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RRSDiscoveryCruiseDY081,July6th–August8th2017

StJohn’s,Canada–Southampton,UK

ICY-LAB

IsotopeCYclingintheLABradorSea

CruiseReport

KatharineR.Hendry,UniversityofBristol

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CONTENTS

TableofContents

CONTENTS....................................................................................................................................2

Chapter1:Personnelonboard.....................................................................................................4Allcrew..................................................................................................................................................4Sciencepartywatchlist..........................................................................................................................5

Chapter2:Rationale,aimsandobjectives....................................................................................6Thesamplingobjectivesofthecruise......................................................................................................6

Chapter3:Cruiseoverview...........................................................................................................8Timeline.................................................................................................................................................8Cruisenarrative....................................................................................................................................10Stationlist............................................................................................................................................14

Chapter4:Sitesummariesandmaps..........................................................................................17OrphanKnoll........................................................................................................................................17Nuuk.....................................................................................................................................................21SouthernGreenland.............................................................................................................................21

Chapter5:Technicalreport........................................................................................................26Acousticsoperations.............................................................................................................................26Coringoperations.................................................................................................................................38CTDoperations.....................................................................................................................................40Glideroperations..................................................................................................................................43RemotelyOperatedVehicleoperations................................................................................................46SAPsoperations....................................................................................................................................56Towfishoperations...............................................................................................................................57

Chapter6:Physicaloceanography..............................................................................................58Introduction.........................................................................................................................................58Summaryofsensordeploymentsandpreliminaryresults.....................................................................58Summaryofgliderdeployments...........................................................................................................69

Chapter7:Watersampling.........................................................................................................70Introduction.........................................................................................................................................70Summaryofwatersamplingevents......................................................................................................70SummaryofICY-LABprojectseawaterparameters...............................................................................74Samplingprotocolsforcomplementarystudies....................................................................................77Porefluidsamplingandcoreincubations...............................................................................................83Shipboardwateranalyses.....................................................................................................................86

Chapter8:StandAlonePumps...................................................................................................89Introduction.........................................................................................................................................89SummaryofSAPSevents......................................................................................................................89Samplingprotocol.................................................................................................................................89

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Chapter9:Sedimentsampling....................................................................................................91Introduction.........................................................................................................................................91SampleCollection.................................................................................................................................91SedimentRecovery...............................................................................................................................93ShipboardAnalyses..............................................................................................................................96

Chapter10:Biologicalsampling.................................................................................................101Introduction.......................................................................................................................................101Corals.................................................................................................................................................102Sponges..............................................................................................................................................103

Chapter11:Scleractiniancorals.................................................................................................106SamplingProtocol...............................................................................................................................106SamplingLocations.............................................................................................................................106

Chapter13:Microplasticssampling...........................................................................................108Introduction.......................................................................................................................................108Summaryofsamples...........................................................................................................................108SampleProcessing..............................................................................................................................108

References................................................................................................................................110

ManythankstotheMasterandcrewoftheRRSDiscoveryforalltheirassistanceduringthismission.

ICY-LABisfundedbytheEuropeanResearchCouncil.

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Chapter1:PersonnelonboardAllcrew1 COX JOANNALOUISE Master2 MAHON ANDREW C/O3 LEGGETT COLINJAMES 2/O4 WILLIAMS THOMASJAY 3/O5 WOODLAND HAZELELIZABETH Doctor6 BILLS JAMES C/E7 KEMP CHRISTOPHERMARTIN 2/E8 EVANS DANIELCHRISTOPHER 3/E9 QUITHER MARTIN 3/E10 BRAZIER THOMASPHILIP ETO11 BULLIMORE GRAHAM PCO12 MACDONALD JOHN CPOS13 COOK STUARTCLIVE CPOD14 GREGORY NATHANIELJAMES POD15 CRABB GARY SG1A16 WILLCOX SIMONPAUL SG1A17 PEPPIN CHRISTOPHER SG1A18 DWYER ANDREW SG1A19 BROOMHALL NATHAN ERPO20 LYNCH PETERANTHONY H/Chef21 LINK WALTERJOHNTHOMAS Chef22 CARAHILLO CLEMENTINAMARIA Stwd23 WILLIAMS DENZIL A/Stwd24 ANNETT AMBERLUELLA Scientist25 BADGER MARCUS Scientist26 BATES STEPHANIELAUREN Scientist27 COOPER ADAMJOHN Scientist28 CUSHMAN GRACEGARCIA Scientist29 GOODWIN CLAIREELOISE Scientist30 HENDRY KATHARINE PI31 HOY SHANNONKELSEY Scientist32 HUVENNE VEERLEANNIDA Scientist33 JACOBEL ALLISONWOOD Scientist34 NG HONGCHIN Scientist35 OPHER JACOBGEORGE Scientist36 PICKERING REBECCAANN Scientist37 ROBINSON LAURAFRANCES Scientist38 ROWLAND GEORGEHENRY Scientist39 SAMPERIZVIZCANINO ANA Scientist40 TAYLOR MICHELLELISA Scientist41 WILLIAMS JAMES Scientist42 TURNER DAVIDRUSSELL Tech43 MOUNTIFIELD DOUGAL Tech44 CAMERON CANDICEANNE Tech45 EDGE DAVID Tech46 DAVIES ALLAN Tech47 LOCKE RUSSELLANDREW Tech48 WEBB ANDREWTHOMAS Tech49 RICHARDS ELLALOUISE Tech50 LEADBEATER ANDREWJOHN Tech51 VIERARIVERO JOSUEDANIEL Tech52 BRIDGER MARTINJOHN SST

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Sciencepartywatchlist

8am–8pm

DrKatharineHendry(UniversityofBristol)

4am–4pm

WatchLeader:DrVeerleHuvenne(NationalOceanographyCentre,Southampton)DrAmberAnnett(UniversityofSouthampton)DrMarcusBadger(TheOpenUniversity)GraceCushman(ColumbiaUniversity,US)DrClaireGoodwin(HuntsmanMarineScienceCentre)DrAllisonJacobel(ColumbiaUniversity,US)JacobOpher(BritishAntarcticSurvey)RebeccaPickering(DauphinLaboratory,UniversityofAlabama,US)*AnaSamperiz(UniversityofBristol)*watchrescheduledonsomedaysforincubationexperiments

4pm-4am

WatchLeader:ProfLauraRobinson(UniversityofBristol)ShannonHoy(UniversityofNewHampshire,US)DrHongChinNg(UniversityofBristol)DrMichelleTaylor(OxfordUniversity)GeorgeRowland(UniversityofBristol)AdamCooper(UniversityofSouthampton)JamesWilliams(CardiffUniversity)DrStephanieBates(UniversityofBristol)

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Chapter2:Rationale,aimsandobjectives

Thehigh-latituderegionsareexperiencingsomeofthemostrapidchangesobservedinrecentdecades.Arctictemperaturesarerisingtwiceasfastastheglobalmean,Greenland’sglaciersareexperiencingsignificantmassloss,multi-yearArcticsea-iceisdeclining,andtheNordicSeasarewarmingatanacceleratedrate.Theseprocessesareimportantlocally,buttheireffectsarelikelytohaveaglobalimpact:forexample,theNorthAtlanticreceivesfreshwaterfromtheArctic,GreenlandandCanadaandisaformationlocusofthedeep-watermasses,whichrepresentamajorcomponentofoceancirculationthatdrivesglobalheatandnutrientfluxes.

Concurrentlytotherecentlyobservedchangesinicedynamicsandaccessibility,therehasbeenasignificantincreaseincommercialinterestofthenaturalresourcesintheecosystemsoftheArctic,surroundingseasandhigh-latitudeNorthAtlantic.Anunderstandinghownaturalresources-includingfisheries,birdandmammalstocksthatareessentialforfoodandtourism–willrespondinthefuturetoincreasinganthropogenicstressonaregionalandglobalscalereliesonanunderstandingofmarinebiogeochemistryandthesourcesandsinksofessentialnutrients.

TheoverallaimofICY-LABistounderstandnutrientandisotopecyclingintheclimaticallycriticalbutunderstudiedregionsoftheLabradorSeaandGreenlandfjords,andtheimpactofcryosphere,biosphereandhydrosphereonthebiogeochemistryoftheregionandtheglobaloceans.TheapproachofICY-LABwillbetocapturethewholebiogeochemicalsysteminareasofmarkedenvironmentalchangeusingcarefulfieldsamplingstrategies,withresearchexpeditionstocoastalGreenlandandtheopenoceanLabradorSea.DY081representsthekeyoceaniccomponentofthissamplingcampaign,focusingontheinfluenceofmeltwateronnutrientcyclingintheLabradorSea,usingthesiliconcycleasamodelsystem.Siliconisakeynutrientfordiatoms,algaethatareresponsibleforalargeproportionofcarbonuptakeinmarinesystems.

ThesamplingobjectivesofthecruiseObjectivestobecarriedoutbyDrKateHendryandDrHong-ChinNg,withprojectpartnersnamedinparentheses.

1) Mappingofsamplingareas(DrVeerleHuvenne)

2) Detectionandsamplingoffreshwaterinputfromglaciatedenvironmentsa. Physicaloceanography(JacobOpher;DrKateHendryandresearchgroup)b. Watercolumnacoustics(ShannonHoy)c. Geochemicaltracersoffreshwater(DrKateHendryandresearchgroup)d. Nutrientandnutrientisotopesampling(KateHendryandresearchgroup;alsosamplingforDr

SianHenley(UniversityofEdinburgh))

3) Investigationofinteractionsatthesediment-waterinterface(DrKateHendryandresearchgroup)a. Megacoreandpushcoresamplingb. Porefluidsamplingc. Coreincubationexperiments

4) Investigationofbiogeographyofsiliceousorganismsa. Chlorophyllsampling(KateHendryandresearchgroup)b. Silicon-32uptakeexperiments(RebeccaPickering,ProfJeffreyKrause(DauphinLab))

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c. Spongesamplingfortaxonomyandbiogeography(ClaireGoodwin)

5) Complementarystudiesandprojectsa. Tracemetalsandtracemetalisotopes(DrAmberAnnett,andsamplingforDrSusanLittle,Prof

TinaVanderFlierdt(ImperialCollege,London),andDrKevinBurton(DurhamUniversity))b. Benthicbiologyandgenetics(DrMichelleTaylor,andsamplingforDrJoanaXavier)c. Phytophysiology(samplingforDrRupertPerkins(CardiffUniversity))d. Organicgeochemistry(DrMarcusBadger)e. Habitatmapping(DrVeerleHuvenne)f. Palaeoclimate(ProfLauraRobinsonandGeorgeRowland;DrAllisonJacobelandsamplingfor

ProfJerryMcManus(ColumbiaUniversity);JamesWilliams)g. Microplasticsresearch(ProfLauraRobinson,withDrLucyWoodall)

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Chapter3:CruiseoverviewTimelineTABLE1:TIMELINEOFCRUISEEVENTSANDLOCATIONS.

Date Location ActivityJuly6th Transit July7th Transit OrphanKnoll CTDoperationsCTD01,SAP01;MultibeamsurveyJuly8th OrphanKnoll Multibeamsurvey;CoringMGA01+GVY01;ROVdive

327(start)July9th OrphanKnoll ROVdive327(end);DeployTowfishFSH01;SurveyJuly10th OrphanKnoll RetrieveTowfish;ROVdive328(aborted);ROVdive

329(start)July11th OrphanKnoll ROVdive329(end);CoringMGA02+GVY02;ROV

dive330(start)July12th OrphanKnoll ROVdive330;CTD02;ROVdive331(start)

July13th Transit OrphanKnoll ROVdive331(end);DeployTowfish;Multibeamsurvey;StarttransittoGreenland;SADCPturnedon.

July14th Transit

July15th Transit

July16th Transit

July17th Transit Nuuk GLD01;GLD02;SAPStest;MGA03;StartofCTDgrid

July18th Nuuk CTDgridcontinues.Badweatherhaltsoverthesidescience.

July19th Nuuk Sciencecontinuesasweatherimproves.CTDgridcontinues.

July20th Nuuk ROVdive332(aborted)followedbyROVdive333.

July21st Nuuk ROVdive334;transittosouthernline;SAPS.

July22nd Nuuk ROVdive335.

July23rd Nuuk Multibeamsurvey;ROVdive336.CTD15.

July24th Transit Nuuk CTD16,andSAPSatsamelocation.Recoveredgliderssuccessfully;MGA04.

July25th Transit

July26th Transit SWGreenland CTD17.Towfishrecovered.ROV337(aborted),towfishdeployed,CTD18.

July27th SWGreenland CTD19,SAP05,MGA05,ROV338(start).

July28th SWGreenland ROV338,MGA06.

July29th SWGreenland ROV339,Towfishin,CTD20.

July30th SWGreenland CTD21,CTD22.

July31st Transit SWGreenland CTD23,CTD24,SAP06,MGA07,GVY03,GVY04,GVY05.

August1st–8th Transit

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FIGURE1:OVERVIEWMAPOFDY081SHIPROUTE.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF55˚N.

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Cruisenarrative

Timesareshiptime,unlessstated.

Sunday2ndJuly2017:MostofthesciencepartyarriveinStJohn’s,Canada.

Monday3rdJuly2017:RemainderofsciencepartyarriveinStJohn’s,Canada.

Tuesday4thJuly2017:Safetybriefingforscienceparty1100.Briefingwithcaptain1300;informedbycaptainthatsailingduetobedelayedapprox.24hoursduetocrewchange.

Wednesday5thJuly2017:Radionuclidesafetybriefing1030.ROVwalkthrough1300.Databaseplanningmeeting1600.

Thursday6thJuly2017:Shipsails0800(shiptimechangedtoGMT-2).CTDwalkthrough1400.Musterandlifeboatdrill1600.Introductorysciencetalk1700.

Friday7thJuly2017:ShiparrivesatOrphanKnoll.STN001CTDdownto3800mat1600withbottlesfiredat12depths(timeondeck2036GMT).STN002SAPSat2400and200metreswaterdepth(twoSAPSateachdepth,withGFFandSuporfilters)(timeondeck0212GMT).OneSAPSflooded,andtwobatteryfailurespartwaythroughpumpingbutmaterialcollectedonallfilters.CTDcableapparentlydamagedpost-SAPS,butsuccessfullyfixed.MultibeamsurveyofOrphanSeamount.

Saturday8thJuly2017: SurveycompleteandcoresitelocatedtonorthwestofOrphanSeamount.STN003Megacoreat3700mmetresdepth,with8successfulcores(timeondeck1024GMT).STN004gravitycoreinsamelocation,successful,with5m15cmcollectedfrom3700m(timeondeck1346GMT).Corecatchercollected,andcoresectionedinto1.5metrelengths.

Sunday9thJuly2017:RecoveryofSTN005ROV327in3600mwaterdepthonOrphanSeamount,southernside;successfulcollectionofspongesandcorals;12xsedimentcores;6xNiskin(1failure).STN006towfishdeployedovernight,withthreesamplingevents(deployed1815GMT;recovered0720GMT).ItwasnotedthattheTowfishneededtobepulledinbeforefinalisingtheROVpositionforadive.

Monday10thJuly2017:DeploymentofSTN007ROV328in1700mwaterdepth.Collectionofcupcorals,blackcoral,sponges,andophioroidsforgenetics;pushcoresandNiskins.Horizontalthrustergroundfaultledtoaborteddive(timeondeck1632GMT).Alsosomeproblemswiththesuctiondevice.Groundfaultproblemsnotdiagnosedatsurface,butallsystemsappearedtobeoperatingfully.RedeployedSTN008ROV239.Collectionofliveandfossilsolitarycorals,andarmouredholothurians;pushcoresandNiskins.

Tuesday11thJuly2017: ROV239ondeck1737GMT.STN009MegacoreMGA02deployed1900GMTinwaterdepthof1770m;fourtubessuccessfulsampledforporefluids,coreincubationexperimentandsections.STN010gravitycoreGVY02deployed2035GMT,with4.5msedimentsrecovered.DeploymentofSTN011ROV330at2315GMT,collectionoffossilandlivecorals,spongeswithcrinoids,andcollectionofimagesforphotogrammetry.

Wednesday12thJuly2017:ROV330continued,recoveredat1214GMT.STN012CTD02deployedin1800mwaterdepth,with24bottlesfiredat8depths(recovered1453GMT).DeploymentofSTN013ROV331at1609GMT,collectionoffossilcorals,livingcorals,spongesandotherbiology,pushcores.TheKraftarmleakedoil,sotherewasaslightlyearlyrecovery.

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Thursday13thJuly2017:ROV331continued,butanoilproblemrelatingtoanarmmeantthatthecrewretrievedtheROVapproximatelyanhourearlyat0630GMT.TowfishinwaterforSTN014.MultibeamsurveytonorthofROV328-331,beforecommencingtransittoGreenland.ShipboardADCPturnedon,andMultibeamsurveycarriedoutontransit.Towfishsamplescollectedatintervals.Duetoweather,decisionwastakentovisitSWGreenlandsitefirst.

Friday14thJuly2017:Transitcontinued.

Saturday15thJuly2017:Transitcontinued.Weatherforecastimproved,sodecisionmadetogotoNuuksitefirstasoriginallyplanned.

Sunday16thJuly2017: Transitcontinued.

Monday17thJuly2017:TransittoNuuksite.ArrivetosouthofNuuksite,deployedSTN015GLD01(Coprolite)offstarboardsideinwaterat0611GMTanddivingby0650;STN016GLD02(HSB)inwaterat0755GMT.Connectivityissuesresultedinminorfilecorruption,whichwasresolvedbeforethegliderdivedat0910GMT.STN017CTD03wasdeployedat0949GMTnearbytocalibratethegliders(approx.2000mwaterdepth),andtoprovideaSVPfortheMultibeamacoustics.Watersampleswereonlytakenforsilicon32experimentsandradiummeasurements.TransitandMultibeamsurveytoNuuksite,stoppingbeforeCTDgridforSAPstest(inwater1810GMTandbackondeck2040);previouslyfloodedcasingwasshowntobewatertightat1000mfor1hour.STN018MGA03deployedandrecoveredat2212GMT,with8fulltubes.Afterashorttransit,the“GloriousGrid”startedwithSTN019CTD04deployed.Highfluorescencelayerwasshallowerinthewatercolumnonthewayup,withotherevidencefordynamicsurfacelayers.

Tuesday18thJuly2017: STN020SAP02;oneSAPonlypumped8L,theothersworkedwell.Didn’tmanagetogetthebottomSAPsdownfullytodepthduetoslowdeploymentofwire,sosampledatapproximately650ratherthan900m.CTDgridcontinuedwithSTN21CTD05(Niskin7leaked),STN22CTD06(Niskins9and18didn’tfire),andSTN23CTD07(7leakedand18didn’tfire)onthefirstline.Weatherpreventedcontinuingworkontheshelf;transitandMultibeambathymetrysurveyduringbadweather.

Wednesday19thJuly2017:Over-the-sidesciencecontinuesafterweatherimproved.STN24CTD08(potentiallymovedduetocurrent)andSTN25CTD09onthirdline(notethattherewasacautiousapproachtothebottomduetosteeptopography).PauseforwindtodiedownbeforemovingontoSTN26CTD10(Niskins5and7didn’tfireorleaked)andSTN27CTD11(withnewNiskin7)ontheshelf,followedbySTN28CTD12(noLADCP)andSTN29CTD13offtheshelf.TowfishrecoveredatendoflastCTD.

Thursday20thJuly2017: STN030ROVdive332wasdeployedbutrecoveredduetoagroundfaultondeployment.ProblemrectifiedandSTN031ROVdive333wasdeployedwithsameaimsandobjectivesas332.Collectionofsponges,corals,bivalves,fossilcoralsandsedimentcoreswithNiskinsfired.ROVdiverecoveredat2305GMT.STN32Towfishinwaterat2323GMT.

Friday21stJuly2017:FinalCTDofthe“GloriousGrid”STN33CTD14;furtherCTDsshorewardswerenotconsideredduetotimeandwaterdepthconstraints,andconsiderationofwaterprofile.STN34ROVdive334resonandphotogrammetrydivebackonwallfoundduringROV333,recovered1605GMT;alsocollectedpushcores(onebroken)forporefluidsandanothernetoffossilcorals.STN35SAP03recovered2340GMT;Minniefailed(onlypumped14L)butotherSAPSsuccessfulwithapproximately600LpumpedthroughbothSupors.

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Saturday22ndJuly2017: TransitfurthersouthforSTN36ROVdive335;collectionofliveandfossilcorals,sponges,sediments(withporefluidsampling).Attheendofthedive,thecurrentswereverystrongandtherewerenogoodsedimentstosample.

Sunday23rdJuly2017: RecoverROV335at0337GMT.TransitandMultibeamsurveytoprepareforSTN37ROV336;collectionofsponges,corals,phototransit(interruptedbyoctopus),sediments(withporefluidsampling).TowfishSTN38FSH04at2105GMT.ContinuethirdgridlinefurtherintoglacialtroughwithSTN39CTD15,attemptingtosamplelowersalinitylayers(Niskin9leaked).

Monday24thJuly2017:ContinuedthirdgridlineintotroughwithSTN40CTD16;STN41SAPSatsamelocationwithlastunitondeckat0714GMT,withthreesuccessfulfilters.TransitandMultibeamtositeofgliderrecovery.SuccessfulrecoveryofCoproliteat1313GMT(endofSTN15);successfulrecoveryofHSBat1425GMTdespitethefogrollingin(endofSTN16).Transitsouth,viaman-over-boarddrillandMegacoreatSTN42MGA04witheightsuccessfulcores.BegintransittoSWGreenlandsite.Multibeamsurveyonroute.

Tuesday25thJuly2017: TransittoSWGreenlandsite.Multibeamcontinues.

Wednesday26thJuly2017:ArrivalatSWGreenlandsite.STN43CTD17instrongcurrents;bottle9leakedagain.Otherwise,asuccessfulcast.MultibeamsurveyforROVsite.Towfishrecovered.STN44ROV337wasdeployed,butwasabortedduetostrongcurrents.TowfishredeployedatSTN45.TransittoSTN46CTD18intrough.Notedsurfacesalinitydroppedconsiderably.

Thursday27thJuly2017: ContinuetoworkatsamelocationwithSTN47CTD19,sampledforDrAmberAnnettonly(notepossiblejellyfishfoulingcouldhaveimpactedbackscatter),andSTN48SAP05,withfoursuccessfulpumps.Lookforsedimentcoringsiteonthetroughsite,resultinginSTN49MGA05with8successfulcores,andoneNiskin(filtered).FurtherMultibeamtolocatepossiblenewROVsite;alsokeepinganeyeontheADCPforcurrentstrength.Sitelocated,withsurfacecurrentslessthanpreviously,droppingatdepth.STN50ROV338deployed;initiallydivedtoseafloortochecklandinginthecurrents(allwasfinewithdeploymentanddiving)andtotakepushcores,beforeheadingtoplanneddivestart.

Friday28thJuly2017:ContinuedROV338,managingtomakeacoursedespitechallengingconditionsofstrongsurfacecurrentsandicebergs.Collectedsponges,fossilcoralframework,andDesmophyllumsolitarycoral.Haddifficultyfindingfurthergoodsedimentpushcoresatdepth;ondeck1814GMT.STN51MGA06,with8successfulcores,andoneNiskin(filtered);recovered2217GMT.Multibeamsurveyfornewdivesite.

Saturday29thJuly2017: ContinueMultibeamsurvey,findingnewsiteforSTN52ROV339.Startofdiveatdeepestpoint,withsandybottom,rocks,sponges,solitarycorals,holothuriansandaray.Divehadto‘bluewater’toavoidicebergactivity;restartedagaintocompletedive,recoveredat2151GMT.TowfishinforSTN53FSH06.ShortsteamtonearbyopenwaterforSTN54CTD20,1200m.AllNiskinsnowworkingafterpreviousbottlechangeandmaintenance.

Sunday30thJuly2017: CTD20recoveredat0018GMT.TransitandMultibeamtoCapeFarewell.Arrivalatstation,withslightdelaytoallowtheROVtobewinchedtomid-aftdeckfordemob.FollowedpromptlybySTN55CTD21.AllNiskinsworked.TransitedfurtherintolandtoattemptaCTD,butwasrepositionedduetosea-iceconditions.STN56CTD22ascloseaspossibletosea-iceedge(allNiskinsworked),thenretreatfurtherforadditionalpotentialCTDsite.Decidedtosearchforcoringsite,andcarriedoutSTN57MGA07;alleightcores,butshortlengths.

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Monday31stJuly2017:Furtherretreatfromsea-iceforSTN58CTD23(forDrAnnettonly)andSTN59CTD24.FollowedatthesamelocationsbySTN60SAP06;allworkedexceptdeeperGFFfilter,Chloe.ShorttransittoErikDrift.STN61GVY03at1660m,4.8m,butwithvoidsodecidedtotryagain.STN62GVY04camebackwithonly82cm,butdecidedtocarryontodeeperwaters.STN63GVY05.Increasingwindsbroughtforwardtheendofover-the-sidescience.MultibeamandshipboardADCPcontinuedduringtransitbacktoUK.

Saturday5thAugust2017: MultibeamandshipboardADCPturnedoffonentryintoIrishEEZat1202GMT.

Tuesday8thAugust2017: DockingatNationalOceanographyCentre,EmpressDock,Southampton.

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StationlistTABLE2:STATIONLISTFORCRUISEDY081.CTD=CONDUCTIVITYTEMPERATUREDEPTHAND24-NISKINROSETTE;SAP=STANDALONEPUMPS;MGA=MEGACORE;GVY=GRAVITYCORE;ROV=REMOTELYOPERATEDVEHICLE;FSH=TOWFISH;GLD=GLIDER.

Site Station Gear JdayStart StartTime

(GMT)

StartLat

(DD)

StartLon

(DD)

Start

Depth(m)

JdayEnd EndLat

(DD)

EndLon

(DD)

EndDepth

(m)

OrphanKnoll 1 CTD001 188 17:25:00 50.17428 -45.43948 3813.0 188 50.1743 -45.4395 3814.0OrphanKnoll 2 SAP001 188 22:03:00 50.17430 -45.43948 3815.0 189 50.1743 -45.4395 3814.0OrphanKnoll 3 MGA001 189 07:57:00 50.15915 -45.50830 3721.0 189 50.1592 -45.5083 3721.0OrphanKnoll 4 GVY001 189 11:24:00 50.15919 -45.50835 3721.0 189 50.1592 -45.5083 3721.0OrphanKnoll 5 ROV327 189 16:19:00 50.04158 -45.37940 3550.8 190 50.0832 -45.3594 1941.0OrphanKnoll 6 FSH001 190 18:10:00 50.08318 -45.35940 1932.0 191 50.5528 -46.1944 1677.0OrphanKnoll 7 ROV328 191 07:50:00 50.55481 -46.19323 1669.2 191 50.5564 -46.1956 1576.7OrphanKnoll 8 ROV329 191 20:48:00 50.55182 -46.19227 1792.0 192 50.5698 -46.1836 1527.0OrphanKnoll 9 MGA002 192 19:02:00 50.51547 -46.27902 1769.8 192 50.5155 -46.2790 1770.0OrphanKnoll 10 GVY002 192 20:35:00 50.51546 -46.27900 1770.0 192 50.5155 -46.2790 1770.0OrphanKnoll 11 ROV330 192 23:23:00 50.55118 -46.19071 1825.5 193 50.5512 -46.1934 1717.0OrphanKnoll 12 CTD002 193 13:11:00 50.54236 -46.17057 1850.0 193 1846.0OrphanKnoll 13 ROV331 193 16:15:00 50.50629 -46.08250 1848.0 194 1586.0OrphanKnoll 14 FSH002 194 07:11:40 50.50770 -46.08840 1837.1 200 50.5755 -45.9865 1594.0Nuuk 15 GLD001 198 06:11:00 62.90416 -52.62882 2357.0 205 63.7147 -53.0865 1313.0Nuuk 16 GLD002 198 07:55:00 62.92231 -52.65246 2333.0 205 62.9269 -52.6561 620.0Nuuk 17 CTD003 198 09:49:00 62.92231 -52.65246 2123.0 198 2064.0Nuuk 18 MGA003 198 21:14:00 63.81541 -53.77431 1301.0 198 63.8154 -53.7743 1301.0Nuuk 19 CTD004 198 23:22:00 63.85162 -53.79918 1084.0 199 63.8516 -53.7992 1084.0Nuuk 20 SAP002 199 02:42:00 63.85227 -53.79763 1080.0 199 63.8530 -53.7981 1080.0Nuuk 21 CTD005 199 07:14:00 63.87635 -53.56517 966.0 199 63.8822 -53.5674 972.0Nuuk 22 CTD006 199 10:17:00 63.90095 -53.36405 659.0 199 63.9010 -53.3641 657.0Nuuk 23 CTD007 199 12:56:00 63.91773 -53.13293 103.0 199 63.9177 -53.1329 103

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Nuuk 24 CTD008 200 01:11:00 63.41803 -53.14670 1681.0 200 63.4286 -53.1528 1711Nuuk 25 CTD009 200 05:22:00 63.45380 -52.87985 915.0 200 63.4538 -52.8799 922Nuuk 26 CTD010 200 09:43:00 63.49629 -52.61218 339.0 200 63.4963 -52.6122 338Nuuk 27 CTD011 200 14:55:00 63.72713 -52.83125 69.6 200 63.7271 -52.8313 70.2Nuuk 28 CTD012 200 17:44:00 63.69635 -53.08266 653.3 200 63.6963 -53.0827 653Nuuk 29 CTD013 200 20:28:00 63.66162 -53.33311 1550.0 200 63.6616 -53.3331 1549Nuuk 30 ROV332 201 02:45:00 63.86858 -53.28953 964.0 201 63.8704 -53.2901 950Nuuk 31 ROV333 201 03:49:00 63.86612 -53.28869 970.0 201 63.8657 -53.2834 805Nuuk 32 FSH003 201 23:23:00 63.86599 -53.28424 822.8 202 63.9535 -52.9167 67Nuuk 33 CTD014 202 02:24:00 63.95358 -52.91682 66.5 202 63.9536 -52.9168 66.7Nuuk 34 ROV334 202 07:00:00 63.86511 -53.28258 807.0 202 63.8651 -53.2784 683Nuuk 35 SAP003 202 20:36:00 63.59505 -52.95646 786.0 202 63.5950 -52.9565 784.8Nuuk 36 ROV335 203 03:38:00 63.33217 -52.77710 1281.00 204 63.3317 -52.7550 898Nuuk 37 ROV336 204 10:51:00 63.60375 -52.91897 515.0 204 63.6112 -52.9032 345.9Nuuk 38 FSH004 204 21:05:00 63.61123 -52.90324 351.2 207 60.0941 -47.3158 1056Nuuk 39 CTD015 204 23:54:00 63.51954 -52.35627 446.4 205 63.5195 -52.3563 445.6Nuuk 40 CTD016 205 02:29:00 63.57532 -52.14668 487.3 205 63.5753 -52.1467 486.6Nuuk 41 SAP004 205 04:41:00 63.57537 -52.14660 486.0 205 63.5754 -52.1463 488Nuuk 42 MGA004 205 20:23:00 63.55297 -52.22512 518.8 205 63.5530 -52.2291 519S.Greenland 43 CTD017 207 05:10:00 59.84621 -47.24472 2780.0 207 59.8517 -47.2485 2782S.Greenland 44 ROV337 207 17:33:00 60.09451 -47.31853 1037.2 207 60.1063 -47.4009 1048S.Greenland 45 FSH005 207 20:30:00 60.11090 -47.41771 1050.00 208 60.0898 -46.6496 1111.4S.Greenland 46 CTD018 207 23:37:00 60.24523 -46.88678 536.0 208 60.2452 -46.8868 536S.Greenland 47 CTD019 208 02:46:00 60.23971 -46.85244 501.0 208 60.2391 -46.8544 503S.Greenland 48 SAP005 208 05:30:00 60.24474 -46.88747 534.0 208 60.2447 -46.8875 534S.Greenland 49 MGA005 208 10:53:00 60.26180 -46.89084 522.3 208 60.2618 -46.8908 572S.Greenland 50 ROV338 208 18:46:00 60.09000 -46.62533 603.50 209 60.0862 -46.6497 1064S.Greenland 51 MGA006 209 21:20:00 60.11595 -46.66351 1326.0 209 60.1160 -46.6635 1327

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DY081CRUISEREPORT

S.Greenland 52 ROV339 210 07:04:00 59.94672 -46.54810 1148.0 210 59.9423 -46.5069 589S.Greenland 53 FSH006 210 22:07:00 59.94239 -46.50713 596.0 212 59.9395 -43.7783 1907S.Greenland 54 CTD020 210 23:00:00 59.90837 -46.49170 1270.6 211 59.9084 -46.4917 1270S.Greenland 55 CTD021 211 12:56:00 59.21163 -44.58042 2030.4 211 59.2162 -44.6061 2036S.Greenland 56 CTD022 211 18:16:00 59.48646 -44.36462 884.7 211 59.4865 -44.3646 884S.Greenland 57 MGA007 211 21:21:00 59.45644 -44.41508 1291.0 211 59.4565 28.1216 1292S.Greenland 58 CTD023 211 23:37:00 59.39499 -44.49790 1521.0 212 59.3950 24.4314 1522S.Greenland 59 CTD024 212 01:33:00 59.39502 -44.49837 1522.0 212 59.3951 24.4419 1522S.Greenland 60 SAP006 212 03:44:00 59.39518 -44.49851 1522.0 212 59.3953 24.4501 1521S.Greenland 61 GVY003 212 11:14:00 58.99701 -43.58429 1670.0 212 58.9967 60.5188 1669S.Greenland 62 GVY004 212 13:11:00 58.94073 -43.59906 1608.0 212 58.9397 57.0991 1608S.Greenland 63 GVY005 212 17:49:00 58.60611 -43.77831 1907.0 212 58.6061 37.0833 1907

17

DY081CRUISEREPORT

Chapter4:Sitesummariesandmaps

OrphanKnoll

OrphanKnollsitewasselectedasadistalcomparisonsitefortheICY-LABproject,andforcomplementarypalaeoclimate,biologicalandhabitatmappingstudies.Thesitewasdividedintosouthernandnorthernregions.

FIGURE2:MAPOFORPHANKNOLLWITHSHIPTRACK.PRODUCEDINMERCATORPROJECTIONWITHASTANDARD

PARALLELOF50˚N.

FIGURE3:MAPOFSOUTHERNORPHANKNOLLWITHSTATIONLOCATIONS.PRODUCEDINMERCATORPROJECTIONWITHA

STANDARDPARALLELOF50˚N.

FIGURE4:MAPOFNORTHERNORPHANKNOLLWITHSTATIONLOCATIONS.PRODUCEDINMERCATORPROJECTIONWITHA

STANDARDPARALLELOF50˚N.

18

DY081CRUISEREPORT

Figure2

19

DY081CRUISEREPORT

Figure3

20

DY081CRUISEREPORT

Figure4

21

DY081CRUISEREPORT

Nuuk

TheNuuksitewasselectedthemainstudylocationfortheICY-LABproject,andincludedaCTDgridandgliderdeploymentforhigh-resolutionwatercolumnstudiessurroundingglacialtroughs,inadditiontotheothermethodologiesemployedthroughoutthecruise.

FIGURE5:MAPOFNUUKSITEWITHCRUISETRACKANDSTATIONS(OVERTHEPAGE).PRODUCEDINMERCATOR

PROJECTIONWITHASTANDARDPARALLELOF63˚N.

SouthernGreenland

TheSouthernGreenlandsitewasselectedforprovidingglacialtroughsthatcouldactasdirectcomparisonstotheNuuksitefortheICY-LABproject.Thesiteisstronglyinfluencedbybothicebergsandsea-ice.ThesiteisdividedintotworegionstermedNarsaqandCapeFarewell.

FIGURE6:MAPOFSOUTHERNGREENLANDSITEWITHCRUISETRACK(OVERTHEPAGE).PRODUCEDINMERCATOR

PROJECTIONWITHASTANDARDPARALLELOF63˚N.

FIGURE7:MAPOFSOUTHERNGREENLANDSITE(NARSAQ)WITHSTATIONS.PRODUCEDINMERCATORPROJECTIONWITH

ASTANDARDPARALLELOF63˚N.

FIGURE8:MAPOFSOUTHERNGREENLANDSITE(CAPEFAREWELLANDERIKDRIFT)WITHSTATIONS.PRODUCEDIN

MERCATORPROJECTIONWITHASTANDARDPARALLELOF63˚N.

22

DY081CRUISEREPORT

Figure5

52°0'W52°30'W53°0'W53°30'W54°0'W

64°0

'N

64°0

'N

63°3

0'N

63°3

0'N

63°0

'N

63°0

'N

0 20 40Nautical Miles

0 30 60Kilometers

NUUK, GREENLAND

Ship TrackBathymetry

50°W55°W

65°N

64°N

63°N

62°N

100 m900 m1400 m2200 m

Projection: World Mercator, Standard Parallel = 63 Degrees North

CTDFSHGLDGVYMGAROVSAP

CTD014

CTD005

MGA003

CTD004

CTD007

FSH002ROV334ROV332

ROV333

CTD006

SAP002

CTD013CTD012

CTD011

CTD008CTD009

CTD010

ROV335

SAP004

CTD015

MGA004

CTD002GLD001

GLD002

ROV336

SAP003

FSH004

CTD016

23

DY081CRUISEREPORT

Figure6

24

DY081CRUISEREPORT

Figure7

25

DY081CRUISEREPORT

Figure8

26

DY081CRUISEREPORT

Chapter5:Technicalreport

Acousticsoperations

DuringDY081,sixacousticsystemswererunfromtheship,andonefromtheROV:

- EM122multibeamechosounder(12kHz)- EM710multibeamechosounder- SBP120sub-bottomechosounder(2.5–6.5kHz)- EK60fishfindingechosounder(18,38,70,120,200,333kHz)- TeledyneOS075ADCP(75kHz)- TeledyneOS150ADCP(150kHz)- Reson7125multibeamechosounder(400kHz)

TheshipacousticsystemswerecoordinatedviatheK-Syncsystem(Figure9),toavoidinterferenceandcrosstalk.Forthemajorityofoperations,theEM122,SBP120,EK60,andtheOS150weresyncedtopingconcurrently,withtheEM122setasthemasterexternaltrigger.TheOS75wasoffsetfromthemaintriggergroupandtheEM710wassettofreeping.

FIGURE9:K-SYNCSET-UPFOROPERATIONSWITHALLSYSTEMSRUNNING.

Basicmanuallogswerekeptduringtheoperations,andhavebeenscannedaspdfdocuments.Summariesoftheseareprovidedinthetablesbelow.

27

DY081CRUISEREPORT

EM122MultibeamEchosounderTheEM122multibeamechosounderwasthemainmappingsystemusedthroughoutthecruise.Themapswereusedtoinformfurthersampling,andspecificallytodesigntheROVdives.EM122datawerecollectedcontinuouslyduringtransits,inadditiontothespecificsurveysthatwerecarriedoutateachofthestudyareas.Table4summarisesthebasicparametersforeachofthesectionsofdata.Intotal,55,868squarekilometresweremappedwiththeEM122.Thetablebelowsummarisesthebasicparametersforeachofthesectionsofdata.

TABLE3:RECORDINGTIMES,SVPANDLINENUMBERSFOREM122DATAFOREACHOFTHESTUDYAREAS.

Acquisitionsettings:Vesselspeed:specificsurveyswerecarriedoutat8kn,otherwisedatawerecollectedatthespeedthatwasmostappropriateforthevessel(e.g.10-11knduringtransit);

Swathangle:60deg,exceptincaseswhenoverlapwasnotsufficient,e.g.whenthecoursehadtobealteredbecauseofice;

Dataformat:datawerestoredasKongsberg.allfiles,with.wcdfilesforthewatercolumninformation;Navigation:GPSdatafromthePOS-MVsystem(theusualSeaPathGPShadproblemsatthestartofthecruise,hencethePOS-MVwasusedforthedurationoftheexpedition);

FurthersettingsinformationisprovidedintheFigure10.

28

DY081CRUISEREPORT

FIGURE10:SETTINGSFOREM122ECHOSOUNDER.

SoundvelocityinformationwastakenfromthevariousCTDcastscarriedoutthroughoutthecruise,whichwereappliedtothedataassoonastheywereavailable(seeTable3forinformationonwhichSVPwasusedinwhicharea).Inaddition,thesoundvelocityatthetransducerwasalsoused.Itwasnotedthat,duetoworkinginshallowconditionsclosetoriverandmeltwaterinputs,thesoundvelocityatthetransducerwasoftensignificantlydifferentfromthesurfacewatersoundvelocityintheSVPprofiles(redalarmonSIS).

DataProcessing:ThedatatypesrecordedfromtheEM122systemincludebathymetry,backscatterandwatercolumndata.Bathymetrydatawereprocessedon-boardwiththeCarisHIPS&SIPSsoftwarev.8,usingstandardsettingsandprocedures(dataimport,navigationandattitudecheck,applicationofa“zerotide”,griddingintoa25mx25mpixelBASEsurface).Eachbathymetrygrid,aswellasaninterpolatedsurface,wasexportedtoanASCIIgrid,aGeoTiff,aswellasaFledermausSDobject.ThevesselfileDisco_EM122_POS_MV.hvfwasusedforprocessing,withthefollowingoffsets:

TimeCorr:0.00X(m):-0.005Y(m):35.219Z(m):7.438Pitch(deg):0.00Roll(deg):0.00Yaw(deg):0.00

Whilepostprocessingon-board,someerrorswereapparentinthebathymetricgrids.Thesecouldbeeitherduetotherapidlychangingwatermasses,ortosomesystematicoffset.Furtherprocessingisrequiredtodetermineandfixtheseerrors.

29

DY081CRUISEREPORT

ThefinalbathymetrygridsarelistedinTable4andpresentedinFigure11.BackscatterdatawereprocessedusingthedefaultsettingsinFledermausFMGTandexportedasGeoTiff.Watercolumndatawerecollected,butexceptforoccasionalqualitycontrol,werenotprocessedfurtheron-board.

TABLE4:FINALEM122GRIDS.

Location FileName LinesContained

Projection Resolution(m) Area(km2)

TRS1 DY081_EM122_TRS_1a_25m 0000-0015 WGS84UTM22N

25 108

TRS1 DY081_EM122_TRS_1b_25m 0016-0038 WGS84UTM22N

25 1083

TRS1 DY081_EM122_TRS_1c_25m 0039-0055 WGS84UTM23N

25 1962

OrphanKnoll

DY081_EM122_OK_25m 0056-0147 WGS84UTM23N

25 3414

TRS2 DY081_EM122_TRS_2a_25m 0147-0170 WGS84UTM23N

25 2558

TRS2 DY081_EM122_TRS_2b_25m 0168-0195 WGS84UTM23N

25 2716

TRS2 DY081_EM122_TRS_2c_25m 0194-0221 WGS84UTM23N

25 2816

TRS2 DY081_EM122_TRS_2d_25m 0220-0244 WGS84UTM22N

25 3183

TRS2 DY081_EM122_TRS_2e_25m 0242-0285 WGS84UTM22N

25 4354

TRS2 DY081_EM122_TRS_2f_25m 0284-0317 WGS84UTM22N

25 3230

Nuuk DY081_EM122_Nuuk_25m 0318-0479 WGS84UTM22N

25 2538

TRS3 DY081_EM122_TRS_3a_25m 0478-0509 WGS84UTM22N

25 2406

TRS3 DY081_EM122_TRS_3b_25m 0508-0531 WGS84UTM22N

25 1981

Narsaq DY081_EM122_Narsaq_25m 0530-0637 WGS84UTM23N

25 1295

TRS4 DY081_EM122_TRS_4_25m 0636-0653 WGS84UTM23N

25 429

CapeFarewell

DY081_EM122_CapeFarewell_25m

0653-0688 WGS84UTM23N

25 1088

TRS5 DY081_EM122_TRS_5d_25m 0829-0874 WGS84UTM27N

25 4711

TRS5 DY081_EM122_TRS_5e_25m 0871-0904 WGS84UTM28N

25 3780

TOTALAREA= 55868

30

DY081CRUISEREPORT

FIGURE11:OVERVIEWOFTHEBATHYMETRICGRIDSOBTAINEDINTHEMAINSTUDYAREAS.

EM710MultibeamEchosounderTheEM710systemwasusedinitiallyforseabedmappingonthefirsttransitintheshallowwatersoffshoreStJohn’s.However,lateroninthecruisethissystemwassetupspecificallyforwatercolumnsurveyingdownto250mwd,whichmeantthatnofurtherseafloormapswerecreatedwiththissystem.AnoverviewofthebasicparametersandlinenumbersforeachofthecruisesectionsisprovidedinTable5.

TABLE5:RECORDINGTIMES,SVPANDLINENUMBERSFOREM710DATAFOREACHOFTHESTUDYAREAS.

Settings:Vesselspeed:specificsurveyswerecarriedoutat8kn,otherwisedatawerecollectedatthespeedthatwasmostappropriateforthevessel(e.g.10-11knduringtransit);

Swathangle:60deg,exceptincaseswhenoverlapwasnotsufficient,e.g.whenthecoursehadtobealteredbecauseofice;

Dataformat:datawerestoredasKongsberg.allfiles,with.wcdfilesforthewatercolumninformation.

Tocollecthighresolutiondataoftheupper250metersofthewatercolumn,thefollowingmethods(assuggestedbyJohnHughesClarke)werefollowed:

• SonarMode(RuntimeParameters>FilterandGains>SonarMode)• PingModesettoShallow• DepthSettings(min=0meters,max=250m)• EM710freepinging(unsyncedfromtheEM122)

Furthersettingsinformationisprovidedinthefigurebelow.

31

DY081CRUISEREPORT

FIGURE12:SETTINGSFOREM710ECHOSOUNDER.

Dataprocessing:DataprocessingfortheEM710wassimilartotheEM122:usingCarisHips&Sipsv.8forbathymetry(Table5),FledermausFMGTforbackscatter,andnofurthersystematicon-boardprocessingforthewatercolumndata.EquallytotheEM122,thePOS-MVbasedDiscoveryEM710vesselfilewasusedforthebathymetryprocessing(Disco_EM710_POS_MV.hvf).

Offsetswere:

TimeCorr:0.00X(m):-2.051Y(m):36.819Z(m):7.427Pitch(deg):0.00Roll(deg):0.00Yaw(deg):0.00

AnexampleofthewatercolumndataisprovidedinFigure13.

32

DY081CRUISEREPORT

FIGURE13:EXAMPLEIMAGEOFTHEEM710WATERCOLUMNSIGNAL,PLOTTINGPINGNUMBER(HORIZONTALAXIS)

AGAINSTDEPTH(VERTICALAXIS,0-250M).COLOURINTENSITYINDICATESBACKSCATTERSTRENGTH.THEDEEP

SCATTERINGLAYERCANBEIDENTIFIEDINTHEUPPERWATERCOLUMN.

SBP120Sub-BottomProfilerProfilesoftheseabedandsub-seabedwereobtainedwiththeKongsbergSBP120sub-bottomprofiler.Thisisachirpsystemwithvaryingfrequency,whichsharesthereceivertransducerswiththeEM122multibeamechosounder.Thesystemwasswitchedonforeverytransit,duringmultibeamsurveysandwhentheshipmovedbetweenstations.Itwasusedspecificallyhelpdeterminesuitablecoringsites.AnoverviewofthebasicparametersandrecordingtimesfortheSBP120isprovidedinTable6.

TABLE6:RECORDINGTIMES,SVPANDLINENUMBERSFORSBP120DATAFOREACHOFTHESTUDYAREAS.

Acquisitionsettings:Dataformat:SBP120dataweresavedbothasrawsegyfiles(.raw)andas‘processed’data(.seg),i.e.convolutedwiththesourcesweep,usingadateandtime-stampasfilename.Duringoperations,screenshotswerealsosavedasidentificationofsuitablecoringsitesetc.

FurthersettingsweremainlybasedonthedefaultconfigurationavailableontheRRSDiscovery,andarepresentedinFigure14.

33

DY081CRUISEREPORT

FIGURE14:SETTINGSFORSUB-BOTTOMPROFILER.

Dataprocessing:BasicdataprocessingandvisualisationfortheSBP120profileswascarriedoutusingtheLinuxfreeware‘SeismicUnix’software.Asimplecommandlinewasusedtoreadinthe.segfiles,addinthetimedelaysandplottheprofilesinpost-scriptformat.AnexampleoftheresultisshowninFigure15.

Segyreadtape=/cdrive/Data/SBP120/seg/20170718221312.segendian=0|segyclean|sushifttmin=1.2tmax=2.2|supsimageperc=98>/cdrive/Data/SBP120/ps/20170718221312.ps

FIGURE15:EXAMPLESBP120PROFILEFROMTRANSIT2,DISPLAYINGTWO-WAYTRAVELTIMEAGAINSTSHOTPOINT

NUMBER.

34

DY081CRUISEREPORT

EK60fish-findingechosounderTheKongsbergEK60systemwasusedtoimagethewatercolumn,morespecificallytoimagethedeepscatteringlayerandthepotentialcontactsbetweenwatermasses(showninFigure16).ItwasonlyswitchedonatthestartoftheworkaroundNuuk.Datawererecordedbothduringtransitsandwhilestationaryate.g.CTDstations.AnoverviewoftherecordingtimesforeachoftheresearchareasduringthecruiseisgiveninTable7.

TABLE7:RECORDINGTIMESFOREK60DATAFOREACHOFTHESTUDYAREAS.

FIGURE16:EK60DISPLAYSHOWINGDIURNALMIGRATIONATTHENUUKSITE.

Acquisitionsettings:TheEK60wassetupasperinstructionsbyKevinJerram,CenterforCoastalandOceanMapping,asshowninFigure17.

35

DY081CRUISEREPORT

FIGURE17:ACQUISITIONSETTINGSUSEDFORTHEDIFFERENTFREQUENCIESOFTHEEK60SYSTEM.

ThreedaysafterswitchingontheEK60,itwasdiscoveredthattheEK60hadpreviouslynotbeenreceivingnavigationinformation.Thiswascausedbyanincorrectpositiontalkeridusedduringsetup(INvsGP).Tocorrectthis,thefollowingmethodwasemployed:

INSTALL>NAVIGATION

POSITIONTALKERID=GP

Nodataprocessingwasperformedon-boardfortheEK60.

TeledyneAcousticDopplerCurrentProfilersTheOceanSurveyor(OS)instrumentsareVesselMountedAcousticDopplerCurrentProfilers(VMADP)manufacturedbyTeledyneRDinstruments.TheyaresecuredonadropkeelinsurfacewatersnearthecentreandbeneaththeRRSDiscovery.TheVMADPsmeasurethehorizontalcurrentvelocityprofile.TheparameterswereheldconstantforthedurationofOSmeasurements(13thJuly–5thAugust),andthetrackingmodewasalternated.Bottomtrackingmodewassuitableforperiodsspentontheshelfwhenthewaterwassufficientlyshallowandwatertrackingmodewasselectedindeeperwatersandonthecontinentalslope.Thecollectionofbottomtrackingdataisnecessaryfortheinstrumentcalibrations,notcarriedoutonboardthiscruise.Inrealitysuccessforthebottomtrackingmodewasonlyachievedinregionswherethebottomdepthwasnomorethan200mforthe150kHzdevice.Bottomtrackingdatawereonlycollectedforthe150kHzinstrumentclosetoNuukintermittentlybetween18thJuly–24thJuly.

Real-timedatawasperiodicallyacquiredfromtheVMADCPs.Asitcamein,thesedataweredisplayedthroughtheVmDassoftware(version1.48)onamonitorforeachADCP.Standardloggingcheckswereestablishedtoensurethatthecurrentprofilerswerecontinuingtocollectdata.Logsheetswerefilledouttoconfirmthattheensemblenumberwasincrementingandthatthedatafilesintheoutputdirectorywereincreasinginsize.AnotherimportantthingtomonitorwasthedriftoftheinternalclockofthecomputerrunningtheVmDassoftwarefromtheshipsGPSclock.Therewerenoproblemswiththedataacquisitiontoreport.Tolimitthesizeoftheoutputdatafilesandassistfutureprocessing,theVMADCPswereresetandthusnewfilesinitiated.Fileswereresetusuallydailybutoccasionallyranwithoutresettingforaslongas3days.RawdatafileswereautomaticallystoredintheAcousticsfolderofthecruisenetworkdrive.

36

DY081CRUISEREPORT

TABLE8:CONFIGURATIONSFORSHIP-MOUNTEDADCPS.

TeledyneOS075ADCPConfigurations:Narrowband,singlepingprofilemode16mdepthbins8mblankingdistance3secondsbetweenensembles1200mmaximumsearchingdepth

TeledyneOS150ADCPConfigurations:Narrowband,singlepingprofilemode8mdepthbins4mblankingdistance2secondsbetweenensembles800mmaximumsearchingdepth

Reson7125multibeamechosounderOneROVswathdivewascompletedduringthecruise(Dive334),andtheset-upchosenwasforforwardmappingasdevelopedundertheCODEMAPprogramme(Huvenneetal.,2011;Robertetal.,2017).ThismeantthattheSCORPIOcamerawastakenoffthevehicletomakespacefortheReson7125tobemountedonthefront.TheportbioboxandNiskinbottles(seetechnicalreportfortheROVoperations)weretakenoff,inordertoaccommodatetheelectronicsbottleoftheResonsystem.ThesetupisillustratedinFigure18.

FIGURE18:RESON7125TRANSDUCERSETUPONROVISIS.

ThesystemsettingsforthissurveyarelistedinTable9,andtheoffsetsofthevarioussensorsversusthecommonreferencepointonISISarelistedinthetablebelow.Inaddition,insidethe7Skacquisitionsoftware,thehardwareconfigurationoffsetsbetweenRxandTxweresetasfollowX=-0.125m,Y=-0.125mandZ=0.031mwithheadtilt=0°.Rollstabilisationwasswitchedoff,asithasbeennotedbeforethatthisgiveserrorsduringthesurvey.

Thevehiclewasflowninasetofparallelpasses,eachpassbeingcarriedoutataconstantdepthandwithanapproximatelyconstantdistancefromthecliffface(seetablesbelow).Surveyswerecarriedoutwithanominalheadingof135°forthefirstsectionofthecliff,and214°forthesecondsection.Datawererecordedat40-50m(depthsof755mand775m)and20-25m(depthsof740m,765mand790m)distancefromthewall.

37

DY081CRUISEREPORT

TABLE9:RESONSURVEYSETTINGSFORDIVE334

MBESFrequency 400kHz

Distancewall 40m 20m

Depth 755m 775m 740 765 790

Beamangle 120-140°

Power 203-207dB

Gain 40dB

Absorption 90dB/km

Spreading 30dB/km

Duration (atseabed)

4h40min

Surveyspeed 0.2-0.3kn

Maxpulserate 10p/s

Pulselength 40µs

TABLE10:OFFSETSFORTHEVARIOUSSENSORSVERSUSACOMMONREFERENCEPOINTONISIS(FRONTOFVEHICLE)AS

USEDFORTHEFORWARDMAPPINGAPPROACH,WITHINTHECONVENTIONALVEHICLEREFERENCEFRAME(X:POSITIVE

STARBOARD,Y:POSITIVEFORWARD,Z:POSITIVEUP,ALLINMETRES).

X Y Z

Compatt(USBL) 1.46 -1.01 0.36

Doppler -0.17 -0.58 2.19

MBES 0.34 -0.22 -0.12

Octans(attitude) -0.49 0.00 0.86

Parascientific(depth) 0.00 -0.55 1.48

38

DY081CRUISEREPORT

Coringoperations

IdentificationofcoringsitesSeabedsurveyingwasperformedpriortocoringoperationsateachlocationusingaKongsbergSub-BottomProfiler(SBP-120)andaKongsbergMultibeamEchosounder(EM-122).Samplingsiteswereselectedinareasofflatbathymetry,characterizedbythicklayersofsedimentdisplayingfeaturesconsistentwithquasi-linearsedimentation(e.g.identifiablestratigraphiclayers).Anexampleofasub-bottomprofileacquiredfromNuukformegacoreMGA04canbeseeninthefigurebelow.

FIGURE19:EXAMPLEOFSBPPROFILEFROMNUUK.

MegacoreSedimentswerecollectedusingtheNMFmegacorer(Figure20),toobtainshortcoresandundisturbedsediment-waterinterfacematerialforbiogeochemicalresearch.Themegacorerwasdeployedandrecoveredoffthestarboardsideonthetrawlwinch.Eighttubeswereusedforeachdeployment:fourwithoutholesandfourwithholesdrilledforporefluidsampling(tapedupwithducttapefordeployment).Onceondeckallcorebarrelswereremovedfromtherigandpluggedwithrubberbungs.Coresweresecuredinarefrigeratedroomusingawoodenrackandremainedinthislocationuntilsubsamplingcommenced.Sedimentsub-sampleswerestoredineithertherefrigeratedroomorina-20°Cfreezerdependingontheanalysesplanned.

Inadditiontosediments,themegacorerwasequippedwitha10LNiskinbottletocollectbottom-watersamples.TheNiskinbottledwasriggedtofireonimpactwiththeseafloor.

39

DY081CRUISEREPORT

FIGURE20:RECOVERYOFMEGACOREMGA04ONJULY24TH.ALLEIGHTCORESCONTAINEDSEDIMENTANDTHE

SEDIMENT-WATERINTERFACE:HALFOFTHETUBESWEREDRILLEDFORPOREFLUIDSAMPLING,ANDTAPEDUPFOR

DEPLOYMENT.PHOTOBYM.BADGER.

GravitycoreSedimentswerecollectedusinga6mlongbarrelgravitycore(Figure21)loweredtotheseafloor,deployedfromthestarboardsideonthetrawlwinch,loweredinitiallyat40m/minbeforeslowingto10-15m/minat100mabovetheseafloor.Thecorerwassunkintosedimentswiththeaidofa1-ton(approximate)weightontopofthebarrel.Duetothelimitationsofthetrawlwinch,thebarrellengthwaslimitedto6manddeploymentto4000m.

FIGURE21:GRAVITYCORERECOVERY.PHOTOBYA.JACOBEL.

PushcoresTheROVwasequippedwith6-12tubesforthecollectionofsmallcores.TheKraftarmwasusedtopickupeachcoreusingaT-handleinsertedatthetopofeachcylinder,andpushitintothesediment.Threeorfourreplicatecoreswerecollectedateachsamplingsite.Sometubesweredrilledwithholesforthecollectionofporefluids(tapedupduringdeployment).SeeROVtechnicaldetailsforfurtherinformation.

40

DY081CRUISEREPORT

CTDoperations

AllCTDcastswereundertakenwiththestainlesssteelCTDframeandused10LNiskinwatersamplers(Figure22).Sea-Bird35TemperatureandSea-Bird3Ptemperaturesensorswereinstalledonthe9Plusunderwaterunit.AcableconnectedtheSea-Bird35toboththe9PlusandtheSea-Bird32carousel.HousedonthevaneweretheSea-Bird43OxygenandthesecondarySea-Bird3Ptemperatureand4Cconductivitysensors.

Foreachdeploymentthecrewdirectedalldeckoperationsanddrovethewinch,lineswereattachedtotheframetosteadythepackagewhilstitwaseitherliftedoffthedeckoverboard,orliftedondeckinboard.Thetechnicianassistedinthisprocess.Onceinthewater,thecrewloweredthepackagetoaninitialdepthof10m,allowingtheSea-Bird5Tpumpstoprimeandstartoperating.Oncethishadoccurredformostcasts,andwhereweatherallowed,thepackagewasraisedtonearthesurfacethenloweredtoanearbottom.Inputfromthescientificpartydictatedtherequiredbottlestops,andthenumberofbottlestofireateachdepth.Bottleleakagesoccurredonseveralcasts(seecruisenarrativefordetails),buttheseissuesweresolvedbyreplacingbottlesandspareparts.Otherwise,therewerenofurtherissueswithhardware.RefertoNMFtechnicalreportforfurtherdetails.

Uponcompletionofthecastthepackagewaseitherlandedondeck,movedintothehangerandstowedintheCTDdeckplateforthescientiststocommencesampling.Duetotheconfigurationoftheliftinghoistandslowoperatingspeed,thistypicallyaddedafive-minutedelaytothescientistsbeforetheywereabletostarttheirsampling.

BetweenstationssensorswereflushedwithMilli-QandthewholeCTDrinsedwithfreshwatertopreventsaltcrystalsforminginthesensors,associatedtubingandcarousal.

Immediatelyaftereachcasttherawdatawasbackeduptothenetworkdrive,toreducetheriskofdatalossandtomakethedataavailabletothescientificparty.

BasicSea-BirdprocessingoftherawdatathentookplacebyNMFtechniciansusingSea-BirdDataProcessingsoftware.ThefullBODC“RecommendedstepsforbasicprocessingofSBE-911CTDdata.”Version1.0October2010wasfollowedforallcasts.Bottledatawereprocessedproducingaverage,standarddeviation,minimumandmaximumofdatafrom2.5secondsbeforeandafterbottlefiring(5secondtotal).TheCTDdatawasadditionallyusedtoproduceaSBEDataProcessedSoundVelocityProfile(SVP)ineachmainsite.

FIGURE22:CTDDEPLOYMENT,SHOWINGLADPCSANDOTHERSENSORS.PHOTOK.HENDRY.

41

DY081CRUISEREPORT

LADCPTwoLADCPsweremountedontheCTDrosette(Figure22):Master(downwardlooking,attachedtobaseofframe)andSlave(upwardlookingattachedtooutsideofframe).EachcastthefittedLADCP’sweresetuptologdataviathePCusingapre-configuredscriptfile.TheLADCPsweresetupbeforeeachcastwiththefollowingcommands:

TABLE11:COMMANDFILESFORMASTERANDSLAVELADCPS.

; DY081 Hendry, Bristol. LADCP Master

; Dougal Mountifield

PS0 ; Display System Confuration

CR1 ; Restore Factory Defaults

WM15 ; LADCP Water Mode 15

CF11101 ; Disable Serial Output

EA00000 ; Zero Beam 3 Misalignment

EB00000 ; Zero Heading Bias

ED00000 ; Zero Transducer Depth

ES35 ; Salinty 35PSU

EX11111 ; Earth Coordinates use defaults

EZ0011101 ; Use Heading pitch and roll sensors

TE00:00:01.00 ; 1 Second Minimum Time Per Ensemble

TP00:01.00 ; 1 Second Minimum Time Between Pings

LP00001 ; 1 Ping Per Ensemble

LD111100000 ; Collect and Process all data

LF0500 ; LADCP 5m Blank

LN016 ; LADCP 16 Bins

LS1000 ; LADCP 10m Bins

LV250 ; LADCP 250cm/s Ambiguity Velocity

LJ1 ; LADCP High Receiver Gain

LW1 ; LADCP Narrow Bandwidth

LZ30,220 ; LADCP Default Bottom Detect and Correlation Thresholds

SM1 ; RDS3 Master

SA001 ; Send Sync Pulse Before Water Ping

SW05000 ; Ping 500ms after Sending Sync Pulse

CK ; Save As User Defaults

CS ; Start Pinging

; DY081 Hendry, Bristol. LADCP Slave

; Dougal Mountifield

PS0 ; Display System Confuration

CR1 ; Restore Factory Defaults

WM15 ; LADCP Water Mode 15

CF11101 ; Disable Serial Output

EA00000 ; Zero Beam 3 Misalignment

EB00000 ; Zero Heading Bias

ED00000 ; Zero Transducer Depth

ES35 ; Salinty 35PSU

EX11111 ; Earth Coordinates use defaults

EZ0011101 ; Use Heading pitch and roll sensors

TE00:00:01.00 ; 1 Second Minimum Time Per Ensemble

TP00:01.00 ; 1 Second Minimum Time Between Pings

LP00001 ; 1 Ping Per Ensemble

LD111100000 ; Collect and Process all data

LF0500 ; LADCP 5m Blank

LN016 ; LADCP 16 Bins

LS1000 ; LADCP 10m Bins

LV250 ; LADCP 250cm/s Ambiguity Velocity

LJ1 ; LADCP High Receiver Gain

LW1 ; LADCP Narrow Bandwidth

LZ30,220 ; LADCP Default Bottom Detect and Correlation Thresholds

SM2 ; RDS3 Slave

SA001 ; Send Sync Pulse Before Water Ping

ST0 ; Wait Indefinitely FOr Sync Pulse From Master

CK ; Save As User Defaults

CS ; Start Pinging

Beforeonecast(CTD12),therewasnocommunicationbetweentheLADCPandthedataloggingcomputer,sonocurrentdatawererecorded.ThiswaspartoftheCTDgridatNuuk,sothecastcontinuedasitwasconsideredthatcurrentdatadensitywasalreadysufficient.ForCTD21,theMasterandSlaveLADCPswereswitched,andthiswasrecordedintheloggingsheets.RefertoNMFtechnicalreportforfurtherdetails.

42

DY081CRUISEREPORT

SensorsThefulllistofmountedsensorsisasfollows:

TABLE12:LISTOFSENSORSMOUNTEDON24-WAYSTEELCTDROSETTE.

Instrument/Sensor:

Model:

SerialNo:

Channel:

CastsUsed:

Stainlesssteel24-wayframe

NOCS SBECTD1 N/A Allcasts

24-wayCarousel SBE32 32-0423 N/A AllcastsPrimaryCTDdeckunit SBE11plus 11p-0589 N/A AllcastsCTDUnderwaterUnit SBE9plus 09p-0943 N/A Allcasts

PrimaryTemperatureSensor

SBE3P 3p-2729 F0 Allcasts

PrimaryConductivitySensor

SBE4C 4c-3258 F1 Allcasts

DigiquartzPressuresensor Paroscientific 110557 F2 AllcastsSecondaryTemperatureSensor

SBE3P 3p-4816 F3 Allcasts

SecondaryConductivitySensor

SBE4C 4c-2165 F4 Allcasts

PrimaryPump SBE5T 05-3085 N/A AllcastsSecondaryPump SBE5T 05-7371 N/A AllcastsDissolvedOxygenSensor SBE43 43-2818 V0 AllcastsDissolvedOxygenSensor SBE43 43-2575 V1 AllcastsAltimeter Benthos916T 59494 V2 AllcastsLightScatteringSensor WETLabsBBRTD BBRTD-169 V3 AllcastsPARDown-lookingUWIRR BiosphericalQCP

CosinePAR70520 V4 Allcasts

PARUp-lookingDWIRR BiosphericalQCPCosinePAR

70510 V5 Allcasts

Transmissometer WETLabsC-Star 1602DR V6 AllcastsFluorometer CTGAquatracka

MKIII88-2615-126 V7 Allcasts

10LWaterSamplers OTE 1A-24A N/A AllcastsDown-lookingMasterLADCP(Aluminium)

TRDI/WHM300kHz 1855 n/a n/a

Up-lookingSlaveLADCP(Aluminium)

TRDI/WHM300kHz 23444 n/a n/a

LADCPbatterypackpressurecase

NOCS WH007 n/a n/a

43

DY081CRUISEREPORT

Glideroperations

ConfigurationPriortoloadingonRRSDiscoveryinSouthampton,UKSlocumUnits331and439underwentin-houserefurbishmentandwereballastedfor1027.0at3˚Cinpreparationfordeployment.Thegliderswereconfiguredasinthetablebelow.

TABLE13:CONFIGURATIONOFSLOCUMGLIDERS.

Unit331SlocumTWRFWD:SN:1400153(INV.260002528)SlocumTWRAFT:SN:1400115(INV.260002513)Slocumdeeppump:SN:120(INV.260001982)�G2DigiFin:SN:1467(INV.260000277)Slocumsciencebay(pumpedCT):SN:1115(INV.250008907)AanderaaOptode:�SN:143(INV.250008327)�Firmware:�GliderDos:7.18/SciDos:3.21WETLabspuck:SN:3354(INV.260002075)

Unit439SlocumTWRFWD:SN:1300108(INV.260002521)SlocumTWRAFT:SN:1300100(INV.260002505)Slocumdeeppump:SN:210(INV.260000276)�G2DigiFin:SN:____(INV.26000____)Slocum science bay (pumped CT): SN: 1103(INV.260001980)AanderaaOptode:�SN:243(INV.250002409)�Firmware:�GliderDos:7.18/SciDos:3.21�WETLabspuck:SN:3347(INV.260002070)

DeploymentplanDuetothestrengthanddirectionofprevailingcurrents,adeploymentplanwasfinalisedsuchthatthegliderswouldtravelinanortherlydirection,followingthecurrentwhilsttransectingtheshelfinrepeated‘zig-zags’.RecoverypositionwasanticipatedtobeinapproximatelythemiddleoftheNuuksurveysite.DeploymentwascarriedoutinaccordancewithNMFproceduraloperations,withoutanyissues.

TheunitswerepilotedbySteveWoodward(NOC,Southampton),withCandiceCameronastheonboardtechnician.Theunitsweredeployedfrom62o54.198’N,52o37.816’Won17thJuly2017.Unit331–“Coprolite”–wasdeployedfirst,followedbyUnit439–“HSB”.Theanticipatedrecoverypositionwas63o35.096’N,53o16.663’W.

MissionThepathoftheglidersdifferedfromplannedduetostrongcurrents(Figure23).However,bothglidersrecordeddataonthreecrossingsoftheshelfbreakeach.Seetechnicalreportfordetailsonthemissionandpilotlogs1.

RecoveryRecoverywascarriedouton24thJuly2017at1320(Unit331)and1430(Unit439)GMTinaccordancewithNMFguidelinesand,despitepoorglidervisibilityduringthesearch,thegliderswereeventuallylocatedandrecoveredsafelyondeckwithoutfurtherissue.SeeFigure24.

1MARS–GlidersExpeditionReportforDY081:ICY-LAB,C.Cameron.2017.

44

DY081CRUISEREPORT

FIGURE23:MAPOFGLIDERROUTESONDY081.

45

DY081CRUISEREPORT

FIGURE24:RECOVERYOFGLIDERUNIT331‘COPROLITE’.THETOWLINEINTHENOSECONEISUSEDTOWINCHTHE

GLIDERVERTICALLY,BEFOREBEINGLOWEREDONTODECKANDSECURED.PHOTOSBYK.HENDRY.

46

DY081CRUISEREPORT

RemotelyOperatedVehicleoperations

TheRemotelyOperatedVehicle(ROV)–Isis–wasdeployedtocollectsedimentsamplesfromglaciatedregions,whereconventionalcoringmaybeinappropriate,andtocollectsamplesforcomplementaryprojects.Diveplansandmapsweregeneratedpriortoeachlaunch,tosuittheobjectivesofthespecificdive.

Generaldescription

• Depthrated6500m• ROVistetheredtoshipwithhighvoltage,opticfibrecableforrealtimevideofeeds• Twomanipulatorarms(Kraft(port)andSchilling(starboard))• “Slurp”suctionsystemandnetsforsamplecollection• Mainbiobox,biotubes,pushcores,netsonthefronttray,withportandstarboardbioboxes,andsix1.7L

Niskinsbottes,five“slurp”chambersattherear(seeFigure25)• ASeabird49CTDisattachedtotheROVframeanddataarerecordedthroughoutthedive;processingof

therawCTDdatathentookplacebyPSOusingSea-BirdDataProcessingsoftware• Threehighdefinitionvideocamerasareattached:HDSci(onpan-tiltmodule,controlledbyleadscientist),

HDPilot(onpan-tiltmodule,controlledbypilot)andScorpio(fixedview,with4672x2628(16:9Format)stillstakentypicallyevery30seconds);lowerdefinitionmini-cams(uplook,drawer,sampler/gauges)andlow-definitionMercurymonochromeaftcameraarealsoattached;aftcameraalsorecordedonPALonoccasion

• AllvideosarerecordedontoKiProtapes,with2hourintervalsthensavedontoMasterandBackupLaciedrives

• LaserswereattachedtoScorpioandHCSciat10cmspacing• ROViscontrolledfromvanwithtwopilotsandleadscientistatfrontconsole,and2-3otherobserversat

therearconsole• LoggingiscarriedoutonhardcopyandusingOFOPloggingsoftware• Navigation,Sensor,andstillsarealsocopiedontoaMasterandBackupLaciedrives,andNavigation,

Sensor,ScorpioimagesandvideowereadditionallybackedupasaworkingcopyonafurtherLaciedrivefortheUniversityofBristol

FIGURE25:EXAMPLEOFROVTRAYCONFIGURATIONFROMROVDIVE337.

47

DY081CRUISEREPORT

TABLE14:TABLEOFLOCATIONSOFROVDEPLOYMENTS;OK=ORPHANKNOLL;SG=SOUTHERNGREENLAND.

Note:a=ROV331andROV337wereaborted;ROV334wasaMultibeamresondiveandnoScorpioimagesareavailable

Site Station Gear JdayStart

StartTime(GMT)

StartLat(DD)

StartLon(DD) Startwaterdepth(m)

JDayEnd

EndTime(GMT)

EndLat(DD)

EndLon(DD)

Endwaterdepth(m)

OK 5 ROV327 189 16:19:00 50.04158 -45.37940 3550.8 190 18:01:00 50.0832 -45.3594 1941.0

OK 7 ROV328 191 07:50:00 50.55481 -46.19323 1669.2 191 16:21:00 50.5564 -46.1956 1576.7

OK 8 ROV329 191 20:48:00 50.55182 -46.19227 1792.0 192 17:28:00 50.5698 -46.1836 1527.0

OK 11 ROV330 192 23:23:00 50.55118 -46.19071 1825.5 193 12:00:00 50.5512 -46.1934 1717.0

OK 13 ROV331a 193 16:15:00 50.50629 -46.08250 1848.0 194 06:24:00 1586.0

Nuuk 30 ROV332 201 02:45:00 63.86858 -53.28953 964.0 201 03:06:00 63.8704 -53.2901 950.0

Nuuk 31 ROV333 201 03:49:00 63.86612 -53.28869 970.0 201 23:11:00 63.8657 -53.2834 805.0

Nuuk 34 ROV334b 202 07:00:00 63.86511 -53.28258 807.0 202 16:05:00 63.8651 -53.2784 683.0

Nuuk 36 ROV335 203 03:38:00 63.33217 -52.77710 1281.0 204 03:32:00 63.3317 -52.7550 898.0

Nuuk 37 ROV336 204 10:51:00 63.60375 -52.91897 515.0 204 20:53:00 63.6112 -52.9032 345.9

SG 44 ROV337a 207 17:33:00 60.09451 -47.31853 1037.2 207 20:19:00 60.1063 -47.4009 1048.0

SG 50 ROV338 208 18:46:00 60.09000 -46.62533 603.50 209 18:12:00 60.0862 -46.6497 1064.0

SG 52 ROV339 210 07:04:00 59.94672 -46.54810 1148.0 210 21:46:00 59.9423 -46.5069 589.0

48

DY081CRUISEREPORT

SeeAcousticsOperationssectionfordetailsonresonsettingsfordiveROV334.

SeeROVtechnicalreportforfurtherinformationonthevehicle’stechnicalperformance2.

FIGURE26:RECOVERYOFROVDIVE338.PHOTOSBYVEERLEHUVENNE.

FIGURE27:ROVDIVESITE327(OVERTHEPAGE).PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF50˚N.

FIGURE28:ROVDIVESITE328-330.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF50˚N.

FIGURE29:ROVDIVESITE331.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF50˚N.

FIGURE30:ROVDIVES333AND334.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF63˚N.

FIGURE31:ROVDIVE335.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF63˚N.

FIGURE32:ROVDIVE336.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF63˚N.

FIGURE33:ROVDIVE338.PRODUCEDINMERCATORPROJECTIONWITHASTANDARDPARALLELOF63˚N.

2IsisROVSystem:ExpeditionReport.RRSDiscovery(DY081).D.Turner.2017.

49

DY081CRUISEREPORT

Figure27

50

DY081CRUISEREPORT

Figure28

51

DY081CRUISEREPORT

Figure29

52

DY081CRUISEREPORT

Figure30

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53°16.7'W53°17'W53°17.3'W

63°5

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63°5

2'N

63°5

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63°5

1.8'N

0 0.1 0.2Nautical Miles

0 0.2 0.4Kilometers

DIVE 333 and 334

50 metersBathymetry

100 m900 m1400 m2200 m

Projection: World Mercator, Standard Parallel = 63 Degrees North

_̂ GRB!@ NET$ NSK# PSHÅ SLP

Dive 333

Dive 334

53

DY081CRUISEREPORT

Figure31

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52°45'W52°45.5'W52°46'W52°46.5'W

63°2

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63°1

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63°1

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0 0.25 0.5Nautical Miles

0 0.4 0.8Kilometers

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50 metersBathymetry

100 m900 m1400 m2200 m

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!@ NET_̂ GRB$ NSK# PSHÅ SLP

54

DY081CRUISEREPORT

Figure32

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52°53'W52°54.5'W52°55'W

63°3

6.5'N

63°3

6.5'N

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63°3

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0 0.25 0.5Nautical Miles

0 0.4 0.8Kilometers

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50 metersBathymetry

100 m900 m1400 m2200 m

Projection: World Mercator, Standard Parallel = 63 Degrees North

!@ NET_̂ GRB$ NSK# PSHÅ SLP

55

DY081CRUISEREPORT

Figure33

56

DY081CRUISEREPORT

SAPsoperations

Standalonepumps(SAPs)weredeployedtocollectparticlesfromthewatercolumntoaddressthekeyquestionsoftheresearchprojectandforotherbiogeochemicalresearch.FourSAPswereavailablefortheexpedition:“Minnie”(S/N88395331),“Chloe”(S/N94K004003),“Sandie”(S/N01K000394)and“Polly”(S/N94K004001).Ateachstation,oneortwopumpsweredeployedattwodifferentdepths,witheitheraGlassFibreFilter(GFF)orSupor0.45µmfilterfittedintopancakefilterhousings.TheSAPswereclampedtoCTDwire(Figure34)andweigheddown,initiallywith100kgforthefirstdeployments,thenwiththe500kgweighttohelpwithdeploymentspeed.Thepumpswereprogrammedtopumpfor1.5hoursatdepth,thenrecovered.

TheSAPswereeachfittedwithaSeabird39(SBE39-6756)andastrain-gaugepressuresensor.BasicSea-BirdprocessingoftherawdatathentookplacebyNMFtechniciansusingSea-BirdDataProcessingsoftware.

ThereweresomeminorissuesthatarosewiththeSAPs,mainlysurroundinghousing“Minnie”(seecruisenarrativefordetails).Despitetheseproblems,onlyonefilterwassignificantlycompromised(SAP05“Chloe”).RefertoNMFtechnicalreportforfurtherinformation.

FIGURE34:RECOVERYOFSAPS.PHOTOBYK.HENDRY.

57

DY081CRUISEREPORT

Towfishoperations

TheTowfishwasusedtocollectuncontaminatedwaterfortracemetalsampling,andwaskindlyloanedtousbyProfEricAchterbergofUni.SouthamptonandGEOMARinKielfollowingDY080.Thesystemconsistsofaweightedfishloweredintothewaterasfarfromtheshipaspossible~5mbelowthesurface.Thefishholdsalengthofacid-cleanedtubingconnectedtoanair-poweredpumpondeck.Theglider-shapedfishkeepsthetubingpointedintocleanwaterandawayfromtheship,andflowisdirectedintothecleanchemistrylabforsampling.

DeploymentsweredonewiththehelpofthecrewandNMFtechnicians,keepingtheopenendofthefishtubingcoveredasmuchaspossibletopreventcontamination.TheTowfishwasdeployed6timesonDY081(Table15)fromthecraneontheportsideoftheaftdeck.

TABLE15:DEPLOYMENTOFTHETOWFISHDURINGDY081.

Gearnumber

Timein Lat/Long Timeout Lat/Long

FSH01 9/7/1718:10

50.08318 -45.35940

10/7/1707:20

50.5528 -46.1944

FSH02 13/7/1707:11

50.50770 -46.08840

19/7/1722:19

50.5755 -45.9865

FSH03 20/7/1723:23

63.86599 -53.28424

21/7/1704:51

63.9535 -52.9167

FSH04 23/7/1721:05

63.61123 -52.90324

26/7/1716:34

60.0941 -47.3158

FSH05 26/7/1720:30

60.11090 -47.41771

27/7/1717:14

60.0898 -46.6496

FSH06 29/7/1722:07

59.94239 -46.50713

31/7/1719:18

59.9395 -43.7783

Whilstthefishwasinthewater,thepumpwasleftoncontinuously.Samplingfortracemetalswasperformedonlywhentheshipwasmovingat>0.5kts.Whenstationaryandwhenevertheuncontaminatedwatersupplywasnotbeingsampledfortracemetals,thewaterwasdirectedoutofthecleanlabandintothehangar,whereitcouldbesampledforradiumisotopesorwasdrainedviathedeckdrains.

58

DY081CRUISEREPORT

Chapter6:PhysicaloceanographyIntroduction

PhysicaloceanographicstudieswerecarriedoutonDY081,tocharacterisethewatercolumnstructureineachlocation,specificallytolocateandquantifythefreshwaterinputsintheGreenlandsites.ThesedatawillhelpusunderstandtheoceanographicpathwaysofwatermassesintheLabradorSea,andassesstheimpactoffreshwaterinputsonthebiogeochemistryofWestGreenland.

PhysicaldatawereobtainedusingrosetteandROVmountedsensors,glidermountedsensors,andwatercolumnacoustics(tobeprocessedonshore).

Geochemicaldatawillbeusedtosupportthephysicalsensordata(SeeChapter7).

SummaryofsensordeploymentsandpreliminaryresultsSensordatafromCTDrosettes

PreliminaryresultsfromOrphanKnollCTDprofilesshowedsub-thermoclinewarm,salinewaterswereunderlainbyLabradorSeaWaterandlikelyoverflowwaters.ThewatercolumnstructurewasmorecomplexoverOrphanKnollitself,likelyillustrativeofmesoscaleprocesses(Figures35,36).

FIGURE35:T-SPLOTFROMORPHANKNOLL.

FIGURE36:CTDDEPTHPROFILESFROMCTD01ORPHANKNOLL(OVERTHEPAGE).

59

DY081CRUISEREPORT

Figure36

PreliminaryresultsfromNuukFollowingarelativelyopenoceanCTDcast(CTD03)tothesouthofthestudyarea,furtherCTDcastsinthestudyareaformedagridtocovertheoff-slope,slope,andshelfregionsofthearea,toinvestigatefreshwatersupplyandtransportfromGreenland.ThefirstlineofthegridwasdesignedtooverlapwiththeFyllaBankline(e.g.Stein&Buch,1991),withthesouthern-mostlinecoveringaglacialtrougharea.

1) GeneralstructureillustratedbyCTD03tothesouthofthisstudyareaandCTD004(Figure37):Cold,subsurfacewaterisfoundat<100m,overlyingastrongthermocline;AtlanticWater(T>3˚C,salinity<34.5)isfoundbelowthethermocline;temperaturepeakingatapproximately400m,mostlikelythecoreofIrmingerWaterinflowfromEastGreenland.

2) Shelfareatonorth(FyllaBank)generallywellmixed:athermoclineispresentatapproximately40matpoint2.3(CTD11),butabsentinpoint1.5,CTD14(Figures38,39).

3) Analysisofthesouthernportionofthegridindicatesmid-waterpolarwaterinputs,whichwerethentargetedforSAPSdeployment.Layersofcold,marginallyfresherwaters(alsoassociatedwithhigherturbiditypeaks)areobservedatapproximately220and420matpoint3.3(CTD10).Theselayersarealsoobservedatsimilardepths(slightlydeeper)atpoint2.2(CTD12),suggestingtheinputfromthetroughflowswestwardintotheboundarycurrentandiscarriednorth(Figure38;supportedbyLADCPdata,seebelow).

4) Highproductivityatallsitesresultedinhighturbidityinsurfacewaters.PARdeclinedrapidly,generallyat0%by15-40m.Subsurfacepeaksinturbiditywereobservede.g.atapproximately160-170mdepthinCTD16,whichwerealsotargetedforSAPSdeployment.

FIGURE37:DEPTHPROFILE(OFFSLOPE)FORCTD04(OVERTHEPAGE).

FIGURE38:TEMPERATUREANDSALINITYPLOTSFORCTDGRID,PLOTTEDWITHBATHYMETRYDATA.

61

DY081CRUISEREPORT

Figure37

0

500

1000

1500

2000

2500

3000

3500

4000

De

pth

[D

ep

Sm

]

34 35Salinity [Sal11; psu]

2017 Jul 20 06:29:23 DY081_CTD004_DATCNV_Filter_AlignCTD_CellTM_LoopEdit_Derive_down_1m_strip.asc

0.0 0.5 1.0 1.5Fluorescence [FlC; ug/l]

0.0000 0.0005 0.0010Turbidity [TurbWETbb0; m^−1/sr]

0

500

De

pth

[D

ep

Sm

]

3 4 5 6 7

Temperature [T190C; degC]

260 280 300 320 340 360

Oxygen [Sbox0; Mm/L] DY

081_019_

CT

D04

62

DY081CRUISEREPORT

Figure38

FIGURE39:T-SPLOTSFORNUUKCTDS.

PreliminaryresultsfromSWGreenlandTwoadditionalglacialtroughswereidentifiedatthesoutherntipofGreenland,andwerestudiedasadditionalcasestudiesforfreshwatersupplyandroutingfromtheshelfofftheslope.ShortertransectsofthreeCTDs(offslope,onslopeandshelf)wereplannedineachoftheselocations,nearNarsaqandCapeFarewellrespectively.

Agenerallytypicalopenoceanprofilegavewaytoprofilescharacterisedbyverylowsalinitysubsurfacepolarwatersoverlyingwarmer,AtlanticwatersinregionstowardsshorenearNarsaq;lowsalinitysurfacewaterswerealsoencounterednearalikelysea-iceedgeonCapeFarewell(Figures40-42).

FIGURE40:DEPTHPROFILEFORCTD17(OFFSLOPE,NEARNARSAQ).

FIGURE41:DEPTHPROFILEFORCTD19(ONSHELF,NEARNARSAQ;NOTETHELOWSALINITYSURFACEWATERS).

64

DY081CRUISEREPORT

Figure40

65

DY081CRUISEREPORT

Figure41

66

DY081CRUISEREPORT

FIGURE42:T-SPLOTFORALLCTDDATAFROMNARSAQANDCAPEFAREWELL.

LADCPdatafromCTDrosetteRawLADCPdatafileswereprocessedwiththeLDEOLADCPprocessingsoftwareversionIX_8,whichwasrunon

Matlab.TheprocessingversionwassettobottomtrackingmodeandemployedauxiliaryCTDtimeseriesdata.

ProcessedCTDprofilefilesalsoincorporatedGPSdatastoredparallelintime,arrivingfromtheship’s1Hzfeed.

PairingtheCTDprofiledatawiththeLADCPcastsintimeisexecutedbycorrelatingthepressuretimeseriesofthe

CTDfilewiththedepthoftheLADCPcast,itselfcalculatedthroughintegrationoftheverticalvelocity.Shipboard

ADCPdatawerenotincludedintheprocessingprocedure.Throughouttheprocessingtask,therewereonly

intermittentandminorissueswiththecastsflaggedupbythesoftware.Onewarningconsistentlygeneratedafter

cast14was=‘nofixedpingingrate’.Thiswarningwasdeemednoteworthybutinsignificant.

Tocustomisetheinput,thescript‘set_cast_params_v4.m’wasusedasatemplatethatwasmodifiedaccordingly.

Here,thedown-lookingandup-lookingLADCPfileswereselectedandtheoutputfilepathsset.TheCTDinput

datawerethe2Hz.cnvfileswithheaderintact.Onceallthenecessarymodificationsweremade,

‘process_cast_v4.m’wasranwiththestationnumberastheonlyargument.Runningthiscodeautomatically

saved14figuresin.psformataswellotheroutputloggingfilesandtheverticalprofilessavedina.ladfile.All

processedfilesforeachcastwerestoredinthecruisedriveinthedirectory:

‘/Volumes/public/DY081/LADCP_processing’.

DifficultieswereencounteredfortheCTDstationsnearNuukinwaterswithabottomdepthshallowerthan100m

(station11andstation14).Herethesurfaceandbottomechointerferenceresultedinabrokencodeandno

inversesolution.TherewerealsoissueswiththecastfromCTDstation22.Here,thevelocitymagnitudeswere

impossiblyhigh.Uponinspection,theerrorseemstooriginatefromthelackofcorrelationfoundbetweenthe

CTDandLADCPprofiledata,sotheCTDprofileisdiscardedresultinginanendcoordinateof0oN0oW.Scrutinising

theCTDinputfileyieldsnoobviousreasonforthesecorrelationissues.Itmayberelatedtodiscontinuitiesinthe

67

DY081CRUISEREPORT

CTDtimeseriesonthecastascent–withsamplinggapslongerthan2minutes.Forthetimebeing,thisLADCP

castwasranthroughtheprocessingsoftwarewithoutauxiliarydata.

PreliminaryLADCPresultsareshowninFigures43and44.Figure43showsLADCPvelocityinaCTDlinebetween

station8(63.418oN’-53.15oW)andstation16(63.58oN’-52.15oW),withstations9,10and15intheinterior,

collectedovera5-dayperiod.Figure44showstheLADCPvelocityprofileatstation16producedbytheLDEO

softwarecarriedoutfollowingthestepsoutlinedabove.

FIGURE43:ZONAL(TOP)ANDMERIDIONAL(BOTTOM)VELOCITYATTHECTDSECTIONNEARNUUK.YELLOWINVERTEDTRIANGLESARE,FROMLEFTTORIGHT,THECTDSTATIONS8-10AND15-16.THEBATHYMETRYWASOBTAINEDFROMTHE

MULTIBEAMDATAGATHEREDDY081.

68

DY081CRUISEREPORT

FIGURE44:THEPROCFIG1OUTFROMLDEOPROCESSINGSOFTWARESOLUTIONFROMCAST#16WITHVERTICALVELOCITYINTHELEFTPANEL.VELOCITYCOMPONENTSAREMERIDIONAL(GREEN)ANDZONAL(RED)ANDVELOCITYFROM

BOTTOMTRACKINGISBELOWINTHEBOTTOMLEFTPANEL.TOPRIGHTPANELCONTAINSMETADATAANDKEYPARAMETERSUSED.CENTRERIGHTPANELGIVESTHETARGETSTRENGTHANDRANGEOFINSTRUMENTSANDBOTTOMRIGHTISTHEPOSITIONOFTHE

SHIPANDINSTRUMENTDURINGTHECAST

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DY081CRUISEREPORT

InstrumentationandsensorsonothertetheredequipmentAdditionaltemperature,salinityanddepthdatawereprocessedfromboththeSAPs(temperatureonly)andROV

CTD.Thedatawillbeusedforthemainprojectasadditionalconstraintsonwatercolumnstructure,andby

complementaryprojects.Theresultshighlightthedynamicnatureofthestudyareas(e.g.Figure45).

ShipboardADCPdatawillbecalibratedandworkeduponshore.

FIGURE45:EXAMPLET-SPLOTFORROVCTDDATA,COMPAREDTONEARBYCTDROSETTEDATA,FROMORPHANKNOLL.

Summaryofgliderdeployments

Gliders(NMFSlocumgliders,units331and439)weredeployedintheNuukregiontoobtainhighspatialand

temporalinformationaboutthewatercolumnstructure,specificallythetransportoffresherwateroutofthe

shelfregionandacrosstheslope.Theplannedgliderpathscoveredtheshelfbreak,severaltimes,andthemouth

ofthemainglacialtrough.

AsperNMFprotocol,thegliderswerenotopenedatsea,anddatawillbedownloadedoncereturnedtothe

workshopinSouthampton.Preliminarydatatransmittedbytheglidersshowthatcolder,fresherwaters,were

captured,inadditiontovariabilityinchlorophyllcontentandturbidity.

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DY081CRUISEREPORT

Chapter7:WatersamplingIntroduction

WatersamplesarebeingcollectedaspartofDY081,toquantify:1)freshwaterinputs(seeChapter6);2)nutrient

concentrationsandfluxes;3)nutrientisotoperatios;andtocarryoutothercomplementaryprojects.Particulates

werecollectedforbiogenicsilica,chlorophylla,andotherpigmentsinsurfacewaters,tohelpquantifythe

productionofsiliceousorganisms.

Summaryofwatersamplingevents

TABLE16:CTDWATERSAMPLINGEVENTSDURINGCRUISEDY081(OVERTHEPAGE).

TABLE17:MEGACOREWATERSAMPLINGEVENTS.

TABLE18:ROVWATERSAMPLINGEVENTS.

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DY081CRUISEREPORT

Site Gearno.

Events(Niskins)

CO3 DI14C Nuts d30Si d14N U-ser d18O StableNd

RadNd Sal BSi Chla POC/PON

OrphanKnoll

CTD01

24 12 12 12x2 12 12x2 12x2 12 6 5 4 1

OrphanKnoll

CTD02 24 8 8 8x2 8x2 3 8 4 8

Nuuk CTD04 24 12 12 12x2 12 12x2 12x2 12 12 7 4 7Nuuk CTD05 24 12x2 12 12x2 12x2 12 4 4 4Nuuk CTD06 24 11x2 11 11x2 11x2 4* 11 4 4 4Nuuk CTD07 24 8x2 8 8x2 8x2 8 4 4 4Nuuk CTD08 24 12x2 12 12x2 12x2 3* 12 4 4 4Nuuk CTD09 24 12x2 12 12x2 12x2 12 4 4 4Nuuk CTD10 24 8 8 8x2 8 8x2 8x2 8* 8 4 4 4Nuuk CTD11 24 8x2 8 8x2 8 4 4 4Nuuk CTD12 24 12x2 12 12x2 12 4 4 4Nuuk CTD13 24 12x2 12 12x2 12 4 4 4Nuuk CTD14 24 12x2 6 12x2 12x2 1 12 12 12 12Nuuk CTD15 24 12x2 12x2 12 4 Nuuk CTD16 24 12x2 8 12x2 12 5 SGreen CTD17 24 12 12 12x2 12 12x2 12x2 2 10 12 7 SGreen CTD18 24 12x2 12 12x2 12x2 3 4 12 4 4 4SGreen CTD20 24 12 12x2 12x2 3 4 4 SGreen CTD21 24 12x2 12 12x2 3 4 4 4SGreen CTD22 24 12x2 12 12x2 12x2 12 12 4 4 4SGreen CTD24 24 12x2 12 3 12x2 12 5 5 5

*RadiogenicNdsamplesplitsforU-serieswork

CO3=carbonatechemistry;DI14C=dissolvedinorganicradiocarbon;Nuts=nutrients;d30Si=dissolvedsiliconisotopes;d15N=nitrogenisotopes;U-ser=uraniumseriesisotopes;StableNd=stableneodymiumisotopes;RadNd=radiogenicneodymiumisotopes;Sal=salinity;BSi=biogenicsilica;Chla=chlorophylla,b,c;POC/PON=particulateorganiccarbonandnitrogen

Table16

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DY081CRUISEREPORT

Site Gearno. Events(Niskins)

Nuts d30Si d14N RadNd

OrphanKnoll

MGA01† 1 1x2 1 1x2

OrphanKnoll

MGA02† 1 1x2 1 1x2

Nuuk MGA03† 0 Nuuk MGA04† 1 1

SGreen MGA05 1 1

SGreen MGA06† 1 1

SGreen MGA07† 0

†Coretopwateralsosampledfornutrientsandsilicon/nitrogenisotopes

Table17

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DY081CRUISEREPORT

Site Gearno.

Events(Niskins)

CO3 Nuts d30Si d18O

OrphanKnoll

ROV327 6 2x2

3

4 2

OrphanKnoll

ROV328 6 2x2 2 1x2

OrphanKnoll

ROV329 6 3x2 3 3x2

Nuuk ROV333 3 3x2 3x2

Nuuk ROV335 6 3x2 3x2 3x2

Nuuk ROV336 6 3x2 3x2 3x2

SGreen ROV338 6 2 2 2x2

SGreen ROV339 3 2 2

Table18

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DY081CRUISEREPORT

SummaryofICY-LABprojectseawaterparameters

Parameters,listedintheorderofcollectionfromtheNiksinrosette

1. Dissolvedoxygen

NotethatcalibrationofbottledatawithCTDoxygensensorswasbadduetotitratorfailure,andnofurtherbottleoxygenanalysiswascarriedoutbytitrationafterOrphanKnoll.Protocolfollowedisgivenbelowforreference.

Priortofirstuse,thePVCtubeshouldbesoakedincleanseawaterforatleastonedaytopreventbubbleformation.ThePVCtubingisplacedovertheNisinoutletvalve.Asmallvolumeofseawaterisrunthroughtoremoveair.A250mLglassbottleisrinsed3timeswithseawaterfromtheNiskinbottlebeforebeingfilledandallowedtooverflowforabouttwicethevolumeofthebottle.Carewastakentoavoidbubblesinsidethesamplingtubeandbottle.Thetemperatureofthewaterwasimmediatelyrecordedto0.1˚Cusingahandheldthermometer.MnCl2andNaOH/NaI(1mLeach)isaddedimmediatelytoseawaterusingbottle-topdispensingpipettes,beforestopperingthebottle.Inthelaboratory,thebottleisswirledtomixtheprecipitates,andthegaparoundthestopperisfilledwithunfilteredsurfaceseawatertocreateawatersealtopreventevaporationandbubbleformation.Thesamplesarestoredatroomtemperatureinthedark,andanalysedwithin12hoursofcollection.

2. Carbonatechemistry

Carbonatechemistryparameters(pH,alkalinity)canbeusefulparametersininvestigatingfreshwaterinput,andareusefulforanumberofcomplementarystudies(e.g.growthofscleractiniancorals).

A250mLborosilicateglassbottleisrinsedtwicewithseawaterfromtheNiskinbeforebeingfilledusingaPVCtubeandallowedtooverflowonevolume.Theglassstoppedisplacedin,todisplaceexcessseawater;another2.5mLofseawaterispipettedofftoallowa1%headspace.Thesampleispoisonedwith50µLsaturatedmercuricchloridesolution.ThebottlestopperissealedusingApiezonLgrease,andtapedwithelectricaltape.Thesampleishomogenisedandstoredinacool,darkplace.

CarbonateanalysiswillbecarriedoutinGEOMAR,Germany.ForTDICcarbonatespeciesareconvertedtoCO2byadditionofphosphoricacid(10%in0.7MNaCl),thisgeneratedCO2isthencarriedintothemeasurementcellusingN2andanalysedbycoulometrictitrationusingaVINDTA3C(Marianda,Germany)connectedtoa5011coulometer(UIC,USA).ForTAsamplesaretitratedwith0.1MHCl(preparedin0.7MNaCl)in150μLincrementsuntilthecarbonicacidequivalencepointisreached.ThetitrationismonitoredwiththeVINDTA3Cinaclosedcelltitration(Dickson,SabineandChristian,2007)

Thetemperature,salinityandnutrientconcentrationsofthesamplesattimeofsamplingarethencombinedwiththeTDICandTAmeasurementstocalculateCO2systemparameters.

3. Radiocarbon

Theradiocarboncontentwillbeusedtodeterminetheageofthewaters.

Rinsea250mLglassbottleandcapthreetimes,withseawaterfromtheNiskinviaadedicatedsiliconetube.Thebottleisfilledandallowedtooverflowonevolume.Thesampleispoisonedwith25µLsaturatedmercuricchloridesolution,sealedandhomogenised.Theglassbottleishandledwithcare,andonlyplacedonclean,newplastic.Thebottleisstoredinaplasticbag,inacool,darkplace.

Theradiocarboncontentofdissolvedinorganiccarbonwillbeanalysedatalaterstage.

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DY081CRUISEREPORT

4. Nutrients

NutrientmeasurementsareakeycomponentoftheICY-LABproject.Thesamplesweretakenwhilstwearingvinylglovesonly,andtakeninduplicate.ThebottleswererinsedthreetimeswithseawaterfromtheNiksin,filteredusingeitheranAcropakorinlinefilter(0.2µm)3.Headspaceisleft,andthesampleisfrozenat-20˚C.

Thenutrientswillbeanalysedbackashorebyusinga5-channelsegmentedflowautoanalysermadebyBranandLuebbe,andwithhighresolutioncolorimeters,thenutrientsanalysedwillbeNitrate+Nitrite,Nitrite,Silicate,PhosphateandAmmonium(Brewer&Riley,1965;Grasshoff,1976;Mantoura&Woodward,1983;Kirkwood,1989;Zhang&Chi,2002).Sampleswillbedefrostedfromfrozenandthebottleswashedanddriedtoensurenocontaminationonopeningthebottlesfromoutsideinfluences.Sampleswillbeanalysedalongwithanutrientreferencematerial(KANSOTechnos,Japan)thatwillbesampledtoensurecorrectcalibrationsaremadeandtoactasacrossreference.

5. Siliconisotopes

Siliconisotopes(denotedbyd30Si)provideinformationabouttheprocessesinvolvedinthesiliconcycle,andsoareakeycomponentoftheICY-LABproject.ThebottleswererinsedtwicewithseawaterfromtheNiksin,filteredusingeitheranAcropakorinlinefilter(0.2µm).Thebottlesarestoredinthecoolanddark.

SiliconisotopeswillbeanalysedonshoreusingamethodadaptedfromdeSouzaetal.,2012,intheBristolIsotopeGroup,UniversityofBristol.Briefly,seawaterwillbeprecipitatedusingsodiumhydroxide,beforebeingredissolvedandchemicallypurifiedusingcationexchangeresin,andanalysedusingaMulti-CollectorInductivelyCoupledPlasmaMassSpectrometer(ThermoNeptuneMC-ICP-MS).

6. Oxygenisotopes

Wateroxygenisotopes(denotedbyd18O)areusedinfreshwaterbudgetcalculations,andsoareakeycomponentoftheICY-LABproject.60mLofunfilteredseawateraresampledcleanlyinduplicate,sealedandstoredincoolstow.

ThesampleswillbemeasuredattheNERCIsotopeGeosciencesLaboratory,NIGL,usingtheVGSIRA(withisoprep18)massspectrometersystem.

7. Salinity(bottle)

Bottlesalinitiesweremeasuredforfreshwaterbudgetcalculations,byNMFtechnicians(seebelowandtechnical

reportforfurtherinformation).Unfilteredwatersamplesarecollectedinglassbottlesandsealedwithaplastic

stopperandmetalcapformeasurementonboard(seebelow).

8. Uraniumseries

Uraniumseriesisotopescanbeusedtoinvestigateweatheringprocesses,andsoareanimportantpartoftheICY-LABproject.5litresofwaterwerefilteredleanlythrough0.2µmAcropakorpolycarbonateinlinefilterandacidifiedto0.1%v/vhydrochloricacid(RomilUpA).ThesampleswerestoredincoolstowforanalysisintheUK.

UraniumseriesisotopeswillbeanalysedattheUniversityofBristolfollowingAuroetal.,2012.

3Giventheyhavethesameporesize,thesetwofiltertypeswereusedinterchangeablyinallcasesoffilteringwiththeexceptionofPOC/PONandchlorophyll.

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DY081CRUISEREPORT

9. Particulates

Remainingwaterwasfilteredforbiogenicsilica(polycarbonatefiltersdriedandsealed),chlorophylla,b,andcanalysis(GFFfilters,seeshipboardanalyses),POC/PON(GFFfilters,flashfrozenat-80˚Candstoredat-20˚C)andphytophysiologyexperiments(seeshipboardanalyses).Volumespassingthrougheachfilertypewerelogged.

Particulatebiogenicsilicawillbeanalysedafteralkalineextractionusingaphotospectrometricmethod,followingDemasteretal.,1981.POC/PONwillbeanalysedbyDrSianHenley,UniversityofEdinburgh.

Sampleswereinitiallycollectedforphytophysiologicalresearch,butthePulseAmplitudeModulation(PAM)devicedidnotfunctionduringthecruiseandnodatawerecollected.OnthefirstrunthePAMwasexhibitingproblemswiththesaturatingpulse.Aftertroubleshooting,itwasdeterminedthatthebatterywasfriedandwasnotchargingtothepropervoltage.Afterreplacement,thegainwasstilltoohighandtherewasnoriseinyieldfromfluorescencebeforethesaturationpulsetotheyieldreachedduringthelastsaturationpulse.Afternumeroustriestogetthedetectorworkingandtroubleshootingotherproblems,itwasbelievedthatthedetectorwasfriedandthesaturatingpulsewasnotworkingcorrectly.SampleswerenolongercollectedforPAManalysis.

SomeadditionalsurfacesampleswerefilteredforSEMimagingofdiatomassemblagesatCardiffUniversity,andstoredundercool,darkconditions(Williams,Cardiff).

TABLE19:TABLEOFSAMPLESTAKENFORDIATOMIMAGING.

Site StationNo GearNo Niskinbottlesfiltered

Nuuk 19 CTD004 20Nuuk 19 CTD004 12Nuuk 19 CTD004 9Nuuk 19 CTD004 24Nuuk 24 CTD008 24-1Nuuk 24 CTD008 24Nuuk 26 CTD010 18Nuuk 26 CTD010 20Nuuk 27 CTD011 18,16,2Nuuk 28 CTD012 24,20Nuuk 28 CTD012 22,18Nuuk 29 CTD013 22,18Nuuk 29 CTD013 24,20Nuuk 33 CTD014 12,18,4Nuuk 33 CTD014 24,20,18,12Nuuk 33 CTD014 22,20Nuuk 33 CTD014 20,14,8,6Nuuk 33 CTD014 4Nuuk 39 CTD015 24,22,20,19,18Nuuk 40 CTD016 24,20S.Greenland 46 CTD018 22,17S.Greenland 46 CTD018 24,20S.Greenland 54 CTD020 24,23,22,21S.Greenland 56 CTD022 24,22,20,18S.Greenland 59 CTD024 24,22,20,18

77

DY081CRUISEREPORT

Samplingprotocolsforcomplementarystudies

Nitrogenisotopes

Nitrogenisotopes(denotedbyd15N)provideinformationaboutnitrogencyclinginseawater,acomplementarysystemtothesiliconcycle.Thesamplesweretakenwhilstwearingvinylglovesonly,andtakeninduplicate.ThebottleswererinsedthreetimeswithseawaterfromtheNiksin,filteredusingeitheranAcropakorinlinefilter(0.2µm).Headspaceisleft,andthesampleisflashfrozenat-80˚C,thenfrozenat-20˚C.ThesampleswillbewillbeanalysedbyDrSianHenleyattheUniversityofEdinburgh.

Silicon-32incubationexperiments

Incubationswithradioactivesilicon-32werecarriedout(Table20)toquantifythedegreeofkineticlimitationofSiuptakebyambientsilicicacidtodeterminewhethersilicicacidlimitationlimitstheproductionofdiatomsilica,andpotentially,diatomgrowth.TheresultsfromDY081willbecompliedandcomparedtoresultsfromsimilarexperimentsfromtheKrauseLaboratoryintheBeringSea(June2017)andcoastalGreenland(April–June2017).

TABLE20:SILICON-32SAMPLINGEVENTSDURINGCRUISEDY081.

ICY-LABStation SamplesCollected 32SiDepths

Sampled

A,E,orK Incubation

Time

DY081_001_CTD001

Full12DepthProfile 5SurfaceDepths Ambient&Enhanced

24hours

DY081_012_CTD002

Full12DepthProfile+Kinetic

4SurfaceDepths Ambient&Enhanced

24hours

DY081_012_CTD002

Full12DepthProfile+Kinetic

20.9 Kinetic 12hours

DY081_017_CTD03

KineticfromAUVCalibration

7.7 Kinetic 12hours

DY081_019_CTD04

Full12DepthProfile+Kinetic

4SurfaceDepths Ambient&Enhanced

24hours

DY081_019_CTD04

Full12DepthProfile+Kinetic

17.2 Kinetic 12hours

DY081_022_CTD06

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_023_CTD07

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_024_CTD08

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_025_CTD09

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_026_CTD10

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_027_CTD11

Full8DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_029_CTD13

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_033_CTD14

Full12DepthProfile+Kinetic

14.9 Kinetic 12hours

DY081_033_CTD14

Full12DepthProfile+Kinetic

10TopDepths Ambient&Enhanced

24hours

DY081_039_CTD15

Full13DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

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DY081CRUISEREPORT

DY081_040_CTD16

Full13DepthProfile 5SurfaceDepths Ambient&Enhanced

24hours

DY081_043_CTD17

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24hours

DY081_046_CTD18

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24Hours

DY081_054_CTD20

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24Hours

DY081_055_CTD21

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24Hours

DY081_056_CTD22

Full12DepthProfile 4SurfaceDepths Ambient&Enhanced

24Hours

DY081_059_CTD24

Full12DepthProfile 5SurfaceDepths Ambient&Enhanced

24Hours

AteachCTDlocation,surfacewatersinorjustbelowthephoticzonewerecollectedfor32Siincubations.Thesampleswerespikedwiththeradionuclideandallowedtoincubateinambientwaterconditions(temperature,lightsaturation)fora24-hourlightcycle.Replicatesateachdepthweregiven20µMsilicateenhancementsforcomparisonagainstambientwatersamples.Followingincubations,thesampleswerefilteredthrougha1.2µm25mmpolycarbonatefilteranddriedforfurtheranalysisfollowingthecruise.Duringthecruise,wecompletedtwenty24-hourincubationsandfive12-hourkineticincubations,finishingthecruisewithatotalof202samples.UponreturningtotheDauphinIslandSeaLab,sampleswillbeallowedtositfor5-monthstoestablishsecularequilibriumwith32PandanalyzedonaBetacountertodetermineSiuptake.

Radiumisotopes

Radium(Ra)isproducedcontinuouslyfromlithogenicmaterialbythedecayofthorium(Th)andthusdisplayselevatedconcentrationsnearanysediment-waterinterface.Thus,Racanbeusedtoinvestigatethefateofsolutessourcedfrombenthicsedimentsorglacialmeltwater.Radiumispresentintheoceanasfournaturally-occurringradioactiveisotopes:223Ra,224Ra,226Raand228Ra,withhalf-lives(11.4d,3.66d,1600yand5.75y,respectively)spanningarangeoftimescalesrelevanttobothverticalfluxesof(micro)nutrientsoutofsedimentsintotheoverlyingwatercolumn,aswellashorizontaladvection.AsRaisnotparticlereactive,thedecreaseinconcentrationofeachshort-livedisotopeawayfromthesource(sediments)canbeusedtotracepathwaysofadvectionaswellasconstraintimescalesoftransport.Theprimaryobjectiveoftheradium(Ra)workdonewithICY-LABistoinvestigatethefateoftracemetalsfromGreenlandglacialmeltwaterwhenthiswaterenterstheLabradorSea.Rameasurements,tracemetalsandoxygenisotopeswillbecombinedtoinvestigatethemagnitudeofanyFesupplyintheNuukregionandalongthecoastofsouthwestGreenland(AnnettNERCFellowship).

Rasamplingrequiresverylargevolumesofwater,asRaactivitiesaretypicallyverylowawayfromsedimentsources.Samplesof~200LwerecollectedfromthetracemetalcleanTowfish.TheTowfishwasdeployedfromtheaftportcrane,toadepthof~5m(depthwhenstationary).Thepumpwasruncontinuouslywhilethefishwasunderwater,towingatspeedupto10knots.Whennecessary,thefishwasbroughtupto1mforCTDops,orrecoveredontodeckforROVwork.

Sampleswerecollectedwhileunderwayorstationary(Table21),andstoredin20Lcollapsibleplasticcontainers.Each20Lwatersamplewasweighedusingabeamscale,andstoredonshelvesinthehangarspace.Additionalsampleswerealsocollectedfromthestainless-steelSea-BirdCTDsystem,Niskinbottleonthemegacoreframe,andcore-topwaterfrommegacores.Thesesampleswerecollectedinto20LbottlesasforTowfishwater.

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DY081CRUISEREPORT

Thesampleswerethenpassedthroughacolumnholding20gofMnO2-coatedacrylicfiber,whichstronglybindsRa.ThefiberswerethenrinsedwithMilli-QandloadedintoaRaDelayedCoincidenceCounter(RaDeCC;ScientificComputerInstruments,USA)systempurgedwithHegas,anddecayofRawascountedfor6-10htoquantify223Raand224Racontent.Followingdecayoftheseshort-livedisotopes,thefiberswillbere-analysedusingtheRaDeCCtodeterminetheactivityoftheparentisotopes(227Acand228Th).

Fortowfishsamples,asubsamplewascollectedintoacid-clean250mLLDPEbottlesforanalysisofthelong-lived226Raisotopesbymassspectrometryforcalibration.

Atotalof43sampleswerecollectedforRaisotopes,fromallthreemainsitesaswellastheNuuktosouthwestGreenlandtransit.Ofthese,25weresurfacesamplescollectedfromthetowfishprovidingagoodspatialcoveragetoinvestigatemeltwaterderivedRadistribution.ElevensampleswerelargevolumespooledfromNiskinbottlesontheCTDrosette,2werenear-bottomsamplescollectedfromtheNiskinbottleonthemegacoreframe,and4coretopwatersampleswerecollectedfromthemegacores,givingadditionalinformationonbenthicfluxesateachofthethreesites.

TABLE21:RADIUMSAMPLINGEVENTSDURINGCRUISEDY081.

DY081 Radiumsamplelist

Location Date Station Gear Event Vol(L)1 OK 07/08/17 3 MGA01 1 2.52 OK 07/08/17 3 MGA01 9 0.983 OK 07/10/17 6 FSH01 2 199.344 OK 07/12/17 12 CTD02 1-9 90.225 Nuuk 17/7/17 17 CTD03 1-10 103.276 Nuuk 17/7/17 17 CTD03 11-22 1257 Nuuk1.1 17/7/17 14 FSH02 14 230.258 Nuuk1.2 18/7/17 14 FSH02 17 211.189 Nuuk1.3 18/7/17 14 FSH02 19 209.3410 Nuuk1.4 18/7/17 14 FSH02 21 200.3811 Nuuk1.4 18/7/17 23 CTD07 11-20 72.7512 Nuuk3.1 19/7/17 14 FSH02 22 205.9413 Nuuk3.2 19/7/17 14 FSH02 25 209.5414 Nuuk3.3 19/7/17 14 FSH02 27 199.3315 Nuuk2.3 19/7/17 14 FSH02 29 215.516 Nuuk2.3 19/7/17 27 CTD11 7-14 82.9717 Nuuk2.2 19/7/17 14 FSH02 31 203.9818 Nuuk2.1 19/7/17 14 FSH02 33 211.7519 Nuuk1.5 21/7/17 32 FSH03 2 144.2820 Nuuk1.5 21/7/17 32 FSH03 2 116.521 Nuuk

CTD1523/7/17 38 FSH04 3 184.92

22 NuukCTD16

24/7/17 38 FSH04 5 164.88

23 NuukCTD16(2)

24/7/17 38 FSH04 9.5 183.98

24 NuukCore 24/07/17 42 MGA04 6 0.9625 SWG-400 25/07/17 38 FSH04 11 215.92

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DY081CRUISEREPORT

26 SWG-300 25/07/17 38 FSH04 14 211.927 SWG-200 25/07/17 38 FSH04 17 206.5628 SWG-100 25/07/17 38 FSH04 20.5 214.929 SWG1 25/07/17 38 FSH04 25 206.6930 SWG2 26/07/17 45 FSH05 2 206.7231 SWG2 27/07/17 47 CTD19 1-8 81.9332 SWG2 27/07/17 47 CTD19 9-16 83.3533 SWG2 27/07/17 47 CTD19 17-24 82.4134 SWG2 27/07/17 49 MGA05 xx 1.6335 SWG3 29/07/17 53 FSH06 2 208.17536 SWG3 30/07/17 53 FSH06 11 213.5837 SWG3 30/07/17 53 FSH06 16 212.6338 SWG3 31/07/17 58 CTD23 1 82.1539 SWG3 31/07/17 58 CTD23 9 81.74540 SWG3 31/07/17 58 CTD23 17 82.65541 SWG3 30/07/17 57 MGA07 1 9.4642 SWG3 30/07/17 57 MGA07 1 10.0543 SWG3 30/07/17 57 MG07 9 9.12 Total: 5991.315

Tracemetalsandtracemetalisotopes

Tracemetalsampleswerecollectedfromthetrace-metalcleantowfishsystemwhentheshipwasmovingat>0.5kts.Thewaterflowwasdirectedintothecleanlab,andleftrunningfor~1minutetoflushthetubing.A0.2µmacropakcartridgefilterwasattachedandflushedwithatleast0.5Lofseawater.Dissolvedtracemetal(dTM)sampleswerethencollectedintoacid-washed250mLHDPEbottles,andacid-washed4Lbottlesfortracemetalisotopeanalysis.Filteredwaterwasalsocollectedfornutrientanalysis.Unfilteredwaterwascollectedinto125mLacid-washed125mLHDPEbottlesfortotaldissolvabletracemetal(TdTM)analysis,anda4Lsamplewascollectedforparticulatetracemetals(pTM).Samplesforoxygenisotopes(d18O)werealsocollectedfromtheunfilteredtowfishwater.Allsamplingandhandlingwasperformedfollowingcleanlabprotocols,wearingtyveklabcoats,hairnets,andclass-100particle-freegloves.Nutrientsampleswerefrozenat-20˚C,andwillbeanalysedatthePlymouthMarineLaboratory,UK.SamplesfordTMandTdTMwereacidifiedwith1mLL-1ultrapurehydrochloricacidandstoredatroomtemperatureinthedark.

SamplesforpTMswereimmediatelyfilteredonto25mmSuporfilters,0.45µmporesize.Filterswereattachedtoadaptorsonthe4Lbottles,andpressurefilteredat<5PSIfor2-3hoursoruntilthebottlewasempty.Filtersweregentlydriedusingacleansyringeforsuction,andbydabbingthefilteronanacid-cleanblotterfilter.pTMsampleswerestoredfrozenat-20˚C.Allfiltermanipulationswereperformedinalaminarflowhoodwithacidwashedequipment.dTM,TdTMandpTMsampleswillbeanalysedattheSherrellLabatRutgersUniversityinNewJersey,USA.

Atotalof83samplingeventswereundertakenfortracemetals(Table22).Allthreemainsamplinglocationswerecovered,includingthefullCTDgridatNuuk.SampleswerealsocollectedduringthetransitsfromOrphanKnolltoNuuk,NuuktosouthwestGreenland,andsouthwestGreenlandtoErikDrift.Additionallarge-volumesampleswerealsocollectedfromthefiltered,cleanseawatersupplyforprojectpartnersfromselectedsites,e.g.fortracemetalisotopeanalysis(DrSusanLittleatImperialCollegeLondon),andneodymiumisotopeanalysis(forProfKevinBurton,UniversityofDurham).

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DY081CRUISEREPORT

TABLE22:TRACEMETALSAMPLINGEVENTSDURINGCRUISEDY081.

Stn Gear Evnt Date dTm TdTM pTM TM-

isos

Nd

isos

d18O d30Si Nuts

1 3 FSH01 1 07/09/17 � � � 2 3 FSH01 3 07/10/17 � 3 14 FSH02 2 13/07/17 � 4 14 FSH02 3 14/07/17 � 5 14 FSH02 4 14/07/17 � �6 14 FSH02 5 14/07/17 � �7 14 FSH02 6 15/07/17 � 8 14 FSH02 7 15/07/17 � � � �9 14 FSH02 8 16/7/17 � �10 14 FSH02 9 16/7/17 � �11 14 FSH02 10 16/7/17 � �12 14 FSH02 11 17/7/17 � � � �13 14 FSH02 12 17/7/17 � �14 14 FSH02 13 17/7/17 � � � � 15 14 FSH02 15 18/7/17 � � 16 14 FSH02 16 18/7/17 � � � � 17 14 FSH02 18 18/7/17 � � � 18 14 FSH02 20 18/7/17 � � � � 19 14 FSH02 21.5 18/7/17 � � 20 14 FSH02 23 19/7/17 � � � 21 14 FSH02 24 19/07/17 � � � � 22 14 FSH02 26 19/7/17 � � � � 23 14 FSH02 28 19/7/17 � � � � 24 14 FSH02 30 19/7/17 � � � � 25 14 FSH02 32 19/7/17 � � � � 26 32 FSH03 1 21/07/17 � � � � 27 38 FSH04 1 23/07/17 � �28 38 FSH04 2 23/07/17 � � � 29 38 FSH04 4 24/07/17 � � � � 30 38 FSH04 6 24/07/17 � 31 38 FSH04 7 24/07/17 � �32 38 FSH04 8 24/07/17 � �33 38 FSH04 9 24/07/17 � � �34 38 FSH04 10 25/07/17 � � � �35 38 FSH04 12 25/07/17 � � � � �36 38 FSH04 13 25/07/17 � � � � �37 38 FSH04 15 25/07/17 � � � � � �38 38 FSH04 16 25/07/17 � � � � �39 38 FSH04 18 25/07/17 � � � � �40 38 FSH04 19 25/07/17 � � �

82

DY081CRUISEREPORT

41 38 FSH04 20 25/07/17 � � � � � �42 38 FSH04 21 25/07/17 � � � � � �43 38 FSH04 22 26/07/17 � � � � � �44 38 FSH04 23 26/07/17 � � � � 45 38 FSH04 24 26/07/17 � 46 38 FSH04 26 26/07/17 � � �47 38 FSH04 27 26/07/17 � �48 45 FSH05 1 26/07/17 � � � �49 45 FSH05 3 27/07/17 � � � � �50 45 FSH05 4 27/07/17 � 51 45 FSH05 5 27/07/17 � � 52 45 FSH05 6 27/07/17 � �53 45 FSH05 7 27/07/17 � � � �54 45 FSH05 8 27/07/17 � �55 45 FSH05 9 27/07/17 � �56 45 FSH05 10 27/07/17 � �57 45 FSH05 11 27/07/17 � � �58 45 FSH05 12 27/07/17 � �59 45 FSH05 13 27/07/17 � �60 45 FSH05 14 27/07/17 � � � �61 45 FSH05 15 27/07/17 � � �62 45 FSH05 16 27/07/17 � � � �63 45 FSH05 17 27/07/17 � � � �64 53 FSH06 1 29/07/17 � � � 65 53 FSH06 3 30/07/17 � � 66 53 FSH06 4 30/07/17 � � � �67 53 FSH06 5 30/07/17 � � � �68 53 FSH06 6 30/07/17 � � � �69 53 FSH06 7 30/07/17 � � � �70 53 FSH06 8 30/07/17 � � � �71 53 FSH06 9 30/07/17 � � � �72 53 FSH06 10 30/07/17 � � � 73 53 FSH06 12 30/07/17 � � � 74 53 FSH06 13 30/07/17 � � � � �75 53 FSH06 14 30/07/17 � � � � � �76 53 FSH06 15 30/07/17 � � 77 53 FSH06 17 31/07/17 � � 78 53 FSH06 18 31/07/17 � � �79 53 FSH06 19 31/07/17 � � � �80 53 FSH06 20 31/07/17 � � � �81 53 FSH06 21 31/07/17 � � � �82 53 FSH06 22 31/07/17 � � � �83 53 FSH06 23 31/07/17 � � � �

83

DY081CRUISEREPORT

Neodymiumisotopes(radiogenic)

Neodymiumisotopes(radiogenicandstable)inseawaterreflectweatheringandseafloorexchangeprocesses,andhavebeensampledfor,tohelpconstraininputsofmaterialfromterrestrialandmarineweathering.SamplesforradiogenicNdisotopeswerecollectedforProfTinavanderFlierdt(ImperialCollege);samplesforstableNdisotopeswerecollectedforProfKevinBurton(UniversityofDurham).

Filter10litresofwaterthrough0.2µmAcropakfilterorinlinefilterandacidifiedto0.1%v/vhydrochloricacid(RomilUpA).StoredincoolstowforanalysisintheUK.

Neodymiumisotopes(stable)

Filter10litresofwaterthrough0.45µmAcropakfilterorinlinefilter.StoredincoolstowforanalysisintheUK.SomesamplesalsotakenbyTowfish(seeabove).

Porefluidsamplingandcoreincubations

OneofthekeyaimsofICY-LABistoinvestigatetheinteractionbetweenseawaterandsedimentsinglacialregions.Tothisend,wecollectedporefluidsamplestobepairedwithsedimentandoverlyingseawatersamples,andwecarriedoutcoreincubationexperiments.

Porefluids

Rhizonfilters(Rhizosphere®)wereusedtofilterporefluidsfrombothmegacoreandpushcoretubes(Figure46).Approximatelyhalfofthesolutionswerestoredundercoolconditions,andtheremainderwasfrozenat-20˚C.Someoftheporefluidsweremeasuredfordissolvedsiliconontheship(theremainderwillbecarriedoutonshore).PorefluidsiliconisotopeanalysiswillbecarriedoutattheUniversityofBristol(followingunpublishedmethodsfromLucieCassarinoandDrKatharineHendry).Thefrozensampleswillbeanalysedforremainingnutrients,andfornitrogenisotopesbyDrSianHenley.

FIGURE46:POREFLUIDSAMPLINGOFAPUSHCORE.PHOTOBYA.JACOBEL.

Inaddition,whenmaterialwasavailable,twomegacoresweresectionedat2-5cmintervalsandfrozenforProfTinavanderFlierdt,ImperialCollege.

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DY081CRUISEREPORT

Coreincubations

Coreincubationswereusedtoassessthesupplyofdissolvednutrientsfromsedimentsandporefluidsintooverlyingseawaterviadiffusionovertime.

Onemegacoretubeperrecoverywasfittedwithatightlowerseal,andanuppersealwithasamplingdeviceandmagneticstirrerattachedwhilstondeck(Figure47).Initially,smallamountsofairwereremovedfromtheoverlyingspace(sothatonlyoverlyingseawaterremained)andasamplewastaken.Thecorewasleftundercontrolledtemperatureandlightconditionsandsampledevertwohoursforatleast24hours.Thesampleswerefiltered;84pprox..25-30mLwasstoredundercoolconditions,and25-30mLwasfrozenat-20˚C.

85

DY081CRUISEREPORT

FIGURE47:COREINCUBATIONDESIGN(BASEANDTOPPLUGS,OVERTHEPAGE)ANDIMPLEMENTATION(ABOVE)DURING

DY081.

TABLE23:POREFLUIDANDCOREINCUBATIONSAMPLESFROMDY081.OK=ORPHANKNOLL;

SG=SOUTHERNGREENLAND.

Station Gear Event Site Depth(m) Lat Long Purpose #Samples

003 MGA001 002 OK 3721 50.16 -45.51 Incubation 26

003 MGA001 004 OK 3721 50.16 -45.51 PoreFluids 1

003 MGA001 007 OK 3721 50.16 -45.51 PoreFluids 1

003 MGA001 009 OK 3721 50.16 -45.51 PoreFluids 34

008 ROV329 020 OK 1745 50.55 -46.19 PoreFluids 9

008 ROV329 040 OK 1682 50.56 -46.19 PoreFluids 9

008 ROV329 053 OK 1711 50.57 -46.18 PoreFluids 3

009 MGA002 002 OK 1770 50.52 -46.28 Incubation 245

009 MGA002 003 OK 1770 50.52 -46.28 PoreFluids 13

018 MGA003 001 Nuuk 1301 63.82 -53.77 PoreFluids 32

018 MGA003 002 Nuuk 1301 63.82 -53.77 Incubation 20

034 ROV334 001 Nuuk 940 63.87 -53.29 PoreFluids 12

034 ROV334 007 Nuuk 683 63.86 -53.28 PoreFluids 12

035 ROV335 074 Nuuk 845 63.33 -52.75 PoreFluids 10

035 ROV335 003 Nuuk 1326 63.33 -52.78 PoreFluids 8

035 ROV335 042 Nuuk 1002 63.32 -52.77 PoreFluids 0

035 ROV335 002 Nuuk 1326 63.33 -52.78 PoreFluids 4

035 ROV335 041 Nuuk 1002 63.33 -52.77 PoreFluids 11

035 ROV335 073 Nuuk 845 63.33 -52.75 PoreFluids 2

037 ROV336 043 Nuuk 381 63.61 -52.90 PoreFluids 15

037 ROV336 034 Nuuk 499 63.60 -52.91 PoreFluids 16

037 ROV336 005 Nuuk 549 63.60 -52.92 PoreFluids 19

037 ROV336 035 Nuuk 497 63.60 -52.91 PoreFluids 16

037 ROV336 006 Nuuk 569 63.60 -52.92 PoreFluids 16

86

DY081CRUISEREPORT

037 ROV336 045 Nuuk 349 63.61 -52.90 PoreFluids 7

42 MGA004 002 Nuuk 519 63.55 -52.23 PoreFluids 18

42 MGA004 003 Nuuk 519 63.55 -52.23 Incubation 24

049 MGA005 002 SG 573 60.26 -46.89 Incubation 24

059 MGA005 003 SG 573 60.26 -46.89 PoreFluids 29

050 ROV338 004 SG 742 60.09 -46.63 PoreFluids 16

050 ROV338 005 SG 742 60.09 -46.63 PoreFluids 12

050 ROV338 023 SG 957 60.09 -46.64 PoreFluids 8

050 ROV338 058 SG 983 60.08 -46.64 PoreFluids 12

050 ROV338 059 SG 983 60.08 -46.64 PoreFluids 24

051 MGA006 002 SG 1326 60.12 -46.66 PoreFluids 30

051 MGA006 003 SG 1326 60.12 -46.66 Incubation 24

052 ROV339 003 SG 1085 59.93 -46.50 PoreFluids 19

052 ROV339 038 SG 807 59.93 -46.50 PoreFluids 17

052 ROV339 040 SG 532 59.94 -46.51 PoreFluids 18

052 ROV339 004 SG 1085 59.93 -46.50 PoreFluids 21

052 ROV339 037 SG 807 59.93 -46.50 PoreFluids 21

052 ROV339 041 SG 532 59.94 -46.51 PoreFluids 8

052 MGA007 002 SG 2149 59.46 -44.42 Incubation 24

052 MGA007 003 SG 2149 59.46 -44.42 PoreFluids 12

Shipboardwateranalyses

SalinitySalinitywasmeasuredonboardbyNMFtechniciansaccordingtostandardprotocolusinganGuildlineAutosalsalinometerandsoftware,cross-checkedwithIAPSOstandards(seeNMFtechnicalreportformoredetails).AtthewestGreenlandsites,allNiskinsthatweresampledforoxygenisotopeswerealsosampledforsalinity,tocarryoutfreshwaterbudgetcalculations(e.g.Hendryetal.,2011).Atothersites,only3-4Niskinsweresampledforsalinity,tocarryoutasensorcalibration.

DissolvedsiliconDissolvedsiliconwasmeasuredinsomeporefluidprofilesusingHachLtdreagentsforultra-lowrangeSiO2detection.MeasurementswerecarriedoutonaV-1200Visspectrophotometer,andsampleswerecalibratedagainstaten-pointstandardcurve.

Themeasurementprotocolisasfollows:

• Fourteendropsofmolybdatesolutionareaddedtoblank,standardsandsamplesandleftforfourminutes.

• Citricacidpowder(1sachet)isaddedtoeachblank,standardandsampleandleftforoneminute.• Aminoacidcatalyst(1sachet)isaddedtoeachstandardandsample(notblank)andleftfortwominutes.• Thesolutionsaremeasuredat810nm,blank-correctedandstandardised.

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DY081CRUISEREPORT

DissolvedoxygenDissolvedoxygenmeasurementswereattempted,tocalibratetheoxygensensorontheCTD.However,duetotitratorfailure,themeasurementswereabandoned.Instead,theoxygensensorswillbecalibratedpost-cruise.

Forreference,themeasurementprotocolisasfollows:

Startup

• Moveburettetiptotheelectrodeholder.• Flushtheburettetipwithfreshthiosulphate.

o Menu>OK>Manualcontrol>OK>PREP>OK.o Thisflushes10mLthroughtheburette,2cyclesbythepiston,goodifnotusedrecently.o DOS>OK>Start(holddown)tomanuallydispensedesiredamount.o PressBacktoreturntomainmenu.o RinseexcessthiosulphatefromtheburettetipwithMQ.

• SelectDissolvedO2method.o Method>OK>DissolvedO2>OK.

• Moveelectrodetoelectrodeholder.• RinsetheelectrodewithMQ,ifabigdropofMQishangingofftheelectrodebulbremoveitgentlywithakimwipe.• Dispense1-2mLofH2SO4togetfreshacidinthepipettetip.Runningsamples• Selectnextsample.• Removewatersealwithpipetteandcompletelydryaroundthestopperwithakimwipe.• Removestopperbytwistingandgentlypulling.Avoid“chinking”thestopperasthiscanchipthestopperandrenderthebottlecalibrationincorrect.Ifyoucannotremovethestopperdonotforceit.• Add1mLofH2SO4tothesamplewiththepipettetipjustbelowthesamplesurface.Gentlytipthebottleandruntheaciddownthesideofthebottle.Thisistopreventtheintroductionofbubblesandtoavoiddisturbingtheprecipitate.• Usingthestirrerbarretriever,traceasmallstirrerbardowntheneckofthebottleandtothebottomofthebottle.Thisalsoistopreventtheintroductionofbubblesandtoavoiddisturbingtheprecipitate.• Placesampleonstirrerplate.• Lowertheelectrodeandburettetipintothesample.• OntheTitrino.

o Ensurethe“DissolvedO2”methodisselected.Ifnotrefertothestartupsection.o Press“Start”o EntertheshortIDinID1.ID1>OK>WXXXX>Accept>OK.Thekeypadcanbeusedtoenternumbers(NumLockmustbeon)butnotletters,andBS=backspace.o EnterthebottlenumberinID2.ID2>OK>XX>Accept>OK.o Ignoretheunitline.o Press“Start”tobeginthetitration.

• Thetitrationwilltakeabout60sec.• WritedownthetitervolumeontheDissolvedO2logsheet.• Raisetheelectrodeandburettetiphighenoughsoasnottocatchthebottleontheelectrodebulb.• Removethesample.• RinsetheelectrodeandburettetipwithMQ,ifabigdropofMQishangingofftheelectrodebulbremoveitgentlywithakimwipe

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DY081CRUISEREPORT

• Retrievethestirrerbarfromthesample,drythestirrerbar,capthebottle,returntotheboxandselectthenextsample.

ChlorophyllpigmentsAtrichromaticmethod(Mackerethetal.,1978)wasusedtodeterminechlorophyll-a,bandcspectrophotometricallyinthenearsurfaceseawatersamples(exceptCTD01).Thesampleswerepassedthrougha25mmGFFfiltersandfrozenuntilextraction.Extractionwascarriedoutusingaqueousacetoneandmagnesiumcarbonate,inordertopreventaciditythatcoulddamagethepigments.Oncelefttosteepfor24hoursinthedarkat4˚C,thesampleswerecentrifugedandanalysedat750nm(tocorrectforturbidity),664,647and630nmonaV-1200Visspectrophotometer.Absorbancevalueswerethenusedinequations1to3tocalculatetheconcentrationofchlorophyll-a,bandcpervolumeoffilteredsample(Eq.4).

Chlorophyll a (mg/L) = 11.85*(OD664) – 1.54*(OD647) – 0.08*(OD630) (1)

Chlorophyll b (mg/L) = 21.03*(OD647) – 5.43*(OD664) – 2.66*(OD630) (2)

Chlorophyll c (mg/L) = 24.52*(OD630) – 7.60*(OD647) – 1.67*(OD664) (3)

Chlorophyll x, mg/m3 = (Chl x) * extract volume, L/ Volume of sample, m3 (4)

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DY081CRUISEREPORT

Chapter8:StandAlonePumps

Introduction

WecollectedwatercolumnmaterialusingStandAlonePumps(SAPs)forbiogenicsilica,major/minorelements,andorganicmatter,toquantifytheparticulatesreleasedinfreshwatersfromWestGreenlandandtocomparethemtoparticulatesfromanopenoceancomparisonsite(OrphanKnoll).

SummaryofSAPSevents

TABLE24:TABLEOFSAPSSAMPLINGEVENTSDURINGCRUISEDY081(OVERTHEPAGE).

SamplingprotocolNylonpre-filtermesheswereacidcleanedandGFFfilterswereashedpriortothecruise,andwrappedinashedfoil.GFFandSuporfilterswerecleanlyfittedintothecleanedpancakefilters(oneperfilter)andattachedtotheSAPS.

TheSAPSweredeployed(seeChapter5)andpumpedfor1.5hours.Whenretrieved,totalvolumepumpedisrecordedandthepancakefiltersremovedandallowedtodrainundercoolconditions.GFFfilterswereremovedcleanlyinafumehoodandsplitintwo,labelledandphotographed,foldedintwoandwrappedinpre-ashed,cleanfoil,andflashfrozendirectlyat-80˚Candthenstoredat-20˚C.TheSuporfilterswereremovedcleanlyinalaminarflowhood,dividedintothreepieces,whicharephotographedandlabelled,foldedinhalfandplacedinacleanbag,andflashfrozenat-80andmovedto-20forstorage.Nylonmeshfilterswerefrozenforstorage,oracidwashedandreused.Blanksweretakenbyinstallingandremovingbothtypesoffiltersintothepancakehousingsundertheconditionsinthelaboratory.

Site StationNo

GearNo JDay(Start)

Depth(m)

Filtertype

Pumptime(mins)

Pumpingvol(L)

ID Comments

OrphanKnoll 2 SAP001 188 2400 GFF 90 1212 CHLOE

OrphanKnoll 2 SAP001 188 2400 Supor 47? 338 SANDIE

OrphanKnoll 2 SAP001 188 200 GFF 90 1170 POLLY

OrphanKnoll 2 SAP001 188 200 Supor 90? 604 MINNIE Smallerpumpingvolumemaybepartlyduetoshorterbatterylife

Nuuk 20 SAP002 199 630 GFF 90 1074 CHLOE

Nuuk 20 SAP002 199 630 Supor 90 679 SANDIE

Nuuk 20 SAP002 199 100 GFF 90 1015 POLLY

Nuuk 20 SAP002 199 100 Supor 90 8 MINNIE Filterhousingwasfullofwaterthatwasreluctanttodrainwhenopened

Nuuk 35 SAP003 202 450 GFF 90 1228 CHLOE

Nuuk 35 SAP003 202 450 Supor 90 723 SANDIE

Nuuk 35 SAP003 202 250 GFF 90 14 MINNIE MINNIEstillpumpingsmallvolume,latertofindfaultypumpparts

Nuuk 35 SAP003 202 250 Supor 90 593 POLLY

Nuuk 41 SAP004 205 400 GFF 90 1139 CHLOE

Nuuk 41 SAP004 205 165 Supor 90 557 SANDIE Suporfilternotcutduringsampling

Nuuk 41 SAP004 205 100 GFF 90 238 MINNIE Spiralplateinstalledupsidedown

SGreen 48 SAP005 208 350 GFF 90 990 CHLOE

SGreen 48 SAP005 208 350 Supor 90 636 SANDIE

SGreen 48 SAP005 208 100 GFF 90 513 POLLY

SGreen 48 SAP005 208 100 Supor 90 816 MINNIE

SGreen 60 SAP006 212 500 GFF 90 13 CHLOE Filtertorn

SGreen 60 SAP006 212 500 Supor 90 723 SANDIE

SGreen 60 SAP006 212 150 Supor 90 673 POLLY

SGreen 60 SAP006 212 150 GFF 90 1110 MINNIE Smalltearinfilter

Table24

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DY081CRUISEREPORT

Chapter9:SedimentsamplingIntroduction

SedimentsamplingwascarriedoutonDY081,toassesstheroleofsediment-waterinteractionsinbiogeochemicalcyclingintheLabradorSea,andforcomplementarypalaeoceanographicandproxycalibrationprojects.Sediment-waterinteractionswerecharacterisedusingporefluidprofilingandcoreincubations.

CoringstrategyandsamplecollectionTheDY081sedimentcoringstrategywasdesignedtoobtaincoretopsedimentsandlongsedimentcoresfrommultiplelocationsateachofthethreemainstations:OrphanKnoll,NuukandSouthwestGreenland.Specifically,atOrphanKnollweselectedcoresiteslikelytobeinfluencedbyProto-NorthAtlanticDeepWaterandoutflowfromtheHudsonStraitasacomponentofLabradorSeaWaters(LSW).AtNuuk,wetargetedsedimentslocallyinfluencedbytheoutflowofshallowsubglacialmeltwaterandparticulates,inadditiontosedimentslocatedatthebottomofthecontinentalshelfandinfluencedbytheambientwatermasses.Finally,atSouthwestGreenlandoursamplingstrategywastargetedatobtainingsedimentsinfluencedbythesurficialflowoftheEastGreenlandCurrent(bringingcoldandfreshwaterfromtheArcticOcean),Iceland-ScotlandOverflowWater(ISOW)andrecirculatedLSW.

SampleCollection

SedimentsamplestofulfillDY081objectiveswerecollectedusingthreedifferenttechniqueswhichwereappliedateachofthestudysitesaccordingtothespecificsiteobjectives.WherepossiblesedimentsweresampledsuchthatundisturbedcoretopsamplescanbematchedwithNiskin,CTD,andSAPSdataandwatersamples.Ideally,sedimentandporewaterdatacanbepairedwithdatafromtheoverlyingwatercolumntoprovideinsightsintoprocessesoccurringatthesediment-waterinterface.Undisturbedcoretopsampleswerecapturedusingbothan8roundmegacorerigandpushcorestakenusingtheROVIsis’sarms.

AtOrphanKnollandSouthwestGreenlandanadditionalobjectivewastoobtainlong,continuoussedimentcoresthatwillbeusefulforpaleoceanographicreconstructions.Long-coresamplingwasperformedusingagravitycorerig.Afterrecovery,sedimentcapturedbythegravitycorebarrelwereextrudedandcutinto1.5msectionsfollowingstandardprotocol.

Sedimentsamplesandsubsampleswerenamedfollowingtheconventionsoutlinedelsewhereinthisreport.GearidentifiersareMGA,PSHandGVYformegacores,pushcoresandgravitycoresrespectively.Sub-samplesarelabeledwiththecruisename,stationnumber,gearnameandnumber,eventnumberandsedimentinterval.Anexampleofacompleteidentifierforthefirstgravitycoreofthecruisewouldbeasfollows:DY081_004_GVY001_EV01_0-1cm.

MegacoringSedimentssuccessfullyretrievedusingthemegacorewereslicedandpreservedinplasticbagsforfuturesamplingandstudy.Thesamplingresolutionwasdeterminedonthebasisofthedesignatedrecipientandplanneduseofthesediment.SuccessfulMCHtubesdesignatedforporefluidsamplingwerefirstrelievedofcoretopwaterandthensubsequentlyRhizonswereinsertedevery2cmdowncoretoextracttheporefluids.Toincreasetheefficacy

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ofporefluidremoval,50mLsyringeswereattachedtotheRhizonsandavacuumwascreatedinsidethesyringesbylockingthem‘open’usingwoodenblocks4.

EachofthemegacoresdeployedonDY081hadonetubeofmudselectedforcoreincubation.Additionalinformationaboutcoreincubationscanbefoundinthewatersamplingchapterofthisreport.

Inadditiontocapturingsediment,themegacorerigalsodeployeda10-LNiskinbottletocapturewatersamplesfromjustabovetheseafloor.Detailsonthesub-samplingandanalysisofthiswatercanbefoundinthewatersamplingchapterofthisreport.

PushCoringToobtainalargernumberofcoretopsamples,theROVIsiswasoutfittedwithupto12cylinderstoretrievesmallsedimentcores(seeChapter5;Figure48).Toobtainthemaximumamountofcoretopmaterialatagivenlocation,thesepushcoreswereoftentakenintriplicate.Replicateswerealsocommonlytakeninlocationswherepushcoreswithporefluidholesweredeployed,retrievebothsedimentsforporefluidextractionandtraditionalanalyses.Dependingonthesuccessofretrieval-andwhetherornotporefluidswereobtainedfromthecores-pushcoresweresubsampledatupto1cmresolution.Allsamplesweresubsequentlystoredunderrefrigeratedconditions.

FIGURE48:PUSHCORINGFROMTHEROV.

GravityCoringGravitycoresweredeployedatOrphanKnollandSWGreenlandtoobtainlongsedimentsequencesforpaleoceanographicanalysis.Successfulcoreswerecutinto1.5msectionsandlabeledalphabeticallyinorderofextrusionfromthecorebarrel.Subsequentlycoresectionswerere-labeledsuchthatoldersedimentsareinsuccessivelyhighernumberedtubes.CoresectionsweresplitonboardusingaspeciallydesignedrouterandcradleprovidedbyVeitHuhnebachofNOC.Thecorelinerwasfirstroutedononesideandthenrotated180degreesandroutedasecondtime.Thecorewasthenliftedfromthecradleandamonofilamentlinewaspassedlengthwisebetweenthetwocutstoseparatethecoreintotwohalves.Oneofthehalveswasdesignatedtobethearchivehalfofthecoreandtheothertheworkinghalf.Bothsidesofthecorewerethencleaned/leveledusingglassslides,photographed,andthearchivehalfdescribed.Subsamplingwasthencarriedoutontheworkinghalf.

4Informationonmegacoreandpushcoreporefluidsampling,storageandanalysescanbefoundinthewatersamplingsections.

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SedimentRecovery

SiteSummaries CoringoperationsonDY081recovered5gravitycores,52megacorebarrelsand89pushcoresamplesforatotalofmorethan52mofsediment.ThebreakdownofsedimentretrievalbysiteandcoringtechniqueispresentedinTable25andFigure49.ROVpushcoresarenotdepictedinmapviewbecauseofthehighdensityofcorestakenateachofthethreelocations.Furtherdetailsaboutthedistributionofcoreswithinwatermassescanbefoundbelowinthesectionsoncorerecoveryateachsite.

TABLE25:SUMMARYOFCORINGSITESATEACHLOCATION.

FIGURE49:MAPSOFGRAVITYCORE(DOTS)ANDMEGACORE(DIAMONDS)LOCATIONSONABASEMAPOFPSS-78SALINITYAT50MWATERDEPTHFROMTHEGLODAPV2DATABASE.MAPSGENERATEDUSINGOCEANDATAVIEW.

SiteName Lat.Range(DDS)

Long.Range(DDS)

#GravityCores

GravityCoreSediment(m)

#Megacores

MegacoreSediment(m)

#Pushcores

PushcoreSediment(m)

OrphanKnoll

(50.05)-(50.57)

(-46.28)-(-45.10) 2 9.64 12 4.26 33 6.14

Nuuk (63.33)-(63.87)

(-53.77)-(-52.23) 0 0 16 6.05 34 5.46

SWGreenland

(58.61)-(60.26)

(-46.89)-(-43.58) 3 9.23 24 7.06 22 4.41

Totals 5 18.87 52 17.37 89 16.01

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DY081CRUISEREPORT

OrphanKnollCoringoperationsatOrphanKnolltargetedsedimentbetween3,721and1,628mwaterdepth(Figure50).MGA002andGVY002at1,770mmayhavesampledsedimentsbathedbytheupperlimbofthedeepLabradorCurrentasindicatedbytheoxygenminimainthefigurebelow.ThebathyaldistributionofallsedimentcoresfromOrphanKnollarealsodepictedinthefigurebelow,illustratingthegoodcoretopcoverageprovidedbypushcoresamplesbetweendepthsof1,682and2656m.

FIGURE50:DEPTHDISTRIBUTIONOFSEDIMENTCORESFROMORPHANKNOLL.OVERLAYISLOCALCTDDATAREFLECTINGWATERTEMPERATURESANDDISSOLVEDOXYGENCONCENTRATIONS.

NuukCoringoperationsatNuuktargetedthesedimentsthatlayerthecontinentalshelfandslopebetween1,326and349mwaterdepth.Becauseofthestronggradientsintemperatureandsalinitythatresultfromthesite’sproximitytoconduitsforglacialmeltwater,samplingatNuuksiteswasmorespatiallydistributedthanatotherDY081siteswherewatermassesweretargetedbyvaryingthedepthofcoringefforts.ThespatialheterogeneityofwatermassesatNuukiswellillustratedinFigure51,whichdepictscoringlocationsinrelationtoCTDprofilesofwatertemperature.CoresatNuukincludesedimentsbathedbyboththeflowofambientwatersinthetroughsurroundingGreenlandaswellasthoseinfluencedbyfresh,coldwatersourcedfromglacialmelt.

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FIGURE51:BOTTOMBATHYMETRYOFNUUKSAMPLINGSITESWITHCTDTEMPERATUREPROFILESINRED,GREENTRIANGLES=MGA(EXCEPT04),BLUESQUARES=ROVPUSHCORESITES(SAMECOLOUR=SAMEDIVE).

SWGreenlandCoringoperationsatSWGreenlandsites(CapeFarewellandErikDrift)targetedsedimentbetween1,907and532mwaterdepth.AlthoughthedeepCTDprofiletakenat59.21˚N,-44.58˚Wdoesnotshoweasilyidentifiablewatermassstructureintemperaturespace(Figure52),thedissolvedoxygenmeasurementdoessuggestthatatleasttwodifferentwatermassesmaybathethecoredepthssampled.Wehypothesizethatbetween500and1,000mwatersarerepresentativeofrecirculatedLabradorSeawaterasitflowssouthwardsalongtheeasterncoastofGreenland.Below~1,500mwatersmayberepresentativeofagreaterproportionofIcelandScotlandOverflowWater(ISOW)anditispossiblethatthedeepestcoreat1,907mmaybeinfluencedbyamixtureofwatermassesthatincludeDenmarkStraitOverflowWaterandISOW.FurtheranalysisofDY081CTDdataandNiskinsampleswillbenecessarytoconfirmthesetentativewatermassdesignations.Ifourhypothesisprovescorrect,sedimentcoresfromSWGreenlandbeautifullycapturethedeep-watermassespresentatthesoutherntipofGreenland.

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FIGURE52:DEPTHDISTRIBUTIONOFSEDIMENTCORESFROMSOUTHWESTGREENLAND.OVERLAYISLOCALCTDDATAREFLECTINGWATERTEMPERATURESANDDISSOLVEDOXYGENCONCENTRATIONS.

ShipboardAnalyses

Uponretrievaleachsedimentcorewasenteredintothesedimentdatabaseanditslengthrecorded.Coreswerephotographedwiththeircruiseidentifierandarulerforscale.Subsequentlyadescriptionwasmadeofthecoretodenoteitsmajorcharacteristics.Featuresnotedincludedcolor,grainsize,mineralogy,foraminiferaabundance,sedimentarymatrix,cohesiveness,watercontent/porosity,smell,andthepresence,abundanceandsizeofanomalousclasts(oftenicerafteddebris).Coredescriptionsweredonebyhand,scannedandgroupedbyeventnumberforeaseofaccess.

SedimentSub-samplingSignificanteffortwasmadeonboardtosub-samplesedimentcoressothattheycouldeasilybedistributedtolabsforanalysis.Acompleteaccountingofthenatureofeachofthesesubsamplesisbeyondthescopeofthisreportbutisreadilyavailableonline.Asummaryofsubsamplestakencanbefoundinthetablesbelowwheretheyaregroupedbygeartypeinchronologicalorder.

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TABLE26:SUMMARYOFSUBSAMPLESFROMORPHANKNOLL.

Station Gear Event

WaterDepth(m)

Lat(DDS)

Long(DDS) Date

Maxlength(cm)

#Subsamples

003 MGA001 002 3721 50.16 -45.51 8/7/17 23.5 0003 MGA001 003 3721 50.16 -45.51 8/7/17 39.5 37003 MGA001 004 3721 50.16 -45.51 8/7/17 37.3 14003 MGA001 005 3721 50.16 -45.51 8/7/17 40.5 46003 MGA001 006 3721 50.16 -45.51 8/7/17 36.5 10003 MGA001 007 3721 50.16 -45.51 8/7/17 31.5 14003 MGA001 008 3721 50.16 -45.51 8/7/17 38.5 34003 MGA001 009 3721 50.16 -45.51 8/7/17 40 0004 GVY001 001 3721 50.16 -45.51 8/7/17 514 620005 ROV327 021 2344 50.05 -45.37 8/7/17 17 13005 ROV327 022 2348 50.05 -45.37 8/7/17 ? 1005 ROV327 023 2349 50.05 -45.37 8/7/17 19 19005 ROV327 047 2656 50.06 -45.36 9/7/17 13.5 7005 ROV327 048 2656 50.06 -45.36 9/7/17 17 13005 ROV327 049 2656 50.06 -45.36 9/7/17 25 20005 ROV327 054 2458 50.07 -45.35 9/7/17 27 26005 ROV327 055 2457 50.07 -45.35 9/7/17 21 21005 ROV327 056 2447 50.07 -45.35 9/7/17 22 22005 ROV327 067 2152 50.08 -45.36 9/7/17 18 13005 ROV327 068 2152 50.08 -45.36 9/7/17 18 9005 ROV327 069 2152 50.08 -45.36 9/7/17 20.5 22007 ROV328 004 1800 50.55 -46.19 10/7/17 18.5 15007 ROV328 005 1800 50.55 -46.19 10/7/17 29.5 24007 ROV328 021 1628 50.55 -46.20 10/7/17 19 14007 ROV328 022 1628 50.55 -46.20 10/7/17 13 1007 ROV328 023 1628 50.56 -46.20 10/7/17 24 1007 ROV328 024 1628 50.56 -46.20 10/7/17 17 1008 ROV329 020 1745 50.55 -46.19 11/7/17 24 1008 ROV329 021 1745 50.55 -46.19 11/7/17 11 11008 ROV329 040 1682 50.56 -46.19 11/7/17 24.5 1008 ROV329 041 1682 50.56 -46.19 11/7/17 27.5 27008 ROV329 052 1711 50.57 -46.18 11/7/17 19 19008 ROV329 053 1711 50.57 -46.18 11/7/17 26.5 1009 MGA002 002 1770 50.52 -46.28 11/7/17 38 0009 MGA002 003 1770 50.52 -46.28 11/7/17 28 1009 MGA002 004 1770 50.52 -46.28 11/7/17 35.5 40009 MGA002 005 1770 50.52 -46.28 11/7/17 37.5 40010 GVY002 001 1770 50.52 -46.28 11/7/17 450 535011 ROV330 001 1808 50.55 -46.19 12/7/17 17 17011 ROV330 002 1808 50.55 -46.19 12/7/17 10 2

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011 ROV330 003 1808 50.55 -46.19 12/7/17 15 4011 ROV330 004 1808 50.55 -46.19 12/7/17 16 16011 ROV330 005 1808 50.55 -46.19 12/7/17 8 2011 ROV330 006 1808 50.55 -46.19 12/7/17 5 1013 ROV331 001 1827 50.52 -45.10 12/7/17 27 24013 ROV331 002 1827 50.52 -45.10 12/7/17 27 23013 ROV331 003 1827 50.52 -45.10 12/7/17 18 4

TABLE27:SUMMARYOFSUBSAMPLESFROMNUUK.

Station Gear Event

WaterDepth(m)

Lat(DDS)

Long(DDS) Date

Maxlength(cm)

#Subsamples

018 MGA003 001 1301 63.82 -53.77 17/7/17 37 1018 MGA003 002 1301 63.82 -53.77 17/7/17 36.5 14018 MGA003 003 1301 63.82 -53.77 17/7/17 36 10018 MGA003 004 1301 63.82 -53.77 17/7/17 36 10018 MGA003 005 1301 63.82 -53.77 17/7/17 38 15018 MGA003 006 1301 63.82 -53.77 17/7/17 37 64018 MGA003 007 1301 63.82 -53.77 17/7/17 37 34018 MGA003 008 1301 63.82 -53.77 17/7/17 38.5 28031 ROV333 003 953 63.87 -53.29 20/7/17 19.5 16031 ROV333 004 953 63.87 -53.29 20/7/17 19 16031 ROV333 005 953 63.87 -53.29 20/7/17 18 16031 ROV333 046 704 63.87 -53.28 20/7/17 12 10031 ROV333 047 704 63.87 -53.28 20/7/17 10 9031 ROV333 048 704 63.87 -53.28 20/7/17 16 14031 ROV333 053 658 63.86 -53.28 20/7/17 19.5 16031 ROV333 054 658 63.86 -53.28 20/7/17 14.5 11031 ROV333 055 658 63.86 -53.28 20/7/17 6 6034 ROV334 001 940 63.87 -53.29 21/7/17 25 1034 ROV334 002 940 63.87 -53.29 21/7/17 10 2034 ROV334 003 940 63.87 -53.29 21/7/17 26 24034 ROV334 005 683 63.86 -53.28 21/7/17 18 11034 ROV334 006 683 63.86 -53.28 21/7/17 -- --034 ROV334 007 683 63.86 -53.28 21/7/17 20 1036 ROV335 001 1326 63.33 -52.78 22/7/17 11 10036 ROV335 002 1326 63.33 -52.78 22/7/17 11 1036 ROV335 003 1326 63.33 -52.78 22/7/17 10 1036 ROV335 004 1326 63.33 -52.78 22/7/17 12 12036 ROV335 041 1002 63.33 -52.77 22/7/17 17.5 1036 ROV335 043 1002 63.33 -52.77 22/7/17 14.5 11036 ROV335 073 845 63.33 -52.75 23/7/17 8 1036 ROV335 074 845 63.33 -52.75 23/7/17 13 1036 ROV335 075 845 63.33 -52.75 23/7/17 8 3037 ROV336 003 569 63.60 -52.92 23/7/17 21 19

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037 ROV336 005 549 63.60 -52.92 23/7/17 21.5 1037 ROV336 006 569 63.60 -52.92 23/7/17 23 1037 ROV336 032 497 63.60 -52.91 23/7/17 22.5 19037 ROV336 033 499 63.60 -52.91 23/7/17 20 17037 ROV336 034 499 63.60 -52.91 23/7/17 18 1037 ROV336 035 497 63.60 -52.91 23/7/17 19 1037 ROV336 042 381 63.61 -52.90 23/7/17 25.5 22037 ROV336 043 381 63.61 -52.90 23/7/17 20.3 1037 ROV336 044 349 63.61 -52.90 23/7/17 6 5037 ROV336 045 349 63.61 -52.90 23/7/17 11 1042 MGA004 002 519 63.55 -52.23 24/7/17 41 1042 MGA004 003 519 63.55 -52.23 24/7/17 41 1042 MGA004 004 519 63.55 -52.23 24/7/17 38 10042 MGA004 005 519 63.55 -52.23 24/7/17 35 10042 MGA004 006 519 63.55 -52.23 24/7/17 40 39042 MGA004 007 519 63.55 -52.23 24/7/17 41 80042 MGA004 008 519 63.55 -52.23 24/7/17 38 34042 MGA004 009 519 63.55 -52.23 24/7/17 35 15

TABLE28:SUMMARYOFSUBSAMPLESFROMSWGREENLAND.

Station Gear Event

WaterDepth(m)

Lat(DDS)

Long(DDS) Date

Maxlength(cm)

#Subsamples

049 MGA005 002 573 60.26 -46.89 27/7/17 38 1049 MGA005 003 573 60.26 -46.89 27/7/17 37 1049 MGA005 004 573 60.26 -46.89 27/7/17 36 16049 MGA005 005 573 60.26 -46.89 27/7/17 39 33049 MGA005 006 573 60.26 -46.89 27/7/17 37 64049 MGA005 007 573 60.26 -46.89 27/7/17 34 25049 MGA005 008 573 60.26 -46.89 27/7/17 36 11049 MGA005 009 573 60.26 -46.89 27/7/17 32 9050 ROV338 002 741 60.09 -46.63 28/7/17 20 16050 ROV338 003 742 60.09 -46.63 28/7/17 23.5 20050 ROV338 004 742 60.09 -46.63 28/7/17 20 1050 ROV338 005 742 60.09 -46.63 28/7/17 18 1050 ROV338 022 957 60.09 -46.64 28/7/17 12 9050 ROV338 023 957 60.09 -46.64 28/7/17 10 1050 ROV338 056 983 60.08 -46.64 28/7/17 24 20050 ROV338 057 983 60.08 -46.64 28/7/17 24 20050 ROV338 058 983 60.08 -46.64 28/7/17 22 1050 ROV338 059 983 60.08 -46.64 28/7/17 26 1051 MGA006 002 1326 60.12 -46.66 28/7/17 38 1051 ROV339 002 1085 59.93 -46.50 28/7/17 26 19051 MGA006 003 1326 60.12 -46.66 28/7/17 41 1051 MGA006 004 1326 60.12 -46.66 28/7/17 37 10

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051 MGA006 005 1326 60.12 -46.66 28/7/17 39 11051 MGA006 006 1326 60.12 -46.66 28/7/17 42 70051 MGA006 007 1326 60.12 -46.66 28/7/17 35 25051 MGA006 008 1326 60.12 -46.66 28/7/17 38 17051 MGA006 009 1326 60.12 -46.66 28/7/17 37 32052 ROV339 003 1085 59.93 -46.50 29/7/17 24 1052 ROV339 004 1085 59.93 -46.50 29/7/17 22.5 1052 ROV339 005 1085 59.93 -46.50 29/7/17 25 21052 ROV339 035 807 59.93 -46.50 29/7/17 17 15052 ROV339 036 807 59.93 -46.50 29/7/17 18.5 15052 ROV339 037 807 59.93 -46.50 29/7/17 23 1052 ROV339 038 807 59.93 -46.50 29/7/17 20 1052 ROV339 039 532 59.94 -46.51 29/7/17 14 12052 ROV339 040 532 59.94 -46.51 29/7/17 21.5 1052 ROV339 041 532 59.94 -46.51 29/7/17 12 1052 ROV339 042 532 59.94 -46.51 29/7/17 18.5 16057 MGA007 002 1286 59.46 -44.42 30/7/17 15 1057 MGA007 003 1286 59.46 -44.42 30/7/17 16 1057 MGA007 004 1286 59.46 -44.42 30/7/17 15 14057 MGA007 005 1286 59.46 -44.42 30/7/17 13 13057 MGA007 006 1286 59.46 -44.42 30/7/17 14 13057 MGA007 007 1286 59.46 -44.42 30/7/17 14.5 12057 MGA007 008 1286 59.46 -44.42 30/7/17 10 10057 MGA007 009 1286 59.46 -44.42 30/7/17 13 10061 GVY003 001 1669 59.00 -43.58 31/7/17 480 570062 GVY004 001 1608 58.94 -43.60 31/7/17 81.5 100063 GVY005 001 1907 58.61 -43.78 31/7/17 362 437

CoretopsamplesfrommegacoresandpushcoreswillbestoredatTheUniversityofBristolandgravitycoresampleswillbestoredattheBritishOceanSedimentCOreResearchFacility(BOSCORF).

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DY081CRUISEREPORT

Chapter10:Biologicalsampling

FIGURE53:GHOSTSHRIMPFOUNDLIVINGINSIDEEUPLECTELLASPONGE.

Introduction

RemotelyOperatedVehicleoperationsweretheprimarytoolforbiologicalcollectionsonDY081.Everytimeasamplewascollecteditwasrecordedasaneventinthesampleeventlogandnotesweretakenaboutthetime,depth,latitude,longitude,physicaldescription(colour,sizeetc.),andanyinsituphotostakenofthespecimen.Onceondecksampleswerecarriedinpre-chilledseawaterintothecoldroom(4°C)tocommencesamplingtriage.EachcontainerontheROV(trayarea,net,biotubes,andbioboxes)thatcontainedspecimenswasgivenauniquenumber–thiswastheparentnumbertoeveryspecimenwithinthecontainer.Eachspecimenitselfwasthengivenauniquenumber,its“parentnumber”notedalongsideitseventnumber,ageneraltaxonomicdescription,anyfurthercommentsanddetailsofanysubsampletakene.g.forgeneticswork,dryingforisotopicresearch,etc.Mostspecimensweresub-sampledforgeneticanalysis(preservedin95%ethanol),theremainderofthespecimenwaspreservedineither100%ethanolorina-20°Cfreezer(withsomespecialconsiderationsforspongecollections,explainedbelow).Beforesub-samplingeachspecimenhadascaledpicturetaken.

Therewere1117lotsofspecimenscollectedtotalling1551specimensacross10Phyla(Figure55).

FIGURE54:ACESTASP.CLAMSBEINGCOLLECTED.

Ofthesecollections,severalwillformkeypartsoffuturepopulationgenomicanalyses.ThisincludesmembersoftheOphiuroidea,Psolussp.,Acestasp.(Figure54),Lopheliapertusa,Solenosmiliasp.,andAnthomastus.

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FIGURE55:BREAKDOWNOFPHYLAFROMDY081.NOTE'CHORDATA'WEREEMPTYSHARKEGGCASESANDONEUNFORTUNATEHAGFISHSAMPLESINAMEGACORE.

CoralsAfterthediscoveryofLopheliaoffGreenlandin2011(Tendaletal.,2013;Kenchingtonetal,2017)itisunsurprisingthatassessmentofthesereefswasoneofthebiologicalaimsofDY081.Intotaltherewere315Cnidariacollected.Scleractiniaweretargetedforundergoingpopulationgenomic,phylogenomicandgeochemicalresearch(seeChapter11).

Althoughonly104werecollectedtherewereawidervarietyofOctocorallia,asseeninFigure56.Thesespecimenswillformpartofphylogenomicresearchthatiscurrentlyunderway.

FIGURE56:BREAKDOWNOFMAJOROCTOCORALLIAGROUPSCOLLECTEDONDY081.

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DY081CRUISEREPORT

ForfurtherdetailsaboutbiologicalcollectionspleasecontactDrMichelleTaylor:michelle.taylor@zoo.ox.ac.uk.

FIGURE57:ISIDIDAECORALFOUNDONORPHANKNOLL.

SpongesSpongecommunitiesatOrphanknollwerecharacterisedbyGeodiaspongegrounds(Figure58)withhexactinellid-dominatedcommunitiesinthedeeperareas(Figure59).AttheGreenlandsitescommunitiesseemedtohavemorediversedemospongecommunitiesandlargenumbersofencrustingspecies(Figure60).

FIGURE58:GEODIADOMINATEDSPONGECOMMUNITIESATORPHANKNOLL,ROV327,DEPTH2666M.

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DY081CRUISEREPORT

FIGURE59:HEXACTINELLIDDOMINATEDCOMMUNITYAT3440M,(ROV327).

FIGURE60:SPONGECOMMUNITIESONBEDROCK,GREENLAND,(ROV339).

Intotal291specimensofspongeswerecollected.Specimensthatwerelargeenoughweresubsampledasfollowing:

1) Geneticsamplefortaxonomy(95%ethanol)2) Geneticsampleforpopulationgenomics(95%ethanol)3) Drysampleforsiliconisotopework4) -80frozensampleforstudyofbacterialcommunities5) Remainderpreservedin95%ethanolorfrozenfortaxonomicwork.

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DY081CRUISEREPORT

AfewspecimenswerefrozenintactforstudyoftheirstructureandsamplesofspecimensfromGeodiapopulationsfromOrphanKnollwerefrozenformetabolomicwork(tobecarriedoutbyDrPacoCardenas,UppsalaUniversity,aspartoftheseparateSponGESproject.TaxonomicworkonthecommunitiesandstudyofspongestructurewillbeundertakenaspartofaPhDstudentshipattheUniversityofBristol(commencingautumn2017).InformationcollectedonROVdivesonspongecommunitieswillbeusedbyDepartmentofFisheriesandOceansCanadatoground-truthspeciesdistributionpredictionmodels.

FurtherinformationonspongescollectedcanbeobtainedfromDrClaireGoodwinclaire.goodwin@huntsmanmarine.ca.

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Chapter11:Scleractiniancorals

LiveandfossilscleractiniancoralswerecollectedfromOrphanKnoll,NuukandSouthGreenland.Coralswillbeanalysedasacollaborativeprojecttoexamine(paleo)biogeography,controlsofdeep-seacoralpopulations.Samplesofsuitableageswillbeusedforpaleoclimatestudiesofthepasthistoryoftheoceans.

SamplingProtocol

SampleswerecollectedusingtheROVusingthemanipulatorarms,theslurpgunorthroughusinganet.ThesampleswerebroughtondeckandintothecoldroomwheretheywerecategorisedusingBiologySpecimennumbers(seeChapter10).Aftersamplingforgeneticmaterialssampleswerecleanedanddried.Livespecimenswerebleached,rinsedanddriedtoremovetissue.Deadspecimenswererinsedinseawaterthenfreshwaterthenairdried.Sampleswerethencataloguedandpackedusingbiologyspecimennumbersandsub-divisions(a,betc.)wheremultiplesampleswererecoveredunderoneID(e.g.fromnets).

SamplingLocations

OrphanKnollSampleswererecoveredondives327,328,329,330and331.Livesolitarycoralsrangedindepthfrom2638mto1573m.Deadsolitarycoralswererecoveredfrom1826mto1581m.Deadcoralsweretypicallycoatedinthickblackferromangnesecrusts,unlesstheywererecoveredfromunderthesediment.Manyspecimenswereboredbyendolithicorganisms.Collectionsusingnetsprovedparticularlyeffectiveatcollectingfossilcoraldebrisfoundatthebaseofverticalfeatures(Figure61).

FIGURE61:FOSSILD.DIANTHUSINTHESEDIMENTATTHEBASEOFSMALLVERTICALWALLONORPHANKNOLL.LASERSSEPARATEDBY10CM.

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DY081CRUISEREPORT

NuukSampleswererecoveredondives333and334.Livesolitarycoralsrangedindepthfrom1216m-943m.Deadsolitarycoralswererecoveredfrom1171m-1107m.Livecolonialcoralsrangedindepthfrom1144-752m.Deadcolonialcoralswererecoveredfrom1231-761m.Deadcoralsrangedfromadarkbrownishcolourtoverypalewithlittleevidenceofboringorheavyferromanganeseencrustation(Figure62)

FIGURE62:DARKBROWNCOLONIALDEADCORALSFROMOFFSHORENUUK.SCALEBARINCMDIVISIONS.

SouthGreenlandSampleswererecoveredondives338and339.Livesolitarycoralsrangedindepthfrom1084-794m.Deadcolonialcoralswererecoveredfrom934m.Deadcoralswerebrownish,withlittleevidenceofboringorheavyferromanganeseencrustation.

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Chapter13:Microplasticssampling

Introduction

Microplastics(fibres)havebeenobservedinopenoceandeepseasediments.However,thedistributionandfluxesindifferentpartsoftheoceanarenotwellknown.WecollectedsedimentsfromDY081totestwhethermicroplasticsarealsoaccumulatingintheLabradorSea.ThecruiselocationsallowedforsamplingsedimentsfromOrphanKnoll,andfromGreenlandclosetoNuukandfurthersouth.MarinelitterwouldhavebeencollectedbytheROVifpossible,butsuchlitterwasrareandcouldnotbecollected,e.g.largefishingnet,anobjectthatappearedtobeatyrecompletelycolonisedbysponges.

Summaryofsamples

Ninecoreswerededicatedtomicroplasticswork,including6megacoresand3pushcores(Table30,overthepage).ThesamplesweredistributedacrossthethreemainworkingsiteswiththreeeachfromOrphanKnoll(3721-2152m),Nuuk(1301-519m)andsouthwestGreenland(1326-573m).

SampleacquisitionSedimentsformicroplasticswereeithercollectedbymegacoreorbypushcore.Drilledcoreswerenotselectedformicroplasticwork.Formegacoresapieceofcottonwasplacedoverthecoresbeforetherubberbungwasplavedonthecoretube.Sampleswerestoredandcoveredundercoldconditions,untiltheycouldbesubsampled.

SampleProcessing

Wholesedimentcoresweretakentobeprocessedinthe‘sealedlab’.Thesealedlabisasmalllabwhichwasclosedtootherpurposesandonlyenteredbytrainedpersonnel.Itwascleanedthoroughlyusingfilteredwateratthebeginningoftheexpedition,andbeforeeverysamplingactivity.Theairinletwascoveredwithcottontofilteroutplasticfibres.Wherepossibleplasticswereremovedfromthelaboratory,andanyplasticsintheroomwerethoroughlywashedbeforeentry.Samplersdonnedprotectivegear(cottonboilersuit)andthenstandardcoreslicingprocedureswerefollowedusinganallmetaldeviceforslicingthecore.Nogloveswereworntominimisethepossibilityofcontamination.Dampfilterpaperswereexposedtothelaboratoryenvironmentduringthecoreslicingprocesstoprovidebackgroundsamplesofambientcontamination.Allsedimentsliceswerewrappedinaluminiumfoil,thenplacedintoacardboardboxandremovedtoafreezer(orfridgeforthelastsampleswherefreezerspacewasnolongeravailable).SubsamplesandfiltercontrolsaresummarisedinTable30.

ThecorewillbeworkedbyincollaborationwithDrLucyWoodallfollowingestablishedproceduresfordeepseasediments.

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DY081CRUISEREPORT

NotesforcontaminationGravitycoresweretakenusingyellowplasticcoreliners.Openingthesecoresproducedlargeamountsofyellowplasticshavings.Thisworkwasperformedondeckandinthemainhanger.Crosscontaminationshouldbeminimisedbyperformingthesamplinginthesealedlab.However,fragmentsofthisdistinctyellowplasticshouldbeexcludedfromanyfuturemicroplasticcounts.

TABLE29:SUMMARYOFSAMPLESANDSUBSAMPLESTAKENFORMICROPLASTICSSTUDY.

Gear Event WaterDepth

Lat(Deg) Long(Deg) TotalLength(cm)

Numberofsamples

Lengthofsample(cm)

MGA001 006 3721 50.16 -45.51 36.5 10 2MGA001 006 na na na na 4blanks naROV327 47 2656 50.06 -45.36 13.5 7 2ROV327 47 na na na na 4blanks naROV327 68 2152 50.08 -45.36 18.5 9 2ROV327 68 na na na na 4blanks naMGA003 005 1301 63.82 -53.77 38 7 1MGA003 005 1301 63.82 -53.77 38 8 2MGA003 005 1301 63.82 -53.77 38 2 5MGA003 005 na na na na 3blanks naROV334 005 683 63.86 -53.28 18 8 1ROV334 005 683 63.86 -53.28 18 3 2ROV334 005 na na na na 3blanks naMGA004 009 519 63.55 -52.23 35 10 1MGA004 009 519 63.55 -52.23 35 5 2MGA004 009 na na na na 3blanks naMGA005 004 573 60.26 -46.89 36 11 1MGA005 004 573 60.26 -46.89 36 5 2MGA005 004 na na na na 3blanks naMGA006 008 1326 60.12 -46.66 38 9 1MGA006 008 1326 60.12 -46.66 38 5 2MGA006 008 1326 60.12 -46.66 38 2 5MGA006 008 na na na na 3blanks naMGA007 009 1286 59.46 44.42 13 10 1MGA007 009 na na na na 3blanks na

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