What are Invasive Alien Species?
- Conservation scientists warn that “stealth invader” species — invasive aliens spreading silently across India — are destroying native biodiversity and transforming natural landscapes.
What are Invasive Alien Species?
- The Convention on Biological Diversity (CBD) defines invasive alien species (IAS) as those whose introduction and spread outside their natural distribution threaten biodiversity.
- IAS can include animals, plants, fungi, and even microorganisms, affecting various ecosystems.
- The CBD summarises the characteristics of IAS as “arrive, survive, and thrive.” This means they need an introduction, either naturally or by humans, to survive on native food, reproduce quickly, and outcompete native species for resources.
- Approximately 37,000 established alien species have been introduced globally, with around 200 new species introduced annually.
- Since the 17th century, invasive alien species have contributed to nearly 40% of all animal extinctions.
Characteristics of Invasive Species
- Rapid reproduction and growth
- High dispersal ability
- Broad dietary range
- Physiological adaptability to new conditions
- Tolerance to a wide range of environmental factors
- Capacity to alter growth forms based on surroundings
Common Invasive Species Found in India
- Viper grass
- Lantana camara
- Prosopis juliflora
- Water hyacinth
- African catfish
- Cotton Mealy Bug
- Primrose Willow
Impacts of Invasive Species
- Invasive species disrupt food chain, alter ecosystem balance, and threaten native flora and fauna.
- In the absence of natural competitors or predators, they can dominate entire habitats.
For instance, in Keoladeo National Park, Rajasthan, the African catfish preys on native waterfowl and migratory birds, disturbing the park’s ecosystem.- Similarly, the cotton mealybug has devastated cotton crops in the Deccan region, causing significant yield losses.
- Globally, the economic cost of invasions exceeded $423 billion in 2019, due to ecosystem damage, loss of biodiversity, and reduced agricultural productivity.
Initiatives to Control Invasive Alien Species
- CBD Aichi Target 9: Aims to identify, prioritise, and manage invasive alien species.
- Global Invasive Species Programme: It is supporting the implementation of Article 8(h) of CBD with IUCN as a partner organisation to address the global threat from Invasive Alien Species (IAS).
- Convention on Migratory Species of Wild Animals (Bonn Convention): It considers IAS as a threat to migratory species.
- Ramsar Convention: COP 7 resolution addresses threats of invasive species to wetland ecosystems.
- IUCN SSC Invasive Species Specialist Group (ISSG) aims to reduce threats to ecosystems and their native species by increasing awareness of ways to prevent, control or eradicate invasive species.
