INVASIVE ALIEN SPECIES (Syllabus: GS Paper 3 – Env and Eco)

Context: In a bid to manage the teeming population of chital (spotted deer) in Ross Island, the Andaman and Nicobar Islands administration recently sought help from the Wildlife Institute of India.

Invasive Alien Species

• About: Invasive alien species (IAS) are defined by the Convention on Biological Diversity (CBD) as species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity.
• Scope: IAS encompass animals, plants, fungi, and microorganisms, affecting various ecosystems.
• Characteristics: According to the CBD, IAS exhibit the traits of "arrive, survive, and thrive," needing introduction, native food resources, fast reproduction, and outcompeting native species.
• Legal Definition in India: India's Wildlife Protection Act, 1972 (amended in 2022), defines IAS more narrowly as species not native to India, whose introduction or spread may threaten wildlife or its habitat.
• Exclusion of Regional Invasives: The Indian definition excludes species within India that may be invasive to specific regions, like the chital in the Andamans, which are protected in mainland India but pose a threat in the island chain.
• Examples: African catfish, Nile tilapia, red-bellied piranha, and alligator gar, and turtle species such as the red-eared slider.

Impact on Native Flora and Fauna:

• In the absence of competition, invasive species can dominate entire ecosystems, altering their dynamics.
• The African catfish in Keoladeo Park, Bharatpur, preys on water fowls and migratory birds, illustrating the direct impact of invasive species on native fauna.
• Economic Impact of Invasive Alien Species
• The IPBES report highlights that approximately 37,000 established alien species have been introduced worldwide, with around 200 new alien species added annually.
• The proliferation of invasive species can result in significant economic losses due to damage to agriculture, infrastructure, and ecosystems.