Protect the Uninfested West from Zebra and Quagga Mussels and Other AIS

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The North American Invasive Species Management Association (NAISMA) supports the implementation of mandatory watercraft inspection and decontamination (WID) and other cross-jurisdictional containment and prevention strategies to stop the spread of zebra and quagga mussels and other Aquatic Invasive Species (AIS) from overland dispersal via recreational watercraft.

Zebra and quagga mussels have cost the USA more than other invasive species, an estimated $6 billion in prevention and control efforts since their arrival in 1988. WID, combined with monitoring, education and enforcement, are proven to stop the spread of harmful AIS and protect limited water supplies for future generations.

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  • The potential estimated costs of a quagga mussel introduction into the Pacific Northwest is more than $500 million annually, including costs to control mussels at irrigation, hydropower, and municipal drinking water facilities. Endangered native salmon and steelhead stocks in the Columbia, Upper Missouri and Sacramento River basins would also be threatened.
  • The Flathead Lake Biological Station found that zebra/quagga mussels could cost up to $234 million in damages to the state of Montana in only one year.
  • Lake Tahoe, the second deepest lake in the U.S., has estimated an impact of more than $20 million annually if zebra or quagga mussels invade.

In the West, the use of federally owned, operated and managed multi-jurisdictional reservoirs are extremely important for water storage, supply and delivery for municipal, agricultural and industrial uses. They also serve important functions as places for outdoor recreation and to conserve the aquatic ecosystems within. Zebra and quagga mussels, and other invasive species, are negatively impacting water users and costing millions of dollars in mitigation costs annually.

Containment at source waters provides the best chance at stopping the spread by preventing the overland movement of AIS on watercraft exiting through mandatory boat inspection, decontamination (if necessary), education, and enforcement. Containment refers to providing WID services upon exiting or leaving the water body in an attempt to stop the invasive species from spreading.

It is widely accepted that prevention at negative waters is necessary to protect high priority infrastructure, natural resources, recreation- based economies, and public access. Prevention refers to the strategy of protecting uninfested water bodies, regions, and river basins by providing WID services at entry points to those areas.

Decontamination is typically required when invasive species are attached to the watercraft or if the watercraft has standing water that cannot be drained. Not all inspections result in a decontamination. WID programs invest significant resources on outreach to educate boaters on what they can do to prevent the need for decontamination, which helps protect resources and saves programs valuable dollars spent on decontaminations.

Invasive mussels travel great distances overland by hitchhiking on recreational watercraft enabling them to infest new waters and basins. Mandatory watercraft inspection and decontamination is effective in protecting precious western water infrastructure, aquatic resources, recreation- based economies, and public access.

Current and past funding levels and federal authorities have been insufficient to contain invasive mussels at federal waters in the West and prevent their irreversible spread to new locations.

NAISMA advocates for legislation, policy, and funding priorities to further the implementation of WID prevention and containment programs. Invasive species management experts have identified the following specific areas of emphasis to protect western waters from AIS including, but are not limiting to:


  1. Continued appropriations for invasive species provisions within the Water Resources Development Act.
  2. Continued appropriations for Section 1204 of the National Invasive Species Act of 1997.


  1. Implement and Fund Containment Mandatory WID at Infested Waters – The Departments of the Interior and Agriculture should implement and fund mandatory inspection and decontamination of recreational watercraft leaving federal waters in the southwestern US and at Pactola Reservoir in South Dakota. The responsibility of preventing the movement of invasive species on watercraft must be shared by local, state and federal agencies.
  2. Reduce Mussel Impacted Watercraft Leaving Glen Canyon National Recreation Area – Alternate management strategies should be explored to reduce the number of mussel impacted watercraft leaving Lake Powell within Glen Canyon National Recreation Area.
  3. Enable Rapid Response – The Secretaries of the Interior, Agriculture, and Commerce in consultation with the Army Corps of Engineers and the Aquatic Nuisance Species Task Force, should develop a funding process to direct resources to entities responsible for prevention, containment, control, and rapid response.
  4. Adopt the Regional WID Data Sharing System at federally owned or managed waters and require federal grant recipients to use the system and share data across jurisdictions.


  1. Continue to provide appropriations of $15M in FY24 and beyond to meet the expanded geographic scope for watercraft inspection, decontamination, and rapid response; and $3M for monitoring per the Water Resources Development Act.
    1. Create separate appropriations of $10M each for the Arkansas, South Platte, and Upper Colorado basins ($30M total).
    2. Reduce the state match requirement to 25% with a federal share of 75%.
  2. Appropriate $4M for State AIS Management Plans, as authorized in Section 1204 the National Invasive Species Act of 1997.
  3. The Quagga Zebra Action Plan for Western Waters (QZAP) was requested by Senator Feinstein, published by the Western Regional Panel in 2010 and updated in 2020. Congress authorized the U.S. Fish and Wildlife Service to administer a QZAP grant and it is recommended that the grant program be continued at $2M per year focused on providing resources to states for WID.
  4. Designate continuous funding of $100,000 per year for each of the six Regional Panels on ANS, as authorized in the National Invasive Species Act of 1997.

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