Aquatic Invasive Weeds - PDF Free Download

Aquatic Invasive Weeds Mark Sytsma Center for Lakes and Reservoirs Aquatic Bioinvasion Research and Policy Institute Portland State University Benton County CWMA Aquatic Applicator Short Workshop Corvallis 10 March 2016

Overview Why manage invasive aquatic weeds? Some common and not-so-common invasive species (focus on the Pacific Northwest) Options for aquatic plant management Some nonplant invasive species to watch for

Introduction Management of aquatic weeds is complicated because: Many species are easily confused with native or legally imported species Common names are confusing and often misapplied Many aquatic weeds reproduce vegetatively from small fragments Water moves Aquatic systems contain many sensitive and endangered iconic species that complicate management

Algae Microscopic greens, diatoms, golden, dinoflagellates, cyanobacteria Nitella Chara

Ecological impacts Reduce light penetration & mixing Reduce species diversity Alter temperature, dissolved oxygen & ph Degrade fish habitat Altered nutrient cycling can lead to algae blooms and toxicity

Impacts on biodiversity Madsen et al. 1991

Food web and nutrient cycling Carpenter and Lodge 1986

Reduce flow in irrigation canals and drainage ditches Increased cost of irrigation Flooding Clogged pumps & intake structures Loss of recreational resources Negative impacts on property values Economic impacts

Human safety

Myriophyllum spicatum Eurasian watermilfoil Feathery leaves divided into leaflets. 3 to 5 leaves grow in a whorled pattern around the stem. When out of water, leaves lose their rigidity and collapse around the stem. Easily confused with native milfoil species Eurasian watermilfoil Northern watermilfoil

Kev Alexanian Myriophyllum spicatum x sibiricum Hybrid watermilfoil Intermediate characteristics Rapidly spreading in Great Lakes region Increased resistance to several herbicides commonly used on EWM Confirmed in Howard Prairie Reservoir & multiple sites along the Rogue River

Myriophyllum heterophyllum variable leaf watermilfoil, two-leaf watermilfoil, & red foxtail Siltcoos Lake, Oregon Present at 22 of 297 sampling locations Extensive monocultures in protected bays Class A noxious weed in Washington 5 lakes being treated

Hydrilla verticillata Monecious biotype in Washington (10yrs, $10M eradication) Dioecious biotype (only female) thermally-influenced Bruneau River, Idaho Endangered snail present Diquat and handpulling

Hydrilla verticillata hydrilla, Florida elodea, water thyme

Dioecious Egeria densa Brazilian elodea Only male plants outside native range in South America Dispersal by fragments only Most common invasive aquatic plant in west-side lakes

R. Vid-ki / www.bugwood.com Elodea canadensis/nutallii American waterweed, common elodea Native species common throughout Oregon E. canadensis E. nutallii

USDA PLANTS database Similarities in the Hydrocharitaceae Elodea canadensis/nutallii (native) Egeria densa (B-list noxious weed) Hydrilla verticillata (A-list noxious weed) Turions and tubers are features of hydrilla

Potamogeton crispus Common throughout Oregon curly leaf pondweed Turions form in spring on small plants, sprout in fall and overwinter Typically bimodal biomass curve most abundant in spring and fall, dies back in summer Long-term control requires interrupting turion formation

Cabomba caroliniana Appears to be restricted to low-ph, dystrophic (tea colored) lakes Easily confused with submersed form of water buttercup (which has alternate leaves) gobotany.newenglandwild.org Ranunculus aquatilus

Native Not rooted Ceratophyllum demersum Bifurcated leaves Inconspicuous, submersed flowers coontail

Duckweeds Mail-Tribune file photo http://www.ruduckweed.org/

duckweed http://waynesword.palomar.edu/1wayindx.htm

Eichhornia crassipes water hyacinth Umpqua River infestation 10 miles of thermally influenced Snake River infested eradicated

Salvinia molesta salvinia Cryptobagous salviniae

Annual releases of Cryptobagous salviniae on Lower Colorado R. Source: Dewey Murray, USDA APHIS PPQ

Efficacy of Cryptobagous salviniae on Lower Colorado R. 2004 2005 Photos: Dewey Murray, USDA APHIS PPQ

Limnobium laevigatum South American spongeplant Redding pond (June 2005) 0.25 m 2 quadrat: >2,000 plants Chokes out water primrose and parrotfeather; grass growing on the mat A-listed noxious weed in OR

Azolla pinnata feathered water fern Federally listed noxious weed

Azolla filiculoides and A. mexicana Natives

Identification: Nymphaea odorata fragrant water lily Rooted aquatic perennial Grows in depths of 3-6 feet Floating heart-shaped or circular leaves (30 cm); purplish underneath, leathery, slit in one side Large (6-12 cm) fragrant flowers; 20-30 petals, range of colors with yellow centers Seed and rhizomes

Nymphoides peltata yellow floating heart Native to East Asia A-listed noxious weed Scattered populations in southern and eastern OR, and Portland metro areas

Bacopa rotundifolia disk water hyssop Considered imperiled in neighboring states Herbarium specimen in WY from 1891and from ID in 1933 First occurrence in Oregon in Columbia River in 2014 Weedy in rice fields in CA What to do about it in Oregon? Natureserve.org

NATIVE Similar habitat Larger, oval to heartshaped leaves with a prominent midvein Flowers yellow petals and centers, 9-petals Nuphar polysepala yellow pond-lily

NATIVE Similar habitat Oval, peltate leaves Inconspicous flowers Brassenia schreberii watershield

Iris psuedacorus Lythrum salicaria Phalaris arundinacea Yellowflag Iris Purple loosestrife Reed canary grass

Cattails Typha latifolia Native X Typha angustifolia Invasive Typha glauca hybrid

Phragmites australis reed ssp. australis ssp. americanus

Sagittaria spp. Sagittaria platyphylla (1 lake in WA/ Blue Heron Wetland, Portland Potential noxious listing) Sagittaria graminea Class B in WA (3 locations) Sagittaria rigida Class B in WA (6 locations)

Myriophyllum aquaticum parrotfeather milfoil Native to South America Only female plants present Dispersal by fragmentation Difficult to control

Ludwigia spp. Water primrose water primrose Abundant in middle reaches of the Willamette downstream to Columbia R. Active control efforts underway Delta Ponds, Eugene Willamette (Willamette Riverkeepers)

Aquatic perennial Butomus umbellatus Flowering rush Moving down Columbia River from infestation in Montana Large infestation in Yakima River Suction harvesting of small populations near McNary Dam Submersed and emergent growth forms Dispersal by rhizome fragments

S. patens Spartina spp. Estuarine cordgrasses 4 non-native, invasive species S. alterniflora (Eastern & Gulf coast of North America) S. patens (Eastern & Gulf coast of North America) S. anglica (hybrid of English S. maritima & S. alterniflora) S. densiflora (South America) 1 native (S. foliosa)in California Hybrids S. alterniflora S. densiflora S. anglica

Known Spartina Distribution Comox Harbor, BC Fanny Bay, BC Boundary Bay, BC Puget Sound, WA Gray s Harbor, WA Willapa Bay, WA Columbia River Sand Lake, OR Siuslaw River, OR Coos Bay, OR Humboldt Bay, CA San Francisco Bay, CA on the West Coast

Aquatic Weed Control Methods Biological Manual Physical Mechanical Chemical

Biological Control Options Purple loosestrife Galerucella spp. (leaf feeding), Hylobius (root) & Nanophyes (flower/seed) Very successful reduction in growth, occurrence & competitiveness Eurasian watermilfoil native weevil - Euhrychiopsis lecontei Results difficult to predict (fish predation, overwintering habitat) Grass Carp (Ctenopharyngodon idella) Generalist feeders low/no selectivity Very limited applications biological success vs impact success

Manual Control Options Hand-pulling, or underwater weeding Target specific weeds, move around obstructions, minimal equipment Labor intensive, creates murky water and fragments Rakes, cutters Inexpensive Labor intensive, creates murky water and fragments

Physical Control Options Benthic barriers Sediment blanket that blocks light, compresses plants Controls rooted plants Expensive for large ponds Requires regular maintenance Interferes with bottom habitat Unruly to anchor in large ponds Drawdown May be ineffective in wet conditions and without freezing Increase in some weeds (Potatmogeton, hydrilla)

Shading Physical Control Options Aquatic dyes - preemergent, depths > 2 Labeled as herbicides Weed rollers/rakes www.theweedersdigest.com

Mechanical Control Options Cutting and shredding boats ( cookie cutters ) Rotovators tills sediments Dredgers sediment removal Harvesters cut & remove Pros: Site specific, public perception, use of harvested biomass Cons: Requires opens water surface & off-site disposal, $$$ Creates fragments Nonselective, by-catch

Chemical Control Options Prerequisites for Efficacy Adequate Concentration Adequate Contact Time Appropriate Water Quality Turbidity interferes with diquat Optimal season and phenological stage Appropriate chemical for weed species 2,4-d for dicots

EPA registered herbicides for aquatic use Selective Contact Copper Peroxygen granular (GreenClean & Phycomycin ) Systemic 2,4-D (Aquaclean/ Navigate) Triclopyr (Renovate) Fluridone (Sonar) Penoxsulam (Galleon) Bispyribac-sodium (Tradewind) Mention of tradenames does not indicate endorsement compounds may be available from multiple manufactures and under different tradenames Broad spectrum Endothall, dipotassium salt (Aquathol) Diquat (Reward) Carfentrazone (Stingray) Flumioxazin (Clipper) Glyphosate (Rodeo) Imazapyr (Habitat) Fluridone (Sonar) Imazamox (Clearcast)

Aquatic Herbicides Broad spectrum contact herbicides Endothall (Aquathol K) Inhibits respiration & protein synthesis Typically non-selective (early season applications can control over-wintering or early emerging weeds) Liquid and pellet formulations allow spot treatment Not affected by alkalinity or turbidity Diquat (Reward, Weedtrine) Inhibits photosynthesis & destroys cell membranes Binds to suspended sediment not for use in turbid waters Both can cause quick kill and potential dissolved oxygen problems

Aquatic Herbicides Broad spectrum contact herbicides Carfentrazone (Stingray) Use-patterns still being established Effective on milfoils & some floating plants (Lemna, Pistia, Eichhornia, Salvinia) but not others (Landoltia punctata, dotted duckweed) Single applications not effective on plants with high nodal regeneration capacity (Ludwigia, Hydrocotyle) Irrigation restrictions 1-14 days (depending on treatment area) Flumioxazin (Clipper) Watermeal, duckweed, milfoil, hydrilla Kill by cell membrane disruption (Protox inhibitors chl biosynthesis) Quick kill in terrestrial settings, slower with aquatics

Aquatic Herbicides Selective systemic herbicides 2,4-D (AquaKleen, Navigate) Granular formulation contains butoxy-ethyl-ester and should not be used in water with T&E salmonids Triclopyr-TEA (Renovate) Also commonly used on purple loosestrife Liquid and granular Auxin mimic, plant growth regulator Selective for dicots (e.g., milfoils, ludwigia, water chestnut)

Aquatic Herbicides Selective systemic herbicides Fluridone (Avast, Sonar) Selective for Eurasian watermilfoil when contact time and dose can be maintained (long contact time at a low concentration) Low toxicity, but requires long contact time (45-80 days), carotenoid pigment inhibitor Non-selective at high application rates Liquid and various pellet formulations Acts on carotenoid biosynthesis pathway

Aquatic Herbicides Selective systemic herbicides Penoxsulam (Galleon) Inhibits plant-specific enzyme (acetolactate synthase inhibitor branched chain amino acid inhibition) Emergent, floating or submersed weed control Slow-acting; exposure times for submersed treatments similar to Fluridone Irrigation restrictions: Do NOT apply to water to be used for irrigation of greenhouse or nursery plants or hydroponics Optimum use patterns still being established

Aquatic Herbicides Broad spectrum systemic herbicides Glyphosate (Rodeo, AquaMaster) Deactivated by sediments Not effective on submersed weeds Minimal restrictions on irrigation & potable water Inhibits amino acid and hormone production by blocking shikimic acid pathway Imazapyr (Habitat) Inhibits plant-specific enzyme (ALS-inhibitor) Slow-acting Moderate residual soil activity Effective for control of floating and emergent weeds with extensive rhizome/root systems (Phragmites, Typha)

Aquatic Herbicides Broad spectrum systemic herbicides Fluridone (Sonar) Broad spectrum at high application rates Imazamox (Clearcast) Similar use patterns to Imazapyr (ALS-inhibitor) + some extended biomass reduction with submersed plants (hydrilla) Slow-acting (impacts in 60-120 days) Irrigation restrictions vary (still/moving water, depth)

Aquatic Herbicides Selective Contact Herbicides Various copper formulations (copper sulfate & chelated copper compounds) Cu is persistent in the environment Peroxygen granular (GreenClean & Phycomycin ) Relatively new algaecides Non-copper based (sodium carbonate peroxyhydrate) Primarily algaecides Cu is problematic due to effects on salmonid olfaction

Source:Whetstone and Heaton. 2013. South Carolina Pest Management Handbook for Field Crops Note: These tables are meant only as guidelines. Some herbicides carry specific warnings regarding toxicity to fish, irrigation water, etc. Please read, understand, and follow all label instructions! Applications should be made by a certified applicator in accordance with all state and federal regulations.

Things to consider The label! Perceptions / community Movement of propagules Implications of no treatment Herbicide resistance NPDES requirements addressed by OR DEQ s: Pesticide General Permit (2300-A): discharge in, over or near surface water General Permit for Pesticide Use in Irrigation Systems (2000-J)

Dreissenid Mussels Dreissena polymorpha (zebra mussel) D. rostriformis bugensis (quagga mussel) Small, epifaunal, freshwater bivalves

Dreissenid Mussles Rapid growth (15-20 mm/yr) Prolific reproducers (40K 1 M eggs/yr) Form dense colonies (200,000+/m 2 ) $0.5 Billion impact if introduced in Columbia Basin

Dreissenid Mussels

Watercraft Inspection Stations Set up for mussels but find more aquatic weeds than anything else

Crayfish Signal native to OR and WA Invaders can impact benthic community, macrophyte abundance, and aquatic foodwebs Ringed Rusty Red Swamp Signal Northern Orcon- Orcon- Procamb- Pacifast- Orconectes ectes ectes arus acus virilis neglectus rusticus clarkii leniusculus

Potamopyrgus antipodarum New Zealand Mudsnail Small (<5 mm) primarily freshwater snail Herbivorous scrapers, grazers Can develop very high densities (400k/m 2 in Columbia R) Density-dependent impacts Consume primary production/compete with native gastropods, grazers, and detritivors Management Prevention Gear cleaning Photo by D.L. Gustafson

Mark Sytsma (503) 725-3833 mark.sytsma@pdx.edu