Aquatic Noxious Weed Program
Invasive weeds threaten the ecological integrity of aquatic environments in Montana. Eurasian watermilfoil, curly-leaf pondweed and flowering rush have become established in the state, and there is a high risk of invasion by other non-native aquatic plants.
These plants are highly competitive and affect fisheries, native plants, waterworks, power generation and irrigation. Increased aquatic plant biomass also impacts water quality and recreational resources.
Invasive aquatic plants are transported by hitching a ride on animals, watercraft and recreational vehicles, as well as scuba, fishing and hunting equipment.
How can you help?
Boating
- Inspect boat, trailer, and equipment.
- Remove aquatic plants, animals, and mud.
- Drain water from boat, motor, bilge, live wells, and bait containers.
- Spray/rinse boats and recreational equipment with high pressure, and/or water above 140 degrees, or let recreational equipment dry for at least five days.
Fishing
- Clean waders and boots.
- Drain water from bait containers.
Hunting & Other Outdoor Activity
- Inspect equipment, decoy lines, anchors, waders and pets.
- Remove weeds/seeds by washing equipment and brushing or cleaning animals.
Montana Aquatic Noxious Weeds
- Eurasian Watermilfoil ( Myriophyllum spicatum)
- Flowering Rush ( Butomus umbellatus)
- Curlyleaf Pondweed ( Potamogeton crispus)
Other Aquatic Plants of Concern in Montana
Guide to Montana's Freshwater Aquatic Plants
Click on the items below to download the complete guide or parts, meant to help with identification of Montana's freshwater aquatic plants.
- Complete Guide (5.21 MB, PDF)
- Table of Contents, Acknowledgements & Introduction (345 KB, PDF)
- Plant-Like Algae (285 KB, PDF)
- Floating Leaved, Rooted Plants (1.01 MB, PDF)
- Submerged Plants (2.44 MB, PDF)
- Free-Floating Plants (285 KB, PDF)
- Shoreline Plants (1.23 MB, PDF)
- Glossary, Index & References (273 KB, PDF)
Montana Pollutant Discharge Elimination System
State requirements regarding discharge permits have changed. Please visit the Montana Department of Environmental Quality website for information.
Aquatic Pesticide License
Application of aquatic herbicides in Montana requires a special-use license. The Montana Department of Agriculture oversees the licensing and training of aquatic pesticide applicators. Applicators who intend to treat waters with state restricted-use aquatic herbicides (xylene or acrolein) must attend a special aquatic training session and pass an Aquatic Pest Control Exam for initial certification. Training and testing is offered once a year by the Department.
The Department conducts aquatic herbicide applicator recertification training sessions periodically. These are listed with other applicator training opportunities on the Pesticides page.
