Question

Alien species are highly invasive and are a threat to indigenous species. Substantiate this statement with any three examples.

Answer 1

Alien species are highly invasive and pose a threat to indigenous species by causing competition, predation, habitat destruction, and disease transmission. For example, the introduction of the Nile perch into Lake Victoria in East Africa led to the extinction of over 200 native cichlid fish species. Invasive weeds like carrot grass (Parthenium), Lantana, and water hyacinth (Eichhornia) damage native ecosystems. Additionally, the illegal introduction of the African catfish (Clarias gariepinus) threatens indigenous catfish in rivers. These invasions reduce biodiversity and disrupt ecological balance.