The cost to control invasive species and the cost of damages they  inflict, or could inflict, on property or natural resources are estimated to  total billions of dollars annually. Not all nonnative species, however, cause harm. More Comprehensive Analysis of the Economic Impacts of Invasive Species Would Better Inform Decision Makers

The scope of existing analyses of the economic impact of invasive species  in the United States range from narrow to comprehensive. In addition, some of  the actions that agencies have reported to the council are not clearly linked  to coordinated implementation of the management plan. However, while the national  management plan calls for many actions that would likely contribute to  preventing and controlling invasive species, even if the actions in the plan  were more fully implemented their effect would be uncertain because they  typically do not call for quantifiable improvements in invasive species  management or control. However, the council did not articulate in the plan a long-term outcome  or condition toward which the federal government should strive. The Current Regulations Concerning Ballast Water Management Are Not Keeping Invasive Species Out of the Great Lakes

According to experts and agency officials we consulted, current efforts by  the United States and Canada are not adequate to prevent the introduction  of nonnative aquatic organisms into the Great Lakes via ballast water of  ships, and they need to be improved. Compliance with U.S. Recommendations for Executive Action

To better manage the threats posed by invasive species in the United States,  we recommend that the cochairs of the National Invasive Species  Council—the Secretaries of Agriculture, Commerce, and the Interior— direct council members to:  Include within the revision to the National Invasive Species  Management Plan a goal of incorporating information on the economic  impacts and relative risks of different invasive species or pathways  when formulating a crosscuting invasive species management budget  for the federal government. To determine the experts’ views on the adequacy of U.S. and Canadian  efforts to control the introduction of invasive aquatic species into the  Great Lakes via the ballast water of ships, we selected and interviewed  experts from various stakeholder interests.
Why GAO Did This Study

Harmful invasive species--nonnative plants and animals that are spreading throughout the United States--have caused billions of dollars in damage to natural areas, businesses, and consumers. In 2001, the federal government issued a National Invasive Species Management Plan to focus attention on invasive species and coordinate a national control effort involving the 20 or so federal agencies that are responsible for managing them. This report discusses the economic impacts of invasive species, implementation of the management plan, and coordination of U.S. and Canadian efforts to control invasive species, including those introduced to the Great Lakes via the ballast water of ships.

What GAO Found

Existing literature on the economic impacts of invasive species is of limited usefulness to decision makers, although it indicates that the effects of invasive species are significant. Most economic estimates do not consider all of the relevant effects of nonnative species or the future risks that they pose. New initiatives may prompt more comprehensive analysis that could help decision makers make better resource allocations. While the National Invasive Species Management Plan calls for many actions that are likely to contribute to preventing and controlling invasive species in the United States, it does not clearly articulate specific long-term goals toward which the government should strive. In addition, the federal government has made little progress in implementing the actions called for by the plan. Even with high levels of compliance, U.S. regulations have not eliminated the introduction of invasive species into the Great Lakes via the ballast water of ships. The United States and Canada are working on strengthening the existing control system, but developing stronger regulations and the technology needed to meet them will take many years. The continued introduction of invasive species could have high economic and ecological costs for the Great Lakes.