New Study: 24% of Assessed Freshwater Species at High Risk of Extinction

Freshwater ecosystems, though covering just 1% of Earth's surface, support over 10% of known species, illustrating their crucial role in global biodiversity. However, a new study highlights the alarming state of these environments, revealing that 24% of 23,496 assessed freshwater species, including fishes, crustaceans, and insects, are at high risk of extinction. Major threats include pollution, dams, water extraction, agriculture, invasive species, and overharvesting, underscoring the critical need for conservation efforts.

The study, published in Nature, fills a gap in data on freshwater biodiversity by providing a comprehensive overview of species across diverse food webs, reflecting the overall health of these ecosystems. Since 1970, more than a third of inland wetlands like lakes, rivers, and swamps have been lost. Crustaceans face the highest threat levels (30%), followed by fishes (26%), and dragonflies and damselflies (16%). The study highlights the unique ecological importance of freshwater systems, which often harbor species found nowhere else, emphasizing the urgent need to address the threats they face.

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Sayer, C.A., Fernando, E., Jimenez, R.R. et al. One-quarter of freshwater fauna threatened with extinction. Nature (2025). https://doi.org/10.1038/s41586-024-08375-z

Feature photo by David Clode on Unsplash