How do they get here?
Plants and animals have always traveled with us. The more we travel, the more species we unknowingly transport. Our transportation methods then become pathways for invasive species.
For example, birds or the wind can carry seeds from garden plants into the wild. Exotic pets escape or are released into parks, lakes, and rivers. People can carry seeds on their clothing, in suitcases, or on cars. Packets of birdseed can contain seeds of invasive plants.
Solid waste and soil that have invasive plants can be dumped as fill into wetlands. Plant seeds, insects, small animals, and organisms can hide in ship cargoes or ballast water, on the outside of boats, and on planes.
There are many such pathways, some more important than others:
- Importation of seeds, plants, fruits, and vegetables. Visit the U.S Department of Agriculture's Import and Export Web site.
- Ballast water discharged from ships. Visit the U.S. Environmental Protection Agency's Web site.
- Soil brought in with nursery stock. Visit the Washington Invasive Species Coalition’s Garden Wise booklet.
- Abandoned pets and ornamental plants. Visit the Habitattitude Web site.