•Ofthe73re-identifiabledolphins,33hadnoverifiablelesions,25hadonetypeand15hadtwotypes(Figure4)•CommondolphinsobservedtravellinginamixedspeciespodwithSABDsappearedtobelesionfree•BlacklesionsonSABD(Figure6A)identifiedbyDrMarie-FrancoiseVanBressemastattoolesionsbasedonimages•CloudylesionphotographedonaSABDonApril7thwasbarelyvisible10dayslater(Figures5Aand5B)
Presence of epidermal lesions in resident southern Australian bottlenose dolphins Tursiops australis and short-beaked common dolphins Delphinus delphis
in Port Phillip, Victoria, Australia
Suzanne Mason(1,2),JeffreyWeir(1),JenniferParsons(1)(1) DolphinResearchInstitute,POBox77,Hastings,Victoria,Australia3915(2) CurtinUniversity,CentreforMarineScienceandTechnology,GPOBoxU1987,Perth,WesternAustralia,Australia,[email protected]
Reference Wilson,B.,P.M.ThompsonandP.S.Hammond(1997). “Skin lesions and physical deformities in bottlenosedolphinsintheMorayFirth:Populationandprevalenceandage-sexdifferences.”Ambio26(4):243.
Location PortPhillip,Victoria,Australia(Figure2)isasemi-enclosedembaymentof1930km2andishometoapproximately120residentSABDand20short-beakedcommondolphins.DRIhasmonitoredtheSABDinPortPhillipsince1991andthecommondolphinssince2007.
Background•ProlificepidermallesionsphotographedonjuveniledolphinFebruary2011.ThiswasthefirstrecordofadolphinprofoundlyaffectedbylesionsinPortPhillip(Figure1)•LesionshadbeenpreviouslyobservedonPortPhillipdolphinsbutwerelessconspicuous•DrPadraigDuignanaffirmedthatlesionsmaybecetaceanpoxbasedonimages•DRIcontactedVictorianDepartmentofSustainabilityandEnvironment(DSE)wildlifemanagerstoinformthemofthesignificantincreaseinlesionslevels•DSEsponsoreddedicated‘lesion’surveys•RecentchangesinenvironmentalconditionsinPortPhillipduetodroughtbreaking
Image analysis•1426highqualityimagesexamined•Lesionsonanypartofthedolphin’sbodythatcouldbeclearlyseeninthephotographwerescrutinised•LesionscategorisedbasedoncharacteristicsinWilsonet al.(1997)(Table1)•FinimagesmatchedagainstDRI’shistoricalcataloguetoallowforon-goingmonitoringofindividualdolphinhealth
Findings•73re-identifiabledolphins,consistingof72SABDandoneshort-beakedcommondolphinphotographedduringsurveys•FivedifferentlesionstypesclearlyobservedonSABD(Figure3,Figures5Aand5BandFigures6A-F)•WhitelesionswerethemostprevalenttypeobservedonSABD(Figure3andFigures6Cand6D)
Acknowledgements KateCharlton-Robb,MonashUniversity,forassistanceduringsurveys.DrPadraigDuignan,UniversityofCalgary,forcommentsonimagesoflesion-affecteddolphins.IanPotterFoundationforsupportofcoreresearchprogram.DrHughFinn,DrCarlyHolyoakeandDrNahiidStephens,MurdochUniversity.DrMarie-FrancoiseVanBressem,CetaceanConservationMedicineGroup,Germany for comments on images of lesion affecteddolphins. Victorian Department of Sustainability andEnvironment.AllimagestakenunderDSEresearchpermitno10004770.
Cetaceanpoxvirusandepidermallesionsareprevalentinmanydolphinpopulationsacrosstheworld.SeverelesionoutbreakshavebeenrecordedinAustraliaintheSwanRiver,WesternAustraliaandGippslandLakes,Victoria.Priorto2011,epidermallesionswerepresentbutinconspicuousontheresidentsouthernAustralianbottlenosedolphins(SABD),Tursiopsaustralis,inPortPhillip.AsignificantchangewasnotedinFebruary2011whenajuvenile,‘clean-finned’animalwasphotographedwithextensiveepidermallesions.DedicatedphotomonitoringsurveysconductedbytheDolphinResearchInstitute(DRI)inApril2011recordedfivedifferentepidermallesiontypeson73re-identifiableresidentPortPhillipdolphins(72SABD’sand1short-beakedcommondolphinDelphinus delphis).Ofthese,40SABDdolphinsshowedevidenceoflesions;15animalsexhibitedtwotypesoflesionsand25dolphinsasingleformoflesion.Allaffecteddolphinsdisplayed
normalbehavioursandappearedtobeingoodcondition.Themostprevalenttypeoflesiononre-identifiabledolphinswaswhite;thistypewasobservedon26ofthere-identifiabledolphins.Twelvere-identifiableanimals,werephotographedwithwhite-fringedspots,thesecondmostcommontype.Photographstakentendaysapartofoneindividualwithalargecloudylesion,showedsignificanthealingwithlimitedsignsofthelesionaftertendays.ThesituationinPortPhillipisconsistentwithdescriptionsintheliterature,withlesionsoccurringafterachangeinsalinityandmostlyinyoungeranimalspriortothemdevelopingadultimmunity.Thereisaneedtodevelopasystematicclassificationprotocolforlesions.DRIwillcontinuetomonitorthepresenceandextentofepidermallesionsintheresidentSABDandshort-beakedcommondolphinsaspartofouron-goingcoreresearchprogram.
Abstract
Figure 1: Heavily lesioned juvenile dolphinphotographed during core research surveyFebruary,2011.
Table1:LesioncategoriesascharacterisedinWilsonet al.(1997)
Figure3:Lesiontypesclearlyverifiableonresidentdolphins inPortPhillip,72SABDandoneshort-beakedcommondolphin.CategoriesbasedonWilsonet al.(1997)
Num
berofaffecteddolphins
Lesiontypes
SuzanneMason
DRIWebsite
Figure 5A: SABD photographedApril 7th, 2011with cloudy lesion below dorsal (arrow showslocation)Figure5B:Samedolphinphotographed10dayslater,cloudylesionisbarelyvisible
PosternoP04
Figure 4: Number of lesion typesverifiableonre-identifiabledolphinsinPortPhillip,72SABDandoneshort-beaked common dolphin. CategoriesbasedonWilsonet al.(1997)Noverifiablelesions1verifiablelesiontype2verifiablelesiontypes
Figure2:LocationofresidentSABDandshort-beakedcommondolphinsinPortPhillip,Victoria,Australia
April17th,2011
Figures6A-E:Lesion types identifiedonPortPhillip dolphins. 6A: Black lesion, identifiedas a tattoo lesion by Dr Marie-FrancoiseVan Bressem from photos. SABD identifiedas ‘Ariel’s Calf’. 6B: Black-fringed lesion onSABD.6C:Two lesion typesonsameSABD,whiteandwhite-fringedlesions.6D:Numeroussmall,whitelesionsonSABD.6E:Generalisedblemisheson‘Jeb’s’bodywereconfirmedbyDrMarie-FrancoiseVanBressembutnotincludedinanalysis.6F:CommondolphinsswimminginSABDpodappearedclean
April7th,2011(ImagetakenbyKCharlton-Robb)
ImagetakenbyKateCharlton-Robb
White-fringed
White
A
B
C
D
F
EWhere to from here? DRIwill:•Monitorlesionsontheresidentdolphinsaspartofouron-goingcoreresearchprogram•CollaboratetodevelopasystematicapproachtomonitorepidermallesionsinsouthernAustralian•Reviewtwo-decadephotodatasetforhistoricaltrends•Continuetocommunicatefindingstoagencies
