Controlling Introduction of Alien Species
As you know the alien species can cause the existing population to decrease or even become extinct. The individuals of alien species may affect the other species by preying on them, providing tough competition for food, or destroying their habitat. The alien species can also cause a population explosion of existing species by killing off their natural predators.
Island species are particularly vulnerable to the alien species, because they have evolved in ecosystems with few if any natural herbivorous or carnivorous species. SO before introducing the alien species, all these aspects should be kept in mind.