Twenty four per cent of the world’s freshwater species are at high risk of extinction. These include fish, dragonflies, crabs, shrimp, and crayfish, says a groundbreaking global assessment published in Nature provides this information. The study, the largest of its kind, draws on data from the IUCN Red List of Threatened Species. It showcases the growing threats to these vital ecosystems.
The analysis revealed alarming trends:
- Extinction Risk: 4,294 out of 23,496 freshwater species are at high risk of extinction.
- Hotspots of Threat: Lake Victoria and Lake Titicaca have the highest concentrations of threatened species. Sri Lanka’s Wet Zone and India’s Western Ghats also have significant numbers of threatened species.
- Underground Threats: Subterranean water systems also host many at-risk species like the Vulnerable daisy burrowing crayfish in Arkansas, USA.
- Historical Losses: In 2020, 15 fish species from Lake Lanao in the Philippines were declared extinct.
THE DRIVERS OF DECLINE
Freshwater species face a range of threats, including:
- Pollution: Agricultural and forestry runoff impacts over half of all threatened species.
- Habitat Loss: Land conversion, water extraction, and dam construction block fish migration routes and degrade habitats.
- Overfishing and Invasive Species: Overexploitation and non-native species introductions drive extinction, as seen with the carp Squalius palaciosi, declared extinct in 2023.
REGIONAL INSIGHTS: A NEED FOR TARGETED CONSERVATION
Threatened freshwater species often coexist with endangered mammals, birds, and reptiles but face unique challenges due to their specific habitats.
For instance, in India’s Western Ghats, tiger and elephant conservation efforts can’t help the Critically Endangered humpbacked mahseer. This fish faces threats from river engineering projects, sand mining, poaching, and invasive species. Protecting its habitat requires focused action, including fishing regulations and bans on invasive species introductions.
MISLEADING INDICATORS AND CONSERVATION GAPS
The study found that areas with high water stress or eutrophication do not necessarily house more threatened species. This underscores the importance of including freshwater species data in conservation strategies and water management plans.
“Increased investment in measuring and monitoring freshwater species is critical to ensure effective conservation action,” said Dr. Topiltzin Contreras MacBeath, Co-Chair of the IUCN SSC Freshwater Conservation Committee.
CRABS, CRAYFISH, AND SHRIMPS AT HIGHEST RISK
Among the groups studied, 30% of crabs, crayfish, and shrimps face extinction. This is followed by 26% of freshwater fish. Additionally, 16% of dragonflies and damselflies are at risk.
A CALL TO ACTION
As the IUCN Red List celebrates its 60th anniversary, experts emphasize the need for urgent conservation efforts:
- Catherine Sayer (IUCN): “Freshwater landscapes are crucial for biodiversity and human well-being. Lack of data can no longer excuse inaction.”
- Tim Lyons (New Mexico BioPark Society): “Pollution, habitat modification, and invasive species must be addressed collaboratively.”
- Stephanie Wear (Conservation International): “Freshwater ecosystems support billions. Protecting them ensures our health, water, and livelihoods.”
SOLUTIONS FOR A BRIGHTER FUTURE
The study offers a roadmap for protecting freshwater species:
- Enhanced Monitoring: Collect and utilize freshwater species data to guide conservation strategies.
- Targeted Conservation: Focus efforts on regions and species most at risk.
- Collaborative Action: Governments, industries, and communities must work together to address pollution, habitat loss, and invasive species.
MOVING FORWARD: A GLOBAL EFFORT
This comprehensive study, the result of two decades of work by over 1,000 experts, is a rallying cry for action. Protecting freshwater biodiversity is vital not only for these species but also for the millions of people who depend on these ecosystems.
As the world moves toward achieving the Sustainable Development Goals and the Kunming-Montreal Global Biodiversity Framework by 2030, the insights from this study can serve as a cornerstone for global conservation efforts.