Question

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

Answer 1

Hint:-In modern times the loss of Biodiversity is increasing which causes serious damages to the whole earth as an ecosystem (biome). The loss of biodiversity in a region may lead to a decline in plant production, lowered resistance to environmental calamities such as drought, increased variability to certain ecosystem processes such as plant productivity, water use, and disease cycles.

Complete step-by-step solution:-
● The major causes of the accelerated biodiversity losses are namely — Habitat loss and
fragmentation (Deforestation), Overexploitation, Alien species invasion, and Co — extinctions.
These together are called “Evil Quartet”.
● The introduction of an alien species to a particular place whether unintentionally or deliberately
for whatever purpose, they turn invasive and cause decline or extinction of indigenous species.
● An alien species of fishes called the Nike perch which is being introduced in Lake Victoria in East
Africa led eventually to the extinction of an ecologically unique assemblage of more than 200
species of Cichlid fishes in the lake.
● The invasive alien weed species like Parthenium (carrot grass), Lantana, and Eichhornia (water
hyacinth) have caused tremendous threat and environmental damage to our native species.
● Another illegal introduction of the alien species which is an African Catfish, Clarias gariepinus,
for aquaculture purposes is posing a threat to the indigenous species of catfishes in our rivers.
● All the alien species becoming invasive leads to an imbalance in the ecosystem.
● The extinction of a particular species can also lead to the extinction of other species that are
closely related to them. This is another reason for the loss of biodiversity called Co-extinction.

Note:- The major cause of biodiversity loss is Habitat loss and fragmentation (Deforestation). When large habitats are broken up into small fragments due to various human activities, certain animals with migratory habits are badly affected, leading to population declines. Humans have always depended on nature for food and shelter, but when need turns to greed, it leads to overexploitation of natural resources, thus, leading to extinctions.