Flowering Rush An Invasive Aquatic Macrophyte Infesting the Columbia River Basin Peter Rice, University of Montana, Virgil Dupuis, Salish Kootenai i College
Flowering Rush (Butomus umbellatus) umbel shaped cluster of ~30 flowers 3 whitish pink petals & 3 similar sepals green leaves are triangular in cross section leaf tips may be spirally twisted strongly rhizomatous
Flowering Rush ( (Butomus umbellatus) East Bay Flathead Lake MT
North American Invasion circa 1895-1905 1905 St. Lawrence River region 1949 Snake River Idaho (Idaho Falls) 1964 Flathead Lake (north shore) Infested Counties in WA, OR, ID, MT, WY
Fully Submerged Form Emergent Form Shoreline Form
Four Forms of Dispersal 1. seeds 2. vegetative bulblets inflorescence 3. vegetative bulblets side of rhizomes 4. rhizome fragments
Diploid self-compatible prolific flowering high seed production prolific bulblet production (rhizome & inflorescence) partial dispersal by vegetative means Triploid self-sterile sterile within clones infrequent flowering low production of sterile seeds inflorescence bulblet production not evident disperses only by rhizome fragmentation
Buoyant Rhizome Fragments
Rhizome Fragments on Unvegetated Littoral Zone Sediments
Invasives of Wetlands & Shoreline (Displacing Native Plants)
Infesting Previously Unvegetated Littoral Zones
Shoots Emerging in Late March/Early April
Kerr Dam Induced Low Pool in Spring Favors Flowering Rush Over Native Macrophytes
Larger Infestations Partial Survey Data Through 10/13/2008
Robust Triploid Dispersing Out of Flathead Basin Lateral Rhizome Bud
Kerr Dam Spillway from Flathead Lake to River
American Falls
Dispersal Down the Columbia River System Kerr Dam into Flathead and Clark Fork Rivers (MT) Thompson Falls, Noxon,, Cabinet Reservoirs (MT) Lake Pend Oreille Clark Fork River delta (ID) Snake River Aberdeen-Springfield Canal Irrigation Systems (ID)
Flathead River Below Kerr Dam
American Falls
Aberdeen-Springfield Canal System (Spills to Snake River at American Falls ID)
Aberdeen-Springfield Canal System (Spills to Snake River at American Falls ID)
Aberdeen-Springfield Canal System (Spills to Snake River at American Falls ID)
Aberdeen-Springfield Canal System (Spills to Snake River at American Falls ID)
Aberdeen-Springfield Canal System (Spills to Snake River at American Falls ID)
Pablo Reservoir Irrigation Lift Station Flathead Lake/River Flowering Rush Colony
Flathead Valley Pablo Reservoir Irrigation Canal
Private Boat Docks Surrounded by Flowering Rush
Swimmer s s Itch ( (schistosome cercarial dermatitis) Trematode Parasite ( (Trichobilharzia Great Pond Snail ( (Lymnaea stagnalis) Trichobilharzia ocellata)
Obvious Negative Impacts Displacement of Native Plant Communities Formation of Monotypic Vegetation Loss of Open Water Recreation Irrigation Impediment Higher Level Impacts Have Not Been Assessed Increases in Water Temperatures Sediment Transport & Deposition Food Chain Alterations / Native Fisheries
Mouth of Dayton Creek Historic Spawning Habitat For Adfluvial Cutthroats & Bull Trout
Black Bullhead Yellow Perch Schultz 2006
One Cautionary Hypothesis Native Bull Trout Native Cutthroat Introduced Lake Trout Introduced Yellow Perch Yellow Perch Eggs on Vegetation
Early Detection Rapid Response Opportunity Flathead Lake ~2,000 ac Flathead Lake 18.5% FoO Thompson F. 2.3% FoO Noxon <1% (Present) Cabinet 0.1% L. Pend Oreille (~8 acres) L. Pend Oreille Preliminary Data from: Rice & Dupuis Madsen & Cheshier 2008 Woolf 2007, Madsen & Wersal 2008
Flowering rush Eurasian watermilfoil
Current Project Objectives Salish Kootenai College, Salish & Kootenai Tribes, University of Montana Mapping Flathead Lake Spatial model to predict spread and inform management decisions (Flathead Lake) Phenology in relation to management options Foliar applied herbicide and hand digging trials Karyotyping various CRB infestations Informing Columbia River system managers of threat
Need for A System-Wide / Multi-Partner Comprehensive Scientific Assessment Main Stem Survey Water Level Management & Invasion Success Reproductive Phenology & Rhizome/Seed Dispersal Higher Trophic Level Impacts Sediment Deposition & Transport Control Methods Professional Awareness Strategic Plan for Columbia River Basin
Questions & Comments? Peter Rice (406) 243-2671 2671 peter.rice@umontana.edu Photos by Alvin Mitchell & Dave Boldt SKC, Sue Ball CSKT, Peter Rice UM, Chris Eckert Queens University