AquaticAquatic WeedWeed IdentifiIdentifi caca tiontion andand BiologyBiology

JohnJohn RoncoroniRoncoroni UCCEUCCE WeedWeed ScienceScience Advisor,Advisor, NapaNapa

PondPond WorkshopWorkshop && MaintenanceMaintenance JanuaryJanuary 29th,29th, 20102010 CatheyCathey ’’ss ValleyValley

Algae

From C. A. Lembi 1997 Microscopic or Planktonic Algae Microscopic or Planktonic Algae

ØØNotNot reallyreally algae,algae, actuallyactually bacteria.bacteria. ØØMicroscopicMicroscopic algae:algae: Anabaen,Anabaen, Aphanizomenon,Aphanizomenon, andand MicrocystisMicrocystis ØØAKAAKA ‘‘Annie,Annie, FannyFanny andand Mike.Mike. ’’ ØØProduceProduce toxins,toxins, butbut poisoningspoisonings rare.rare. Algae Bloom Algae Bloom

ØØBloomBloom causedcaused byby warmwarm waterwater andand nutrientnutrient introductionintroduction ØØ‘‘FishFish KillsKills ’’ occuroccur duringduring respirationrespiration oror whenwhen algaealgae diedie -- oxygenoxygen depletion.depletion. FilamentousFilamentous AlgaeAlgae -- FloatingFloating MatsMats

FilamentousFilamentous AlgaeAlgae -- FloatingFloating MatsMats ØØOftenOften incorrectlyincorrectly calledcalled ‘‘mossmoss ’’ ØØGrowthGrowth usuallyusually startsstarts onon edgesedges andand bottomsbottoms ofof pondpond inin springspring FilamentousFilamentous AlgaeAlgae -- FloatingFloating MatsMats ØØOftenOften incorrectlyincorrectly calledcalled ‘‘mossmoss ’’ ØØGrowthGrowth usuallyusually startsstarts onon edgesedges andand bottomsbottoms ofof pondpond inin springspring ØØSegmentsSegments areare singlesingle cells.cells. ØØCommonCommon Species:Species: Cladophora,Cladophora, RhizocloniumRhizoclonium SubmersedSubmersed AlgaeAlgae CharaChara --stonewortstonewort CharaChara --stonewortstonewort

ØØ UsuallyUsually growsgrows inin veryvery hardhard waterwater ØØ OftenOften confusedconfused withwith floweringflowering plantplant ØØ RoughRough feelfeel andand distinctivedistinctive muskymusky smellsmell ØØ WhereWhere itit isis lowlow growinggrowing itit isis volublevoluble habitathabitat forfor fishfish NitellaNitella

ØØ NativeNative -- veryvery similarsimilar toto CharaChara ØØ NoNo roughrough feelfeel Types of Aquatic Plants

Free-floating plants Each of the four types of aquatic plants favors a certain water depth. Typically the growth areas are not sharply divided. Expect to see overlap in growthgrowth------submergedsubmerged plants interspersed among floatingfloating----leafleaf varieties.

Pacific mosquitofern Azolla filiculoides Pacific mosquitofern Azolla filiculoides ØØ FernFern -- reproducesreproduces byby sporesspores andand stemstem fragmentsfragments ØØ DesirableDesirable nativenative speciesspecies inin naturalnatural habitathabitat ØØ OftenOften growgrow inin eutrophiceutrophic waterwater -- ØØ StillStill soldsold inin aquariumaquarium tradetrade -- carelesscareless disposaldisposal ofof waterwater maymay introduceintroduce intointo newnew areas.areas. Common duckweed Lemna minor Common duckweed

ØØVeryVery smallsmall floatingfloating perennialperennial nativenative ØØInIn highhigh fertilityfertility sitesite cancan doubledouble inin numbernumber everyevery 33 daysdays ØØReproducesReproduces byby buddingbudding (daughter(daughter plant)plant) ØØOneOne rootroot perper frondfrond Water hyacinth Eichhornia crassipes airbladder Water hyacinth Eichhornia crassipes ØØNoxiousNoxious floatingfloating perennialperennial introducedintroduced fromfrom BrazilBrazil ØØFloatingFloating matsmats connectedconnected byby stolonsstolons clogclog waterwater waysways ØØHeavyHeavy infestationsinfestations cancan alteralter waterwater oxygenoxygen content,content, temperature,temperature, pH,pH, andand displacedisplace nativenative plantsplants andand wildlife.wildlife. Water hyacinth Eichhornia crassipes ØØLinkedLinked toto otherother plantsplants byby stolonsstolons ØØFrostFrost maymay killkill foliage,foliage, butbut stemstem basesbases oftenoften survivesurvive andand developdevelop newnew foliagefoliage inin Spring.Spring. ØØReproducesReproduces byby stolonstolon oror seed.seed. HoneyHoney beesbees areare mainmain pollinatorspollinators ØØInsectInsect biocontrolbiocontrol (2(2 weevils,weevils, 11 moth)moth) havehave beenbeen ineffectiveineffective

Smooth frogbit or West Indian spongeplant (Limnobium laevigatum ) Smooth frogbit or West Indian spongeplant (Limnobium laevigatum )

ØØ HydrocharitaceaeHydrocharitaceae --SameSame familyfamily asas HydrillaHydrilla ØØ NativeNative toto CentralCentral andand SouthSouth AmericaAmerica ØØ FirstFirst infestationinfestation inin ReddingRedding (2002).(2002). FoundFound inin 20072007 inin scatteredscattered patchespatches alongalong 1010 --1515 milesmiles ofof thethe SanSan JoaquinJoaquin RiverRiver inin Fresno.Fresno. ØØ LaterLater itit appearedappeared inin thethe SacramentoSacramento DeltaDelta andand ØØ nearnear thethe KingsKings RiverRiver southeastsoutheast ofof Fresno.Fresno. Smooth frogbit or West Indian spongeplant (Limnobium laevigatum ) FloatingFloating toto rootedrooted stoloniferousstoloniferous perennial.perennial. VeryVery differentdifferent fromfrom hydrillahydrilla andand BrazilianBrazilian egeriaegeria -- resemblesresembles aa smallersmaller versionversion ofof waterwater hyacinthhyacinth .. TheThe bottombottom ofof itsits leavesleaves havehave aa diagnosticdiagnostic honeycombhoneycomb --likelike spongyspongy tissuetissue . Placed on CDFA Noxious Weed Q-list

JuvenileJuvenile formform ofof partlypartly submersedsubmersed rosettesrosettes withwith thickthick floatingfloating leavesleaves developdevelop intointo muchmuch largerlarger maturemature clumpsclumps New location Types of Aquatic Plants

Submersed plants PondweedsPondweeds

ØØ AllAll PotamogetonPotamogeton andand StuckeniaStuckenia speciesspecies areare nativenative toto thethe WesternWestern US,US, exceptexcept PotamogetonPotamogeton crispuscrispus --curlyleafcurlyleaf pondweedpondweed (Eurasia)(Eurasia) ØØ ImportantImportant componentscomponents ofof wildlandwildland aquaticaquatic habitatshabitats -- ØØ PerennialsPerennials --mostmost withwith rhizomesrhizomes ØØ CurlyleafCurlyleaf producesproduces turionsturions andand SagoSago producesproduces tuberstubers Sago pondweed Stuckenia pectinatus Seasonal Development of Sago Pondweed

After Kautsky, 1987

JAFMMJJASOND Curlyleaf pondweed Potamogeton crispus Leafy pondweed Potamogeton foliosus Floatleaf pondweed Potamogeton natans American Pondweed Potamogeton nodosus Coontail,Coontail, ParrotfeatherParrotfeather andand MilfoilsMilfoils Coontail Ceratophyllum demersum Coontail Ceratophyllum demersum ØØNativeNative --annualannual toto perennialperennial ØØCrossCross sectionsection -- leavesleaves looklook likelike ““bumpybumpy tuningtuning forkfork ”” ØØModifiedModified stemstem --notnot rootsroots lightlylightly holdhold plantplant -- easilyeasily dislodgeddislodged Parrotfeather Myriophyllum aquaticum

Parrotfeather Myriophyllum aquaticum ØØ NoxiousNoxious perennialperennial introducedintroduced fromfrom SouthSouth AmericaAmerica inin latelate 18001800 ’’ss ØØ EmersedEmersed plant,plant, cancan becomebecome semisemi -- terrestrialterrestrial ØØ TypicallyTypically onlyonly femalefemale plantsplants foundfound inin Calif.Calif. ØØ ReproducesReproduces vegetativelyvegetatively onlyonly -- byby rhizomerhizome andand stemstem fragmentsfragments Western watermilfoil Myriophyllum hippuroides Ø An uncommon native species Ø not considered weedy ØØUnlikeUnlike otherother milfoilmilfoil ’’ss emergesemerges fromfrom waterwater Eurasian watermilfoil Myriophyllum spicatum

Eurasian watermilfoil Myriophyllum spicatum

ØØNoxiousNoxious perennialperennial propagatedpropagated byby rhizomes,rhizomes, axillaryaxillary budsbuds andand seeds.seeds. ØØSeedsSeeds cancan survivesurvive dormantdormant forfor 77 yearsyears underunder drydry conditionsconditions andand areare eateneaten andand spreadspread byby birds.birds. ØØIntroducedIntroduced fromfrom Eurasia,Eurasia, probablyprobably latelate 19401940 ’’ss inin aquariumaquarium trade.trade. Northern watermilfoil Myriophyllum sibiricum Northern watermilfoil Myriophyllum sibiricum

ØØ WidespreadWidespread nativenative ØØ ProducesProduces turionsturions --EWMEWM doesdoes notnot ØØ LooksLooks veryvery similarsimilar toto EWMEWM -- leafleaf lobeslobes differentdifferent -- Northern Watermilfoil

Eurasian Watermilfoil

More than 10 pairs of leaves Elodea,Elodea, Egeria,Egeria, HydrillaHydrilla

Elodea,Elodea, Egeria,Egeria, HydrillaHydrilla

ØØ AllAll areare perennialperennial andand reproducereproduce vegetativelyvegetatively ØØ CommonCommon ElodeaElodea -- NativeNative toto NA;NA; importantimportant toto habitathabitat --rarleyrarley aa problemproblem --highhigh PP-- ØØ BrazilianBrazilian EgeriaEgeria -- onlyonly malemale plantsplants inin US.US. StillStill soldsold forfor aquariumaquarium use.use. CanCan becomebecome problemproblem whenwhen heavyheavy infestation.infestation. HasHas largelarge flowerflower ØØ HydrillaHydrilla --NoxiousNoxious --reproducesreproduces byby stolon,stolon, stemstem fragments,turionsfragments,turions andand tuberstubers -- tuberstubers cancan lastlast upup toto 55 years.years. VeryVery aggressiveaggressive Hydrilla Egeria

Elodea Common Elodea Elodea canadensis Brazilian Egeria Egeria densa

Hydrilla-Hydrilla verticillata

Hydrilla Egeria

Elodea SouthernSouthern NaiadNaiad SouthernSouthern NaiadNaiad

•Same Family as Hydrilla, Egaria, and Elodia •Annual- Spreads primarily by seed •Seeds and foliage important food source for Birds •Not usually considered a weed in natural habitat •Will tolerate polluted water Types of Aquatic Plants

Rooted floating plants Creeping waterprimrose Ludwigia peploides Creeping waterprimrose Ludwigia peploides ØØ33 speciesspecies -- oneone nativenative toto CaliforniaCalifornia ØØCanCan developdevelop thickthick matsmats thatthat interfereinterfere withwith waterwater flowflow ØØRootedRooted inin sideside ofof pondpond oror canalcanal ØØReproducesReproduces byby seed,seed, creepingcreeping stemsstems andand stemstem fragmentsfragments

Types of Aquatic Plants

Emergent plants Purple loosestrife Lythrum salicaria Purple loosestrife

ØØ EscapedEscaped cultivatedcultivated ornamentalornamental andand medicinalmedicinal plantplant ØØ PerennialPerennial -- spreadsspreads byby slowlyslowly spreadingspreading crowncrown --toto 22 ftft diameter.diameter. ØØ CanCan replacereplace nativesnatives -- MonotypicMonotypic standsstands inin NortheastNortheast havehave beenbeen aroundaround 2020 yearsyears ØØ ReproducesReproduces byby seedseed -- largelarge plantplant cancan produceproduce 22 MILLIONMILLION SEEDS!SEEDS! Giant horsetail Equisetum telmateia ssp. braunii Scouringrush Equisetum hyemale ssp . affine Giant horsetail Scouringrush ØØ BothBoth desirabledesirable riparianriparian nativenative -- ØØ SpreadSpread byby rhizomerhizome ØØ ContainContain alkaloidsalkaloids -- cancan bebe toxictoxic -- especiallyespecially toto horseshorses ØØ ProblemProblem ifif standsstands becomebecome excessivelyexcessively densedense Giant reed Arundo donax Seedhead

Sprouts from fallen branch Giant reed Arundo donax

Ø RobustRobust perennialperennial grassgrass -- growsgrows 66 --3030 feetfeet highhigh --spreadsspreads byby rhizomerhizome -- nono viableviable seedsseeds Ø BroughtBrought toto LosLos AngelesAngeles inin 18201820 ’’ss usedused forfor roofingroofing andand fodderfodder materialmaterial Ø UsedUsed forfor erosionerosion controlcontrol -- nownow causescauses floodsfloods Ø DisplacesDisplaces nativenative plantsplants andand wildlifewildlife becausebecause ofof thethe largelarge standsstands andand monopolizationmonopolization ofof soilsoil moisturemoisture -- Common cattail Typha latifolia Common cattail Typha latifolia ØØ WidespreadWidespread desirabledesirable nativenative –– valuablevaluable sourcesource ofof foodfood andand sheltershelter forfor wildlifewildlife -- preventprevent shorelineshoreline erosion,erosion, andand helphelp removeremove excessexcess nutrientsnutrients fromfrom waterwater .. ØØ SpreadsSpreads byby seedseed andand extensiveextensive rhizomerhizome systemsystem -- ØØ ““EverybodyEverybody wantswants 22 feetfeet ofof cattailcattail -- nobodynobody wantswants 1010 feet!feet! ”” Perennial pepperweed Lepidium latifolium Perennial pepperweed Lepidium latifolium

ØØ PerennialPerennial spreadsspreads byby rootroot andand seedseed ØØ FormsForms densedense standsstands inin brackishbrackish oror alkalinealkaline wetlandswetlands -- andand otherother areasareas ØØ IntroducedIntroduced fromfrom EuropeEurope foundfound inin allall countiescounties inin CA,CA, exceptexcept DelDel Norte,Norte, HumboldtHumboldt andand Imperial.Imperial. Himalaya blackberry Rubus armeniacus Himalaya blackberry Rubus armeniacus

ØØ CanesCanes areare typicallytypically biennialbiennial -- rootsroots areare perennialperennial ØØ ReproducesReproduces byby seed,seed, rootroot sproutssprouts andand stemstem tiptip rootingrooting ØØ TheThe mostmost commoncommon nonnon --nativenative bramblebramble invadinginvading riparianriparian areasareas inin CACA andand PNW.PNW. ØØ HimalayanHimalayan blackberryblackberry isis aa nativenative ofof Armenia.?Armenia.? Curly dock Rumex cripus Curly dock Rumex cripus ØØ PerennialPerennial -- cancan accumulateaccumulate toxictoxic levellevel ofof oxalatesoxalates andand plantsplants cancan (rarely)(rarely) becomebecome poisonouspoisonous toto livestocklivestock whenwhen ingestedingested inin highhigh quantity.quantity. ØØ ReproducesReproduces byby seedseed -- buriedburied cancan survivesurvive 2020 yearsyears oror more.more. ØØ SeedsSeeds cancan survivesurvive ingestioningestion byby cattlecattle andand smallsmall birdsbirds -- butbut notnot chickenschickens -- Pale smartweed Polygonum lapathifolium Pale smartweed Polygonum lapathifolium

ØØ DesirableDesirable annualannual nativenative thatthat producesproduces seedsseeds thatthat areare anan importantimportant foodfood sourcesource forfor birdsbirds ØØ CanCan impedeimpede waterwater movementmovement whenwhen populationpopulation becomesbecomes largelarge andand densedense Questions?Questions?

AquaticAquatic WeedWeed && AlgaeAlgae ControlControl Aquatic Systems: Multiple uses

n Fishing n Wildlife

n Swimming n Flood Control

n Boating n Irrigation

n Aesthetics n Frost Protection

n Drinking Water n Hydroelectric AquaticAquatic PlantPlant ManagementManagement PlanPlan

ØØPreventionPrevention ØØAssessmentAssessment ØØSiteSite --specificspecific managementmanagement ØØEvaluationEvaluation ØØMonitoringMonitoring ØØEducationEducation Aquatic Plant Management vPrevention vEducational signs at boat launches, marinas vVolunteer Plant Survey to watch for invasive plants in pond vIdentify plant species vSite Considerations vSelect Management Approach mechanical biological herbicides vMonitor / Follow Up Application Prevention: Educational materials, signs, inspections at boat ramps. Awareness can prevent the introduction of weedy aquatic plants. Prevention Eliminate shallow areas during construction > 3 feet deep, except in designated swimming areas.

Prevent nutrients from entering the pond point sources use 10 - 20 foot wide grass buffer strips fertilize areas adjacent to pond sparingly prevent livestock from entering the pond directly reduce the number of waterfowl Management Goals n Management approach will depend on your goals for the site:

The goal here? Site Considerations vPond Dimensions vAverage Depth vInflows / Outflows vLocation in the Floodplain vTypes of Fish vWater Uses Which is more desirable? CostsCosts ofof aquaticaquatic weedweed managementmanagement

ØRanges from $500 to $3,000 per acre ØRanges from $500 to $5,000 per mile of canal CostsCosts ofof aquaticaquatic weedweed managementmanagement

ØRanges from $500 to $3,000 per acre ØRanges from $500 to $5,000 per mile of canal

What are the costs associated with? §Consumable Materials (e.g. herbicides, fuel) §Equipment (sprayers, harvesters, trucks, boats, safety gear) §Personnel (salaries, training, insurance, benefits) §Regulatory: NPDES-monitoring and compliance (sampling equipment, training, analysis, documentation, record storage) Aquatic Plant Management

• Mechanical Control • Cultural Control • Biological Control • Chemical Control Mechanical Control

n Hand pulling and raking n Cutting and harvesting n Shredding n Dredging n Chaining n Diver-operated suction harvesting n Rotovating Hand operated tools

Cutting/Harvesting Cutting/Harvesting Underwater cutting head The plant material has to be taken to appropriate disposal site.

Small fish and invertebrates become trapped in the plant material. Not all pieces are captured- Plant fragments may cause new infestation elsewhere Shredding

n Shredders chop material in place, pieces too small to clog waterways

n Immediate relief

n A lot of biomass at Before bottom of canal-

After Dredging

Removes nutrient-rich sediments Exposes nutrient poor layers; Deepens resulting in less light penetrating to the bottom. Chaining

Requires a large chain and two large tractors Dislodges weeds, and anything else, from bottom of canal- CulturalCultural ControlControl

ØØDrawdownDrawdown ØØBenthicBenthic BarrierBarrier ØØShadingShading ØØNutrientNutrient InactivationInactivation ØØBarleyBarley StrawStraw Drawdown n Effective on some species, and inexpensive n Damage to other non-target organisms n Can impact human use of water n Must have ability to control water inflow Water Level Drawdown effect on weed populations

Coontail, Egeria, Eurasian watermilfoil, Southern Naiad, Water Lily, Robbin’s Pondweed

Alligator weed, Hydrilla, Bushy Pondweed

Waterhyacinth, Elodea, Cattail BenthicBenthic BarrierBarrier

Advantages

-Last up to 10 years -Frees areas for immediate use. -Easy to install in small areas. -Prevent new plant growth if used early in the spring.

- BenthicBenthic BarrierBarrier

Disadvantages

-Habitat can be eliminated. -Not suitable for large-scale (expensive) -Must be removed and cleaned in the fall. -Too shallow an installation may entangle props. -Installation may be strenuous especially in deep water!

Light Alteration as a Management Approach Increase water depth by dredging. Increase shade from stream banks by planting tall grass, shrubs or trees. Add nutrients to stimulate algal blooms. Increase turbidity due to suspended clay. Use light absorbing dyes. (slow water turnover, dilution, apply early in growing season, most effective in clear water, require minimum depths of > 0.5 to 2 m) ShadingShading n Water-soluble dye n Inexpensive n Discoloration appears artificial

How colorants work

Block light wavelengths that plants need for growth NutrientNutrient InactivationInactivation

Ø ComplexComplex PP withwith Ø MayMay notnot effecteffect plants,plants,

l Alum particularlyparticularly rootedrooted

l Iron onesones

l Other Ø CanCan adverselyadversely effecteffect Ø ControlsControls algaealgae fishfish andand otherother relativelyrelatively organismsorganisms inexpensivelyinexpensively andand cancan clarifyclarify waterwater Barley straw Algae control agent?- conflicting results BiologicalBiological ControlControl

n Insects • Classical • Native n Pathogens • Classical • Native § Herbivorous Fish • Grass carp West Indian Manatee

Water hyacinth control in Florida GrassGrass CarpCarp n Advantages n Disadvantages

n Effective n “All-or-none”

n Inexpensive response

n Long-term n Not selective n Cannot control feeding sites

n Cannot stop fish

n Difficult to contain

n Reproduction? Triploid Grass Carp Prefer Other Species

1000 900 800 700 600 500 400 300 200

Fresh Fresh Weight Consumed (Grams) 100 0 Elodea Curlyleaf Eurasian Pine et al . 1990 ClassicalClassical InsectInsect ControlControl n Advantages n Disadvantages

n Public perception n No agents for several

n Low cost after R&D target nonindigenous plants n Long-term n Long time for R&D

n Unpredictability of results Agasicles hygrophila – Alligatorweed Flea Beetle GoalGoal ofof aa ClassicalClassical InsectInsect BiologicalBiological ControlControl ProgramProgram –– LongLong termterm balancebalance

PLANT GROWTH Not complete control, but a balance at a much lower infestation level Before biological agent release- monoculture of weedy species After- long term balance- some weedy species with a lot of natives Chemical control to submerged or floating leaf aquatics n Contact • Complexed copper • Diquat • Endothall n Systemic • 2,4-D • Fluridone • Glyphosate • Triclopyr Target Species

n Proper identification of the target species of plant (or algae) is critical for optimal control n For instance, herbicide selection:

n Aquathol-K works well on hydrilla

n Aquathol-K does not work well on egeria Submersed Application Techniques

Helicopter, Boat, Airboat Surface spray, Subsurface injection, granular spreader Aquatic Herbicides

Read and follow the label!

Check with Ag Commissioner for local use restrictions. Application Methods

Airplane

Airboat Adding Copper Sulfate to an Irrigation Canal

Submersed Plants: Dose & Exposure

• Herbicide efficacy and selectivity dependent on dose and length of exposure to target plant 85 to 100% • Relationships identified efficacy

for hydrilla and milfoil 70 to 85% – 2,4-D efficacy <70% – Endothall Herbicide Concentration efficacy – Fluridone – Triclopyr Exposure Time HerbicidesHerbicides UsedUsed forfor SubmersedSubmersed WeedWeed ControlControl inin LakesLakes andand ReservoirsReservoirs

Herbicide Uptake Half-life Use (days)

Diquat FAST 1-7 Spot applications

Copper FAST 1-5 Spot applications

Endothall Fast 4-7 Spot applications

Triclopyr Fast 1-4 Spot applications

Fluridone Slow 20-90 Only large areas, except for pelleted formulation Sonar used in golf course pond

Undesired effect –White Cattails Management Goals and Plans

The Question: What’s the best method to control plant X? The Answer: The best method depends on your management goals given your acceptable economic, environmental, and regulatory limitations Example of Goals and Management Selection

Target Plant Your limitation or Technique goal is: Funds Drawdown or Eurasian backhoe watermilfoil Maintain plant Triclopyr Growing in a small diversity farm pond. You have the No fishing Fluridone (SONAR) ability to drain and restriction add water Fish production Shading pond

Summary of biological management methods for aquatic plants.

Management Description Advantages Disadvantages Systems where used Plant species response Method effectively

Grass Carp / White Herbivorous Fish LongLong----termterm Cannot control feeding sites, Isolated water bodies, Fish have strong Amur (decades), relatively difficult to contain in water effective against hydrilla preference for hydrilla inexpensive body, tendency for "all or and other preferred and some native plants, none" community response, species. Operational. avoid Eurasian persistent watermilfoil, generally do not prefer floating plants Neochetina spp. Waterhyacinth Species selective Not effective in reducing Released in Florida, Gulf weevils areal coverage in many Coast states. situations (Developmental) Leaf scars, some reduction in growth Hydrellia spp. Hydrilla fly, hydrilla Species Selective Has not yet been Released in Florida, Limited Bagous spp. stem weevil established Alabama, Texas. (Research)

Euhrychiopsis Weevil ---native or Already established Less selective, currently Currently under study in Plants loose buoyancy, lecontei and other naturalized in U.S. under R&D Vermont, Minnesota weevil interferes with native insects (Research) transfer of carbohydrates

Mycoleptodiscus Fungal pathogen; Low dispersion, Expense, crosscross---- Under R&D for both "Contact Bioherbicide", terrestris (Mt) acts as a contact fairly broad contamination, inconsistent Eurasian watermilfoil and plants rapidly fall apart, bioherbicide spectrum viability and virulence of hydrilla but regrow from roots formulation

Native Plant Planting of Provides habitat, Expensive, techniques still Under R&D around the Native plants provide Community desirable native may slow reinvasion under development country ecosystem benefits, slow Restoration plant species or or initial invasion invasion community Characteristics of physical management techniques.

Management Description Advantages Disadvantages Systems where used Plant Species Response Method effectively

Dredging/ Use mechanical Creates deeper Very expensive, must Shallow ponds and Often creates large usable Sediment Removal sediment dredge to water, very longlong---- deal with dredge lakes, particularly those areas of lake, not selective remove sediments, term results sediment filled in by deepen water sedimentation

Drawdown "De"De----water"water" a lake or Inexpensive, very Can have severe Only useful for Selective based on river for an extended effective, environmental manmade lakes or perennation strategy; period of time moderatemoderate----termterm impacts, severe regulated rivers with a effective on evergreen recreational/ riparian dam or water control perennials, less effective user effects structure on herbaceous perennials

Benthic Barrier Use natural or Direct and Expensive and smallsmall---- Around docks, boat Nonselective, plant synthetic materials to effective, may last scale, nonselective launches, swimming mortality within one month cover plants several seasons areas, and other small, underneath barrier intensive use areas

Shading / Light Reduce light levels Generally Nonselective, controls Smaller ponds, manman---- Nonselective, but may be Attenuation by one of several inexpensive, all plants, may not be made waterbodies, longlong----termterm means: dyes, shade effective aesthetically pleasing small streams cloth, plant trees (rivers)

Nutrient Inactivate Theoretically Impractical for rooted Most useful for Variable Inactivation phosphorus (in possible plants limited by controlling particular) using nitrogen phytoplankton by alum inactivating water column P Characteristics of mechanical management techniques.

Management Method Description Advantages Disadvantages Systems where used Plant species response effectively

HandHand----Cutting/ Pulling Direct hand pulling or LowLow----technology,technology, LaborLabor----intensive,intensive, cost is Most of the undeveloped Very effective in very use of hand tools affordable, can be laborlabor----basedbased world, volunteer labor localized areas selective pools Cutting Cut weeds with More rapid than Large mats of cut weeds HeavilyHeavily----infestedinfested systems Nonselective, shortshort---- mechanical device harvesting may become a health term (typically boatboat----mountedmounted and environmental sickle bar) without problem, may spread collection infestation Harvesting (Cut and Mechanical cutting with Removes plant Slower and more Widespread use with Like cutting, it is Remove) plant removal biomass expensive than cutting; chronic plant problems cosmetic, nonnon----selectiveselective resuspension of shortshort----termterm sediments

Grinder or "Juicer" Mechanical cutting with Immediate relief of Resuspension of Useful for chronic plant Like cutting and (Cut and Grind) grinding of plant plant nuisance, no sediments, problems where disposal harvesting, it is material and inin----lakelake disposal decomposition of plants of plants is problematic cosmetic, nonnon----selectiveselective disposal in lake, floating plant shortshort----termterm material

DiverDiver----OperatedOperated Vacuum lift used to Moderately selective Slow and costcost----intensiveintensive Useful for smaller Typically have minimal Suction Harvester remove plant stems, (based on visibility nuisance plant regrowth for Eurasian roots, leaves, sediment and operator), populations in which watermilfoil; not left in place longerlonger----termterm plant density is moderate effective for tubertuber---- setting hydrilla

Rotovating Cultivator on long arm Disrupts Eurasian May spread large Used extensively in the Effective in disrupting for tilling aquatic watermilfoil stem numbers of fragments; Pacific Northwest and Eurasian watermilfoil sediments bases, intermediateintermediate---- resuspension of British Columbia, with dense stands; not term results sediments mixed results selective and only intermediateintermediate----termterm Use suggestions for US Environmental Protection AgencyAgency----approvedapproved aquatic herbicides.

Compound Exposure Time Advantages Disadvantages Systems where used Plant species response (Water) effectively

Complexed Intermediate (18(18----7272 Inexpensive, rapid Does not biodegrade, but Lakes as algicide, BroadBroad----spectrum,spectrum, acts in Copper hours) action, approved for biologically inactive in herbicide in higher 777-7---1010 days or up to 44----66 drinking water sediments exchange areas weeks

2,42,42,4-2,4 ---DDDD Intermediate (18(18----7272 Inexpensive, systemic Public perception Waterhyacinth and Selective to broadbroad---- hours) Eurasian watermilfoil leaves, acts in 55----77 days control, Lakes and slowslow---- up to 2 weeks flow areas, purple loosestrife Diquat Short (12(12----3636 hours) Rapid action, limited Does not affect Shoreline, localized BroadBroad----spectrum,spectrum, acts in 7 drift underground portions treatments, higher days exchange rate areas

Endothall Short (12(12----3636 hours) Rapid action, limited Does not affect Shoreline, localized Broad spectrum, acts in drift underground portions treatments, higher 777-7---1414 days exchange rate areas

Fluridone Very long (30(30----6060 Very low dosage Very long contact period Small lakes, slow flowing Broad spectrum, acts in days) required, few label systems 303030-30 ---9090 days restrictions, systemic

Glyphosate Not Applicable Widely used, few label Very slow action, no Nature preserves and Broad spectrum, acts in restrictions, systemic submersed control refuges; Emergent and 777-7---1010 days, up to 4 weeks floatingfloating----leavedleaved plants only

Triclopyr Intermediate (12(12----6060 Selective, systemic Not currently labeled for Lakes and slowslow----flowflow Selective to broadbroad---- hours) general aquatic use areas, purple loosestrife leaves, acts in 55----77 days, up to 2 weeks Characteristics of U.S. Environmental Protection Agency-approved aquatic herbicides. Compound Trade Name Company Formulation; Mode of Action Bluegill 96 hr. Contact vs. Systemic LCLCLC 505050 (mg/L)

Complexed Complexed CutrineCutrine----PlusPlus Applied Biochemists Various complexing Plant cell toxicant 1250 Copper Komeen (((Cutrine(CutrineCutrine)))) agents with copper, Koplex Griffin Corporation superior to CuSO 444 KKK-K---TeaTea Systemic

2,4-2,4 -DD 2,42,4 --DD AquaAqua----KleenKleen Cerexagri BEE salt Selective plantplant---- 1.11.11.1-1.1 ---1.31.31.31.3 WeedarWeedar----64646464 NuNuNu-Nu ---FarmFarm Ag Products DMA liquid growth regulator 123123----230230 WeeWee----RhapRhap AAA- A---4D4D4D4D Helena Chemical IEE liquid Several Others Systemic

Diquat Diquat Reward Syngenta Professional Liquid Disrupts plant cell 101010-10 ---140140 Products Contact membrane integrity

Endothall Endothall Aquathol KKK United Phosphorous, Inc. Liquid or granular Inactivates plant 125 Hydrothal 191 Contact protein synthesis 0.060.06----0.20.20.20.2 Aquathol granular

Fluridone Fluridone Sonar AS SePRO Liquid or granular Disrupts carotenoid 999-9---12.512.5 Sonar SRP Systemic synthesis, causing bleaching of chlorophyll Glyphosate Glyphosate Rodeo Monsanto Liquid Disrupts synthesis 4.24.24.2-4.2 ---14141414 Systemic ofofofphenylalanine Triclopyr Triclopyr Garlon 3A SePROSePRO,, others Liquid Selective plant 148 Renovate Systemic growth regulator Application restrictions of US Environmental Protection Agency- approved aquatic herbicides .

Compound Persistence Maximum Maximum water Safety Factor Application Notes WES Recommended (half(half----life,life, in days) Application concentration forforfor Rate

Complexed 333 1.5 1.0 mg/L >50 Algicide / Herbicide Hydrilla, other Copper gal/ft/acre submersed spp.

2,42,42,4-2,4 ---DDDD 7.57.57.5 0.5 gal/acre 2.0 mg/L >25 Some formulations for Eurasian watermilfoil, special permits only waterwater----hyacinth,hyacinth, and others

Diquat 111-1---7777 2 gal/acre 2 mg/L 555 Binds with particles AllAllAll (suspended solids) in water

Endothall 444-4---7777 13 gal/acre 5.0 mg/L >10 (Aquathol) Fish are sensitive to All submersed spp. <1.0 (Hydrothal) Hydrothal 191 ---over 1 mg/L may cause fish kill

Fluridone 212121 1.1 qt/acre 0.15 mg/L >20 Applications have been Most submersed spp. (150 ppb) successful below 10 ppb

Glyphosate 141414 2 gal/acre 0.2 mg/L >20 Aerial portions only ---not for Most emergent and submersed plants floating spp.

Triclopyr nanana nanana 2.5 mg/L >50 EUP/Special Needs only --- Eurasian watermilfoil, US EPA label expected in waterwater----hyacinth,hyacinth, 1997 others