Conservationistshaveunveiledplanstopreserveandprotecttheworld'smostimportantspeciesofcoral,inaresponsetoincreasingthreatsthattheysaywillleadto"functionalextinction"withindecades．

LedbyscientistsattheZoologicalSocietyofLondon,theEdgeCoralReefsprojecthasidentified10coralspeciesinmosturgentriskofbecomingextinct．Thescientistssaythatreefsareunderpressurefromavarietyofthreatsincludingrisingseatemperaturesduetoclimaticinstability,increasedacidity（酸性）,overfishingandpollution．

TheEdgeplan,whichfocusesonthemostevolutionarilydistinctandgloballyendangeredspecies,willtakearegionalapproachtoconservation．Thismeansfocusingonthe"coraltriangle"aroundthePhilippines,theWestIndianOceanaroundtheMozambiquechannel,andintheCaribbeanchannel．

"Coralreefsarethreatenedwithfunctionalextinctioninthenext20-50years,duepredominantlytoglobalclimaticinstability,"saidCatherineHead,coordinatorofthereefsproject．"Intheseregions,we'llbesupportingandtrainingin-countryconservationiststocarryoutresearchandimplementtargetedconservationactions,"shesaid．"Theirprojectswilllastinitiallyfortwoyears．Weprovidethemwithawholehostoftoolstocarryouttheirprojectsincludingfundingandintensivetraining．"Sheadded．

Coralreefsaretheplanet'smostdiversemarineecosystem（生态系统）,knownastherainforestsoftheoceans．Despitetakingupunder0．2%oftheoceanfloor,theyprovidefoodandshelterforalmostathirdofallsealife．Ifwelosetheecosystems,welosenotonlythebiodiversity（生物多样性）,butwealsolosethecapabilityofpeopletoobtainincomeandfoodfromcoralreefs．

Climaticinstability,whichleadstorisingseatemperatures,causescoralstobleach．Bleachingoccurswhenseatemperaturesriseandthiscausesthecoraltissuetoexpeltheirsymbioticalgaecalledzooxanthellae-thesearewhatgivethecoraltheircolour．Bleachedcoralsoftendieifthestresscontinues．Amongthe10specieschosentostarttheEdgeprojectarethepearlbubblecoral,afoodsourceforthehawksbill（玳瑁）turtle,andtheMushroomcoral,whichsupportsatleast15brightlycoloredfish．Whatdoesthefirstparagraphmeaninthepa