Bioinvasions are a global threat to ecosystems, says IPBES report

Bioinvasions are a global threat to ecosystems, says IPBES report

Subject : Environment

Section: Biodiversity

Source: DTE

Context:

• Over 3,500 harmful invasive alien species have been introduced into regions and biomes around the world by human activities, says an assessment report.

Details:

• The global economic cost of invasive alien species, that negatively impact nature and people, exceeded $423 billion annually in 2019. Costs have at least quadrupled every decade since 1970.
• About 60% of species extinctions are attributable to invasive alien species either solely, or in combination with other drivers.
• About 90% of documented global extinctions of native species, attributed mainly to invasive alien species, have occurred on islands, especially remote islands.

Threats from Invasive Alien Species (IAS):

• The first comprehensive global report on invasive alien species and their control, published by
• The spread of invasive species is one of the five major threats to biodiversity and ecosystem services.
• Multiple anthropogenic activities have introduced more than 37,000 alien species to regions and biomes around the world, with the number rising at 200 new alien species every year.
• A conservative estimate from India suggests that over the last 60 years, invasive species have cost the Indian economy $127 billion. A pan-India monitoring of invasive plants for the last 16 years suggests that one-time control of invasive plants across India would necessitate $13.5 billion, with uncertain outcomes.

Impact on Island nations and indigenous communities:

• Most countries lack a national legislation or regulations directed specifically towards the prevention and control of invasive alien species.
• 90% of documented global extinctions attributed mainly to invasive alien species have occurred on islands, especially remote islands with high levels of endemism.

Bioinvasion:

• A bioinvasion occurs when a species that originally exists in a certain part of the planet is intentionally or, more often, accidentally introduced into an entirely new location.
• This happens, for example, whenever a ship carrying fruit cargo also carries in a new species of spider among the fruit, or parasites on the ship mascot, or burrs stuck on the captain’s jacket.
• “Invasional meltdown hypothesis” where various invader-invader interactions facilitate further invasions. Interactions among invasive alien species can enable further biological invasions.
• Negative impact of bioinvasion:
  • The more we human beings travel to all parts of the globe, the more bioinvasions we spread.
  • The negative impacts of bioinvasions are far-reaching, affecting the economy, food security, water security and human health.
  • The spread  of South American shrub Lantana camara impacted the  livelihoods and wellbeing of the Soliga Adivasis in Karnataka.
• Positive impact:
  • Prosopis juliflora, an invasive alien tree. Charcoal made from the tree is a source of income for local communities and hence attempts at managing the species have been problematic.