Context – In the last few months, various government and non-governmental organisations in Andhra Pradesh, Odisha, and Punjab have released mosquitofish into local water bodies to address a mosquito menace that locals have complained about.
About the news:
- In the 1960s, such approaches – including introducing mosquitofish in freshwater ecosystems to feed on mosquito larvae – became prominent as alternatives to chemical solutions like pesticides.
- Among mosquito predators were two species of mosquitofish, Gambusia affinis and Gambusia holbrooki.
- Aside from their resilience, these fish also have voracious feeding habits and have demonstrated aggressive behaviour in habitats to which they are introduced.
- In 2018, the National Biodiversity Authority of the Government of India also designatedG. affinis and G. holbrooki as invasive alien species. But both government and non-governmental organisations in India have continued to introduce these species for mosquito-control.
Invasive species in India:
- Invasive species are emerging as a severe threat, especially to natural and agricultural landscapes.
- Invasive species can harm both the natural resources in an ecosystem as well as threaten human use of these resources. An invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and other means.
- India is known to have more than 200 invasive species. Some of India’s most notorious invasives include lantana, parthenium, Siam weed, Mexican devil (Ageratina adenophora) and mesquite (Prosopis juliflora). The water hyacinth (Eichhornia crassipes) has invaded many inland water bodies, while alligator weed (Alternanthera philoxeroides) invades both aquatic and terrestrial habitats in India. C. riisei is the invasive coral which attaches itself to various surfaces in the sea, usurping space and vital nutrients from other marine species, including corals, sponges, algae etc.
- Criteria followed by National Biodiversity Authority to identify whether the species is invasive or not-
Characteristics/Reasons for their dominance:
Impacts:
Invasive species threaten biodiversity and ecosystem processes, with direct and indirect impacts on human wellbeing. They suppress native biodiversity and cause local extinctions. They alter wildlife habitat. They affect livelihoods directly by suppressing species that people depend on (e.g., non-timber forest products, ‘NTFP’) and by encroaching on private and commonly held agricultural and grazing land. They affect livelihoods and wellbeing indirectly by altering hydrology, damaging soils, affecting the provisioning of ecosystem services, and due to costs incurred in their control or management. Further they can also lead to various disasters for eg, Lantana is changing the fire patterns in Himalayan forests making new areas vulnerable to wildfires and deforestation subsequently leading to soil erosion, landslides etc.
