Aquatic Invasive Species Vector Risk Assessments: Recreational vessels as vectors for non-native marine species in California Final Report July 2012 Submitted to the California Ocean Science Trust Funded by the California Ocean Protection Council By: The Aquatic Bioinvasion Research & Policy Institute A Partnership between Portland State University & the Smithsonian Environmental Research Center Gail Ashton, Chela Zabin, Ian Davidson & Greg Ruiz TableofContents 1.ExecutiveSummary.............................................................................................................2 2.Introduction........................................................................................................................5 2.1.TheRecreationalVesselVector...................................................................................6 2.2.HistoryoftheVector....................................................................................................8 3.Aims....................................................................................................................................8 4.Methods..............................................................................................................................9 4.1.InvasionHistory...........................................................................................................9 4.2.ContemporaryVectorOperationinCalifornia..........................................................12 5.Results...............................................................................................................................14 5.1.InvasionHistory.........................................................................................................14 InvasionHistoryKeyFindings................................................................................24 5.2.ContemporaryVectorOperationinCalifornia..........................................................25 ContemporaryVectorKeyFindings......................................................................40 6.Discussion..........................................................................................................................41 6.1.InvasionHistory&Impacts........................................................................................41 6.2.CurrentPatternsandProcessesofVectorOperations..............................................42 6.3.ManagementReviewandRecommendations..........................................................43 6.4.Criticaldatagaps.......................................................................................................52 6.5.KeyManagementRecommendationsforCalifornia.................................................52 7.Acknowledgements...........................................................................................................53 8.References.........................................................................................................................54 1 1.ExecutiveSummary Background TheintroductionofnonͲindigenousspecies(NIS)isrecognizedaroundtheworldasathreatto biodiversity,ecosystemservicesandhumanhealth.Californiaisahotspotfortheintroductionof marineNISinNorthAmericaaswellasglobally.Thenumberofnewmarineinvasionsdetectedper decadehasincreaseddramaticallyoverthepastcenturyinCaliforniaandalsoinotherregions.In response,managementofthevectorsofintroductionhasbeenadvancingasthemosteffectiveand efficientmechanismtocurtailthisincrease.Todate,mostvectormanagementhasfocusedon commercialvessels,whichareimportantandactivevectorsofmarineNIStransfers.Inthisregard, Californiahasbeenagloballeaderindevelopingandimplementingmanagementactionstocurbboth ballastwaterandhullfoulingmodesofintroductionbycommercialshipping.Despitethisprogress, othervectorsalsoexist,creatingadditionalopportunityfortheintroductionandspreadofmarineNIS. Thestateisnowseekingfurtherinformationaboutthesevectors,includinghowthevectorsoperate, thelikelihoodofpastandfutureintroductions,andidentificationofopportunitiesforsuccessful interventions.Here,wecharacterizethecurrentstateofknowledgeaboutrecreationalboatingasa vectorinCalifornia,includingadditionalinformationfromotherregions. Aim TocharacterizetheoperationandpotentialimportanceofrecreationalvesselsasvectorsforNIS introductionandcoastwisespreadinCalifornia. Approach WeusedhistoricalrecordsofNISintroductionsinCalifornia,alongwithrecordsofbiofoulingorganisms associatedwiththehullsandunderwatersurfacesofrecreationalboatsfromglobalstudies,toassess thestateofknowledgeandhistoricimportanceofrecreationalvesselhullfouling.Further,wecollected realͲtimedataonvesselbehaviorandfoulingcommunitiestoassessthecontemporaryandlikelyfuture roleofrecreationalvesselsinthespreadofNISinCalifornia.Finally,wereviewedbrieflysomepotential managementactionsthatcouldreducetheroleofrecreationalvesselsasvectorsofNIS. Findings Availabledataindicatethatrecreationalvesselshavebeenanimportantandpotentvectorforthe spreadofNISinCalifornia,aswellasotherregionsaroundtheworld,andthiscontinuestobethecase today.Theopportunitiesforspreadresultfromthelargenumberofvesselsinthestate,their movementsamongbays,andalsothebiofouling(nonindigenous)organismsassociatedwiththe underwatersurfacesofvessels.Approximately800,000900,000recreationalboatswereregisteredin Californiainrecentyears(2008Ͳ2010).Questionnaireresponsesduringthepresentstudy,andresults frompreviousstudies,indicatethat20Ͳ50%ofthesevesselstraveloutsideoftheirhomeportorbay 2 (dependingonstudyandhomebay).AmongtransientvesselsexaminedbyinͲwaterfieldsurveysduring thisstudy(n=49),86%hadfoulingspeciespresentontheirhulls,26%hadhundredsofindividualfouling organisms,andanother25%hadmorethanathousandindividualsorganismspresent.Onaverage,16 specieswereidentifiedfromtransientvesselfoulingcommunities;29%ofthespeciesidentifiedwere considerednonͲnativeinCalifornia;including3speciesthathavenotbeenrecordedfromCalifornia(or theWestCoast). ThereisaglobalshortageofstudiesontheimpactofmarineNISwhichlimitsunderstandingofthetrue extentofecologicalandeconomicconsequencesofinvasionsduetohullfouling(aswellasother vectors).Ofthefewstudiesthatwereavailable,mostdemonstratedasignificantimpact.Further researchonimpactsiswarrantedandcriticalinsettingprioritiesformanagementresponse(eradication orcontrol),inordertofocussucheffortsonhighͲimpactspeciesofconcern. Overall,whenconsideringthenumberofrecreationalvesselmovementsandassociatedbiofouling organismsdocumentedontransientvesselsinCalifornia,itisevidentthatrecreationalboats(a)transfer alargenumberofnonͲnativeorganismsthroughoutCaliforniaand(b)contributetothespreadofNIS intoandthroughthestate.GiventhatmanyoftheseNISmaycauseimpactsintheintroducedhabitat, thepotentialconsequencesofcontinuedintroductionandspreadareextensive. Whereascommercialvessels(andothervectors)mayoftenbeasourceofinitialintroductionsintothe state,recreationalvesselsarelikelytobeespeciallyimportantinfacilitatingcoastwisespreadof invasions.Californiareceivesapproximately5,000Ͳ6,000commercialvesselarrivalseachyearto commercialports,arrivingmostlyfromoverseasandoutsidethestate.Incontrast,weestimatearrivals ofrecreationalvesselsareatleasttwoordersofmagnitudegreater,mostlyfromwithinthestate, providingahighlevelofconnectivity. Importantly,smallvesselscanaccessharbors,bays,estuariesandcoastlinesthatareinaccessibleto commercialvessels,includingremoteareaswhereothervectors(aquaculture,andthetradein ornamentalspecies,livebaitandliveseafood)canberare.Itisoftennotpossibletopartitionthe sourceofbiofoulinginvasionsamongrecreational,commercial,andfishingvessels.However,the invasionofsmallbays(withoutcommercialvesseltraffic)underscoresthelikelyoverallimportanceof nonͲcommercialvesseltransferstomarineinvasionsinthestate;critically,theabsolutenumberof speciestransfersbyrecreationalvesselsisexpectedtobegreaterinlargebays,wheremorerecreational vesselsarrive,eveniftheexactroleofcommercialversusrecreationalvesselsforparticularinvasionsis notclear. Recommendations TherearecurrentlynoguidelinesorregulationsinCaliforniathataimtomanage(reduce)theriskof marinespeciestransfersassociatedwithrecreationalvessels.Inaddition,thereisonlylimited informationonmovementpatternsandassociatedbiotaforthesevesselsinthestate.Thecurrent approachtomanaginginvasionrisksforrecreationalvessels,whichconsistssolelyofeffortstoeducate boatersbyagenciessuchasCaliforniaSeaGrant,andthemultiͲagencyCleanMarinasprogram,which 3 focusesmostlyonreducingchemicalpollution,isinsharpcontrasttothatforcommercialships.This disparityexistsatboththestateandnationallevels. Werecommendaleadagencybegiventheauthorityandresourcestoevaluate,advance,andassess efficacyofmanagementstrategiestoreducespeciestransfersbyrecreationalvesselsoperatingin Californiawaters.Thiscouldincludevoluntarymanagementpractices,educationandoutreach campaigns,andincentiveprograms.Inadditiontoattemptstoincreasevoluntaryefforts,regulations targetinghighͲriskvesselsatkeycontrolpointsmightbeconsidered,followingtheHazardAnalysisand CriticalControlPoint(HACCP)approach.Thismaybeespeciallyeffectiveforforeignarrivals,asa reportingandinspectionmechanismalreadyexiststhroughCustomsandBorderProtection.Examples ofsimilarprogramsfromAustraliaandNewZealandmayprovideusefulmodelsforCalifornia. 4 2.Introduction TheintroductionofnonͲindigenousspecies(NIS)isrecognizedgloballyasathreattobiodiversity, ecosystemservicesandhumanhealth(Macketal.2000,Carlton2001,MillenniumEcosystem Assessment2005,Charles&Dukes2007).CaliforniaisahotspotfortheintroductionofNIS(Cohen& Carlton1998;Ruizetal.2011b)onthewestcoastofNorthAmerica,nationally,andglobally.Thehigh