Alien species are highly invasine and are a threat to indigenous species. Substantiate this statement with any three examples.
New species entering the geographical region are known as alien species. Introduction of alien species causes a significant loss to the biological community. However, some of the species are able to establish the area. Such successful exotic species eliminate the native species to the point of extinction, and so alter the habitat that many native species are no longer able to persist.
For example introduction of Nile perch into Lake Victoria disturbed the ecosystem of the lake by eliminating several native species of small cichlid fishes.
When the exotic species of water hyacinth were introduced in Idia it caused huge water pollution and occupied all the water bodies.