The Unintended Consequences of Mosquitofish Introductions in India

November 24, 2023

In recent months, various regions in Andhra Pradesh, Odisha, and Punjab have released mosquitofish into local water bodies to address mosquito problems. While the biological control of mosquitoes, including the use of mosquitofish, gained traction in the 1960s as an alternative to chemical pesticides, the unintended consequences have been significant.

What is Mosquitofish?

Mosquitofish, particularly Gambusia affinis and Gambusia holbrooki, were introduced in India in the 1920s and later by various governmental and private organizations as part of mosquito management efforts. The idea was to use these fish to feed on mosquito larvae and control mosquito populations, especially those responsible for spreading diseases.

Unintended Environmental Impact

Despite good intentions, the mosquitofish strategy backfired, leading to severe ecological and environmental problems. Mosquitofish, originally from the U.S., became widespread in India, establishing self-sustaining populations in various habitats. The resilience and voracious feeding habits of these fish have caused them to displace and prey on native fauna, leading to the extinction of native fish, amphibians, and other freshwater communities.

Effects on Biodiversity

Studies reveal the harmful consequences of Gambusia presence in water bodies. In Australia, introduced mosquitofish contributed to the local extinction of an endemic fish species. Similar observations have been made in New Zealand, where Gambusia poses a threat to native aquatic biodiversity. In India, reports suggest a decline in tadpoles following the introduction of mosquitofish.

Recognition as Invasive Alien Species

The World Health Organization stopped recommending Gambusia as a mosquito control agent in 1982, and in 2018, the National Biodiversity Authority of the Government of India designated G. affinis and G. holbrooki as invasive alien species. Despite this, both government and non-governmental organizations in India continue to introduce these species for mosquito control.

Call for Stricter Measures and Native Alternatives

To address the issue, stringent enforcement measures are crucial to prevent further introductions of mosquitofish. The National Centre for Vector Borne Diseases Control’s recommendation for using Gambusia should be removed. Additionally, experts suggest collaboration between mosquito biologists, invasion ecologists, and fish taxonomists to identify and release native fish species capable of controlling mosquito larvae, avoiding the ecological repercussions associated with invasive alien species.

« Previous Post Next Post »