Little-studied river sharks and rays face rising extinction risk
New IUCN data shows freshwater sharks and rays face roughly double the extinction risk of their ocean relatives, even though almost nothing is known about many species.
Sharks and rays that live in rivers and estuaries are disappearing largely unnoticed, according to new analysis highlighted by Mongabay. The IUCN Red List finds about 76% of non-marine sharks and rays in the Indo-Pacific are threatened with extinction — roughly double the rate for their ocean-dwelling relatives — even though these freshwater species remain far less studied than marine sharks.
Around 60 species worldwide spend part or all of their lives in rivers and lakes, including some that tolerate a range of salinity and others confined permanently to fresh water. South America's Amazon, Orinoco and Paraná river basins hold an especially diverse population of freshwater stingrays, which researchers have nicknamed "river jewels" for their markings. Dams, pollution, overfishing, mining and climate-driven changes to river flow all threaten populations that scientists describe as looking abundant but being ecologically fragile.
New tracking data is also upending assumptions about how far these animals travel: one giant freshwater stingray in Argentina covered more than 170 kilometers, suggesting dams could disrupt populations across a far wider area than previously thought. Researchers say basic ecological data is still missing for many species, particularly in remote, hard-to-study river systems.
Based on reporting by Malaka Rodrigo for Mongabay. Read the original: https://news.mongabay.com/2026/09/forgotten-fauna-little-known-river-sharks-and-rays-face-increased-extinction-risk/
This article was produced with the assistance of AI tools and reviewed by an editor before publication.
