CHENNAI: A recent study conducted by researchers at Ashoka Trust for Research in Ecology and the Environment (ATREE) has raised concerns about the vulnerability of the Cauvery and Pennar River basins in Tamil Nadu to the invasion of Invasive Alien Fish (IAF) species. The study attributes this susceptibility to both climate change and the proposed interlinking of rivers in the region.
The research highlights that the import and export of aquarium fish from Chennai could further contribute to the infiltration of IAF in the river basins. According to the study, the Cauvery River basin in Karnataka and Tamil Nadu, the Pennar River basin in Andhra Pradesh and Tamil Nadu, and the Krishna River basin covering parts of Karnataka and Telangana are identified as particularly vulnerable to IAF invasion.
The study notes that states like Andhra Pradesh, Tamil Nadu, and Kerala, being among the top five inland fisheries cultivators of freshwater fish, coupled with Chennai and port cities in Andhra Pradesh being major importers and exporters of aquarium fish in southern India, create an environment conducive to the spread of IAF.
Some of the IAF species, introduced as ornamental fish in aquariums, have entered local water bodies and are challenging to eliminate due to their adaptive life-history traits, the study adds. Additionally, projected climate change is expected to alter the distribution ranges of certain fish species, exacerbating the situation.
The study warns that river interlinking has the potential to connect vulnerable areas harbouring threatened fish species to IAF hotspots. It emphasizes the negative impact of explosive breeders like Gambusia and Poecilia, which can adapt to various environmental conditions and may be introduced into sensitive zones through river linking.
The researchers highlight the risk of increased distribution of Pterygoplichthys, a species with a positive correlation with climate change, posing a significant threat to native species and causing economic losses in commercial fisheries.
The study suggests creating awareness about the culinary uses of most IAF species, except for a few, to reduce their impact while aiding in monitoring and early detection. The researchers also call for a reconsideration of river interlinking plans to mitigate potential environmental risks.
Source: DT NEXT