ReportonatriptotheSelvagensonboardtheM/VYERSINduringtheExplorationsdeMonacoExpeditiontoMacaronesia

2017

9-11September2017

Team:FrancisZinoElizabethZinoConceiçãoOrnelasManuelBiscoito

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BackgroundTheSelvagensIslandsareasmallgroupofislandsbelongingtoPortugalandarelocatedintheeasternAtlantic,160milessouthofMadeiraand80milesnorthofTenerife. They comprise 3 islands, Selvagem Grande, Selvagem Pequena andIlhéudeForaandseveralsmallislets(Figs.1and2).

Figure1.TheSelvagensIslands

Figure 2. Selvagens seen from space. Selvagem Grande (left) and SelvagemPequenaandIlhéudeFora(right).

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TheislandswereofficiallydiscoveredbythePortuguesenavigatorDiogoGomesinthemid15thcentury,althoughtheywereknownasearlieras1345.Eversinceits discovery, the islands have been privately owned until 1971, when thePortuguesegovernmentboughtthemandmadethemaNatureReserve.

Althoughthereweresomecolonizationattempts,theislandshavebeenmostofthe time uninhabited, until the 1980’s when park wardens were stationedpermanentlyonSelvagemGrande.

The main source of income of the owners was the culling rights of Cory’sShearwaters,fish,limpetsandperiwinklesandthecollectionofalichen,Rocellatinctoria,thenusedtoextractpurpledye.Overtheyears,goats,rabbitsandmicewereintroducedinSelvagemGrande,butarenoweradicated.Theotherislandsofthegrouphaveneverbeencolonizedbyintroducedherbivores.

Although visited bymany naturalists and explorers, starting by Captain JamesCook in 1768 and including Prince Albert I of Monaco in 1904 and 1911, theislands have never been systematically studied until 1963, when the FunchalNatural HistoryMuseum (MMF) organized the firstmultidisciplinary scientificexpedition to theSelvagens.Since thisevent, the islandshavebeen thoroughlystudied, with particular emphasis on sea birds, a work started by the FrenchornithologistsFrancisRouxandChristianJouanin,oftheParisMuseum,closelyaccompanied by Paul Alexander Zino, whose interest on the islands’ naturestarted in 1963 andmadehim to build a house in 1967, a crucial step for thesupportofthevisitingscientistsandfortheprotectionoftheislands,evenbeforethey were declared a nature reserve. In fact, Alec Zino not only becameinterested on the breeding birds of the islands, therefore turning him into anauthority on seabirds, but also supported conservation actions before thePortuguese and Madeiran governments assumed their responsibilities on thismatter.Withouthisinterestanddedication,theSelvagenswouldnothavebeenwhattheyarenow,oneofthemostpreciousnaturereservesintheAtlantic.

TheSelvagensareofoceanicvolcanicoriginandarearesultoftheactivityoftheCanarieshotspot,ca.27millionsyearsago.

The most striking biological feature of these islands are the colonies ofProcellariiformbirds,inparticularCory’sShearwaters,Calonectrisborealis(over30.000 pairs) andWhite-faced Frigate Petrels, Pelagodromamarina hypoleuca(over40.000pairs),thelatterhavingintheSelvagensthelargestandnorthern-most colony in theworld. Three other species also breed in the Selvagens (bydecreasing order of abundance): Bulwer’s Petrel, Bulweria bulwerii, MadeiraStormPetrel,OceanodromacastroandBarolo’sPetrel,Puffinusbaroli.Swinhoe’sPetrel,OceanodromamonorhishavebeenregularlyseeninSelvagensandmaybebreedingtheretoo.

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Theislandsalsohavetwoendemicreptiletaxa,thegecko,Tarentolabischoffiandthelizard,Teiradugesiiselvagensis,201arthropodtaxa,44ofwhichendemicandatleast8terrestrialmollusctaxa,oneofwhichendemic.

Figure2.GeneralviewsoftheSelvagens.A,C&D,SelvagemPequena.B,E,F,G&H,SelvagemGrande.

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Apart from the animals, the islands possess a highly interesting flora,extraordinary well preserved on Selvagem Pequena and Ilhéu de Fora, whichhave never by subject to grazing by introduced herbivores. In total, 105 plantspecies have been recorded, 7 of which are endemic to the Selvagens. It isremarkablethepresenceonIlhéudeForaofanendemicplantspecies,Euphorbiaanachoreta,onwhichanendemicbeetle,Deucalionoceanicus,live.

Atmarine level, Selvagens present a unique seascape,with highly transparentwaters,populatedbymorethan80coastalfishspecies,200algae,200molluscs,over 100 crustaceans, etc. Ten cetacean species and 5 turtle species have alsobeenrecordedfromtheirwaters.

Inall,theSelvagensareauniquearchipelagowithnoothertermofcomparisonontheworld’ssubtropicalbelt.

ObjectivesThepresentvisithadthefollowingobjectives:

Torecordtheconditionofthefloraoftheislands; Toobservethepresenceofbirdsotherthanbreedingseabirds; Tocollectstomachsofdeadseabirdsformicro-plasticssearch; ToringjuvenilesofCory’sShearwatersatSelvagemGrande; TorecordmarinelitteronthelittoralofSelvagemPequena.

ResultsDuetounfavourableweatherconditionsitwasnotpossibletovisitIlhéudeFora.Therefore we visited Selvagem Pequena on the afternoon of the 9th and thewholedayonthe10thandSelvagemGrandeonthenightofthe10thandthedayofthe11th,until16:30.

FloraThe timeof theyearwasnot ideal forplants,butstill severalspeciesofplantswereseen,someoftheminflower,suchasAsparagusnesiotes,Frankenialaevis,Lotus glaucus and Lobularia canariensis var. rosula-venti at Selvagem PequenaandSchizogynesericea andMesembrianthemumnodiflorum atSelvagemGrande(Figs.3&4).

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Birds(nonProcellariiformes)Afewseagulls,Larusmichahellis,wereseenatSelvagemGrandeandatleasttwonests of this specieswere seen in Selvagem Pequena (Fig. 5-F). Interesting tonote that these nests were full of bones and feathers of White-faced FrigatePetrel,thusprovingthatseagullsareimportantpredatorsofthisspeciesandaneventualincreaseinitspopulationmayposeaseriousthreat.

Several Berthelot’s Pipits, Anthus berthelotii berthelotii, were seen on bothislands.

Figure3.SomeplantsobservedonSelvagemPequena.A–Zygophilumfontanesii;B – Lotusglaucus; C – Lobularia canariensis subsp. rosula-venti; D – Limoniumpapillatum;E–Patellifoliaprocumbens;F–Asparagusnesiotessubsp.nesiotes.

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Figure4.SomeplantsobservedonSelvagemGrande.A–Schizogynesericea;B&C–Mesembryanthemumnodiflorum;D–fromleft:Patellifoliapatellaris,Senecioincrassatus and Suaeda vera; E – Solanum lycopersicum; F – Rocella tinctoria(lichen).

CollectionofstomachsfromdeadbirdsInordertocontinuethemonitoringofmicro-plasticsinthestomachsofseabirds,two corpsesofCory’s Shearwaters andoneofWhite-facedFrigatePetrelweredissected and the stomachs collected and preserved for future analysis at theFunchalNaturalHistoryMuseum(Fig.5-G&H).

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Figure 5. Bird observations on Selvagens. A, B, C & D – Cory’s Shearwater,Calonectris borealis; E – Ringing of juvenile Cory’s Shearwater; F – Nest ofseagullwithremnantsofWhite-facedFrigatePetrel;G&H–DissectionofCory’sShearwatercorpsesforextractionofstomachsformicro-plasticsdetection.

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RingingjuvenilesofCory’sShearwatersatSelvagemGrandeDue to the little time available on land, only fifty juvenile Cory’s Shearwaterswereringedandweighedonnestatastudyquadrat,belowPicodaAtalaia,onSelvagemGrande(Fig.5-E&6).ThisquadratandanotheronBaíadasPedreirashave been monitored since 1967 by P. A. Zino and F. Zino. All nests arenumberedandeveryyearegg laying,hatchingand fledgingof shearwatersarecontrolled,makingthisthelongestseriesofdataonthisspecieseverrecorded.Totalringingon thesequadratswillbeachievednextOctober,onanothervisitbyF.Zino.

RecordofmarinelitteronthelittoralofSelvagemPequena.Duetocurrents,twoseashoresofSelvagemPequena(NEandNWbays)(Fig.7)tend to accumulate marine litter in large quantities. The accumulated debrishavebeencollected,fromtimetotime,bytheparkwardens.

During this visit we were able to record a large amount of debris strandedashore (Figs. 8 & 9). The vastmajority of debriswere plastic items, includingtrays,fishinggear,cans,jarandbottlecupsandemptyPETwaterbottles.Aspertheoriginofthesedebris,alargequantityseemstohaveoriginatedfromboats,eitherfishingormerchant.YachtsmayalsobeasourceofmarinelitterfoundatSelvagemPequena.

AnemptygascylinderfromthePortuguesecompanyGALPfoundattheNEbay(Fig. 8), may have originated from Madeira, eventually due to the 20th ofFebruary2010flood.

Amongstthedebris,severalemptyshellsofMytilussp.werefoundandcollectedfortheMMF.Sincemusselsarenotnativeofthesewaters,thesespecimensmayhave arrived attached to floating objects, proving that marine litter can be ameanofintroductionofnon-indigenousspecies.

All observations made relate to large plastic items. Micro-plastics in theenvironmentwerenotsampled.

On the NE bay, an old oil spill was observed, with large portions of tar stillattachedtotherocks(Fig.9).

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Figure6.SelvagemGrande,showingthe locationof thequadratwhere juvenileCory’s Shearwaters were ringed (green rectangle) and the houses at Baía dasCagarras(redstar).

Figure 7. Selvagem Pequena, showing the two seashores where marine litteraccumulates (red band) and the location of the wardens’ shed, at the landingpoint.

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Figure7.MarinelitteratSelvagemPequena.Topleft,NWbay,wherethereisthewreckoftheNorwegiantankerCerno.AllotherphotosfromtheNEbay.

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Figure8.MarinelitterfoundatNEbayofSelvagemPequena.Gascylinders(top).TheoneatleftmayhavecomefromMadeira,whiletheoneatrightisacommonmodelonsailingyachts.Vestigesofanoldoilspill(twophotosatbottom).

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RemarksOurstayontheislandswasverywellcaredbythecrewofYERSIN,whoprovidedconfortabletendertransportationandfoodandbeverageingenerousamounts.However, the ship’s tenders (ZodiacHurricane) provednot to be adequate forlandingonrockyshoresandshallowbeaches,asitisthecaseoftheSelvagens.Ifthereweren’tthehelpofN.R.P.Douro’sdinghytomakethefinalapproachtotheSelvagem Pequena, it wouldn’t have been possible to land, with YERSIN’stenders.ThesamehappenedonSelvagemGrande.ThistimethehelpcamefromtheAutoridadeMarítimaNacional(MaritimePolice),whousedhisdinghyforthefinalapproachtothelandingplace.

ItisthereforeofutmostimportancethatYERSINbeequippedwithaflatbottominflatable zodiac, for6-7passengers and equippedwith a light 20Hpoutboardengine, in order to allow landings on remote islands. According to ownexperience, this dinghy should have an extra protection at bow andaluminium/steelfloorpanels(moreresistantthanwoodones).

AcknowledgementsTheteamisindebtedtoExplorationsdeMonacoforhavingmadepossiblethisvisit.ThanksareduetoPierreGilles,Chief-ScientistonboardtheYERSIN,forallhis insurmountable support and good will to accommodate our needs and toCaptain Jean Dumarais and all crewmembersof YERSIN for their helpduringlandingoperationsandforhavingproportionateanexceedinglypleasantstayonboard.TheteamwishesalsotothankCarolinaSantos,andthewardensSandroandPedro,of IFCN, for thewarmreceptionon the islandsand invaluablehelpduring the work. Thanks also to: the Commanding Officer and crew of N.R.PDOURO,forhelponlandingsatSelvagemPequenaandforthetransportationofFZandEZ toFunchal; thestaff fromAutoridadeMarítimaNacional forhelponlandingsonSelvagemGrande.

MB and CO are particularly indebted toRobert Calcagno, Director-General oftheInstitutOcéanographique,forthekindinvitationtoembarkontheYERSINtoCaboVerdeandthereforeforauniqueandunforgettableexperience.