Eileen Ryce, Montana ANS Coordinator 

The 2006 field season brought mostly good news for the Montana Aquatic Nuisance Species Program.  Monitoring continued statewide for aquatic invasive, more time was spent doing shoreline surveys for zebra mussels and aquatic weed surveys, in addition to our annual lake, stream and hatchery monitoring.  The good news is that zebra mussels, Eurasian water milfoil and Asian carp are yet to become established within the state.  Zebra mussels, Eurasian water milfoil and Asian carp all have the ability to survive, become established and cause damage in Montana, they are all found in nearby states and all have a high potential for introduction.  Slight expansions within the state were seen in the distributions of both New Zealand mud snails and whirling disease. 

During 2006 we once again operated boat inspection stations.  There were substantially fewer out-of-state boats than previous years, a few boats did have to be washed prior to launching; however, overall the majority of motor-boats coming through the check stations were clean and ready to launch.  In general, less compliance with cleaning recommendations was observed with the non-motor boat anglers (fly-fishermen, drift boats, rafts, etc.)  As always I want to thank you all for your cooperation and patience at the check stations and especially want to thank you all for keeping clean boats.  It is known that zebra mussels attach to the outside of boats and are moved around that way and recently it was demonstrated that large numbers of the juvenile stage of the mussels can be transported in water carried by boats, such as in live wells, and other watercraft such as jet skis.  Always remember to drain live wells and pull your plug before moving to the next body of water.

            In January 2007 the invasive quagga mussel was discovered in Lake Mead, Nevada.  Quagga mussels are a close relative to zebra mussels but, in a lot of respects their potential to cause significant damage is greater.  Similar to the zebra mussel they grow in dense colonies and can disrupt water flow in power plants, water treatment facilities and can also disrupt flow in irrigation systems.  Ecological impacts include disruption to food webs.  Quagga mussels have similar habitat preferences to zebra mussels with the exception that they can also adhere to soft sediments as well as hard surfaces and be found in deeper waters than zebra mussels but, are also found in shallow areas.  Up until this discovery no zebra or quagga mussels were known to be in the West.  Quagga mussels are now known to be established in Lake Mead, Lake Mohave and Lake Havasu.  Other waters within Nevada may be infested due to transfers from an infested hatchery and waters bordering California and Arizona are known to be infested.  Currently it is not known what the full extent of the distribution in the West is but, it gives us a clear message that we need to be even more vigilant at preventing the introduction of any aquatic invasives into Montana.  If you travel to any of these known infested waters with your boat please be sure to clean your boat thoroughly prior to returning to Montana.  It is illegal to transport zebra or quagga mussels into or within Montana.  Often new populations of invasive species are not discovered until they have been established for 2 to 3 years, it is therefore critical that you consider any body of water potentially contaminated and that care should always be taken when moving between water bodies and particularly when traveling from out-of-state.

           

What you can do to help:

• Ensure that you are not part of the problem
  • Drain all water from your watercraft before leaving the immediate area of the lake
  • Remove all weeds, mud or attached organisms from the boat and trailer
  • Always dispose unwanted bait in the trash, never bring live bait into Montana without authorization
  • Wash the exterior of your boat and trailer, hot-high pressure water is best
  • Rinse and clean live wells, use hot soapy water or a weak bleach solution
  • Allow boat to dry in between trips to different water bodies; ideally for 5 days
  • Never move live fish, aquatic invertebrates or plants from one body of water to another without Fish, Wildlife and Parks authorization.  It is unlawful to release any live aquarium or bait fish
• Report any potential sightings of zebra or quagga mussels (see description below) immediately to the Fish, Wildlife and Parks ANS Coordinator (406-444-2449), if possible, collect a sample, place it in a jar or zip-loc bag and note specific location and date
• Spread the word; tell your neighbors and friends about the importance of taking steps to prevent the spread of Aquatic Nuisance Species
• For further questions call the ANS Coordinator at 406-444-2449.

 

How to identify Quagga or Zebra mussels

• Quagga and zebra mussels are similar in appearance
• Adults look like a small clam with a D-shaped shell
• Usually have alternating dark and light stripes, but these may not be present
• About the size of your fingernail, although can be up to 1-2 inches
• Small juveniles, which have just recently attached to a surface, look like black pepper and feel like sandpaper.

 

Quagga mussel on left, Zebra mussel on right, photo from USGS.

For more information, click on the following link http://fwp.mt.gov/fishing/guide/ANS/default.html