TA) and biotic (i.e., calcifier and epilithic bioeroder communities) variables. Both reef growth metrics revealed similar patterns from nearshore to offshore: net-erosive, neutral, and net-accretion states. The average cross-shelf Gbudget was 0.66 kg CaCO3 m−2 yr−1 , with the highest budget of 2.44 kg CaCO3 m−2 yr−1 measured in the offshore reef. These data are comparable to the contemporary Gbudgets from the western Atlantic and Indian oceans, but lie well below “optimal reef production” (5–10 kg CaCO3 m−2 yr−1 ) and below maxima recently recorded in remote high coral cover reef sites. However, the erosive forces observed in the Red Sea nearshore reef contributed less than observed elsewhere. A higher TA accompanied reef growth across the shelf gradient, whereas stronger diurnal pH fluctuations were associated with negative carbonate budgets. Noteworthy for this oligotrophic region was the positive effect of phosphate, which is a central micronutrient for reef building corals. While parrotfish contributed substantially to bioerosion, our dataset also highlights coralline algae as important local reef builders. Altogether, our study establishes a baseline for reef growth in the central Red Sea that should be useful in assessing trajectories of reef growth capacity under current and future ocean scenarios
dc.description.sponsorshipResearch reported in this publication was supported by funding to Christian R. Voolstra from KAUST.en
dc.language.isoenen
dc.publisherEuropean Geosciences Unionen
dc.relation.urlhttps://www.biogeosciences.net/15/6277/2018/en
dc.rightsArchived with thanks to Biogeosciencesen
dc.subjectCoral reefen
dc.subjectCalcificationen
dc.titleCoral reef carbonate budgets and ecological drivers in the central Red Sea: a naturally high temperature and high total alkalinity environment.en
dc.typeArticleen
dc.identifier.eissn1726-4189
dc.contributor.departmentKing Abdullah University of Science and Technology (KAUST)en
dc.contributor.departmentUniversity of Derbyen
dc.identifier.journalBiogeosciencesen
dcterms.dateAccepted2018-09-28
refterms.dateFOA2019-02-28T17:57:46Z
html.description.abstractThe structural framework provided by corals is crucial for reef ecosystem function and services, but high seawater temperatures can be detrimental to the calcification capacity of reef-building organisms. The Red Sea is very warm, but total alkalinity (TA) is naturally high and beneficial for reef accretion. To date, we know little about how such detrimental and beneficial abiotic factors affect each other and the balance between calcification and erosion on Red Sea coral reefs, i.e., overall reef growth, in this unique ocean basin. To provide estimates of present-day reef growth dynamics in the central Red Sea, we measured two metrics of reef growth, i.e., in situ net-accretion/-erosion rates (Gnet) determined by deployment of limestone blocks and ecosystem-scale carbonate budgets (Gbudget), along a crossshelf gradient (25 km, encompassing nearshore, midshore, and offshore reefs). Along this gradient, we assessed multiple abiotic (i.e., temperature, salinity, diurnal pH fluctuation, inorganic nutrients, and TA) and biotic (i.e., calcifier and epilithic bioeroder communities) variables. Both reef growth metrics revealed similar patterns from nearshore to offshore: net-erosive, neutral, and net-accretion states. The average cross-shelf Gbudget was 0.66 kg CaCO3 m−2 yr−1 , with the highest budget of 2.44 kg CaCO3 m−2 yr−1 measured in the offshore reef. These data are comparable to the contemporary Gbudgets from the western Atlantic and Indian oceans, but lie well below “optimal reef production” (5–10 kg CaCO3 m−2 yr−1 ) and below maxima recently recorded in remote high coral cover reef sites. However, the erosive forces observed in the Red Sea nearshore reef contributed less than observed elsewhere. A higher TA accompanied reef growth across the shelf gradient, whereas stronger diurnal pH fluctuations were associated with negative carbonate budgets. Noteworthy for this oligotrophic region was the positive effect of phosphate, which is a central micronutrient for reef building corals. While parrotfish contributed substantially to bioerosion, our dataset also highlights coralline algae as important local reef builders. Altogether, our study establishes a baseline for reef growth in the central Red Sea that should be useful in assessing trajectories of reef growth capacity under current and future ocean scenarios


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