StarryStonewort:APrimeronanAggressive,InvasiveSpecies

• Anancientplantlikemacroalga whichformslarge,densemats.Itgrowsinwaterfrom0.5>10mindepth.Depthofthematscanbe3m.• Matscanbesodensetheyimpedeboatingorpaddling.Atthepeakofthegrowingseason,lateJulytolateSeptember,theyappearlikehill-likemoundsunderthesurfaceofthewater.• Itisanchoredbyclearfilamentswhichproducesmall,white,starshapedbulbils.Thebulbilsarereproductivestructuresandorgansforhibernation.Itisthebulbilswhichmakethisalgasodifficulttoeradicate.• AllstarrystonewortinN.Americaismale.Thismeansitisspreadbyfragmentationandthedispersalofthebulbils.

IdentifyingCharacteristics

• Thebranchletsandstemareverythin (likeheavyfishing line)andhaveacrisptexture.

• Whorls oflong,narrowbranchletsingroupsof4to6comingoffofmainshoots.

• Orangereproductivestructures(male) occuratbranchletnodes.

• Thebranchesareanchoredtothesediment byaclearfilamentwhichproducesmall,white,starshapedbulbils.

• Thesmall,white,star-shapedbulbilsarethedistinguishingfeaturethatgivesitthenamestarrystonewort.

DenseMat

Thelongstemsandbranchletsbecomeentwinedtoformdensemats.

Hill-likemoundscoveringasectionoftheLostChannelonStoneyLake,Sept.2018

IntroductionandSpreadinInvasiveRange

• Nativerange:NorthernEurasian– fromSpaintoJapan.Nativerangehasexpandedwithclimatechange• IntroducedintoNorthAmericathroughtheSt.LawrenceRiver,1974.• Michigan– nowin27bodiesofwater• NewYorkState -14bodiesofwater• Minnestota – confirmedin13lakes• AlsoinPennsylvania,Indiana,andOhio(LakeErie)• 2016– officiallyconfirmedinPresqu’ile Bay,LakeOntario– firstnoteddateinAmericanpublications/websites

KawarthaInfestation

• Officialreports:LakeScugog,LakeSimcoe,LakeCouchiching• Anemail(Sept.2018)fromDr.EricSager,fromTrentUniversitystated:• “Ithinkwedon’tfullyappreciatehowextensivethegrowthofstarrystonewortisthroughouttheKawarthas.We’veseenitinUpperandLowerBuckhorn,TrentRiver,Pigeon,Chemong ...Justaboutanywherewelook.

• SevernRiver/TrentCanal,justpassedLock42toSparrowLake – sawitlastweek

SoitisnosurprisethatstarrystonewortisonSton(e)yLake

• Sofarstarrystoneworthasbeenidentifiedinonly2areasonStoneyLake• IntheareabetweenFairyLakeIslandandthemainlandknownastheLostChannel– andthebaysoneitherend.• ThebayclosesttoSt.Peter’scontainsonecottage• ThebayclosesttoBurleighcontains3cottages,andadockforanislandcottage• Noneofthesecottagescanavoidboatingthroughittogettotheirdocks.Twoarewateraccessonly

• OnWednesdayIdidsomesamplinginanadjacentbayandfoundstarrystonewortthereaswell.

• ThesecondandmoreconcerningareaisGilchristBay– specificallythebayscontainingLittle’sMarina,PineVistaResort,andWildfireGolf. FromthemapputoutbyASLCacoupleyearsagothereareabout8affectedcottages.Themarinawithitsbusyboattrafficisbyfarthebiggestconcernasasourceforfurtherinfestations.

PotentialImpact• Starrystonewortcanspreadataratethatisbothimpressiveandalarming

• Potentiallywecouldbedealingwiththisinmoreandmoreareas.• Whatdoesthismean tothelakeenvironment?

• Reducedbiodiversity – starrystonewortcanoutcompetenativespecies. Italsooutcompetesotherinvasives suchasEurasianwatermilfoil.Itdoesthisbymakingitdifficultforotherplantstoreceivelight.Aswell,themassofstarrystonewortactsasabenthicbarrieraccumulatingphytotoxinsthatmakethesediment inhospitable forotherplantgrowth.

• NostudiesthatIcanfindhavequantifiedthechangeinbiodiversitybutthereisalotofanecdotalsupportforthis.Fromwhatwe’veseenourselves, sections ofthechannelwhichwerefullofamultitudeofaquaticvegetationarenowexclusivelystarrystonewort.ThebaybehindWildfireisalso now largely starrystonewortaswell. This isaresearchgapthatresearchers,particularlyintheUS,arenowtryingtoclose.

• Candegradefishspawninghabitatandcanimpedefishmovement.• ThismaybeespeciallytrueforsunfishandbassthatspawnindensenativeChara.(USgeologicalsurvey,Nonindigenous aquaticspecies database2019)WWW.nas.er.usgs.gov

• Matswhichreachthesurfacemeanthatfishareblockedfrompassingthroughanarea• Adecline infishcouldmeanadecline inbirdsandmammalsthateatthem.Ourloons,herons,ospreyand minkareatrisk. AhabitatfullofSSwillalsobedifficultforturtles.

Impactforcottagersandrecreationallakeusers

• Starrystonewortcoveringyourshoreline,dockandswimmingareasisanightmare.Remember,thiswillhappilygrowinwateruptoapprox.10m,(30ft) deepandwillformdensematsthatare3m (9ft) thick.• Mostdocksareinmuchshallowerwaterwhichmeansswimmingandboatingwillbeaproblem.Atdocksinwaterlessthan9ftdeepitmaybeadensematrighttothesurface.Enjoymentofyourwaterfrontwillbelimited.Thisiswhat’shappeninginareasofLakeScugog.• Fragmentation byboats andfurtherspreading willbehardtoavoid.• SSWatyourdockwill also likelyaffectyourpropertyvalue.

Eradicatingthisfromthelakeisnotanoption.

• Starrystoneworthasnotbeensuccessfullyeradicatedanywhere. ReportsputoutbyvariousStatesandacademicresearchersallreachthesameconclusion.ONCEESTABLISHEDSTARRYSTONEWORTISHERETOSTAY• Harvesting – ofvariousforms willreducethematsbutitwillgrowback.

• Withanymechanicalmethodsthereisalsotheriskofspreadingfragmentsorbulbils.

• Herbicides/algacides reducedthevolumebutagainitistemporary.• Thebulbilsinthesedimentremainviableandwillquicklyre-sprout.• Anotherproblemwithbothmechanicalorchemicaltreatmentisthattheyarenonselective.Theyalsoimpactnativeaquaticspeciesaswell.ThismeansreducedcompetitionfortheSSwhenitbeginstoregrowandthelossofhabitatforotherorganismandfish.

Management• TheconclusionofastudyofvariouscontrolmethodscarriedoutbytheMinnesotaAquaticInvasiveSpeciesResearchCenterwasthat:

• “Wherelargeinfestationshaveestablished,starrystonewortislikelytopersistfortheforeseeablefutureandrealistic,sustainablegoalsshouldbepursued.

• Thosegoalsarereducingabundanceandminimizingriskofspread.

Sowhatcanwedo?

• Weneedtoeitherformagrouporworkwithanexistinggrouptoprepareanorganizedlakecommunityresponse.Thiswouldinvolvethingslikefundraising,communications,lobbyingvariousgovernmentsandagencies,andvolunteerrecruitment,etc.• Wecanlearnfromwhathasbeendoneinvariousstatesthathavebeendealingwiththisforsometime.Minnesota,Vermont,andNewYorkareparticularlygoodatinvolvingtheircitizensinhelpingtoslowthespreadofstarrystonewort.

Actionstoslowthespread:

• Createanawareness/educationplansopeopleonthelake• knowwhatthisis• whereitis,• howtominimizetheriskofspreadingit• Thiswouldincludeappropriatesignagewhichwe’vestartedworkingon.• ItshouldalsoincludeencouragementforpeopletoleavenativeaquaticplantsinplacesoSShascompetition.Discouragelargescale“weed”harvesting.

Actions(cont.)• Inareasalreadyinfestedandwhereboattrafficisunavoidablewecoulddoselectiveharvestingtocreate“clean”marked,pathways.• Thiswouldlikelyhavetoinvolvebothmechanicalandhandpulling.Bestpracticeswouldneedtobedevelopedandhopefullyvolunteerassistancegiventohelpourfellowcottagers.

• Mechanicalharvestingwillneedtobepaidforsowe’dhavetofigurethatout.IbelieveRamaTownshiponLakeSimcoepaysformechanicalharvestinginLagoonCity,andthereisarecentreportfromtheLakeScugogStewardsthattheTrent-SevernWaterwayisgoingtouseacompanyfromPeterboroughtocleanupanareanearPortPerryBay.Sothatisanotheravenuetobeexplored.

Actions(continued)• Areaswhereboattrafficisnotnecessary(smallsecludedbays,LostChannel)arequarantinedparticularlywhentheSShasreachedaheightthatitcanbebrokenwithpaddlesorprops.

• Anorganizedsurveyofhigh-riskareasshouldbedone• Baysnearinfestedareas• Allmarinasandboatlaunches– sincethat’swhereinfestationstraditionallystart.• CheckcottagedocksofpeoplewhodockatorfrequentLittle’sMarinaorWildfire.

• Weneedtocreateareportingandtrackingsystemfornewoccurrences• Activelypromote“Clean,DrainandDry”practicestopreventspreadtootherlakes.

• LargeClean,dryanddrainsignsshouldbepostedatallmarinasandboatlaunchesandsignsindicatingthepresenceofSS.Peopleneedtoknowwhythisisimportant.Notatheoreticalprecautionbutanattempttostopthespreadofanaggressiveinvasivespecies.

• Provideboatwashequipment?• Targetdayswherevolunteerstalktoboaters,helpwashboats?(AsdoneinVermont)

• SpreadthewordtootherlakesnearusandontheTrentSevern– letpeopledealwiththiswhileitisafewsmallpatches.Notoncethey’vegotbaysfullofit.• Unfortunately,ourlakewasnotwarnedaboutthiswhenitwasknowntobeintheTrentsystematleasttwo

yearsbeforeitwasfirstnoticedintheLostChannel.Weneedtobebetterneighboursthanthat.

Conclusion• Starrystonewortisherebutifwegetorganizedtherearethingswecandotohelpourlake.WecanstartbyimplementingsomeofthepracticesdevelopedintheUStohelpslowthespread.• ThereisalotofattentionandresearchhappeningintheUSandnowCanadaaswell.Theresearchisbecomingmoresystematic,emphasizingresearchgapslikecontrolandmanagement,andactuallyquantifyingtheimpact.

• Doingnothingorwaitingforaneradicationmethodtobefoundisnotanoption.Starrystoneworthastheabilitytospreadeverywhere,quitepossiblychangingthecharacterofthelakewelove.