Environmental threats and the way forward

Pollution tops the list of threats, affecting 54% of at-risk freshwater species. Agriculture and urban development exacerbate the problem, with pesticides, fertilisers, and untreated wastewater flowing unchecked into rivers and lakes.

Dams and water management projects, which alter natural flow regimes and block migratory routes, are the second-largest threat, impacting 39% of species. Invasive species, overharvesting, and climate change further compound the challenges.

According to Dr Rajeev, conservation strategies designed for iconic terrestrial species, such as tigers and elephants, do little to benefit freshwater species in shared habitats like the Western Ghats. For instance, the critically endangered humpbacked mahseer (Tor remadevii), a mega fish that can grow up to 60 kg, is severely threatened by habitat loss.

“Protecting freshwater fauna requires tailored interventions, such as restoring river ecosystems, regulating fishing, and preventing the spread of invasive species,” said Rajeev, who is also the South Asia Chair of the IUCN SSC Freshwater Fish Specialist Group and a co-author of the paper.

The authors also stress the importance of incorporating freshwater species data into broader conservation strategies. “Freshwater ecosystems are not resources for exploitation; they are lifelines for humanity. Saving them will require bold, collective action across disciplines, sectors, and borders. Our health, nutrition, drinking water and livelihoods depend on them,” added Stephanie Wear, Conservation International Senior Vice President at the Moore Center for Science.