Which of the following statements is correct?

Steller's sea cow is an extinct animal .

The correct answer is Option (1)- Stellers's sea cow

Over-exploitation refers to the excessive and unsustainable harvesting of a species by humans. In the case of Steller's sea cow, the uncontrolled hunting by sailors and explorers led to the rapid decline and eventual extinction of this species . This serves as a historical example of the severe consequences of over-exploitation on vulnerable and slow-reproducing species.

Humans have always depended on nature for food and shelter, but when ‘need’ turns to ‘greed’, it leads to over -exploitation of natural resources. Many species extinctions in the last 500 years (Steller’s sea cow, passenger pigeon) were due to overexploitation by humans.

Eichhornia crassipes( water hycinth) also called "Terror of Bengal" due to its rapid proliferation as an exotic shrub on water surfaces. This growth impedes the development of fish and other aquatic life by reducing light penetration and oxygen levels.

When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause decline or extinction of indigenous species. Some examples of invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia). The recent illegal introduction of the African catfish Clarias gariepinus for aquaculture purposes is posing a threat to the indigenous catfishes in our rivers.