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                      |  | GEO-03\INT-10  The geochemical and biological study of corals |  
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                            |  | Predicting the future of scleractinian corals under the influence of expected climate changes (pCO2 and temperature) Tuesday 10th @ 1610-1730 , Conference Room 4
 S-GEO-03\INT-10-01
 Mohamed belasy ismail*   , Department of zoology, Faculty of Science, Al Azher University, Egypt
 Presenter Email: Mohamed_belasy1989@yahoo.com
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                            | Climatechangese.g.oceanacidificationandwarmingcausedbyanthropogenicemissionofCO2arethegreatestglobalthreattocoralreefecosystems.ThechangeintheseawatercarbonatechemistryduetoOAisalarmingbecauseitspotentialaffectstheabilityoftropicalreef-buildingcoralsandothermarineorganismstoform(CaCO3)skeletons.DatashowthatadecreaseinpHfromcurrent(8.2units)toend-of-centuryprojectedlevels(7.7-7.8units)resultsina20-40%declineincoralcalcificationandanincreaseinthedissolutionrateofcarbonateskeleton,duetothesaturationstatusofCaCO3inseawaternegativelyaffectedbychangesinseasurfacetemperatureand/orCO2concentration.Reducedcoralgrowth,combinedwithweakercoralskeletonsandreefsubstrata,willincreasetheprobabilityofdamagetostructurallycomplexcoralsduringextremeweatherevents,leadingtoalossofreefstructurecomplexity,severelyreductionincoralsresilienceandrapiddeclinesinreefecosystembiodiversity.Therefore,thepotentialcapacityofscleractiniancoralsforacclimatizationoradaptationtooceanacidification(OA)anditsassociatedwarmingisakeyfactordeterminingtheirresiliencetofutureclimatechange.Reef-buildingcoralsareinhabitedbyfunctionallydiversemicroorganisms,whichplayvitalrolesinmaintainingholobionthealthandecosystemresilienceunderAnthropocene.Changesincoralmicrobiomecompositionisapotentialmechanismthatmayassistcoralstothriveunderstressfulconditions.Forinstance,thenorthernRedSeacoralsinhabitunderextremetemperaturesanomalies,withoutanybleachingsigns,suggestingthattheymayhaveselectiveandendemicmicrobiomesdonatethemthisuniquetolerability.SingleeffectofOAhadnosignificantinfluenceonbothSymbiodiniaceae&prokaryotic,whilethesynergisticeffectofOAandwarmingexacerbatethebleachingofcoralholobionts.Atthisstage,thereisnoclearconsensusaboutthephysiologicalandmoleculartraitsthatunderliecoraltolerancetoOAand/orwarming,consequently,reliableprojectionsoftheeffectsofclimatechangeonreefecosystemscannotbemade.Sothecurrentstudyaimstounderstandwhetherandhowcoralsacclimatizationoradapttolong-termofOAand/orwarming.WeassumethatthetolerabilityofcoralscorrelatedtoSymbiodiniummetabolismandthestabilityofitsassociatedmicrobiome |  |  |  
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