Invasive Species and their Threat to Natural Ecosystems

Context

The Andaman & Nicobar Islands administration has sought help from Wildlife Institute of India (WII) in order to tackle the teeming population of Chital (Spotted Deer) in Ross Island.

About Invasive Alien Species (IAS)

• Convention on Biological Diversity (CBD) defines IAS as the species which on creation (either certainly or by human intervention)-thrive and continue to exist outside their natural habitat and threaten biological diversity by edging out native species in opposition over resources. 
• African catfish, Nile tilapia, pink-bellied piranha, alligator gar, pink-eared slider (turtle species) are some IAS in India.

Factors Responsible for Rising Invasive Species

• Globalization of Trade and Travel: Increased global trade and tourism have facilitated the unintentional movement of species across borders.
  • Cargo ships, airplanes, and cars can inadvertently deliver invasive species inside shipment, via ballast water, or connected to their surfaces, facilitating their unintentional spread.
  • Introduced to Australia in the late 1800s through shipwrecks and the pearling enterprise, the Black Rat has appeared as one of the “World’s Worst” invasive species via the IUCN.
• Climate Change: Elevated temperatures and shifts in precipitation patterns promote environments conducive to the colonization and proliferation of invasive species.
  • Shifts in the timing of seasons can disrupt the life cycles of local species, making them more susceptible to invasive competition and predators.
• Human Introduction of Exotic Species: Deliberate introduction of non-native species for functions like gardening, landscaping, and pest control can lead to invasions when those species escape cultivation.

Is Chital an IAS? 

• Wildlife Protection Act 1972 defines IAS as a species which isn’t local to India. This leaves out species in India which might be invasive to a specific area just like the Chital in Andamans. 
• Chitals, local to mainland India, are included in India and have been brought there through the British in the early 20th century. Having no natural predators or competition and being good swimmers- Chitals spread swiftly across the Andamans.

Impact of IAS on local plants and fauna

• IAS disrupt the food chain and the environment stability. In habitats wherein there’s no competition, they can dominate the entire environment. 
• For example, in Keoladeo National Park, the African catfish preys on water fowls as well as migratory birds. 
• Proliferation of Chital in Andamans has affected the regeneration of native vegetation, as they eat seeds and seedlings.

Economic effect

• Apart from causing dramatic modifications to biodiversity and ecosystems, the worldwide financial value from the harm inflicted by IAS on a place’s natural environment was over $423 billion yearly in 2019.
• For example, the cotton mealy bug- an invasive species native to North America significantly affected cotton vegetation in the Deccan, leading to yield losses.

Source: The Indian Express

UPSC Prelims Practice Question

Q.With reference to the International Union for Conservation of Nature and Natural Resources (IUCN) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which of the following statements is/are correct? (2015)

1. IUCN is an organ of the United Nations and CITES is an international agreement between governments.
2. IUCN runs thousands of field projects around the world to better manage natural environments.
3. CITES is legally binding on the States that have joined it, but this Convention does not take the place of national laws.

Select the correct answer using the code given below:

     (a) 1 only                    (b) 2 and 3 only

     (c) 1 and 3 only          (d) 1, 2 and 3

Ans: (b)

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