River interlinking and biodiversity risks in Indian freshwater ecosystems.

Area of Science:

• Ecology
• Conservation Biology
• Environmental Science

Background:

• India's National River Linking Project (NRLP) aims to transfer water between basins, potentially causing significant ecological disruption.
• Large-scale hydrological alterations raise concerns about freshwater invasive alien species (IAS) and their impact on native biodiversity.

Purpose of the Study:

• To assess the potential impact of river interlinking on the distribution and dynamics of freshwater IAS in India.
• To evaluate the interactions between IAS and native biodiversity, including threatened species, in relation to the NRLP network.

Main Methods:

• Species distribution models were used to map the potential distribution of 15 naturalised freshwater IAS based on bioclimatic variables.
• Distribution maps were overlaid with data on freshwater biodiversity, threatened species, and the proposed NRLP network.

Main Results:

• A strong positive correlation exists between IAS richness and both overall and threatened freshwater biodiversity.
• Biodiversity hotspots like the Krishna, Godavari, Mahanadi, Brahmaputra, and Western Ghats basins are identified as most vulnerable.
• Proposed interlinking routes are predicted to function as ecological corridors, facilitating biotic exchange and accelerating invasions.

Conclusions:

• River interlinking may enhance connectivity, leading to increased biological invasions and disruption of native ecosystems.
• Urgent incorporation of invasion ecology and biodiversity safeguards into NRLP plans is necessary to mitigate ecological risks.