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SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChinaTHEIMPORTANCEOFTHEINDO-PACIFICHUMPBACKDOLPHIN(SOUSACHINESIS)POPULATIONOFSANNIANGBAY,GUANGXIPROVINCE,PRCHINA:RECOMMENDATIONSFORHABITATPROTECTION.
PanWenshi1,LindsayPorter2,WangYamin3,QinDagong1,LongYu1,JinTong1,LiangZuhong1,WangDezhi1,SuYun4,PeiZixing1,andKoenVanWaerebeek51QinzhouBayChineseWhiteDolphinsResearchCenterofPekingUniversity,PRChina.
Email:panda@pku.
edu.
cn2WWF,1TramwayPath,Central,HongKong.
Email:lporter@wwf.
org.
hk3OfficeofAquaticFaunaandFloraConservation,MinistryofAgriculture,Beijing100026,P.
R.
ofChina.
E-mail:wildlifes66@yahoo.
com.
cn4DirectorofTourism,ManagementOfficeofSanniangBay,GuangxiTourismAuthority,PRChina.
5CEPEC,MuseodeDelfines,Pucusana,Lima20,Peru.
E-mail:cepec@speedy.
com.
peAbstract:DuringtheperiodJune2004-January2006,aresearchteamfromtheQinzhouBayChineseWhiteDolphinsResearchCenterofPekingUniversity,thePeoplesRepublicofChina,conductedsystematicandopportunisticboatsurveysofSanniangBay,GuangxiProvince,inwhichIndo-PacifichumpbackdolphinsSousachinensiswereregularlyseen.
Ninetyeightdolphinswerephotographicallyidentified.
Thedolphinsappeartoinhabitasmall,shallowareaofcorehabitatwithinthegreaterSanniangBayarea.
Theydonotappeartotravelupthetworiverswhicharelocatedtoeachsideofthebay.
OfthefivepopulationsknownfromthecoastalareaofChina,theonethatresidesinSanniangBayisdeterminedashavingtheleastimpactfromanthropogenicactivities.
Theareaitselfhasbeendesignatedasanaturetourismlocationandconsiderableeffortandmoneyhasbeenspentondevelopingappropriatetouristfacilities.
Thedolphinwatchingindustryintheareaisstrictlymonitoredandcontrolledbyonelocalauthority.
ThelargestestuaryadjacenttoSanniangBayhasbeenallocatedforindustrialdevelopmentandapaperpulpmillwillbeestablishedthere.
Consideringtheinvestmentalreadymadeinthenaturetourismindustry,thenaturalbeautyofthebayandthesurroundingareaandthelikelihoodthatthisistheonlypopulationofIndo-PacifichumpbackdolphinswhichremaininuncompromisedandrelativelypristinehabitatinallofChina,itisurgedthatalleffortbemadetomaintainthenaturalintegrityofthebay.
Itisrecommendedthatalldevelopmentandoperationalaspectsofthepaperpulpbethoroughlyscrutinizedandalleffortsmadetominimizeimpactupontheenvironmentandthatallcurrentandfutureindustriesandactivitiesinthisareamustnotdetrimentallyimpactthedolphinpopulationorcompromisetheintegrityofthebayecosystem.
IntroductionInearly2004,SanniangWan,anisolatedbayinGuangxiProvince,southernChina,wasdesignatedasanewtouristdestination.
Majorroadconstructionhasconnectedforthefirsttime,theonlyfishingvillageinthebaytoseverallargecities.
Duetothearea'sastoundingnaturalbeautyandtheregularoccurrenceofIndo-PacifichumpbackdolphinSousachinensisinthebay,tourismbasedonnatureandtheenvironmentwaselected,includingdolphinwatching.
Thefirstdayofoperation,inearly2004,recordedanoverwhelming10,000visitorstothearea.
Thepopularityoftheareaandtheinterestindolphinwatchingsurprisedboththevillageinhabitantsandthelocalauthorities.
Itwasdecidedimmediatelythatthesetouristactivitiesmustnothaveadetrimentalimpactoneithertheenvironmentorthosespecieswhichlivewithinit.
Restrictionsontypesofdevelopmentwereputinplace,i.
e.
,lowrise,non-intrusivebuildingsthatdidnotimpacttheforeshoreandrestrictionsonthedailynumberofboatsthatconducteddolphinwatching.
ThedevelopmentinitsentiretyisstrictlycontrolledbytheTourismAuthority.
Todate,theAuthorityhasspent30MillionRenminbi(eqv.
EUR3Million)inestablishingappropriatelowleveltourismfacilitiesandmaintainingapristineenvironmentinwhichtoconductnaturetourism.
Further,thelocalauthoritiesandfishermenwishedtoensurethatthedolphinswerenotadverselyimpactedbydolphinwatchingandcontactedresearchersinChinaandHongKongforadvise.
Sincethattime,researchteamsfromtheQinzhouBayChineseWhiteDolphinsResearchCenterofPekingUniversity,PRChina,andstaffandassociatesoftheWorldWideFundforNature(WWF)inHongKonghavebeenconductingvisualsurveysonthearea'sdolphinpopulation.
ThereissomeuncertaintyastowherethespecificdivisionsliewithinthegenusSousa.
Rice1SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChina(1998)nominatesthreespeciesbasedonexternalandcranialmorphologyalthoughthereisstilldisagreementwithregardstospeciesdesignation(thegenusSousawasdiscussedindetailatIWC54,Shimonoseki,Japan,2002).
Arecentmultivariateanalysisofgeographicvariationin222skullsconfirmedthesamethreegeographicformscoincidingwithS.
teuszii,S.
plumbeaandS.
chinensis,withoutnecessarilyassigningadefinitivetaxonomicstatus(JeffersonandVanWaerebeek,2004).
On-goingmolecularstudiesareanticipatedtoassistinfurtherdefiningthegenuswithinthenearfuture.
WithinSoutheastAsia,onespeciesoccurs,S.
chinensis,whichconsistsofanumberofsuspectedpopulations.
ApartfromthepopulationwhichdwellswithinthePearlRiverEstuary(JeffersonandLeatherwood,1997;Parsons,1997;Porteretal.
,1997;Porter,1998;Jefferson,2000;Porter,2002),untilveryrecently,littlehasbeenknownofdistributionwithintheregion(Perrinetal,1996;WangandHan,2006).
ThereisconsiderableconcernoverthesurvivalofthisandothercetaceanspecieswithinSoutheastAsiaduetotheaccumulativeimpactsfromfisheriesactivities,heavyshiptraffic,coastaldevelopmentandpollution.
TheSanniangBaypopulationofS.
chinensisisoneofonlyfiveknownfromChina'sSouthChinaSeacoastalarea.
TheotherpopulationsresideinLeizhouandthePearlRiverEstuary(GuangdongProvince),XiamenHarbour(FujianProvince)andwesternTaiwan.
Allofthesepopulationsaresmallandthedistancebetweeneachisconsiderable,suchthatitislikelythateachpopulationisisolatedfromtheother.
Ofallknownpopulations,theonethatresidesinSanniangBayappearsleasteffectedbyanthropogenicactivities.
ThedolphinswhichoccurinthePearlRiverEstuaryandXiamenHarbourareheavilyimpactedbyshippingandcoastaldevelopmentactivitiesandmortalityisregularlyrecorded,e.
g.
,inHongKongonaverageoneIndo-Pacifichumpbackdolphinstrandseverymonth.
InXiamenHarbour,comparisonsbetween1994and2004populationabundanceestimatesindicatethatthepopulationhashalvedinthattime(HuangandLiu,2006;Yangetal,2006).
TheresultsfromasinglesurveyinTaiwanindicatethatthepopulationnumberslessthan200andiscriticallyimpactedbyindustrialactivities(Wang,2005).
ThepopulationwhichoccursinLeizhouhasonlyjustbecomethefocusofadedicatedstudyandresultsfromthefirstsurveyindicatethatthepopulationissmallandencounterrateislow(ZhouKaiya,unpublisheddata).
Addedtothis,anewportdevelopmentisunderwayintheareainwhichthedolphinsaresighted.
TheMinistryofAgriculture,thePeoplesRepublicofChina,recentlyheldaworkshopwhichaimedtocompileallrecentinformationonthedistributionandstatusofIndo-PacifichumpbackdolphinsinChinesewatersandtodevelopacommonstrategyfortheeffectiveconservationofthespecieswithinChina.
Itwasproposedthatthelevelofconservationconcernforthevariousareasshouldbe1)GuangdongProvince,includingthePearlRiverandLeizhouBay.
2)FujianandTaiwan,specificallytheTaiwanchannel.
3)SanniangBay,GuangxiProvince(Wang2006).
Thatis,itwasgenerallyagreedthatthedolphinpopulationswhichresideinSanniangBaywasleastatriskandthosepopulationsinthePearlRiverEstuary,XiamenHarbourandTaiwanwereimpactedbycontinuedandincreasingdevelopmentoftheseareas.
MethodologySanniangBaycoversanareaofapproximately350km2(centredat21°38.
3'N,108°47.
7'E)andislocatedbetweentwoestuarinesystems,tothewestliestheQinjiangandtotheeasttheDafengjiang.
Thebayisveryshallowandinfluencedbyfreshwaterinput,however,littleisknownofthearea'sphysicaloceanographyanditsseasonalfluctuations(Fig.
1).
SinceMay2004,regularsurveysoftheentirebayindicatethatthedolphinsoccupyacoreareaofapproximately120km2andrarelyoccurinwaterdepthsgreaterthan10m(Fig.
2).
Boatsurveys:twotypesofboatsurveyswereconducted;systematicandopportunistic.
Severalrouteswereplottedthatcoveredtheentirebayareadefined.
TheseroutesweresurveyedsystematicallybetweenJune2004andJanuary2006.
Fishingvesselswereusedasplatformsofopportunityandtheroutetheytookwasnotinfluencedbythesurveyteamonboard.
TheexactrouteofthesesurveyswasrecordedusingGPS.
Duringbothtypesofsurveys,thetimeandlocationofeveryencounterwithdolphinswasrecordedusingaGPS.
Detailedinformationoncondition,agecategoryandbehaviourwasalsonoted.
Whenpossible,highresolutionimagesofthedorsalfinareaandindividualcolourationpatternsweretaken.
Thisresultedinthecollectionofmorethan10,000imagesandavarietyoffeatureswereusedtoclearlyidentifyindividuals(Fig.
3).
Theminimumsizeofthepopulationisestimatedas98,fromcountingtheabsolutenumberofindividualsthroughphoto-identificationtechniques.
These98individualscomprise52juveniles(calvesandadolescents),46adultsandsub-adults(usingthecriteriaoutlinedbelow).
Theproportionofnon-identifiableindividualsisstillbeingassessed.
Anestimateofpopulationsizeusing2SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChinamark-recaptureanalysisisbeingconductedbutiscurrentlynotcompleted.
Distinguishingagecategories:usingtheimagesofonlythe98identifieddolphins,individualsweredividedintofourdifferentagecategoriesdependingonsize,behaviouraltraitsandpigmentationpatterns.
Calveswereclassifiedasbeinglessthan1mlong,havingdarkgreyskinandbeingcloselyassociatedwiththesameadultindividual,presumablythemother.
Adolescentswereclassifiedasbeing1minlength,havinggreyskinbutseentobeswimmingindividuallyforextendedperiodsoftime.
Sub-adultswereclassifiedasbeinggreaterthan1.
2m,havinglightgreytopinkskinwithdensedarkgreyspotting.
Sub-adultswereneverassociatedwithcalves.
Adultswereclassifiedashavingpredominantlypinkskinwithafewareasofdarkpigmentationandmaybecloselyassociatedwithcalvesoradolescents.
Twolargeadultswereidentifiedthatwereentirelywhiteincolour.
Usingthiscriteria,thereareto15-16calves,34-35adolescents,7sub-adultsand41adults,twoofwhicharepresumablyaged(Fig.
4).
Mortality:NostrandingsofIndo-Pacifichumpbackdolphinswerereportedduringthesurveyperiodandfishermenreportthatstrandingspriortothistimewererare.
OnedolphinwasphotographedwithanetcaughtarounditsneckinAugust2004.
ThisdolphinhasbeenregularlysightedandwaslastseeninMarch2006.
DiscussionAsappearsusualforthisspecies,thepopulationofdolphinsthatresideinSanniangBayissmallandinhabitsacoreareaofshallowhabitatthatisinfluencedbyfreshwaterinputfromnearbytworivers.
UnlikeotherpopulationsofSousachinensisinSoutheastAsia,thedolphinsofSanniangBayappeartobehealthy,withalargeproportionofyoungindividuals(>50%)andapparentlowmortality.
Thereislittleevidencethatfishinggearsignificantlyimpactsthedolphins,e.
g.
,onlyoneincidenceofnetentanglementhasbeenreported.
Similarly,vesselcollisionsareunknowninthisareaofsouthernChina,incontrastwithotherpopulations(VanWaerebeeketal.
,2006).
Todate,Guangxi,China'smostsouthernProvince,hasbeenrelativelyun-developed.
Thearea'suniquenaturalbeauty,limestonekarstsandfertilefloodplainsremainlargelyintactandcoastaldevelopmenthasbeenminimal.
ItwouldappearthattheSanniangBaydolphinpopulationisuniqueasitisminimallyimpactedbyfisheries,eitherinteractionsorcompetition,anddevelopmentactivities.
Inaddition,itisnotcurrentlysubjectedtopollutionfromindustryorlargemunicipalities.
TheBayhasbeendesignatedasalocallevelmarineprotectedareaandisgoingthroughtheprocessofestablishinghigherstatus.
Inthemeantime,CentralGovernmentauthoritiesareencouragingGuangxiProvincetoincreasecoastaldevelopmentsoasthisProvincemightbenefitfromthesamefinancialgainthatallothercoastalprovinceshaveexperiencedinthelastdecadeofboomingindustry.
Assuch,theestuaryadjacenttoSanniangBayhasbeenallocatedforindustrialdevelopment.
AlthoughoutsidetheSanniangBayareaitself,thereisconcernthattheproposeddevelopmentofapaperpulpmillwilldetrimentallyimpactthebayarea.
Ithasbeensuggestedthatthisparticulardevelopmentshouldnottakewaterfromtheestuaryitselfandthatalleffluentshouldbedischargedoffshoreviaa15kmpipeline.
Effluentfromsuchindustrieshistoricallyhasbeenextremelydetrimentaltotheaquaticenvironmentanditisfearedthatwithoutstringentcontrols,theshallowSanniangBayareaisatriskofbecomingcontaminated.
Theseinitialproposalstomitigatedamagetotheenvironmentareagoodfirststep.
ItwouldbebeneficialiftheCentralGovernmentofthePeoplesRepublicofChinawouldformaliseandsupporttheseproposals.
Itishopedthataclearconservationinitiativeforthepaperpulpmillbedevelopedanditisrecommendedthatthisincludethat:(i)theeffluentfromtheproposedpaperpulpmilladjacenttoSanniangBaybetreatedbeforeemissionintotheaquaticenvironment;(ii)modelsthataccuratelycalculatewatercirculationintheestuary,SanniangBayandadjacentwatersbedevisedsothateffluentcanbeharmlesslydispersedintotheaquaticenvironment;(iii)astringentmonitoringsystembeestablishedthatallowsearlywarningofanypossibleenvironmentaldamage;(iv)anemergencyprocedurebeestablishedandinitiatedtimelytominimisedamagetotheenvironmentintheeventofacontaminationincident.
Consideringtheinvestmentofsome30MillionRMBinthedevelopmentofthetourismindustry,thattouristsareattractedbythecurrentlypristineconditionoftheenvironment,andthelikelihoodthatitsupportstheonlyuncompromisedpopulationofIndo-PacifichumpbackdolphinsinallofChina,itisurgedthattheCentralGovernmentofthePeoplesRepublicofChinarecognisetheveryspecialvalueof3SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChinathisareaandsupportandparticipateinabroadscaleconservationstrategy.
ItisrecommendedthatallfutureandproposeddevelopmentsincoastalandcatchmentareasofGuangxiProvincearethoroughlyscrutinisedandonlyapprovedwhenallmeasureshavebeenputinplacetopreventtheenvironmentandthespecieswhichdwellwithinitfrombeingdetrimentallyimpacted.
Further,thattheIndo-PacifichumpbackdolphinbepromotedasaflagshipspeciesfortheconservationeffortsoftheSanniangBayhabitat.
AcknowledgementsManythankstotheGuangxiAquaticProductandPasturageBureauandtheHongKongOceanParkConservationFoundationforsupportingandfundingtheresearchworkconductedinSanniangBay.
KVWthanksIFAWfortravelsupporttoPRChina.
KVWattendstheIWCannualmeetingfortheFederalPublicService;PublicHealth,FoodChainSecurity&Environment(Brussels)asheadofBelgium'sscientificdelegation.
LJPwishestothankWWFfortravelsupporttoIWC58ReferencesHuang,Z.
G.
andLiu,W.
2006.
Chinesewhitedolphin(Sousachinensis)inXiamenBay.
InTheProceedingsofTheXiamenInternationalWorkshoponConservationofSousachinensis,Xiamen,PeoplesRepublicofChina,March2006.
p13Jefferson,T.
andLeatherwood,S.
1997.
DistributionandabundanceofIndo-pacifichump-backeddolphins(SousachinensisOsbeck,1765)inHongKong.
AsianMarineBiology14:93-110.
Jefferson,T.
2000.
PopulationBiologyoftheIndo-Pacifichumpbackdolphin(Sousachinensis)inHongKongwaters.
WildlifeMonographs144:1-65Jefferson,T.
A.
andVanWaerebeek,K.
2004.
Geographicvariationinskullmorphologyofhumpbackdolphins(Sousaspp.
).
AquaticMammals30(1):3-17.
Parsons,E.
C.
M.
1997.
HongKong'scetaceans:thebiology,socioecologyandbehaviourofSousachinensisandNeophocaenaphocaenoides.
PhDthesis.
TheUniversityofHongKong.
Perrin,W.
F.
,Dolar,M.
L.
andAlava,M.
N.
R.
1996.
ReportoftheWorkshopontheBiologyandConservationofSmallCetaceansandDugongsofSoutheastAsia,Dumaguete,June1995.
UNEP(W)/EASWG.
1/2.
Bangkok:UnitedNationsEnvironmentProgramme.
Porter,L.
,Parsons,E.
,andMorton,B.
1997.
TheStatusandBiologyoftheChineseWhitedolphin(Indo-PacificHump-backeddolphin),Sousachinensis,inHongKong:RecommendationsforConservationandManagement.
AFinalReporttoTheDirectoroftheAgricultureandFisheriesDepartmentoftheHongKongSpecialAdministrativeRegion.
HongKong:TheSwireInstituteofMarineScience.
148pp.
Porter,L.
1998.
TheTaxonomy,EcologyandConservationofSousachinensis(Osbeck,1765)(Cetacea:Delphinidae)inHongKongwaters.
PhD.
thesis,TheUniversityofHongKong,HongKong.
Porter,L.
,2002.
Are-descriptionofSousachinensis(Osbeck,1765)(Mammalia:Delphinidae)anddesignationofaneotype.
TheBulletinoftheNaturalHistoryMuseum271-80.
Rice,D.
1998.
MarineMammalsoftheWorld:SystematicsandDistribution.
Soc.
Mar.
Mammal.
Spec.
Publ.
No.
4.
231ppVanWaerebeek,K.
,Baker,A.
N.
,Félix,F.
,Iiguez,M.
,Sanino,G.
P.
,Secchi,E.
,Slocum,G.
,Sutaria,D.
,vanHelden,A.
,Wang,Y.
2006.
VesselcollisionswithsmallcetaceansworldwideandwithlargewhalesintheSouthernHemisphere,buildingastandardizeddatabase.
SC/58/BC6,presentedto58thMeetingofIWC,StKitts,May-June2006.
Wang,J.
2005.
TheDistributionofIndo-Pacifichumpbackdolphins(Sousachinensis)inTaiwan.
PresentedatThe57thInternationalWhalingCommissionMeeting,ScientificCommitteeAnnualMeeting,Ulsan,Korea,May–June2005.
Wang,P.
andHan,J.
2006.
ThePresentStatusoftheDistributionofChinesewhitedolphin(Sousachinensis)populationinChinesewaters.
InTheProceedingsofTheXiamenInternationalWorkshoponConservationofSousachinensis,Xiamen,PeoplesRepublicofChina,March2006.
WangYamin.
2006.
TheConservationofSousachinensisinChina.
IntheproceedingoftheXiamenInternationalWorkshoponconservationofSousachinensis,Xiamen,China,March2006.
Yang,G.
,Chen,B.
,Xi,X.
,Zhai,F,Sun,P.
andWang,Q.
2006.
AbundanceanddistributionofChinesewhitedolphin(Sousachinensis)inXiamenwaters.
InTheProceedingsofTheXiamenInternationalWorkshoponConservationofSousachinensis,Xiamen,PeoplesRepublicofChina,March2006.
p254SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChinaFigure1.
SanniangBay,Gunagxi,PeoplesRepublicofChina.
Thesurveyareaisindicatedbythedashedlineandtheactualsurveyroutesaredenotedbycoloured,solidlines.
Figure2.
ThelocationofencounterswithIndo-Pacifichumpbackdolphins(Sousachinensis)inSanniangBay,Guangxi,PeoplesRepublicofChina.
Thesurveyareaisindicatedbythedashedlineandtheshadedareawheredolphinswereencountered.
5SC/58/SM18HabitatprotectionofSousachinensis,SanniangBay,PRChinaFigure3.
AgecategoriesofIndo-Pacifichumpbackdolphin(Sousachinensis)inSanniangBay;A,calf;B;adolescent,C;sub-adultandD;adult.
Figure4.
ExamplesofsomeofthefeaturesusedtoindividuallyidentifyIndo-Pacifichumpbackdolphins(Sousachinensis)inSanniangBay,Guangxi,PeoplesRepublicofChina.
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