Origins

Invasive species need a path from their native range to the new area they invade. These paths are typically called vectors. Vectors can include lifeforms (birds, fish, humans) and objects (transport vessels, cargo, ballast water of ships). Some exotics were brought over deliberately, while other have been transported unintentionally.

Move the cursor over the below species to see where they came from and where they invaded, as well as the means of how they invaded.

Dandelions were believed to be introduced to New England in the 1600s by European colonists who used the plant as a salad green. Dandelions are major problems in urban areas.

Fire ants were brought in to Mobile, Alabama in dry ship ballast in the early 1940s. These ants can be a threat to human health.

The Sri Lanka aquatic plant, hydrilla, was brought to the U.S. by a St. Louis aquatic plant dealer in 1947. Now it clogs waterways, removing stretches of water from boating and fishing.

Kudzu was originally introduced to the U.S. by the Japanese government at the Philedelphia Centennial Exposition in 1876. Now a major threat to forests throughout the East.

Miconia is a devastating plant that can destroy vast expanses of tropical rainforests. This plant was brought to Maui as an ornamental in a botanical garden near Hana.

Purple loosestrife came to the U.S. in ship ballast and by humans who used the plant as a medicinal herb or as an ornamental plant. Very destructive to wetlands.

Tamarisk is a severe threat the the arid West due to its ability to use large quantities of water. Brought to the U.S. from Asia for use as ornamental plants, windbreaks, and soil stabilizers.

Zebra mussels have caused billions of dollars of damage to industries along the Great Lakes and greatly modifies the native ecosystems. Accidentally brought over in ship water ballast.