Where do invasive species come from?
The manner in which an invasive species enters or spreads throughout a non-native ecosystem is called a pathway or vector. Pathways can be natural or the resut of human activities. Species can travel via weather patterns, tides and water currents, or within the digestive tract of a migratory animal. New species are imported for use in aquaculture, aquaria, and gardening. Other human pathways include shipping materials, ballast water, trucks and recreational boats, and even the shoes of travelers.
