Context:

• Recently, a report on the status of invasive alien species (IAS) was released at 10th plenary of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

Highlights of the Report:

• Anthropogenic introduction of IAS: 37,000 alien species have been introduced by human activities to regions and biomes around the world.
  • Many IAS have been intentionally introduced for their perceived benefits, without consideration or knowledge of their negative impacts.
• Threat to biodiversity: IAS are one of the five major direct drivers of biodiversity loss globally, alongside land and sea use change, direct exploitation of organisms, climate change, and pollution.
  • IAS have been a major factor in 60% and the only driver in 16% of global animal and plant extinctions that have been recorded, and at least 218 invasive alien species have been responsible for more than 1,200 local extinctions.
• Economic cost: It has at least quadrupled every decade since 1970, as global trade and human travel increased. 
  • In 2019, the global economic cost of invasive alien species exceeded $423 billion annually.
• Impact on food supply: The reduction of food supply is the most common impact of alien invasive species. 
  • Caribbean false mussels have damaged locally important fishery resources in Kerala, by wiping out native clams and oysters. 
• Spread of diseases: IAS like Aedes albopictus and Aedes aegyptii spread diseases such as malaria, Zika and West Nile Fever.
• Amplifying the impact of climate change: Invasive alien plants, especially trees and grasses, can sometimes be highly flammable and promote more intense fires.
  • IAS can reduce the resilience of natural habit, agricultural systems and urban areas to climate change.
• Geographical Impact: 34% of the impacts of biological invasions were reported from the Americas, 31% from Europe and Central Asia, 25% from Asia and the Pacific and about 7% from Africa. 
• Threat concentration: Most negative impacts are reported on land (about 75%) with considerably fewer reported in freshwater (14%) and marine (10%) habitats . 
  • Invasive alien species are most damaging on islands, with numbers of alien plants now exceeding the number of native plants on more than 25% of all islands.
• Threat management: Only 17 percent have enacted specific national laws or regulations for IAS management.
  • 45 percent of all countries do not invest in the management of IAS. It escalates the threat of IAS spilling over into neighboring states.

Significance:

• Impact assessment: It will help improve the understanding of IAS, their impacts, and opportunities for their management across all sectors of society. 
• Action plan under KMGBF: The assessment can be used for updating the national biodiversity strategies and action plans (NBSAPs) mandated under Kunming-Montreal Global Biodiversity Framework (KMGBF).

• Coordinated Actions: It will support countries and the private sector in developing and implementing actions towards meeting the targets under KMGBF.

Impact of IAS on India:

• India stands in second place after the US on the list of invasion-cost bearing countries.
  • Invasive alien species cost the Indian economy $127.3 billion (Rs. 8.3 trillion) in the last 6 decades.
  • IAS cost the Indian economy $127.3 billion in the last 60 years.
• Lantana camara: Its invasion has resulted in the scarcity of native forage plants for wild herbivores; it has invaded more than 40% of India’s tiger range.
• Prosopis Chilensis: A drought-resistant plant native to the arid regions of South American countries is threatening native vegetation of islands in the Gulf of Mannar Biosphere Reserve.
• Prosopis juliflora: It is a water-guzzling invasive species which extracts maximum water from the ground impacting the groundwater levels adversely affecting local biodiversity and ecology.

Important Recommendation from the Report

• Incorporating IAS in Climate change policies: Climate change should be explicitly incorporated into risk assessments of IAS, to help identify those alien species that could become a threat in the future.
  • Example: Native tree species should be used for carbon sequestration or erosion control rather than alien species such as Acacia or Eucalyptus.
• Mapping vulnerability: Ecosystems need to be prioritised according to their vulnerability to climate change and IAS and measures need to be established for preventing IAS introduction. 
• Prevention measures:  Border biosecurity and strictly enforced import controls has worked in controlling the spread.
  • Example: Success has been achieved in Australasia in reducing the spread of the brown marmorated stink bug.
• Protecting marine and connected water systems: Preparedness, early detection and rapid response are shown to be effective at reducing rates of alien species establishment. 
• Surveillance of new alien species: The PlantwisePlus programme in Australia assisted smallholder farmers in Africa, Asia and Latin America in detecting new alien species.
• Eradication: It has been successful and cost-effective for small and slow-spreading IAS, in isolated ecosystems such as islands. 
  • Examples: French Polynesia where the black rat and rabbit(have been successfully eradicated. 
• Containment: IAS must be contained and controlled in land-based and closed water systems as well as in aquaculture.
  • Containment of the IAS Asian tunicate in aqua-cultured blue mussels in Canada. 
  • Introducing a rust fungus to control bitter vine in the Asia-Pacific region has been effective with success in more than 60% of known cases.
• Involvement of local communities: Successful eradication programmes depend on the support and engagement of stakeholders and Indigenous Peoples and local communities.

News Source: Indian Express