Fish and Aquatic Conservation


photo of zebra mussels
Zebra Mussels. Photo credit: USFWS

Invasive Species Prevention: Keeping Risky Species Out of the United States

Commerce in live organisms is a multi-billion dollar industry. On rare occasions, a small fraction of these organisms escape captivity or are released where they are not native. When this occurs in suitable habitat, these organisms may survive, become established in the environment, disperse, and cause harm. Once a nonnative species causes harm, we considered it an invasive species. This harm can include loss of crops, livestock, timber, fisheries, and other resources, as well as increased diseases and damage to property. The collective losses caused by invasive species cost Americans billions of dollars annually. In addition to live organisms being introduced by commerce, invasive species can be introduced or spread from activities related to transportation, such as “hitchhiking” in ships’ ballast water and in packing materials. The U.S. Fish and Wildlife Service (Service) is working on reducing the risk from invasive species from these pathways.

Preventing harmful species from entering the United States is the most cost-effective and efficient approach for avoiding the severe ecological and economic effects caused by many invasive species. One way to prevent nonnative wildlife species from becoming invasive is to list them as injurious species under the Lacey Act (18 U.S.C. 42, as amended), which prohibits their importation into the United States. Listing a species as injurious under the Lacey Act can be a lengthy process that, until the listing is finalized, leaves the environment vulnerable to the introduction and establishment of an invasive species. Once a species becomes established, it is extremely unlikely that it can be eradicated, and such attempts are expensive and may cause unintended environmental injury.

The Service’s Fish and Aquatic Conservation Program (FAC) has been working to streamline the implementation of its regulatory process, but this process should not be the only approach used to solve problems from harmful, nonnative species that may be in the live-organism trade. The Service is also working on the following two approaches:

  1. Ecological Risk Screening Summaries (ERSS): The Service has developed a process to efficiently characterize and prioritize the potential risk of invasiveness from species of wild animals and plants. The final output is a report for each species called an Ecological Risk Screening Summary (also referred to as an ERSS) that provides an estimated prediction of invasivenenss of that species and that can be used by the Service, its natural resource partners, and the public to help inform their decisionmaking.
  2. Partnership for Prevention: The Service is working cooperatively with the Association of Fish and Wildlife Agencies and industries that trade in live animals. Many of these industries understand that some of their trade species have become, or have a high potential to become, injurious, and they do not want to perpetuate the problem.

Ecological Risk Screening Summaries

The Service has developed a process to efficiently characterize and prioritize the potential risk of invasiveness from species of wild animals and plants. Ecological Risk Screening Summary (also referred to as an ERSS) that provides an estimated prediction of invasiveness of that species and that can be used by the Service, its natural resource partners, and the public to help inform their decisionmaking.

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Partnership for Prevention

The Service is working cooperatively with the Association of Fish and Wildlife Agencies and industries that trade in live animals. Many of these industries understand that some of their trade species have become, or have a high potential to become, injurious, and they do not want to perpetuate the problem.

Learn More


Supporting Documents

Links to the Ecological Risk Screening Summaries, as well as links to other web sites and documents mentioned in this website

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