Water hyacinth (Eichhornia crassipes) was introduced in Indian water bodies with the purpose of reducing pollution. This introduction is an example of:

Alien species invasions

The correct answer is Option (3) - Alien species invasions

Water hyacinth (Eichhornia crassipes) is an example of an alien species invasion.

Alien species, also known as exotic or non-native species, are species that have been introduced into an area outside their natural range, either intentionally or unintentionally, by human activities. In the case of water hyacinth, it was introduced into Indian water bodies with the intention of reducing pollution and improving water quality.

However, water hyacinth is a highly invasive species that can reproduce rapidly and spread quickly, forming dense mats on the water surface. These dense mats can block sunlight from reaching other aquatic plants, leading to their decline and disrupting the natural ecosystem balance. Additionally, water hyacinth can deplete dissolved oxygen levels in the water, negatively impacting aquatic life and causing harm to native species.

The unintended consequences of introducing water hyacinth demonstrate the potential dangers of introducing alien species into new environments. Such invasions can have severe ecological and economic impacts, leading to the displacement or extinction of native species and disrupting the functioning of ecosystems. As a result, the control and management of invasive alien species have become important aspects of biodiversity conservation efforts.