Invasive alien species (IAS) are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity. IAS occur in all taxonomic groups, including animals, plants, fungi and microorganisms, and can affect all types of ecosystems. While a small percentage of organisms transported to new environments become invasive, the negative impacts can be extensive and over time, these additions become substantial. A species introduction is usually vectored by human transportation and trade.

If a species’ new habitat is similar enough to its native range, it may survive and reproduce. For a species to become invasive, it must successfully out-compete native organisms, spread through its new environment, increase in population density and harm ecosystems in its introduced range. Ecosystems that have been invaded by alien species may not have the natural predators and competitors present in its native environment that would normally control their populations. To summarize, for an alien species to become invasive, it must arrive, survive and thrive.

Islands are especially vulnerable to IAS because they are naturally isolated from strong competitors and predators. Islands often have ecological niches that have not been filled because of the distance from colonizing populations, increasing the probability of successful invasions. Invasive Alien Species (IAS) is a critical issue in the Caribbean since it may impact