Aquatic Invasive Species (AIS)

AIS is a serious and growing problem across our country, particularly where there is a concentration of waterways. We all need to be on the lookout for aquatic invasive species invasions. It is important for each of us to help increase awareness of AIS and share responsibility for controlling their spread.

Montana’s Aquatic Invasive Species (AIS) Early Detection and Monitoring Program has been in place since 2004. Early detection allows Montana Fish, Wildlife & Parks biologists and partners to locate small or source AIS populations, while monitoring allows FWP to study existing population trends and investigate suspect findings.

NMLN has been a partner in FWP’s AIS Early Detection and Monitoring Program since its inception. For more information on AIS samples collected across the state by FWP staff and partners including NMLN, visit Montana Fish, Wildlife and Parks Aquatic Invasive Species Sampling Dashboard. Click here for last season’s AIS sampling locations and information for NMLN lakes.

Please spend some time reviewing AIS information before going into the field. For help with identifying potential aquatic invasive species visit our AIS Gallery, and please check out Montana Fish, Wildlife & Parks Clean.Drain.Dry website for additional information and a complete list of aquatic invasive species found in Montana.

When doing visual or tactile observations for zebra or quagga mussels, inspect rocks near the shorelines, dock pilings, retaining walls and other hard surfaces that could provide a place for mussels to attach. Please attempt to get a GPS location. Data is recorded on the data sheet provided and should be submitted to WLI. If you suspect a positive sighting, please contact the WLI office immediately. WLI will then coordinate with partner agencies to further evaluate the situation.


CLEAN.  Completely remove all mud, water, and vegetation before leaving the access area.

  • Inspect your boat, trailer, and all gear. Pay attention to crevices and hidden areas.
  • Remove all vegetation (by hand or sprayer).
  • Remove all mud (use a pressurized power sprayer, found at most do-it-yourself car washes).  The hot water kills organisms and the pressure removes mud and vegetation. No need to use chemicals or soap.
  • Dispose of debris in trash or on dry land away from water or ramp.

DRAIN.   Drain all water from watercraft and equipment.

  • Drain or remove water from boat, bilge, live well, engine, internal compartments, and bait buckets by removing drain plugs before leaving the access area.

DRY.   Aquatic invaders can survive only in water and wet areas.

  • Dry your watercraft and fishing equipment thoroughly; this will kill most invasive species.  The longer you keep your watercraft, trailer, waders, and other equipment outside in the hot sun between fishing trips, the better.

Help spread the word about AIS and encourage friends to follow decontamination procedures. If you suspect AIS in your lake, immediately contact Montana Fish Wildlife and Parks Region 1 at 752-5501.