Invasive Alien Species

Source:  TH

Context: A new study published in Nature Ecology & Evolution has revealed that India is massively underestimating the economic cost of invasive alien species, with management costs underreported by over 1.16 billion percent — the highest global discrepancy.

About Invasive Alien Species (IAS)

What it is?

• As per the Convention on Biological Diversity (CBD) and Indian law, an invasive alien species is a non-native organism whose introduction and spread threaten biodiversity, ecosystem services, or human well-being.
• The Indian National Biodiversity Authority (NBA) defines them as species outside their natural range that establish and proliferate, causing ecological or economic harm.

Characteristics of IAS

1. High adaptability – thrive in disturbed or new ecosystems.
2. Aggressive growth – outcompete native species for light, water, and nutrients.
3. Reproductive advantage – rapid breeding or vegetative propagation.
4. Absence of predators – flourish unchecked in new habitats.
5. Economic and ecological impact – alter soil chemistry, hydrology, and crop yields.

Global Impact

• Global cost of invasive species since 1960 exceeds $2.2 trillion.
• Non-native plants account for the highest management cost ($926 billion).
• Arthropods ($830 billion) and mammals ($263 billion) follow.
• Europe reported the highest cost ($1.5 trillion).

India’s Case

• Lantana camara, Parthenium hysterophorus, Prosopis juliflora, and Water Hyacinth dominate forests, rangelands, and wetlands.
• Large swathes of Bandipur, Mudumalai, and other reserves are overrun by lantana.
• Agriculture suffers due to weeds like parthenium reducing crop yields.
• Aquatic invasives clog waterways, impacting irrigation and fisheries.

Threats Posed

1. Biodiversity loss – displacement of native flora and fauna.
2. Agricultural losses – reduced productivity and higher input costs.
3. Health hazards – allergenic weeds cause respiratory and skin diseases.
4. Forest fire risks – highly combustible species like lantana increase wildfire incidents.
5. Economic drain – hidden management costs undermine development goals.

Initiatives for Management

• National Biodiversity Action Plan (NBAP) emphasises IAS management.
• Convention on Biological Diversity (CBD), 1992 – India is a party and obligated to control IAS.
• National Biodiversity Authority (NBA) – coordinates IAS prevention and awareness.
• Ballast Water Management Convention – to prevent marine invasions.
• State-level eradication drives – manual removal, biocontrol measures, controlled grazing, and afforestation.