America's most wanted fishes: Cataloging risk assessments to prioritize invasive species for management action

Hundreds of fish species enter the United States through human intervention (e.g., importation) and some of these fishes pose a substantial risk to the nation’s assets and ecosystems. Prevention, early detection, and rapid response (EDRR) are vital to stop species invasions, but time and resources to manage the large suite of fish species that enter the nation are limited. Evaluating the risk of a species’ invasion in a location is one way to prioritize among many species for management action. Species risk assessments are often associated with information systems or are published within grey literature or peer-reviewed journal articles. Improving access to available risk assessments could help in prioritizing management action for the most potentially invasive fish species. We aggregated fish species risk assessments, synthesizing the current knowledge on the risk of fish invasions in the United States. To accomplish this, we searched information systems and conducted a literature review. We then summarized risk assessment results along with the importation statuses of fish species and identified if imported, high-risk species are managed under federal or state policy. Within the scope of the conterminous U.S., we found 98 high-risk fish species. Eighteen of these species are imported to the country, but only three species have been recently prohibited from importation according to the Lacey Act. We observed similar patterns at the scales of the Great Lakes region and Florida. Collectively, our work provides a baseline estimate of the high-risk fish invaders that enter the U.S. through importation, underscoring species to consider for priority management action, as well as a benchmark of species that lack risk assessments. Insights from this work can be enriched when joined with other invasive species information, which could be accomplished through a national EDRR information system, an information sharing hub in development by the U.S. Geological Survey.