Overview

Exotic species have few natural predators or control agents, allowing them to reproduce and grow rapidly and threaten ecological stability, diversity and abundance of native species. They can also threaten our traditional uses of lakes and rivers for agriculture, domestic water supplies and recreation. Exotic species can be transported to new sites attached to boats, trailers and equipment. Many of these invasive species have the ability to withstand extended periods of time out of water or in small amounts of water, making their transport to new locations possible.

Flathead Lake and the other waters of the Flathead watershed are at risk due to the potential for accidental introduction of exotic aquatic species. Zebra mussels, Eurasian watermilfoil, whirling disease, and New Zealand mud snails are a few of the destructive and aggressive invader species that threaten our waters.

Species specific information

We're assembled more detailed information on several of these species in these pages:

• Zebra and quagga mussels
• Eurasian watermilfoil
• Flowering rush

Montana’s action plan

In October 2002, Montana finalized a statewide management plan to deal with aquatic nuisance species, and in February 2004, Montana Fish, Wildlife and Parks hired a statewide coordinator to implement the plan. The main emphasis of the plan is to prevent the spread of these invaders into new locations. Once introduced into a new location, there is very little that can be done to mitigate the impacts.

• Before leaving any waterbody:
• Remove all plants, sediment or animals from your boat and trailer.
• Drain all water from your boat, including from the motor, live well and bilge. Do not transfer any water from one waterbody into another.
• Never release live bait into a waterbody or transport aquatic animals from one waterbody into another. Always discard unwanted bait with household trash in the landfill. Likewise, dispose of fish carcasses with trash.
• Wash your boat, trailer and all fishing gear and equipment. High pressure hot water is best.
• Air dry your boat and equipment for as long as possible between fishing trips.

• If you find a zebra or quagga mussel or Eurasian watermilfoil:
• Note the date and location where the sample was found.
• Store the mussel or a piece of the plant in rubbing (isopropyl) alcohol.
• Contact your local Montana Fish, Wildlife and Parks office or call the Aquatic Nuisance Species Coordinator at 406-444-2448 as soon as possible. The earlier we detect a new infestation the better.

This and several of the other pages in these section are based in part from an article by Eileen Ryce, the aquatic nuisance species coordinator for Montana's Department of Fish, Wildlife & Parks, that was published in the Fall, 2004, issue of the Flathead Lake Monitor.