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Project3FinalReport

PerspectivesofGulfofMaineLobsterFishermenonReducingLargeWhaleEntanglements

HeatherTetreault,MaineLobstermen’sAssociation

KateMcClellan,ConsortiumforWildlifeBycatchReductionIntroductionTheendangeredNorthAtlanticrightwhale,Eubalaenaglacialis,hasacurrentpopulationofapproximately526individuals(PettisandHamilton,2015).Entanglementinfishinggearhasbeenidentifiedasoneofthemainthreatstothisspecies(Krausetal2005),causinganaverageofobservedmortalityof1.5individualsperyearfrom2001-2010(Waringetal2008;Waringetal2010;Waringetal2013).RopesrecoveredfromentangledrightandhumpbackwhalesfoundalongtheeastcoastoftheUnitedStatedandCanadahavebeenidentifiedaslobsterpot/trapgearandgillnetgearin80%ofthecasesinwhichthegeartypecouldbedetermined(Johnsonetal2005).Thefourpartsoffixedfishinggearmostcommonlyinvolvedinentanglementswerefoundtobe:buoyline(alsoknownastheverticalline),groundline,floatline,andsurfacesystemlines(Johnsonetal2005).Ananalysisof626rightwhalephotographstakenfrom1980to2009suggeststhatatleast83%hadbeenentangledatleastonceand59%hadbeenentangledmorethanonce(Knowltonetal2013).Theseauthorsalsofoundthatthepercentageofanimalsobservedeachyearwithropeonthebodyincreasedsignificantlyduringthestudyperiod,implyingthatitisbecomingmoredifficultforwhalestofreethemselvesfromfishinggear.TheAtlanticLargeWhaleTakeReductionPlan,intendedtoreducetheincidentalmortalityandseriousinjuryofNorthAtlanticright,humpback,andfinwhales,informsregulatoryactionsforcommercialtrap/potandgillnetfishingactivityintheregion(NMFS2002).TheplanaddressesfixedgearfisheriesfromMainetoFlorida.Alltrap/potfishermeninnortherninshorestatewatersofRhodeIsland,Connecticut,Massachusetts,NewHampshire,andMainemustcomplywithmeasurestoreducetheriskoffishinggeartowhales,including:riggingwithoutthebuoylinefloatingatthesurface;haulinggearatleastonceevery30days(nowetstorage);markingsurfacebuoys;riggingbuoys,floatationdevices,and/orweightsattachedtothebuoylinewithaweaklinkhavingabreakingstrengthnogreaterthan600lbs;fishinggroundlinemadeofsinkingline;andgearmarking.Someexceptionstotheserulesapplywithinanexemptionzoneapproximatelyequivalentto2nmoffshorefromthenearestlandmassinMainestatewaters.Fishermenarealsoencouragedtomaintainknot-freebuoylines.RestrictedAreas(CapeCodBay,StellwagenBankJeffrey’sLedge,andGreat

SouthChannel)haveadditionalrestrictionsonweaklinksandthenumberoftrapsandendlinespertrawlduringcertaintimesoftheyear.In2015,additionalregulationswereimplementedthatincludeexpandedgearmarking,aseasonalclosureoffofMassachusetts,andaminimumnumberoftrapspertrawlbasedonareafished,inordertoreducetheoverallnumberofverticallines(NMFS,2015).Since2005,theConsortiumforWildlifeBycatchReduction(“BycatchConsortium”)hasbeentestingmodifiedfishinggearsuchasabrasion-resistantgroundlines,glowrope,weakrope,stiffrope,redrope,andtime-tensionlinecutterswithlobstermenandinthelab,hasmodeledwhaleentanglementscenariosusingcomputersimulation,andhassupportedresearchtolearnmoreaboutrightwhalevisualperception.Thepurposeoftheseprojectshasbeentoidentifywaystoreduceinteractionsandentanglementsinvolvinglobsterfishinggearandwhales,whilemaintainingpracticalfishingmethodsandlobstercatchrates.Manyoftheseprojectshavebeenconductedincollaborationwithlobstermen,specificallybytestingmodifiedfishinggear.TheMaineLobstermen’sAssociation(MLA),amemberoftheBycatchConsortium,hasengagedlobstermeninconversationstoidentifyinnovativeyetpracticalfishinggearandmethodsthathavepotentialforpreventinglargewhaleentanglements.Aspastbycatchreductioneffortshaveshown,fishermen’sunderstandingoftheproblemisimportantforidentifyingsolutionsandadoptingnewtechniques(see,forexample,discussionofshrimptrawlfishermenandtheadoptionofseaturtleexclusiondevices(TEDs)inTuckeretal[1997]).Cooperativefisheriesresearchhasmanybenefits,including:helpingfishermenandscientistsbecomemoreinformedandappreciativeabouteachother’sexpertise;makingfishermenmorelikelytoacceptthecredibilityofscientificobservations;andpromotingthelikelihoodoflastingpartnerships(HartleyandRobertson2006).Recognizingthis,theMLAandtheBycatchConsortiumorganizedaseriesofmeetingsoverseveralyearsto1)developacommonlanguagebetweenscientistsandlobstermenforcommunicatingtheproblemofrightwhaleentanglements,3)discusspastbycatchmitigationresearchandresults,and4)provideopportunitiesforlobstermentooffertheirinsightsonfishingpracticesandpotentialbycatchmitigationtechniques.Ultimately,thegoalwastoincreasetheinvolvementoffishermeninunderstandingtheentanglementproblemwhilesolicitingtheirinputintoidentifyingsustainablesolutions.Thisreportpresentstheresultsoftheseoutreachactivities.OutreachwithFishermenCreatingaCommonLanguageThefirstgoaloftheBycatchConsortiumandMLAwastocreatearesourceforscientists,lobstermen,policymakers,andotherinterestedpartiesthatexplainedthediverserangeoffishinggearandtechniquesusedthroughouttheGulfofMaine.In2010,lobstermenwereinvitedtoparticipateinoneof39meetingsheldalongthecoastofMainetocharacterizethefishinggearandtechniquesusedbytheircommunity(Table1).Meetingswereheldinalllobstermanagementzones(Figure1)


aswellasinNewHampshireandMassachusetts;over150activelobstermenintotalattendedthesemeetings.Fishermenwereaskedtodocument(drawandlabel)theindividualcomponentsandriggingoftheirlobstergear.TheMLAcollecteddrawingsfrom115lobstermen.Thedescriptionsanddrawingsincludedthesizeandnumberoftraps,weightandballast,brand,size,andlengthoflines,typesofflotationdevices,andmethodsofrigginggear.Table1.MLAoutreachmeetingstocharacterizefishingmethodsanddiscusswhalebycatchmitigation.Date MeetingLocation Date MeetingLocation2.23.10 ZoneB,District2-7 5.13.10 ZoneE,District9-103.5.10 ZoneB,District2 5.13.10 ZoneC,District23.15.10 ZoneG,District6-7 5.19.10 ZoneF,District13.22.10 ZoneG,District1-3 5.20.10 ZoneF,District53.23.10 ZoneD,District3 5.26.10 ZoneD,District1-23.25.10 ZoneF,District8-9 5.27.10 ZoneF,District74.5.10 ZoneA,District1-2 6.1.10 ZoneC,District94.5.10 ZoneA,District3-4 6.2.10 ZoneD,District124.6.10 ZoneA,District5-6 6.7.10 ZoneD,District114.6.10 ZoneA,District7-8 6.16.10 ZoneG,District4-54.6.10 ZoneB,District5 8.7.10 ZoneC,District24.7.10 ZoneC,District1-2 12.14.10 ZoneA,District64.7.10 ZoneC,District3-4 12.15.10 ZoneD,District3-44.7.10 ZoneC,District5 1.25.11 ZoneB,District54.8.10 ZoneD,District7 3.31.11 ZoneG,District1-34.8.10 ZoneD,District6

2.11MassachusettsLobstermen’sAssociationAnnualWeekend

4.9.10 ZoneD,District8-10

4.29.10 ZoneG,District8-9 2.11 MLADirectorsMeeting4.30.10 ZoneG,District10-11 3.11 MaineFishermen’s

Forum5.4.10 ZoneD,District10-11

4.11MassachusettsLobstermen’sAssociationDelegatesMeeting

5.5.10 ZoneD,District5

5.6.10 ZoneF,District2 4.11 NewHampshireRegionalMeeting5.11.10 ZoneE,District5-8

Lobstermenwerealsoaskedtodescribetheirfishingarea’senvironmentalconditions,includingtides,currents,andbottomhabitat;thelengthoftheactivefishingseason;depthsfished;theaveragesoaktime;thenumberoftrapspertrawl;numberofbuoylines(endlines);vesselsize;andnumberofcrewmembers.Someofthesecharacteristicschangeoverthecourseoftheseason,solobstermendocumentedhow,when,andwheretheychange.

Figure1.MeetinglocationsinMainetocollectdataongearconfigurations.Afterthisinformationwascollectedandsummarized,itwasreviewedforaccuracybylobstermen,includingtheMLA’sBoardofDirectors.A33-pageillustratedreportwasproducedwithin-depthdescriptionsofthefishinggearandtechniquesusedineachZoneoftheGulfofMaine(McCarronandTetreault2012,AppendixE).Thisreportcollectedlobstermen’sknowledgeaboutthefishery,illustratedthediversityoffishingmethodsintheGulfofMaine,anddisseminatedterminologyforgearwithpeopleandgroupsinterestedinthelobsterfishery.Itisespeciallyimportantforuseinevaluatingtherelativeimpactsofpotentialgearorregulatorychangesinvolvingfishinggear,bygivingscientists,fishermen,andfisheriesmanageracommonunderstandingabouttherangeoffishingtechniquesusedintheregion.Todate,morethan700copiesofthereporthavebeendistributedtolobstermen,marinemammalandfisheriesscientists,governmentofficials,students,andbusinesses.SharingBycatchKnowledgeThesecondgoalwastocommunicatetheproblemofrightandotherlargewhaleentanglementsinfishinggear,andsharethemitigationresearchcarriedouttodate.InFebruaryandMarchof2012,theBycatchConsortiumandtheMLAhostedsevenhalf-daymeetingsinMachias(ZoneA),BarHarbor(ZoneB),Bucksport(ZoneC),Rockland(ZoneD),Boothbay(ZoneE),Yarmouth(ZoneF),andBiddeford(ZoneG)entitled


“UnderstandingInteractionsbetweenWhalesandLobsterGear”.Atotalof40lobstermen,scientists,MaineDMRstaff,andreportersattendedthemeetings.TheBycatchConsortiumandtheMLApresentedslideshowsexplainingthepurposeoftheConsortiumandsummarizeditsresearchrelatedtolargewhaleentanglementsandlobsterfishinggear(Table2).TheMLAandtheConsortiumalsohostedahalf-daymeetingatthe2012MaineFishermen’sForumentitled“Howdowhalesgetentangledinfishinggear?Usingreverseengineeringtounderstandwhaleentanglements”.TheBycatchConsortiumandtheMLApresentedslideshowssimilartothosegivenattheZonemeetings.TheseweresupplementedwithinsightsfromtwolobstermenwhohadattendedtheBycatchConsortium’s2011whaleentanglementreverseengineeringworkshop.Lastly,informationboothsstockedwithprojectreports,videos,andimagesweresetupbytheBycatchConsortiumandtheMLAattheMaineFishermen’sForumandtheMassachusettsLobstermen’sAssociationAnnualweekendin2012.Table2.PresentationtopicsgivenateachoutreachmeetingbytheBycatchConsortiumandtheMLA.

• Rightwhalestatusandverticallineruleupdate• WhatistheConsortiumforWildlifeBycatchReduction?• Fieldtestingexperimentalropesandgear(glowrope,stiffrope,weakrope,

etc.)• CharacterizinglobstergearintheGulfofMaine• Makingsinkinggroundlinesmoreworkable• Whatcanwelearnfromentangledwhales?Thedynamicsofwhale

entanglements• Insightsfromropesandwhaleinjuries• Insightsfromdisentanglementeffortsandnecropsycases• Whathappenswhenarightwhaleswimsintofishinggear?Usingmodelsto

simulateentanglements• Reviewingrightwhaleentanglementcasestudiesandthegearremovedfrom

whalesFeedbackfromLobstermenBasedonpresentationsgivenduringthesemeetingsandinformationsharedbylobstermenabouttheirfishingexperiences,theywereaskedtoprovidefeedbackonfishingpracticestheythoughtmightreducetheriskofgeartowhales.Lobstermenidentifiedtwomainchallengesinconsideringthistopic.First,theyhighlightedthattheymainlyworkaloneandthereforedeveloptheirfishingstrategyindependently,includingthenumberoftrapsfished,gearrigging,geardeploymentandwhenandwheretheyfish.Therefore,manywerenotcomfortablediscussingtheirfishingstrategies,particularlyiftheybelievedthesemightbeusedtodevelopgeneralrecommendationsthatmightdictatehowotherlobstermenshouldfishintheGulfof

Maine.Second,arecurringobservationamonglobstermenwasthattheirgearconfigurationshavebeenoptimizedthroughtrialanderrorovermanyyears.Mostlobstermenreportedthattheircurrentfishingpracticesareusedforeaseofoperation,tomaximizecatch,andtoensurethesafetyofthemselvesandtheircrew.Individualismandthebeliefthatfishingpracticeshavebeenperfectedmakeitchallengingtogarnersupportfordiscussionaboutnewgearorfishingtechniques.Lastly,lobstermenexpressedfrustrationwiththeongoingregulatoryprocesssurroundingtheprotectionoflargewhales,whichhascausedchangestothefishery,includingweaklinks,gearmarking,andtheunpopularrequirementtousesinkinggroundlines.Althoughdiscussionsaboutfishingropesandtheirroleinwhaleentanglementscoveredbothverticallinesandgroundline,theFinalReportforBycatchConsortiumProject2(“ReviewofSinkingGroundlinePerformanceintheMaineLobsterFishery,withRecommendationsforImprovingitsFishability”)discussedgroundlinesinfarmoredetail.ResultsLobstermenidentifiedanumberofideasduringthesemeetingsforavoidingorreducingtheseverityofwhaleentanglements.Thesearenotpresentedastheconsensusviewamonglobstermen,butratheralistofthedifferentideasthatemerged.

1. Maximizethenumberoftrapsperendlinetoreducethetotalnumberofendlinesinthewater.

2. Minimizethelengthoffloatinggroundlinebetweentrapsa. Usesinkingropewheneverpossible,eveninsidetheexemptionlineb. Maximizethegear-settingspeedwhendeployingtrapstokeep

groundlinesastautaspossibleonbottom3. Minimizeentanglementriskfromthesurfacesystem

a. Limittheamountofscopeontheverticallineb. Limitthelengthofropefishedbetweenflotationdevicesinthesurface

systemc. Incorporatesmaller,weakerropesonthetopthirdofthebuoylined. Deployonlytheflotationdevicesinasurfacesystem(suchashighflyers,

polyballs,tidebuoysandtoggles)necessarytohaulthegearbasedontheconditionsfished;avoidusingredundantflotationasaprecautionagainstlosinggear

4. Minimizetheuseofknotsandcoilsontheverticallinea. Usesplicingratherthanknotsb. Uselengthenerstoaddandremovescopeofbuoylinewhenshifting

gearratherthancoilingorshankingropewhichcouldinterferewiththeefficacyofthebreakaway

5. Reducegeardensitythroughtrapreductions


6. Investigatetheuseofstifflineortautline7. Reduceghostgearthroughavarietyofoperationalguidelinesforsinking

groundlinesMaximizenumberoftrapsperendlinetoreduceverticallinesRationaleAnanalysisoffishinggearinvolvedin45rightandhumpbackwhaleentanglementsfoundthatverticallineswerecommonlyinvolvedinentanglementsoflargewhales(Johnsonetal2005).Whenresearcherswereabletoidentifythetypeoflineretrievedfromentangledwhales,in56%ofthecasesitinvolvedverticalline.Giventhatverticallinesposeaseriousthreattowhales,eliminatingthenumberofverticallineswouldbeexpectedtoreducetheriskofwhaleentanglements.NMFSalsobelievesthatreducingthenumberofverticallines,particularlyinareasofhighwhaledensity,couldreduceseriousinjuriesanddeathsoflargewhalesfromentanglementsinfishinggear(NMFS2012).Whatwouldthischangeinvolve?ThereisabroadrangeofgearconfigurationsfishedthroughouttheGulfofMaine.Inmanyinshoreareasshorterstringsofgeararefished,largelyconsistingofsingles,pairsandtriples,generallywithoneendline.IntheMassachusettsOuterCapefishery,singlesarealsofishedwithoneendline.InotherinshoreareasincludingCutler,Boothbay,CascoBay,Kittery,andmostareasofNewHampshireandMassachusetts,longerstringsofgeararefished.TheMaine,NewHampshireandMassachusettsoffshorefisheriesalldeploymuchlongertrawlsof10to40traps,each.Foralobstermanfishingatotalof800traps,achangeingearconfigurationcansignificantlyalterthenumberofendlines.Themoretrapsonatrawl,thefewerthenumberofverticallinesinthewater(Table3).

Table3.Totalnumberofendlinesbasedongearconfiguration(traps/trawl).

Configuration#VerticalLineswith1Endline

#VerticalLineswith2Endlines

Single 800 --Pairs(2) 400 --Triples(3) 267 --4traptrawl 200 --5traptrawl 160 3206traptrawl 133 2668traptrawl 100 20010traptrawl 80 16015traptrawl -- 10620traptrawls -- 80

25traptrawls -- 64

40traptrawl -- 40Table3showsthatlobstermenfishingsinglescanreduceverticallinesby1/2goingtopairs,andby1/3goingtotriples.Lobstermenfishingtriplescanreducethenumberofverticallinesby¼goingtofour-traptrawls.However,atripleslobstermentrawlingupwouldneedtofishmorethansixtrapsonatrawlwithtwoendlinesinordertoseeanyreductioninverticallines.Twoimportantconsiderationsherearethat,first,increasingthenumberoftraps/trawlfrom<5to>5canhavenonetreductioninverticallines,becauselongertrawlsrequiretheadditionofasecondendline.However,ifalobstermanisalreadyusingtwoendlinesbutthenaddsmoretraps/trawl,theremaybeanincentivetoincreasethestrengthoftheendlinesused,whichmightreducethechancethatanentangledwhalecanbreakfreeofthegear(Knowltonetal.,2015).Manyfactorsmustbeconsideredwhencontemplatingtrawlingupgearsuchastides,bottomcurrents,bottomhabitat,depth,leveloffishingcongestion,boattraffic,vesselsizeandequipment,personalsafety,lobstercatch,andthecultureandtraditionsofthelocalfishery.Manyofthesefactorswilllimitthenumberoftrapsthatcanbesafelyandeffectivelytrawledup.Lobstermenwhohavebeenmostsuccessfulinmaximizingthenumberoftrapsperendlinearetypicallylobstermenwhohaveaminimumvessellengthof32feet,fishwithoneormorecrew,fishinareasofmudorgravelbottom,fishinareasofhighboattraffic,orfishindeeperoffshorewaters.Lobstermenalsoidentifiedissuesrelatedtothewidthofthevesselandthetypeofhaulingequipmentaboardthevesselsasfactorsthatcanlimitthenumberoftrapspertrawlthatcanbesafelyfished.


Whenfishingtrawlsoftenormoretraps,lobstermenareseldomabletofishwithonlyoneendline.Thisisduetothehighlikelihoodoflosinganendlinebecauseofgearcongestionfromotherlobstermen,boattraffic(particularlyinMassachusetts,NewHampshireandsouthernMainefromAprilthroughSeptember)orfromchafingandhang-downs.Asecondendlinealsoprovideslobstermenwithanalternatewaytohaulthegearifoceanorweatherconditionsmakeitchallengingtohaulfromoneend.Trawlsfishedwithsinkingropeareextremelydifficulttorecoverifbuoylinesbecomeunavailable,becausegroundlinethatrestsontheseafloormakesitvirtuallyimpossibletolocateusingabottomsounder,particularlyinareaswithuneven,ruggedbottom.Lobstermenidentifiedavarietyofspecificreasonsforfishingsingles,pairsandtriples:

• Abilitytotargetrockybottom,holes,crevicesmorestrategicallytomaintainlobstercatchlevels

• Variablebottomhabitat(suchasboulders,rockoutcroppingsandholes)makesitimpossibletoeffectivelysetlongertrawlsontheseabed,especiallyininshoreshallowwater

• Deployingmoretrapsinalargernumberofareasminimizescompetitionbetweentraps

• Smallervesselscan’thandlelargestringsoftrapsondeck• Itissaferforlobstermenwhofishalonebecausethegearfitsmoreeasilyon

deck,anditissaferandmoremanageabletoredeploythegearandmanagetheropeondeck

• Inareaswithahighdensityoffishingeffortandgear,especiallythosewithvariablebottomtype,lobstermenaremorelikelytosetgearoveroneanother,increasingtheprobabilityofgeartanglesandtraploss.However,theseconflictscanbeminimizedwhenlobstermenconsistentlysetgearinthesameorientationinrelationtothetide.

• Singlesarenecessaryinareasaroundislandstomaintainsafetyduetorugged,shallow,androckybottomhabitats.

SupportingevidenceReductioninthetotalnumberofverticallineshaspotentialtoreducetheincidenceofwhaleentanglements,butthenumberofvariablesthatfactorintoentanglementriskaremany,andwhilethemeasuremakesintuitivesense,itisdifficulttopredictitsimpact.Eventhoughverticallineshavebeenidentifiedmorethanotherpartsofgearinwhaleentanglements(Johnsonetal2005),itmaynotbethecasethattheyconstitutethemostriskypartoflobsterpotgear.Verticallinesmayjustbeeasiertorecognize,

becausebuoysorhigh-flyersareattached.Otherlinesdon’talwayshavedistinguishingcharacteristics.Formostentanglements,itisimpossibletodeterminethegearpartinvolved;Johnsonetal(2005)werenotabletoidentify44%ofthegearinvolvedinentanglementevents.ReducefloatinglinebetweentrapsonbottomtoreduceropeprofileRationaleGroundlineisalsoknowntoentanglewhales.Incasesinwhichgearretrievedfromwhaleentanglementscouldbeidentified,Johnsonetal(2005)foundthat28%involvedgroundline.Since2009,governmentregulationsrequirethatanygroundlineusedintheGulfofMaineoutsidetheexemptionlinemustbenegativelybuoyant.WhiletheNationalMarineFisheriesServicehasdeterminedthatthefisheryinsidethislineposesminimalrisktowhalesduetothelackofwhalessightedinthethesewaters,entanglementshavebeenknowntooccurintheseinshorewaters.Wherepositivelybuoyantgroundlineisstillallowed,lobstermenneverthelessrecommendedshorteningitslengthbetweentrapstoreducetheprofileoftheropeinthewatercolumn.Whatwouldthischangeinvolve?In2003,theMaineLobstermen’sAssociationpartneredwiththeMaineDepartmentofMarineResources(DMR)toconductanunderwaterobservationoffloatinggroundlinesineachlobstermanagementzone.Thisstudyprovidedabaselineofthelengthofgroundlinetypicallyfishedbetweentrapsininshorewaters(rangingfrom10to14fathom),anddocumentedtheunderwaterprofileofmanycommonlyusedlines,includinghowtheirhowarcschangeaccordingtogearconfiguration(StockwellandSummers,2008).TheDMRfurtherinvestigatedtheconceptoffishingneutrallybuoyantorlowprofilelinesthroughfieldworkin2005and2006.Thisworkdocumentedthearcheightoflowprofileversusfloatinglinewithvaryinglengthsoflinethroughexperimentalgeardeployments.Whileoverallthestudyshowedthatthearcoflowprofilelineswaslessthanthatoffloatingline,italsomeasuredthedifferenceinprofileoffloatinglinewithdifferinglengthsoflinebetweentraps(Table5).


Table5.AverageandMaximumHeightsforFloatRopeandLowProfileRope(StockwellandSummers,2008).RopeType N Length

(Fa)Avgarcheight(m)

Maxarcheight(m)

Avgarcheight(ft)

Maxarcheight(ft)

Floatrope 72 18 5.28 11.89 17.33 39.20 72 10 2.99 7.48 9.8 24.54 72 6 2.37 3.80 7.78 12.50LowProfilerope

72 18 0.21 0.90 0.68 2.97

72 10 0.23 0.63 0.75 2.07 72 6 0.43 0.97 1.42 3.20

Thisresearchdemonstratedareductioninthearcofthefloatinglineasthelengthofgroundlineisdecreased.Asignificantreductioninthearcoftheropeinthewatercolumnwasachievedbyshorteninggroundlinesfrom18to10fathoms;theaverageheightofthearcwasreducedby43%(from5.28to2.37meters),andthemaximumarcheightwasreducedby37%(from11.89metersto7.48meters).Whiletherearemanyvariableswhichaffectthearcheightofgroundlineincludingregiondeployedandtautnessofthelinedependingonhowitwasset,overall,theseobservationsindicatethatlobstermencouldreducetheamountoffloatinggroundlineinthewatercolumnbyreducingthelengthoflinefishedbetweentraps.Areductionintheamountofropeinthewatercolumncouldbeachievedbyreducingthelengthoffloatinggroundlinesto10fabetweentraps.SupportingevidenceLobstermenandtheMaineDepartmentofMarineResourceshaveindicatedthatbecausetheNorthernGulfofMaineisrockyandhasextremetides,someflotationisneededingroundlinesforfishingsafetyandoperationalfeasibility(StockwellandSummers2008).Alowerprofilelinewouldbemorelikelytochafeonarockybottomorhangdown.Somelobstermendidindicatethatingeneral,shortergroundlinescanbesuccessfullyfishedinshallower,nearshoreareas.Indeeperwatershowever,theystatedthatlongerlengthsofgroundlineareneededtosafelyhaulatdepthandsuccessfullyfishlongertrawls.RightwhalediveprofilestrackedintheGulfofMainehaveshownthattheyforageveryclosetoorrightagainsttheseafloor(Marsh2005),andtherearemanyphotographicrecordsofrightwhaleswithmudontheirmouths(S.Kraus,pers.comm.).M.WeinrichandD.WileyalsousedinformationfromarchivaltagsonhumpbacksintheGreatSouthChanneltoshowthatthewhalesoftendivetothebottomandthenpropelthemselvesalongtheseabedontheirsidesorupsidedown

withtheirmouthsopen(NMFS2005).Thissuggeststhatreducingtheprofileofthefloatinglinemaynotavoidtheriskofentanglementingroundlinestoforagingwhales,butcouldreduceit.However,ithasalsobeensuggestedthatwhaleforaginginshore,inrockyhabitats,maydifferfromthatobservedfurtheroffshore.Additionalresearchisstillneededtoexaminewhalebehaviorininshorewaters.MinimizeriskfromendlinesandthesurfacesystemRationaleRightwhalesfrequentlyfeedatorjustbelowthesurfaceofthewater(Baumgartner,Mayoetal.2007).Thesurfacesystemoflineshasbeeninvolvedinlargewhaleentanglements(Johnsonetal2005).Lobstermensuggestedreducingtheamountofsurfacegearbyfishingtheminimumamountofropenecessaryfortheendlineandtheminimumamountofropenecessarybetweenflotationdevicesinthesurfacesystemanddeployingonlytheflotationdevicesinasurfacesystem(suchashighflyers,polyballs,tidebuoysandtoggles)necessarytohaulthegearbasedontheconditionsfished.Whatwouldthischangeinvolve?Lobstermennotedthattheyobservesomelobstermenintheirareasfishingmoreropebetweenflotationdevicesatthesurfacethannecessarytosuccessfullyretrievegearunderlocalconditions.Forexample,insomeinstanceslobstermenfish15fathomsoflinebetweenthemarkerandmainbuoys,andmanysuggesteditcouldbereducedto5fathoms.Lobstermenalsosaidthatthediameterofropeonthetop1/3oftheendlineconnectedtothebuoyislarger,andthereforestronger,thannecessary.Manylobstermenuse3/8”diameterropewhenthestrainonthisportionofthelinecouldactuallybehandledwith7/16”orevenassmallas5/16”.Thiswouldreducethestrengthoftheropenearthesurfacesystem.Oneofthechallengeslobstermenfaceiskeepingthesurfacesystemoftheirgearvisibleovertherangeofthetidalcycle.Avarietyofmethodsareemployedtoachievethisdependingonthestrengthofthetidesandbottomcurrents.Lobstermenmayuseoneormoretogglesseveralfathomsbelowthebuoy,orsmallerbuoysreferredtoastideormarkerbuoys,located5to15fathomsdistantfromthemainbuoy.Thesebuoyshelpmaintainthemainbuoyatthesurface,butprimarilyserveasawayforlobstermentogafftheirgearwithoutfightingthestrainonthelinefromtidesandcurrents.Inoffshorewaters,lobstermenusemoreflotationtokeepthesurfacesystemfromsubmerging,typicallyusingtwobulletbuoysorapolyball.Theseconfigurationsgenerallyrequiretheuseofasecond,smallermarkerbuoyattachedbylinetothemainbuoy.Lobstermenfishingoutside12nmarerequiredtomarktheendsoftheirtrawlswithhighflyers.Highflyersarelarge,metalmarkersthatrequiresignificantflotationtostayabovethesurface,suchasapolyballplusamarkerbuoy.Federalregulationsallowfortheuseoffloatinglineatthesurfaceifmorethanonebuoyis


attachedtoasinglebuoylineorifahighflyerandabuoyareusedtogetheronasinglebuoyline.Lobstermensuggestedshorteningthelengthofendlinetominimizetheriskduetotheamountofropeinthewatercolumn.Lobstermentypicallyadd“scope”,oradditionallinelength,toabuoylineinordertoaccountfortidesandcurrents.However,thereisalotofvariabilityinhowmuchextraropeisfishedbasedondifferentdeterminationsamongfishermen.Itmaybepossibleformanylobstermentoshortenthelinestheyareusingandstillfishsafelyandeffectively.Lobstermenseemedtothinkthatshorteningthelineinthesurfacesystemcouldsignificantlyreducewhaleentanglementriskbecausemanybelieveitisdisproportionatelyinvolvedinentanglementsbecauseofskimfeedingbehaviorinrightwhales.However,inareaswithstrongtidesandcurrentsthatrequiremoreropetokeepthesurfacesystemvisible,thisalterationmaynotbeadvisable.SupportingevidenceItisknownthatwhalesgetentangledinthesurfacesystemoffishinggear,althoughtheriskofsurfacesystemgearmaybeoverestimatedbecauseitistheeasiesttoidentify(Johnsonetal2005).Thereisnoinformationonhowtheamountofgearatthesurfacemayimpacttheriskofgeartowhales.Nevertheless,ifthechangeissimpleandpossiblyevenreducesoperationalcostsbyusingropesoflesserdiameter,itisadvisabletoimplementwhereverpossiblegivennoconsequencetofishermenwhilepotentiallybenefittingwhales.MinimizetheuseofknotsandcoilsRationaleFederalregulationsencourage,butdonotrequire,lobstermentofishbuoylineswithoutknots(NMFS2002).Itishypothesizedthataknottedropemaygetstuckinthebaleenofawhale,whileaknotlessropewouldbemoreabletoslidethroughit,andthereforebelesspronetocausinganentanglement.Obstructionsonthelinecanalsobecreatedwhenalobstermancoilshisrope,creatingashankbelowthebuoy.Whatwouldthischangeinvolve?Lobstermenoftenusesplicesinsteadofusingknotswhenconfiguringgear,aprocedurethatiseasieronlandthanduringfishing.Theoperationalchallengesofsplicingwhilefishingoftenmakefishermenpreferusingknotsratherthansplices.Maintainingknotlesslinesbecomeschallengingoverthecourseofthefishingseasonbecausethecircumstancesrequiringlinestobejoinedtogetherincreasesinfrequency.Linesareoftencutbyotherlobstermenduetogearconflicts,andoverthecourseofthefishingseasonendlinesarecombinedforredeployinggearouttodeeper

waters.Muchofthisgearisshiftedduringthecoldermonthsoftheyear,inthedark,creatinganadditionalchallengingtosplicingrope.Creatingshanksisanalternativemethodtoshorteninggearwhenshiftingitfromdeeptoshallowerwater,insteadofreplacingtheentireendlinewithashorterropeorremovingalengthener.Lobstermenproposedalternativemethodsoftyingropestogetherinsteadofusingknots,suchasaneyesplicetuck,thatcouldbemanagedonaworkingvessel.Thismethodoftyinglinestogetherwouldminimizethebulgeontheline,andthereforetheobstructionifawhaleencounterstheline.Acommonconcernlobstermenhadaboutdecreasingtheuseofknotswasthebeliefthatknotsreducethestrengthofrope,increasingthelikelihoodthattheropewillbreakattheknotifencounteredbyawhale.Manylobstermenalsoidentifiedcoilingropeintoshanksaspotentiallyunsafeforwhales,becauseitmaycauseentanglementandcouldrendertheweaklinkineffective.Lobstermensuggesteddiscouragingtheuseofthismethodtoshortenandlengthenendlines.However,shanksrequirelessinvestmentinrope,andlessgearthatneedstobetransportedandhandledondeck.SupportingevidenceTherehavebeendiscussionsatAtlanticLargeWhaleTakeReductionTeammeetingstodeterminewhetherknotsshouldbeprohibitedinbuoylinesandfortheattachmentofthetogglegangiontothebuoyline(ALWTRT2003).Itwasdecidedthatitwasnotoperationallyfeasibletomakethisarequirement.However,thereisnoconclusiveevidencetosuggestthatknotsincreaseentanglementprobability.Thereisalsonoinformationastowhetherreducingtheamountofgearatthesurface,byeliminatingshanks,wouldreduceentanglementrisktowhales.ReducenumberoftrapsdeployedRationaleLessfishinggearshouldresultinalowerprobabilitythatwhaleswillencountergearandthereforebecomeentangledinit.Theassumptionisthattrapreductionwouldalsoresultinareductioninthenumberoffishinglines.Whatwouldthechangeinvolve?Toreducethetotalamountofgear,thenumberoftrapsdeployedwouldneedtoberestrictedbytraplimitsorbyreducingthenumberoflobstermenfishing.Manylobstermenbelievetheirincomeswoulddeclineiftheyfishedfewertrapsbecausetheyuseaportionoftheirtrapstoinvestigatelobstermigration.Lobstermenalsosaidthatiftheyhadtofishfewertraps,theymaydeploytheminsmallerstringsofsingles,pairs,ortriplestomaximizethecatchofeachtrap,leadingtomoreendlinesinthewater.Ofcourse,inmanyareasnewregulationswouldpreventthemfromreducingthenumberoftraps/trawl(NMFS,2005).Somelobstermensuggestedhavingseasonaltraplimitsduringperiodswheretheriskofinteractionswithwhalesishigh,whileallowingafullcomplementoftrapsduringtherestoftheyear.


ThereareareasinMainethathaveimplementedreducedtraplimits,therebyminimizingtheamountofgearinthewater.InZoneB,SwansIslandlobstermenimplementedanislandconservationszonein1984andarelimitedto475traps,whichisa40%reductionperlobstermaninthatzone.In2000,ZoneElobstermenvotedtoimplementa600-traplimit,whichisa25%reduction.InZoneD,MonheganIslandlobstermenin1998establishedaconservationareaandhaveawinterfishingseason,andatrapreductionto300traps,laterincreasedto400trapsbasedonlobstermen’sclaimsthattheywerenotabletomakeadecentlivingunderthe300traprestriction.SupportingevidenceAssumingthatreducingthetotalamountofgeardeployedresultsinfewerendlinesinthewatercolumn,thereshouldbeareducedriskofentanglementtowhales(NMFS2013).DeploylinesundertensionRationaleIthasbeenhypothesizedduringAtlanticLargeWhaleTakeReductionTeammeetingsthatalinewithincreasedstiffnessorunderhightensionmayreducethenumberofentanglementsinverticallines,becauseoflowerentanglingproperties.Whatwouldthechangeinvolve?Linescomeunderhightensionwhenpolyballsareusedatoneendofthebuoylineandananchorattheother,especiallyinextremelystrongtidesandcurrents.ThispracticealreadyexistsineasternMaine(typicallyeastofSchoodicPoint),wherelobstermenfaceuniqueenvironmentalchallengesduetoextremelystrongbottomcurrentsandtides.Todealwithstrongtides,theydeploypolyballspairedwithatidebuoyforgrappling,tomarktheirgearatthesurface.PolyballsprovidemoreflotationthanStyrofoambulletoracornbuoysfishedelsewhere,aswellaspreventingthesurfacesystemfrombeingpulledunderwater.

Confoundingtheproblemofstrongtidesisthespeedofthebottomcurrents,whicharecapableofmovingunder-weightedlobstergeargreatdistancesalongthebottom.Inordertokeepthelobstertrawlswheretheyareset,lobstermendeployheavyDanforthanchors,mushroomanchors,railroadtiesorsimilarlyweighteddevicesattheendoftheirbuoylines.Theyalsosometimesweighdownindividuallobstertrapsfishedassingles,pairs,ortripleswithbricks,windowweights,cementorotherballast.

Otherlobstermenwhofishinareasofstrongtidesandcurrents,includingoffshorelobstermenindeepwaterareasandthosefishingaroundtheOuterCape,alsoreportdeployinggearinasimilarfashion.Todeploylinesundertension,lobstermenwouldhavetouseacombinationofalargeflotationdevice,anchors,andshortverticallines.Anotherpossibilityistouseropesofharderlay,butthesearemoredifficulttocoilondeckandarenotpopularinthisregion’strapfishery.LobstermenfromareasoutsideeasternMainedonotconsidertheuseofapolyballincombinationwithananchorasaviablefishingoption,anddonotbelievethatfishingthissortofgearwouldresultinthedesired“stiffening”ofthelineintheirlocalfishingareas.Thepolyballswouldprovidetoomuchflotationandcreateanexcessiveamountofdragonthegear.Anystrongwindorrunningtidewouldcausethegeartomovesignificantdistancesalongthebottom.Theuseofanchorsorextremeamountsofballastintrapstooffsetthistendencyisconsideredunnecessaryandextremelydangeroustothehauler,ondeckandwhensettingbackgear.Lobstermenalsosaidthatusinglargerfloatsandweightswouldnotcreatethelinetensiondesired,becausethattensioncomesfromthelargetidesandstrongcurrentsmorethanthecharacteristicsofthegear.Insteadofusinglargerfloatsandweights,lobstermenrecommendedmaximizinglinetensionbyshorteningthescopeofverticalline,coupledwithusingadequateballasttoholdtrapsonthebottom.Mostlobstermenreportedthatthiswasalreadythestandardconfigurationandthatthelinesinthewaterwerealreadyverytaut.Lobstermenalsocautionedthatwhenlinesareunderextremetension,lobstermenmustdeploymultipleflotationdevicesinthesurfacesysteminordertobeabletogaffthegearforhauling.Thisstrainonthelinealsoincreasesriskofinjuryifaropesnapsduetochafingorhang-downs.TheoverallconclusionbylobstermenwithregardtocreatinglinesunderextremetensionasseenineasternMaineisthatintheabsenceofstrongtides,anchoringgearisunlikelytoachievethesameleveloftensionontheline.SupportingevidenceTestsconductedbyBaldwinetal(2012)suggestthatahighertensionlinemaynotreducetheriskofinjurytowhales.Theyfoundthatlinesundertensionmaycauselacerationsthroughthesawingactionoftheropeagainstthepointofcontact.Theresultsoftheseexperimentsdidnotcompletelyeliminatethepotentialbenefitsofusingahighertensionlineorastiffline,butindicateahighriskofinjuryusingropediameterstypicallyusedinthisfisheryandathightension.Inaddition,ropesofharderlay,suchasthoseusedintheWesternAustralianrocklobsterfisheryareknowntoentanglewhales(How,Coughranetal.2015).


ConclusionModifyingfishingpracticesisdifficultbecausemanylobsterfishermenreporttheircurrentmethodsarealreadyoptimizedtomaximizetargetcatch,areassimpleastheypreferthem,andaresafeforvesselandcrew.Lobstermendidhoweveridentifyarangeofapproachesforalteringfishingmethodsthatcouldserveasabasisforfutureresearchintopotentialgearmodificationstoreducetheriskofwhaleentanglementsinlobstergear.Table6brieflysummarizesthese,whichwerediscussedaboveinmoredetail.OneofthetechniqueshasbeenunderexaminationbytheBycatchConsortium(stiffrope),butgenerallytheseideasmaynotbetestableinthefield.TheBycatchConsortium’sVirtualWhaleEntanglementSimulator(VWES),acomputerprogramthatmodelsinteractionsbetweenrightwhalesandfishingropes,maybeausefulalternativetoolforevaluatingthesemitigationtechniquessuggestedbylobstermen.(See:http://www.bycatch.org/project/modeling-right-whale-entanglements).Table6.MethodssuggestedbylobstermeninthenortheastUStomitigatelobstergearentanglementrisktolargewhales.MitigationMethod

ScientificallyTested?

Regulated? Potentialtoreduceentanglementrisk

Maximizethenumberoftrapsperendlinetoreducethetotalnumberofverticallines

No

Yes.NewrulesfortheminimumnumberoftrapspertrawlwasimplementedbyNMFSundertheALWTRP(NMFS2015)

Fewerendlinesinthewatercolumnmayreduceentanglementprobability,althoughmanyotherfactorsareinvolved

Minimizethelengthoffloatinggroundlinebetweentrapstoreduceropeprofile

No,althoughshorteningthelengthofgroundlinereducestheprofileoftheline(StockwellandSummers2008)

No.Lobstermenarenotregulatedontheamountofropefishedbetweentraps.

Probablypreferablethanhavingthelinehigherinthewatercolumn,althoughentanglementpronerightandhumpbackwhalesdosometimesfeedattheseafloor

Minimizeriskfromsurfacegear

No

No Shorteningthelengthofline,ifpractical,soundslikeasensiblemeasurethatmayreduceentanglementrisk

Minimizetheuseofknotsandcoils

No

No,butreducingthenumberofknotsisencouragedbyNMFS

Assumptionisthatknotsincreasetheprobabilityofentanglementsinbaleen.However,knotsalsocreateapointalongthelinewithreducedbreakingstrengththatcanalsofacilitatewhalesbreakingfreeofgear

Reducethenumberoftraps

No No

Lessgearandropeinthewatershoulddecreasethelikelihoodofentanglementrisk.

Deploylinesundertension

ExaminedbytheBycatchConsortium(Baldwinetal2012),andinthisreport(Project1-EvaluationofWesternAustralianStiffRopeFishing)

No

Mightdecreaseentanglementriskbutcouldpotentiallyincreaseentanglementseverity(Baldwinetal2012).Evenifadvisable,itisnotclearhowfishingforlobsterusingropesofhighertensioncouldbereproducibleinareasoutsideonesthathaveconditionssimilartodowneastMaine.

Gearmodificationsmadeintheinterestsofreducingendangeredspeciesbycatcharemosteffectiveforfishermenandwildlifewhentheyresultthroughcollaborationsinvolvingstakeholders,especiallyfishermen.InthecaseofNorthAtlanticRightwhaleentanglements,theinputoffishermenisrarelysoughtoutsideoftheformalTakeReductionTeamprocess.Regularengagementandcooperativeresearchshouldbeusedtoincreasetransparencyandaccountabilityoftheresearchandregulatoryprocess.Duringourmeetings,lobstermenreportedthattheystillfeelalotofdistrusttowardsresearchersandmanagersbecauseofhistoricallybeingleftoutofresearchandmanagementdecisions.Thisisunfortunate,becausemanyofthemostpracticalandsustainablesolutionsemergeasideasproposedbyfishermenthemselves,makingtheirparticipationcriticalforbycatchreductionefforts(Werneretal,2006).Supportforcollaborativeresearch,includingwithsomeofthesesuggestionsproposedbylobstermen,remainsacriticalneedastheincidenceandseverityofrightwhaleentanglementsisnotdecreasingdespitemanyyearsofregulatedchangestolobsterandgillnetfishingpractices.


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