Discusses the movement of invasive species, including both natural and man-made pathways. See our Pathways and Risk Assessment sections for more information and resources.

Pathways are 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.

The first type is intentional, which is the result of a deliberate action to translocate an organism. Examples of intentional introductions include the intended movement of living seeds, whole plants, or pets. Intentional introductions as a whole should not be labeled as either good or bad. A specific intentional pathway can only be judged by the positive or negative impact of the specific organisms that are moving along that means.

The second type of man-made pathways are those pathways which 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 and countless other unintentional pathways the movement of species is an indirect byproduct of our activities.

For the purposes of the National Invasive Species Council, the term "vector" is viewed as a biological pathway for a disease or parasite (i.e. an organism that transmits pathogens to various hosts) and is not completely synonymous with the much broader definition of a pathway.