South Pacific南太平洋环境现状与治理措施 英文论文文档格式.docx
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South Pacific南太平洋环境现状与治理措施 英文论文文档格式.docx
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AndMeasurestotheEco-crisis
姓名与学号平帆3120100152
指导教师曹龙
年级与专业2012级应用生物大类
所在学院求是学院
SouthPacific:
AnAnalysisoftheEcosystemand
MeasurestotheEco-crisis
PINGFan
(ZhejiangUniversity,CollegeofEnvironmentalandResourceSciences,Hangzhou)
Abstract:
TheSouthPacificislocatedinthesouthernhemisphere,whichhasmorethantwothousandislandsandone-quarteroftheseaontheearth.Islandanimal’sorigin,breeding,andmigration,isaccompaniedbytheestablishmentandimprovementofmarineecosystems.TheSouthPacificownsanabundantdiversityofspeciesanddevelopedmarineindustry.Itprovidesavaluableresourceforhumanbeings.Butnow,overfishing,greenhouseeffectandallkindsofcrisishappenedinthesouthPacific.Human-beingswillcomeupwithaseriesofmeasurestoturnitaround,makingthesustainabledevelopmentworksinthesouthPacific.
Keywords:
SouthPacific;
MarineCommunity;
GreenhouseEffect
1.Introduction
TheSouthPacific,thisbroadoceanstillremainslittleknownafterCaptainCook’sepicvoyagesin1768.TheturquoiseseasandislandslooklikeheavenonEarth.Inthevastwater,isolatedislandsharborlifethat’sscarcelyseenontheland.Nevertheless,theSouthPacificalsohasatoughsidelikeeruptingvolcanicislands,tremendousstorms,andetc.Thankstothosedestructiveforcesovertheocean,lifeisabletospreadtotheremoteislandsandthousandsofecosystemsarebuiltuptosucceed.
Comparedtolandsandoffshores,theSouthPacificseemstobehealthierocean.Duetolittleornoprotection,however,thisnaturaltreasurestoreisputintothehardestpositionbecauseofthegreenhouseeffect,overfishing,climatechanges,leadingtothecrisisofmarineecosystemconsequently.FortheSouthPacific,21stcenturycanbeitscriticaltimeunlessthehumanbeingstakeactiontomitigatetheseseriesofproblems.Accordingly,peopleshouldtakemultipleandeffectivemeasurestopreservetheSouthPacific.
2.OverviewoftheSouthPacific
2.1Geography
TheSouthPacificisinthesouthofthePacificOcean,mostlylocatingatthelatitudearound60degreessouth.ThetotalareaoftheSouthPacificisabout7100km2andwaterstorageaccountsfor25%ofthetotal.ApartfromAustraliaandNewZealand,thereare27countriesandareasintheSouthPacific,includingPapuaNewGuinea,Fiji,andTonga.Thecountriesandareasconsistof2,000islands,only1%(550,000km2)oftheSouthPacificarea.Thepopulationhasreachedupto7,500,000[1].(Data,2010)
2.2Geology
LyinginthesouthCircum-Pacificseismicbelt[2],theSouthPacificisteemedwithallsortsofvolcanicislands,suchasHawaiiArchipelago,SolomonIslands,generatedbysubmarinevolcanicactivities.
HawaiiArchipelagowascreatedbyagreatmantleplumeundertheseabedofthePacificplate[3].ThisvolcanicchainstartseastfromHawaiiIslandandendsupnorthintheMeijiseamounts[4],anditstillremainsthemostactivegeologicareasontheearth.
Figure1ModeldiagramoftheHawaiianmantleplume.Primaryandsecondaryrocktypesarecolourcodedasfollows:
red,eclogiterepresentingrecycledoceaniccrust;
blue,peridotite;
yellow,reaction(secondary)pyroxeniteproducedbyinfiltrationofeclogite-derivedmeltintoperidotite;
whiteandred,eclogiticrestite;
blackdots,melts;
violet,magmapathways,conduitsandsmallmagmachambers.Recycledmaterialisconcentratedintheplumecentre.Theseismiclow-velocityzoneobservedpreviouslyinthedepthrange170–130kmcorrespondstosignificantmeltingofeclogite.Thismeltdisappearsatlowerpressuresbecauseitseparatesfromeclogiteandisconsumedbyreactionwithperidotitetoproducesecondarypyroxenite.Mixingofmeltsprobablytakesplaceatshallowcrustallevelsinsmallmagmabodiesratherthaninthemantleorinlargestablemagmachambers[4].
60milesundertheseabed,lavaispushedbytheextremelyhighpressurefromthecoreofearthtothesurface.Themovingspeedoflavaisusuallynolessthan100m/h[5].Thoughthecoveriscooleddownbytheseawater,moltenlavacaneruptoutoftheseawhenthepressureishighenough,finallyformingthenewlands.
Inthemeanwhile,theancientvolcanoeskeeperuptingabovethesealevel.Whentheongoinglavaspreadstoedgesoftheisland,thedeep,freezingoceancurrentsareconfrontedwiththeboilinglava(1,000-1,300℃)andthenlavarapidlycoolsdownwiththereleasingvaporandbursting.Inthepast25years,Hawaii’slavahasforgedalmost2,500km2ofnewland[6].Verysoon,thisrigidlandwillpossessitsownterrenelifegarden.
2.3Climate
MostoftheSouthPacificbelongstowarmwater.Theaveragetemperatureofthesurfaceisbetween28-29℃[7].Theoccasionalcoldcurrents,derivingfromthepolararea,maketheseawateraroundNewZealandthecolderone.Thesubtropicalhighandcoldhighpressurecontroldifferentwatersofthedifferentareas,sothemostpowerfulanddestructivewaves,tornadoesandstormsappearintheSouthPacific.
At40degreelatitude,theRoaringFortiesblastthecoastline.Yetitisthefoulweatherthatproducetheabundanceoflife[8].Thewavessparkedbystormsrun3,000miles,unlockingthedeep’sreserveofnutrientsandsendingthemtothesurfacebywashingouttheislands,whichprovidesapossibilityoffoodandlife.Cyclones,formingintheoceanandreachingthediameterof600miles,areabletorecreatetheislands[9].Remarkably,allkindsoftheplantsandanimalsarecarriedtoisolateislandsfromthousandsmilesaway.EachSouthPacificislandhasitsownuniquesetofcreaturesowingtotheevilpowerofclimate.
3.SpeciesProfileintheSouthPacific
ThediversityofcreaturesintheSouthPacificareinfluencedbyuniquegeographyandclimateconditions.Listsofexampleshelpexplainthespeciesandecologysituation.
3.1TheOriginandEvolutionoftheSpeciesonIslands
TherearethousandsofislandsintheSouthPacific,manyofwhichareunbelievablyremote.Eventhecloserneighborscanbehundredsofmilesaway.Theoceanisagiantmoatstretchingtothehorizonineverydirection,cuttingoffthecommunicationofspeciesbetweenislands.Surprisingly,nomatterhowfarorsmallanislandis,animalsandplantshaveconqueredthemassiveoceanbarriertoreachthesespecksofland.ManyofspeciescamefromNewGuineaandthenspreadtothewholearea.Astheconquerors,theyareprovidedwithgreatopportunitiestodevelopalltypesofecosystem.
OnthelittleislandinVanuatulivesthelargestterrestrialinvertebrateonEarth:
RobberCrab.Thebiggestonecanweighupto4kgandhavealegspanof1m[10].Robbercrabsareprobablythefewanimalsintheworldabletobreakintoacoconutfortherewardofamealrichinprotein[10].ThatiswhytheyarealsocalledCoconutCrabs.Withsofewcreaturesmakingittotheremoteislands,thegiantcrustaceansseemtohavefilledanichenormallytakenbymedium-sizedmammals.Maybethatiswhyrobbercrabshavegrownsobig.HowdidthesecrabsgettosomanyoftheSouthPacific’smostisolatedislands?
Thefemalecrabscarriesthethousandsofeggs,alsotheanswer.Millionsofeggswillbelaidintotheseabythefemalecrabs[11].Theeggswillhatchinthewaterimmediately.Thus,thelarvaehavetofindanewlandin50days.
Formostofanimalcastawayslikerobbercrabs,findingnewlandthroughwaterwayinthisvastoceansisachanceinamillion.Butifthetotalpopulationisincrediblylarge,theystillgettheverychancetobecomeColumbiatotheNewWorld.
Occasionally,theblowinginthewindreplacesthecurrenttobethefree-rider.Thermalupdraftscancarrythespores30,000feetintothejetstream,thenthrowingthemontotheremoteislands.Largeinsectsorevenallthecreaturescanbesuckedupintotheskybycycloneswiththespeedinexcessof100mph.Whenthestormsubsides,87%ofspecieswilldropintotheoceanbutaveryfewwilllandonthegroundandfromthesesurvivors,thesuccessionofthenewcommunitywillgoon.Forinstance,theancestorsofHawaii’sfruitfliesarecarriedandthenabandonedonHawaii,for30millionyears,onthebackofcyclones.Theyattractfemaleswithelaboratecourtshiprituals[12],whichdiffersfromtheotherspeciesoffruitflies.Sincethatfirstsettler,theyhaveevolvedintonearly1,000species.MostoftheHawaiifruitfliesdeveloptheabilitytoundergothe10thseawindandrains.
Flyingalsoplaysapivotalroleinreachingnewislands.Sootyterns,oneofthemostsuccessfultravelers,canstayintheairfor4years[13]withoutlanding.Buttobreed,theymustreturntonestingsitesonremoteislands,introducingnewlifeconveniently.Stickyorbarbedseedsfastenontheirfeathersandhitchridesacrossoceans.Onsomeislands,75%ofplantarrivedwiththebirds,eveninthestomachsofwhich.Plus,theseafoodthosebirdsbringbacktotheislandsisturnedintonutrient,richguano[14],plantfertilizer.Combiningtwofactors,therigidislandsarelikelytotransformintotheparadiseofthecreatures.
Tosumup,quitealotoftheplantsandanimalsontheislandsoftheSouthPacificwerefromtheoutside,afterselectedbyoceancurrentsandstorms.Whensettleddown,theyadaptedtotheharshenvironmentandevolvedintonewspecies.Furthermore,someofthenewspeciescanreformtheoriginallandscapeandenvironmentalconditions.Then,afterpassivemigrationstotheotherremoteislands,theyrealizethecommunicationbetweentheSouthPacific’sislands,inthecasethatpromotesthediversityandabundanceofthespecies.It
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