Unusual cold-stunning event of green turtles in Uruguay
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Transcript of Unusual cold-stunning event of green turtles in Uruguay
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7/28/2019 Unusual cold-stunning event of green turtles in Uruguay
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G.Vlez-Rubio1,2,A.Estrades1,V.Ferrando1,J.Toms21Karumb,Avda.Gral.Rivera3245,CP11200,Montevideo,URUGUAY([email protected])
2InsHtutoCavanilles,UniversidaddeValenciaApdo.22085,E-46071Valencia,SPAIN.
Hypothermic,orcold-stunning,occurswhenaseaturtleisabruptlyexposedtocoldwater,normallyasaresultofunusualcoldweatherorsuddencoldfronts,anditcannotcompensatefastenoughtoavoidasuddendropin
body temperature(Witherington & Ehrhart, 1989),when sea turtles trappedin coldwaters may become
lethargicandbuoyant,floaHngatthesurface(Milton&Lutz2003)andtheeffectofthewindsontheseasurface
couldcauseseaturtlemassstrandings.
REFERENCESFelgerRS,etal(1976)Winterdormancyinseaturtles:independentdiscoveryandexploitaHonintheGulfofCaliforniabytwolocalcultures.
Science,191:283-85.
MarHnez-SouzaGetal.(2011)CerroVerde,Uruguay:ayear-roundfeedingareaforjuvenilesgreenturtles?ThirtyoneSymposiumonSeaTurtle
BiologyandConservaHon.InternaHonalSeaTurtleSociety,SanDiego,USA.
MiltonSL&LutzPL(2003)PhysiologicalandgeneHcresponsestoenvironmentalstress,pp.163-197.In:LutzP.L.etal.,Edits.Thebiologyofsea
turtle.VolII.Florida:CRCPress.
RDevelopmentCoreTeam(2010)R:A languageandenviromentforstaHsHcalcompuHng.R FoundaHonforStaHsHcalCompuHng,Vienna,
Austria.ISBN3-900051-07-0.
Stark JDet al.(2007)OSTIA:An operaHonal,high resoluHon,real Hme,global seasurfacetemperatureanalysissystem., Oceans07 IEEE
Aberdeen,conferenceproceedings.Marinechallenges:coastlinetodeepsea.Aberdeen,Scotland.IEEE.
Vlez-RubioG(2011)EstudioespaciotemporaldelosvaramientosdetortugasmarinasenUruguay.Tesisdemaestria.UniversidaddeValencia.
VerspeekJ.Aatal.(2009),ValidaHonandcalibraHonofASCATusingCMOD5.n,IEEETrans.Geosci.RemoteSens.,48,1,386-395.
WitheringtonB.e.&ehrhartl.m(1989)ypothermicstunningandmortalityofmarineturtlesintheIndianRiverlagoonsisytem,Florida.Copeia
During July2012record-breakingcoldweatheroccurred throughout Uruguay (Fig. 2). The
seawater surface temperatures went down
under 10 degrees Celsius (C), normally the
seawatermeantemperaturevariesbetween11
to12Cinthismonth.
From12thto19thofJulyintheRiodelaPlataestuarineinfluencezoneoftheUruguayancoast
thetemperaturedroppedsuddenly;specifically
in Puntadel Este(departmentof Maldonado,
South-EastUruguay)and inMontevideowhere
decreased aslowas9and8.5C, respecHvely
(Fig.3).
Prevailingwinds thosedays werefrom SouthandSouthwest.The15 th ofJuly southwestern
windsreached25-30knots.
NinetyjuvenilegreenturtlestrandingswererecordedintheUruguayancoastfromthe13thto25thofJuly2012,beingthe15th,16thandthe17ththedayswiththehighestnumberofstrandings.Mostofthemwererecordedin
theexternalestuarinezone(departmentsof CanelonesandMaldonado,Fig.1).Twentyof theturtleswere
founddead.The others weresent to Karumb RehabilitaHon Center inMontevideoand othercentersforrecovery.
Most ofthe 35 turtles atthe Karumbcenter appeared tobe ingoodphysical
condiHon but half of them presented
floaHng problems, pneumonia, skin
infecHondiseasesandsepHcemia(Fig.5).
Alltheindividualswerejuveniles(meanSDcurved carapace length, notchto Hp
[CCLn-t]=39.93.96cm).
Karumb realesed 31 of these turtles(Fig.6).
INTRODUCTION
Fig.2:DailyseasurfacetemperatureduringJulyinthethreeareasthatwedividedtheUruguayancoast:IEZ(Innerestuarine
zone)ingreen,OEZ(Outerestuarinezone)inred,AZ(AtlanHczone)inblue.NotethatthehighesttemperaturesintheIEZ
correspondtotheareaswellinsidetheRiodelaPlataestuary.
InUruguayancoastalwaters,thehibernaHonstrategypostulatedbyFelgeretal.(1976)hasbeendescribedasasurvivalstrategyof juvenile greenturtles(Cheloniamydas) to toleratelow temperatures duringthe austral
winter(Marqnez-Souzaetal.2011).Itisknownthatsomegreenturtlesremainintheareaduringthecoldest
months, asreflectedby strandingevents(Vlez-Rubio2011), radiotelemetry,in watersurveys andsatellite
telemetry.
STRANDINGSRESULTS
ACKNOWLEGMENTS
Fig.6:Releasingoneofthegreenturtlesrehabilitatedfromthemass
strandingeventinPiriapolis(Maldonado).
STRANDINGSANDENVIRONMENTALCONDITIONSINTHEAREA
Authorsarereallygratefulto allKarumbmembersandvolunteers
whoonceformedpartof theNGO.Thanksalsoto allthepersons
(fishermen, naval prefecture, life guard service, rangers, civil
organizaHons,ciHzens).AuthorswishtothanktotheMarineZoology
UnitoftheUniversityofValenciainthelastpartof thiswork.JT is
supported by project CGL2011-30413 of the Spanish Ministry of
EconomyandcompeHHveness.
Karumbrecordedpreviouscold-stunnedseaturtlesintheperiodofthelast12years(Fig.4)butthe2012eventhasbeentheonewiththehighestnumberofturtlesstrandedrecorded.Nootherspeciesstranded
duringthosedays.
Inthepresentstudywereportagreenturtlemassstrandingevent occurredinUruguayinJuly2012duetoasuddendramaHcdecreaseofseasurfacetemperatures.
Theabruptdecreaseinseawatertemperatureand theprevailingwindsinthearea
probably caused thismass stranding event in Uruguayan coast. Monitoring these
eventprovidesauniqueopportunitytoobtaininforma]onaboutthisphenomenon
andthe consequentimpacton seaturtlepopula]onsthat spent thewholeyear in
thistemperateregionoftheSouthWesternAtlan]cocean.
Fig.5:GreenturtlesinKarumbRehabilitaHoncenterinMontevideo.
Fig.4:Twostrandedgreenturtles.Note
theweekphysicalcondiHon.
Fig.1:MapofUruguay.IEZ(innerestuarinezone),OEZ(outerestuarinezone)andOZ(oceaniczone).Thegreenturtle
massstranding(bigredpoint)occurredinPuntadelEste.Smallredpointsindicatesolitariesgreenturtlesstrandings.
Fig.3:Sea surfacetemperatureduringJuly2013.Maps
showtheinfluenceoftheMalvinascurrentthatfavours
theentranceof coldwaterinthe Riodela Plataarea.
Notelowertemperaturesinthecentralmap.
DAYS
SST
(C)
