Why in News?

• An ATREE, Bengaluru study in Scientific Reports warns that the National River-Linking Project (NRLP) could spread invasive alien species between river basins.
• The Lower Ganga Basin, with 13–15 invasive species, may spread them to the Mahanadi Basin, which has 69 threatened species.
• Northeast and peninsular basins are more vulnerable than Central and North Indian basins.

Context

• Invasive alien species are non-native species that spread in a new habitat and harm native biodiversity, ecosystems or the economy.
• India’s river basins are naturally isolated, so many freshwater species are endemic to one basin or a small area.
• The NRLP, run by the Ministry of Jal Shakti through the National Water Development Agency (NWDA), proposes to move water from “surplus” to “deficit” basins.
• As reported, it would redistribute about 174 billion cubic metres of water and generate about 34,000 MW of power.
• The Ken-Betwa link is the first link taken up under the project.

• Linking rivers can remove the natural barriers that keep species and pathogens apart.
• Biodiversity hotspots can turn into “invasion hotspots” by accumulating more invasive species.
• The study considered only 15 freshwater invasive species with available data. Across India, about 350 to 400 species are at different stages of invasion.
• Aquatic pathogens can also spread, and fish in one basin may have no immunity to the pathogens of another.
• Reduced downstream flow and sediment can harm downstream and endemic species.

• Environment: Mixing of basin biota can cause biotic homogenisation, and dams and canals fragment habitats and disturb fish migration.
• Economy: Fisheries, farmer livelihoods and the agro-economy can suffer from pathogen spread, loss of native fish and invasive weeds.
• Governance: India has no dedicated invasive species policy, unlike Australia and Europe. “Surplus” and “deficit” labels can also hide seasonal variation in river flows.
• International Relations: The project’s effects may extend to downstream countries on shared rivers.

• Brings in a neglected risk: Most debate on interlinking focuses on displacement, submergence and flows. This study adds biological invasion as a separate threat, which widens the scope of impact assessment.
• Gives a scientific basis for planning: Basin-level vulnerability mapping can help decide which links need extra safeguards, such as the Lower Ganga-Mahanadi link, described as one of the project’s most ecologically sensitive links.
• Supports sustainable development: The findings show that water security goals have to be balanced against ecological security, which is central to SDG 6, SDG 14 and SDG 15.
• Highlights the need for an invasive species policy: The estimate of 350-400 species at various stages of invasion shows that the issue goes well beyond river projects.

• NRLP and the Ken-Betwa Link Project, for inter-basin water transfer.
• Biological Diversity Act, 2002, for biodiversity conservation.
• Wildlife (Protection) Amendment Act, 2022, which has provisions to regulate invasive alien species.
• EIA framework under the Environment (Protection) Act, 1986.
• Kunming-Montreal Global Biodiversity Framework under the CBD, which includes a target to curb invasive species.

Constitutional Provisions

• Article 21 – Right to a healthy environment.
• Article 48A – State’s duty to protect the environment.
• Article 51A(g) – citizens’ duty to protect nature.
• Water is under State List (Entry 17), while inter-State rivers come under Union List (Entry 56).

Legal Framework

• Biological Diversity Act, 2002 – conservation of biodiversity.
• Wildlife (Protection) Amendment Act, 2022 – stronger wildlife protection.
• Inter-State River Water Disputes Act, 1956 – framework for resolving river-water disputes.

Important Data & Global Linkages

• Important Data: Lower Ganga has 13–15 invasive species, while the Mahanadi has 69 threatened species. India has around 350–400 invasive species at different stages of invasion.
• Global Linkages: Relevant to SDGs 6 (Clean Water), 14 (Life Below Water) and 15 (Life on Land), along with the Convention on Biological Diversity (CBD) and Kunming-Montreal Global Biodiversity Framework.