Alien Species Invasions

Published on 04 Apr 2025

Invasive alien species (IAS) are animals, plants or other organisms that are introduced into places outside their natural range, negatively impacting native biodiversity, ecosystem services or human well-being.

Factors Responsible for Rising Invasive Species

• Globalization and Trade: The movement of species across borders has been assisted by increased trade and tourism across borders.

• Example: The Black Rat, which was brought to Australia in the late 1800s by shipwrecks and the pearling business, is considered by the IUCN to be one of the "World's Worst" invasive species.

• Human introduction of exotic species: Intentional introduction of non-native species for objectives such as gardening, landscaping, and pest management.

• Example: Himalayan Balsam is considered an invasive alien in temperate areas of Europe, Asia, New Zealand

• Climate Change: Temperature variations can change the habitat that is suited for a variety of species, enabling certain invasive species to flourish where they may not have been able to do so in the past.

• Example: Water hyacinth is found in parts of every continent except Antarctica, and it is expected to increase its range as the climate warms.

• Introduction of Agriculture and Fur industry: Agriculture, horticulture and other industries have served as gateway to many invasive species in different parts of the world.

• Example: American mink in Europe

• Inadequate Biosecurity Measures: Inadequate biosecurity controls at border crossings, ports, etc. can contribute to the unintended introduction of invasive species.

• Example: African catfish is banned by India’s Agriculture ministry but they are reared in across the country because of their low-cost meat.

Impacts of Invasive Alien Species 

• Biodiversity loss: Certain native species may become endangered or extinct due to predation or competition from invasive species.

• Example: P. julifora reduced the utility of indigenous herbs, trees and wild animals.

• Displacement of native species: Invasive species may outcompete native species for breeding sites, nesting sites, or other critical resources, resulting in changes in community composition.

• Example: Invasive alien tree Senna Spectabilis easily colonises the landscape by destroying the native vegetation in Wayanad Wildlife Sanctuary.

• Human health risks: Certain invasive species can cause allergies, spread disease, or foster an environment that attracts disease vectors, all of which can be harmful to human health.

• Example: Lantana camara is home to malarial mosquitoes and tsetse flies and stands as a reason for causing lethal diseases.

• Economic Costs: Many industries, including forestry, fisheries, and agriculture, can be negatively impacted by invasive species.

• Example: Zebra mussels can clog water pipes and infrastructure, resulting in costly repairs and maintenance.

• Impact on Food Supply: The most common consequence of alien invasive species is a reduction in food supply.

• Example: Water hyacinth in Lake Victoria led to the depletion of tilapia, affecting local fisheries.

• Habitat destruction: Native vegetation is frequently replaced by dense monocultures of invasive plants, which deteriorate wildlife habitats.

• Example: In rubber plantations, cover crops such as Mucuna, a nitrogen-regulating plant, are more likely to establish themselves in new areas and spread into the forest via landslide corridors.

Government initiatives and policy measures

• National Action Plan on Invasive Alien Species (2021-2025): It provides a framework for identifying, monitoring, and managing invasive species in India.

• National Mission on Biodiversity and Human Well-being: It aims to bring biodiversity and conservation to the forefront of Indian science, policy, and society’s attention.

• Regulatory Measures: Laws and regulations such as the Wildlife Protection Act, Biodiversity Act etc. help to regulate the introduction and spread of invasive alien species.

• Biological Control Program: The ICAR and other agencies have developed different biological control programs using organisms such as mites, insects etc. collected from the original home range of invasive species.

International initiatives

• Kunming-Montreal Global Biodiversity Framework: Governments have made a commitment to cut the rate of invasive alien species establishment and introduction by at least 50% by 2030.

• Global Invasive Species Database: It is a free, online searchable source of information about invasive and alien species that negatively affect biodiversity.

• Invasive Species Specialist Group (ISSG): It provides scientific expertise and information also facilitates collaboration and knowledge exchange among researchers, policymakers, and practitioners worldwide.

• Ramsar Convention on Wetlands: The convention's parties cooperate to mitigate the harm that invasive species cause to wetland ecosystems.

Way Forward

• Early detection and Rapid response: Early detection to find invasive species and act before they become established.

• Collaboration among multi-stakeholders: Encouraging different stakeholders in decision-making and addressing invasive species through knowledge sharing and resource exchange.

• Integrated Pest Management: Promote integrated pest management strategies as well as prioritize sustainable and environmentally friendly approaches to invasive species control.

• Capacity Building: Introducing capacity-building programs for local communities and authorities with the help of NGOs.

• International Cooperation: Encourage global cooperation to exchange best practices, insights, and knowledge about managing invasive species.

Tags:
Environment

Keywords:
Invasive alien species Biodiversity Habitat Invasive species

Syllabus:
General Studies Paper 3

Topics:
Biodiversity and Wildlife Conservation