Invasive Alien Species

Syllabus: GS3/Environment 

In News

• Conservation scientists warn that invasive alien species are destroying local biodiversity and habitats in India. 

Invasive alien species

• Definition: They are non-native organisms introduced accidentally or intentionally (e.g., ornamental fish, decorative plants, or for land restoration). 
• They often lack natural predators in the new environment, allowing them to multiply unchecked.
• They often spread rapidly, outcompeting native species, harming biodiversity, causing local or global extinctions, and damaging habitats.

Common Examples in India

• Lantana camara: Invades forests, outcompetes native plants, and hinders regeneration.
• Parthenium hysterophorus (Congress grass): Spreads over farmland and causes allergic reactions.
• Eichhornia crassipes (Water hyacinth): Chokes lakes and rivers, depleting oxygen and affecting fisheries.
• African Catfish (Clarias gariepinus): Outcompetes native fish species, threatening aquatic biodiversity.

Control and Management Measures

• Prevention:
  • Stricter quarantine checks on imports, trade, and shipping.
  • Ballast water management in ships to prevent marine invasions.
• Control Methods:
  • Biological Control: Introducing natural predators, pathogens, or parasites (e.g., insects for Lantana).
  • Mechanical Control: Manual removal, cutting, dredging, or uprooting.
  • Chemical Control: Use of herbicides or pesticides — applied cautiously to avoid ecological harm.
• Eradication & Restoration:
  • Early detection and rapid response for localized infestations.
  • Reintroduce native species and restore degraded ecosystems after removal.

Source: TH