Diversity andstatus ofseaturtle speciesinthe
GulfofGuinea islands
JAVIERCASTROVIEJOandJAVIERJUSTE B
EstaciónBiológicadeDoflana.Avda.MaLuisas/n,41013Sevilla,Spain
JAIMEPEREZDEL VAL, RAMONCASTELOandRAMONGIL
AsociaciónAmigosdelCobde DaiTana,C/PanamaNo.6,41012,Sevilla,Spain
Received12May1994;accepted14August1994
InWestAfrica,theGulfofGuineaislands areimportantnestingplacesfor fourseaturtlespecies. TheGreenturtle(Chelonia mydas), theHawksbill(Eretmochelys imbricata), theOliveRidley (Lepidochelys olivacea) and the Leatherback(Dermochelys coriacea) turtlesneston Bioko’s southernbeaches.TheGreen,Hawksbilland Leatherbackturtlesbreedon PrincipeandSão Tome.TheLeatherbackturtlenests,atleast,onAnnobén. TheLeatherbackturtleisreportedon thefourislandsforthefirsttime,andtheOliveRidleyturtleforBioko.Biokoisprobablythe mostimportantislandintermsofnumberofspeciesandnestingindividuals; theGreenturtle beingthemostabundant species.However,thenestingplaces areatpresentrestrictedtobarely20 kmalongthecoastline.OnPrincipeandSãoTome,themostcommonspeciesistheHawksbill turtle.Seaturtlenestingpopulationsarebeingseverelydepletedonthefourislands.Themain causesofoverexploitationarethemeatandeggtradeonBiokoandtheHawksbillshell-craft tradeonSãoTomeandPrincipe.
Keywords:GulfofGuinea,seaturtles,conservation,exploitation
Introduction
Informationon the turtle populationsinwestern EquatorialAfrica and, in particular, along the Gulf of Guinea is scarce (Brongersma, 1982; Maigret, 1983; Fretey and Girardin,1988; Butynski et at., 1989;Carr and Carr, 1991). For Bioko, some notes appearinCrespo(1949),Guinea(1949) andEsteban(1950)whoalsopublishedturtle photographsfrom thesouthern beaches. More recently,Eisentraut (1964)gaveprecise recordsofsea-turtles nestingontheislandand reports ontheirexploitation onsouthern Bioko havealsoappeared (Butynski and Koster, 1989).For theother Gulf ofGuinea islands,PrIncipeand SãoTome,firstreferencesappear in1883butthereafter onlyanec dotal data areavailable. No sea turtles have beenrecorded for Annobón,thesmallest andmostdistant islandintheGulf.
Despite thecurrent lack ofinformation,there isno doubt that theGulf ofGuinea
Islands aresomeofthemostsignificantseaturtle nestingareas inAfrica.Thisrichness isatpresent threatened inalltheislands,evenbeforeithasbeenproperlyassessed.The aim ofthispaper istopresentsomefactson thestatus oftheseaturtlesaswellason their economic importancefor the local people. Data reported herein werecollected from1985to1994andarisemainlyfromdirectobservationsofanimals,tracksand
Diversityandstatusofseaturtles
othersignsrecordedduringsurveywalksonnestingbeachesonthefourislandsduring thenestingseason.Numerous interviewswithlocalfishermen, relevantauthoritiesas wellasspecializedseaturtlecatchershavealsoprovedtobeveryuseful.
Descriptionanddistributionofnestingbeaches
InallfourGulfofGuineaislands,nestingseaturtlestypicallychoseunshelteredblack orwhitesandorshinglebeaches.Thesebeachesareoftensteepslopingevenatlowtide. Itisacommonfeatureintheislandsthatsomeriversdonotreachtheseaduringthe dryseason,thewaterbeingtrappedbysandorshinglebarrierstoformatemporary estuarywhichturtleshavebeenseenusing.Behindtheshingleorsandyareas,thereis usuallyabeltoftropicalvegetation,composedmainlyofcoconuttrees (Cocusnucfera), Terminaliacatappa,Cammelinaspp.(conf.C.erecta),Begoniaspp.,Polisotahirsutaand thecommonerIppomeapes-caprae.
Bioko
Biokoisprobablythemostimportantislandintermsofnumber ofturtlespeciesand nestingindividuals.Beachesusedbyseaturtlesareatpresentrestrictedtothesouthern part of theisland,barely20kmofcoastline,betweenPunta Santiagoand Punta Oscura.Accordingtolocalinformantsandourownobservationsthemostimportant beachesare:
(i)Sobobeach— betweentheSobo,GrandeandMoabarivers— breedinggroundfor theLeatherbackturtle.
(ii)Mvelóbeach,tothewestofthePotóriver,aftertheEoláriverandarockyarea—
breedinggroundsforLeatherbacksandOliveRidleyturtles.
(iii)Ma andEocabeaches,betweenthePotóand Siórivers— thebestbreeding groundsforthe AtlanticHawksbill.
(iv)Moracabeach,fromPuntaSagrétotheriverOleorTudela— goodbreeding groundforthe Green turtle.
(v)SmallsandybeachbetweentheOlerivertooppositetheEadyórocks— good breedinggroundforthe Greenturtle.
(vi)Banderaand Moalo beaches,betweenthe Eadyórocksand Punta Islote—
reservesfortheGreenturtle.
Apart from thesebeaches,in thepast seaturtlesprobablyusedother northern
beachesinBiokoandmaystilldososporadically,assuggestedbythesightingofa couplematingandisolatedindividualsnearArenasBlancasbeach(Luba)inDecember
1991.
PrIncipe
OnPrincipe,unlikeBioko,seaturtlesnestonsuitablebeachesallaroundtheisland’s perimeterprobablybecauseofthelowerhumandensity.Accordingtosomefishermen the mostimportantbeachesare:
(i)PraiaGrande,afterPontaCaféto theBibiriver— breedinggroundforthree species,andoneofthemain pointsfortheLeatherbackturtle.
(ii)PraiaSãoTome— oneofthemostimportantnestingplacesonPrIncipe.Wehave beentoldthatanumberofindividualsofthreespeciesnest thereeveryyear.
(iii)PraiaFormigaandPraiaRei—breedinggroundfortheAtlanticHawksbiflturtle.
(iv)PraiaMocotóandPraiaRibeiraIzé,includingtheareabetweenPontaMarmita andPontadaFurna— groundsfortheAtlanticHawksbillandtheGreenturtle.
Olderfishermenclaimthatseaturtleshavebecomeevenlesscommoninthesouthern
partoftheisland.Atpresent, theyseemtobemuchmorerarealongthebeachesclose tothecityandalongthePapagaiorivermouthwhichcrossesthecityofSãoAntonio
duringhightide,astheyusedtobeinrecenttimes.
SdoTome
Ithasbeenmoredifficulttoobtaininformationonthebeachesofthis island.However, it isquite certainthatthe mostimportantnestingbeachesare atpresentrestrictedtothe southernandwesterncoasts.Thefollowingcanbeconfirmed:
(i)PraiaMicondó,PraiaPequeirodeDeusandPraiaInhame,nearPortoAlegre—
groundsfortheAtlanticHawksbillandLeatherbackturtles.
(ii)PraiaCafé,PraiaPomboandPraiaS.Antonio,allontheislet‘dasRolas’
commonlyusedbyAtlanticHawksbilland,accordingtolocalpeople,alsobyLeather-
backandGreenturtles.
(iii)PraiaQuijaandPraiaPalma,onthewesterncoast— probablythemostim portantnestingbeachesonSãoTom”becauseoftheirwilderness;groundsforAtlantic Hawksbill,LeatherbackandGreenturtles.
AsonPrIncipe,therearesuitablebeachesforseaturtlesallaroundthecoastbutthese arenormallyavoided becauseofhumandisturbance.OneLeatherbackwaskilledwhile
layingeggsonPraiaLembá(Northwest)inJanuary1993andoneAtlanticHawksbill wasalsokilledwhennestingonPraiaMonteForte(North)inDecember1993.
Annobón
TurtlenestingonAnnobónislimitedbecausetherearefewsuitablebeaches.Themost important are thesmallbaysbetweenPunta Manjoband A Dyibóin theSouth (Mabena).
Speciesaccounts
Cheloniamydas
Greenturtle(English),Tortugaverde(Spanish),Tartarugabranca(Portuguese).Local names:Mulupapa(Bubi,Bioko),Ambo(Forro,SãoTome).
ThisiscertainlythemostabundantspeciesonBioko.Itiseasilyspottedandegg-
layingfemaleswereseenseveraltimesin1986,1987and1991.Similarreportswere madebyEisentraut(1964)andbyButyinskiandKoster(1989).Thenestingpopulation, probablyaroundhundredsofindividuals,mayreachBiokobeachesfromOctoberto February.OldinhabitantsofUreca,asmallvillageonthesoutherncoast,recallGreen turtlescomingashorenearthevillageinconsiderablenumbersevenindaylight,as reportedbyearlynaturalists(Crespo,1949;Esteban,1950).Duringthelast 30years,at least,thespecieshasmadeupthemainyieldforseaturtlecatchersandnumbersof nestingindividualshavedecreasedsharply.
Thisspeciesisalsocommonoverthe otherislandsandonespecimenwasseeninthe southerncoastofPrIncipeinFebruary1994.
Eretmochelysimbricata
Hawksbillturtle(English),Tortugacarey(Spanish),Tartarugavermelha(Portuguese). Localnames:Kuru(Bubi,Bioko),Sada(Forro,SãoTome).
OnBioko,thisspeciesbreedsonthesame beachesastheGreenturtle,occasionally beingcapturedwhennesting.OnbothSãoTomeandPrIncipe,itisgenerallyconsidered
themostcommonspecies.IthasnotbeenpossibletoconfirmHawksbillsnestingon
Annobônalthoughyoungindividualsare frequentlycapturedoffshore.
Lepydochelysolivacea
OliveRidleyturtle(English).Tortugagolfina(Spanish),Tartariigabastarda(Portu
guese).Localname:SanquIa(Bubi,Bioko).
Anegg-layingfemalewasphotographedandidentified(onthebasisofitshighround carapaceandconsiderablenumberoflateralscutes)asbelongingtothisspecies.Thisis
thefirstcitationofthisspeciesbreedingonBiokobeaches.Beingrare,itisonlyocca sionallycaughtbutitspresencewasconfirmedbylocalpeoplewhocaneasilyidentifyit andhaveaspecificnameforit intheirlocallanguage.
InPrincipe,an‘unusual’seaturtle,whosedescriptionfitswellwiththisspecies,was
capturedashoreentangledinapieceofnetin1991.
Dermochelyscoriacea
Leatherbackturtle (English),Tortuga laud (Spanish),Tartaruga grandeencourada (Portuguese).Localnames:Eguin(Bubi, Bioko),Tartarugatractoroambulancia(São Tome).
Severalspecimenshavebeenseenegg-layingonthebeachesbetweenPuntaDolores andPuntaSantiagoinBiokofrom1986to1992.TheLeatherbackhasbeenreportedby
localpeopletonestpersistentlyinSãoTomeandPrincipebeaches,butalwaysinfew numbers.In1994,fourindividualswereseenonPraiaQueija(SãoTome)andbetween FebruaryandMarchthisyearatleastoneanimalwaskilledinPraiaGrandebeach
(Principe)andanotherintheLembárivermouth (SãoTome).Atrackclearlybelonging to thisspecieswasseenon Mabenabeachin thesoutherncoastofAnnobónon December1986.These arethefirstconfirmedrecordsofthisspeciesbreedingonthe fourislandsoftheGulfofGuinea.Itseemstopreferremote,largeandopenbeaches.
Itisinterestingthatthe loggerheadturtle(Carettacaretta)hasnotbeenfound inany oftheislands despitetherebeingseveralcitationsfromtheGulfofGuineaandalong thewesternAfricancoast(JversonandCollege,1992).
Reproductivedata
Thereareapparentlynocleardifferencesinthenestingrequirementsofanyofthe species,sincesuitablebeacheson everyislandaresharedbymorethanoneturtle species.Nevertheless,itseemsthatGreenturtlesareproportionally (andinabsolute scores)moreabundantonBiokobeacheswhileHawksbillsseemtopreferPrincipeand SãoTomefornesting.Thisdifferencemaybeduetothefactthatthelatterspecies needstopenetratewellintotheforesttoegg-lay(PritchardandTrebbon,1984)which maybeeasiertodoinPrIncipeandSãoTome.
Nestingtakesplaceseasonallyonallthe islandsfromNovemberuntilMarch,witha peakinDecember—JanuaryinBioko,andanapparentdelayinPrIncipeandSãoTome.
.
Table1.Comparisonof number ofeggslaid bythe two main speciesofturtles inthe Guinea islands
SpeciesDateNo.eggsLocalitySource
Green’turtleJanuary1963138BiokoEisentraut(1963) March1990 36 Bioko J.P.Gonzalez
(personalobservation)
December199178/128/106BiokoR.Gil
(personalobservation)
November—March100—200BiokoLocalpeople(Urecans)
mean138SurinamPritchardandTrebbon
(1984)
mean147IleEuropePritchardandTrebbon
(1984)
LeatherbackturtleFebruary199158BiokoJ.Castroviejo
(personalobservation)
November—March / 40—60 / Bioko / Localpeople(Urecans)58—160 / SouthAfrica / PritchardandTrebbon
(1984)
This periodcorrespondstothestartofthedryseasononBioko(seca)andtheshortdry season(gravanilla)onthe othertwoislands.Nestsaredugwithincircularareas(witha diameterrangingfrom4to5mfortheLeatherbackandfrom1to2m fortheHawks- billturtle)andclosetotheforestfringeandthebeach.Theseareastypicallyshowthe sand-groundaroundthembeingintenselydisturbed.Onlyscarceinformationabout clutchsizeisavailable,butourdataforBiokofitstherangesreportedintheliterature (Table1).Basicdataonthismatterisurgentlyneededforalltheislands.
Humanimpact
Seaturtleeggsare consumedlocallyandmanisundoubtedlythemainpredatoronthe fourGulfofGuineaislands.Seaturtlenestsaredugout,regardlessofthespecies, throughoutthewholenestingseason.Drills(Mandrillus leucophaeus)wereseeneating eggsonBiokobeachesandlocalsreportcrabs,ratsanddogseatingbotheggs and hatchlingsonalltheislands.Theimpactofthisistotally unknown.
Capturemethods
Therearenospecies-specificcapturemethods(Table2)andbeach-guardingisthemost widespreadmethodinalltheislands.Egg-layingfemalesareturnedupside-downand eggsremovedbypeoplethatstalkthebeacheseverynight.Theanimalsarekepttiedin theshadeuntilthereareenoughtomaketheirtransporttolocalmarketsprofitable.
Netsover100mlongarestrategicallysetupinthebeachfrontonSäoTomeand
PrIncipeduringthenestingseason.Fishermenalsoeasilyhooksomeindividualsasthey restoff-shoreormateonthewatersurface.
Harpoons are usedto catch smallAtlanticHawksbillwhiletheyfeednear the coast; theseare mainlyto bedried,polishedand soldas souvenirsto foreigners.
Table 2. Mainmethodsofcaptureofturtle speciesinthe Guineaislands
CaptureMethod / Species / Time / Hunters / IslandBeachesguarding / Green turtle / November—March / 5—10groupsoftenmen(agrupaciones) / Bioko,PrincipeandSão
Hawksbillturtle / insouthernBioko;atleasttenfamilies / Tome(Annobón?)
OliveRidleyturtle / inPrincipeandaroundother ten
leatherback turtle(sporadically) / familiesinSãoTome
Nets / Greenturtle / November—March / Thesamefamiliesthatguard the / PrincipeandSãoTome
Hawksbillturtle / beaches
Leatherbackturtle
Hook / Hawksbill turtle
Greenturtle / AUyear / Undeterminated fishermen / PrincipeandSãoTome
Harpoon / Hawksbillturtle / Allyear / Undeterminatedfishermen / Bioko,Principe,São
Tomeand Annobén
TheAnnobónesearethemostskilledatthisbothinBiokoandAnnobón,althoughthis activityisalsocommoninSãoTomeandPrIncipe.
Economicimportance
Atpresent,therearenoaccuraterecordsofthenumberofseaturtleskilledeachyearin theGulfofGuineaislandsbutitseemsthatthelargestnumberaretakenonBioko. Fromourdata,about500Greenturtles arecaughteachyear inBioko,mainlybythe inhabitantsofUreca,although thisfigurecanvarybetweenyears.The2000—2500speci mensreportedbyButysnkiandKoster(1989)arelikelytobeanoverestimate.
On averagetheUrecanssellturtlesat 15000FCFA apiece;a total ofaround
7500000FCFA(1US$ 550FCFA).Aseachofthe5—10turtle-huntinggroupspays
100000FCFA intaxestotheGovernorofLubaprovince,thisfigurebecomesaround
6500000FCFA.Agroupconsistsoftenpeopleandatotalof50—100 peoplemaybe engagedinthisactivity.Eachmembercanmakeabout65000—130000FCFAperyear,
excludingpetrolcostsandrentalofthedugoutcanoe.Althoughlow(particularlywhen consumptioncostsare takeninto account),profitsmadefrom thisactivityarethe
Urecans’solesourceofincometoday.Thesituationhasworsenedsincethemostrecent declineincocoa.
InLuba,turtlesareslaughteredandcarriedtothecapital’smainmarketsbyinter
mediarydealers.Themarketpriceofturtlemeatisabout1000—1500 FCFAakilo. Consideringthat eachturtleweighsapproximately120kg(PritchardandTrebbon,
1984;Márquez,1990)with70kgofmeatonaverage,500sampleswouldfetchbetween
35and52.5millionFCFA.
IncomesgeneratedbytheseaturtletradearemoredifficulttocalculateforPrIncipe
andSãoTomesinceseaturtleextractionisnotconcentratedinoneareaasinBioko. Moreover,shell-handicraftisanimportanttraditionalactivityintheseislandsandmany
turtlesaresolddirectlytocraftsmenratherthanbeingsenttothemarkets.Arough estimatewouldgiveabout100adultHawksbillscaughtoneachisland perannum.For anaverageof40—60kgofmeatfromeachturtle,soldforamarketpriceof400Dobras perkilo(1US$=600Db),200turtleswouldfetcharound5millionDb.Ontheother hand,Hawksbillshellissoldtocraftsmenatapricewhichfluctuatesbetween15000 and20000Dbperkilo(dependingonshellquality,andcheaperonPrIncipe).If3 kgof scutescanbeobtainedfromeachadultturtlecarapace,asumof 9—12000000Dbcould beobtainedfromthisactivity.ThisroughestimateclearlyshowsthatinSãoTomeand Principe,theshelltradeproduceshigherprofitstolocalfishermenthanthesaleofturtle meat.
Shell handicraftproductsaresoldinlocalmarketsbuttradewithAngolahasbeen reported(StuartandAdams,1990)anditisalsolikelywithEurope.
Ingeneral,seaturtlecommerceproduceslowreturnsforthelocalpeopleinallthe islands.However,when putintothecontextofthecountries’weakeconomiesandthe
absenceofalternativesourcesofincome,thecaptureofseaturtlesbecomesan portantcomplementaryrevenueandmaythusevenintensifyintheshort-term.
Conservationmeasures
AllfourturtlespeciesareincludedinAppendix1oftheConvention onInternational
TradeinEndangeredSpecies(CITES);tradeintheirproductsandinlivespecimensis
prohibited.TheIUCN RedData Book(Groombridge,1981)considersthemas‘en
dangered’.
Turtlefishingis nowillegalinEquatorialGuinea(Law8/88,regulatingthehuntingof
wildlifeinprotectedareasanddecree183/87regulatingfishing)butitisstillnot regu
lated inSãoTomeandPrIncipe.Thereisagenerallackofknowledgeoftheimpactof
adultfemaleextractiononthedynamicsofthesepopulations,butifitpersistsatthe presentscaleitislikelytohaveserious,irreversibleeffects.Itisessential,therefore,to implementaseriesofurgentmeasuresthroughresearchandconservationinthefour islandsofthe GulfofGuineaby:
(i)EstablishingaresearchprogrammetoassessimpQrtantdemographicdataforall thebreedingpopulationsofseaturtlesthatwouldinclude:
(a) Sizeandcharacteristicsofthebreedingpopulations. (b) Intra.andinter-seasonalnestingfrequencies.
(c) Nestingsuccess:no.ofviableeggs,nestpredation,etc.
(d)Dynamicsofbreedingbeachesandfactorsinvolvingnest-placingchoice. (e)Contactandrelationshipbetweenbreedingpopulationsonalltheislands.
(ii) Protectingandmonitoringneststoassure100%ofhatchlingsreachthesea.
(iii)Establishingacompensationprogrammeforlocalpeopleinvolvingthefollowing:
(a) Paymentof theequivalent,or higher,ofthemarketpriceforeachturtle foundandnotkilled.
(b)Exchangeoffoodandotherbasicproducts(e.g.chickeneggs,soap,petrol, lantern-batteries, rice, etc.)forthenon-consumptionofturtleeggs.
(c) Organizationofcommunalshopsintheimportantnestingareaswithpriceson aparwiththe maincitymarketstocompensateforincomelosses.
(d)Employmentoflocalpeopleforbreedingturtles,nestmonitoringandreleas
inghatchlings.
(iv)Initiatingaprogrammeforrearingwildlife(giantrat,blueduiker)ordomestic animalsforsaleinthemarket-placetoprovideprotein.Trainingandtransporttobe paidforby theproject.
(v) Drawingupastudy planforecotourism.This projectshouldbecombinedwitha broader one fortheconservationoftheprotectedareasinwhichlocalpeopleshould playanimportantrole.
(vi)Publicisingtheprojectsthroughouttheislands.
Attitudes andperspectivesoflocalpeople
ThesemeasureshavealreadybeendiscussedwiththeUrecansin Biokoinseveral meetingsoverthelasttwoyears.Theyareawareoftheextraordinaryvalueoftheir naturalheritageintheirtraditionalterritory.Theyknowthatatthepresentrateofex ploitation,thesurvivalofturtlesisthreatened.TheUrecansarepreparedtoconserve thesereptilesifalternativesourcesofincomefortheirsubsistencecanbefound.Propo salsweremetwithaveryfavourableresponse.
Similaractivitiesmustbeundertakenintheotherislands.PeoplecontactedinPrIncipe showthesameawarenessaboutthedecliningsituationofseaturtles.Atpresent,nothing isbeingdonetoimprovethesituationinBioko,whileinSãoTomeandPrincipeonlya smallmonitoringprojectwithaneducationalcomponentisduetostartshortly.Yet, clearly,thesituationis soprecariousthattoguaranteethesurvivaloftheseaturtleson theseislandsamuchmoreambitiousprojectwithbroadercoverageisessential.
Acknowledgments
Wethank allthefishermenand peoplethat helpedustogather informationonthesea turtles from the Gulf of Guinea islands during all these years. We are especially indebted totheUrecans(Bioko)fortheirkindhospitality during allourvisits.C.Keller andA.Andreu readthefirstdraft andJ.E.Fahelpedinimproving themanuscript.
References
Brongersma,L.D.(1982)MarineturtlesoftheEasternAtlanticOcean.InBiologyandConserva tionof Sea Turtles. (K.Björdal,ed.)pp.407—16.WashingtonDC:SmithsonianInstitution Press.
Butynski,T.M.andKoster,S.H.(1989)MarineturtlesonBiokoIsland(FernandoPoo), Equator
ial Guinea: A Call for Research and Conservatioh. WashingtonDC:WWFUnpublished
Report.
Carr,T.andCarr,N.(1991)Surveysoftheseaturtlesof Angola.Biol.Conserv.58,19—29.
Crespo, C.(1949)Notas paraunEstudio AntropológicoyEtnológicodelBubideFernandoPoo.
Madrid: InstitutoEstudiosAfricanos.(CSIC).
Eisentraut,M.(1964)Meeresschildkröten anderKüstevonFernandoPoo.NaturundMuseum
94,471—5.
Esteban,J.(1950)GuineaColonial.EstoesEspaila. Madrid:ArgosSA.
Fretey,J. and Girardin,N. (1988)La nidificationdela tortueluth,Dermochelys coariacea
(Vandeldi,1761)(Chelonia,Dermochelyidae)surlescôtesduGabon.J.Afr.Zoo!.102,125—
32.
Groombridge,B.(1982)TheIUCN Amphibia— ReptiliaRedDataBook(Part1).Gland,Switzer
land:IUCN.
Guinea,B.(1949)EnelPalsdelosBubis.RelatoilustradodeMi PrimerViajeaFernandoPoo.
Madrid: InstitutoEstudiosAfricanos(CSIC).
Iverson,J.B.andCollege,B.(1992)ARevisedChecklistWith DistributionMapsoftheTurtlesof
theWorld.Richmond,Indiana:PrivatelyPrinted.
Maigret,J.(1983)RepartitiondestortuesdemersurlescôtesouestafricainesBull.Soc.Herp.Fr.
28,22—34.
Márquez,M.(1990)SeaTurtlesoftheWorld.FAQFisheriesSynopsis125(11).Rome:FAO. Pritchard, P.C.andTrebbon,P.(1984)TheTurtles ofVenezuela.Athens,Ohio,Societyforthe
StudyofAmphibiansandReptiles.
Stuart,S.N.andAdams,R.J.(1990)BiodiversityinSub-Saharan AfricaandItsIslands: Conserva
tion,ManagementandSustainableUse.Gland,Switzerland:IUCN.