Wildlife Damage Management, Internet Center for



Date of this Version



Published by the Aquatic Nuisance Task Force and the National Invasive Species Council (2007) 59 pp.


The purpose of pathway risk analysis is to provide scientific analyses and policy recommendations in support of U.S. National Invasive Species Council’s Management Plan. These analyses and recommendations must comply with the Plan’s mandates to:

• ensure Federal efforts are coordinated and effective

• promote action and partnership at local, State, tribal and ecosystem levels

• identify recommendations for international cooperation; and,

• facilitate networks to document, monitor and prioritize invasive species pathways

Though many definitions for invasive species and pathways may exist, we are defining these terms as they relate to Federal regulatory functions. Definitions are recounted, below:

Invasive species (IS) - - an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.

Pathways - - the means by which species are transported from one location to another. Natural pathways include wind, currents, and other forms of dispersal in which a specific species has developed morphological and behavioral characteristics to employ. Man-made pathways are those pathways which are enhanced or created by human activity. These are characteristically of two types:

• Intentional pathways - - these result from deliberate actions to translocate an organism.

• Unintentional pathways - - these are man-made pathways that unintentionally move organisms. Examples of unintentional pathways are ballast water discharge (e.g. red-tide organisms), soil associated with the trade of nursery stock (e.g. fire ants), importation of fruits and vegetables (e.g. plant pests), and the international movement of people (e.g. pathogens). In these, the movement of species is an indirect byproduct of our activities.

This guide only addresses analysis of the second type of pathway: existing unintentional, man-made invasive species pathways; with a section devoted to policy synthesis. Though guide processes may be used for potential pathway analysis, such analysis must be based upon statistical predictive indicators of past trends - - which at this time is not feasible due to lack of consolidated data sources. For our purposes, analysis and policy synthesis are defined as:

Analysis-- the procedure by which we scientifically break down a ‘whole’ phenomena (i.e., unintentional IS incursions) into its parts or components.

Policy Synthesis-- the process by which we combine the analysis components into a comprehensive perspective to devise copasetic IS policies and actions on the local, regional, national and international levels.