Technical Recommendation 17

Invasive Species


The most serious threats to the Columbia Basin’s native fishes and water resources include the following aquatic invasive species: zebra and quagga mussels (Dreissena polymorpha and Dreissena rostriformis bugensis, respectively); Asian carp (Hypophthalmichthys spp.); hydrilla (an aquatic plant); spiny water flea (a planktonic animal); and viral hemorrhagic septicemia (VHS), a deadly fish virus, represent the most serious threats to the Columbia Basin’s native fishes and water resources.

Not native to the basin, aquatic invasive species negatively impact the region’s natural resources, ecology and/or economy. Because water provides a barrier to detection, unlike terrestrial invasive plants, managers cannot quickly identify and eliminate aquatic invasive species. Many states have enacted taxes on specific user groups to fund invasive species prevention programs. The federal budget for invasive species is very limited, with less than $5 million available for all states that have control and eradication plans.

The most urgent threat to the Columbia River system is from zebra and quagga mussels. These short lived (<4 years) mussels are very prolific and often present for years before being documented because of their small size and benthic (i.e., bottom dwelling) nature. In the Great Lakes, invasive mussels carpet most areas of the lake bottom and have greatly affected the food web and altered the habitats of numerous native species of fish and invertebrates. The mussels have crossed the Mississippi River and now are spreading westward. In January 2008, quagga mussels were discovered in Lake Mead, Nevada. This has vastly increased the probability of these invasive mussels getting into the Columbia River drainage.

Tribal resources in the Columbia River Basin are very vulnerable and will remain so until prevention (and eventually control) options for aquatic invasive species are developed and proven in the field.

Hypothesis and Needed Actions

The zebra and quagga mussels have the potential to permanently alter the Columbia River ecosystem, likely resulting in greater impacts to salmon recovery. No salmon-safe toxins, pathogens or chemicals are presently available to control or eradicate these mussels if they become established in the Columbia River system. As prevention is the only option that exists at this time, the following actions are necessary to address this issue.

  • Pursue through legislation greater levels of funding for prevention, monitoring and outreach.
  • Work with the tribes’ Columbia Basin partners for appropriate regulation and taxation in all western states to address invasive species and transport pathways.
  • Exert greater political pressure on the National Park Service to reduce unauthorized exits from Lake Mead National Recreation Area for uninspected boats.
  • Explore additional funding opportunities to maintain and increase CRITFC capacity to monitor and act on aquatic invasive species issues, including participation in regional and national forums for invasive species management.

Expected Outcome

Taking swift action may result in the delay or prevent the introduction and establishment of new invasive species, particularly those like zebra or quagga mussels. Timeliness is critical as the mussels, along with many other invasive species, are firmly established in most of the United States and can easily spread to the rest of the nation.

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