Hundreds of migratory freshwater fish species are in serious trouble, and a new report is calling for much stronger protection before it’s too late. Released in March 2026, the report flagged 325 migratory freshwater fish species as needing urgent international conservation action — many of which have been quietly ignored for decades despite how much ecosystems and local communities depend on them. The report came out under the Convention on Migratory Species and covered more than 15,000 freshwater fish species in total. Nearly 97% of the migratory freshwater fish listed under the convention are now threatened with extinction and in Asia, populations of huge freshwater megafish have plummeted by more than 95% since 1970.
Among the species at risk are the Mekong giant catfish in Southeast Asia, the European sturgeon in the Danube River system, the Amazonian dorado catfish in South America, and various eel and salmon species across North America and Europe. Scientists point to several overlapping causes: habitat destruction through the clearing of mangroves, wetland conversion for farming, and sand and gravel mining that wipes out breeding grounds; dam construction that cuts off migration routes; pollution and overfishing that prevents populations from recovering; and shifting weather patterns that are altering water temperatures and river flows in ways these fish simply can’t adapt to fast enough.
The problem doesn’t stop at the water’s edge. Salmon and other migratory species carry nutrients from the ocean deep into river systems, feeding the land and everything living on it. Cut off those migrations and that flow of nutrients dries up, and the ecosystems downstream start to feel it. Other wildlife loses a food source it has relied on for as long as anyone can measure, and without the natural balance these fish help maintain, things like algae can take over in ways that cause lasting damage. The human cost is just as real. Across Asia, Africa, and Latin America, freshwater fish aren’t a dietary preference — for millions of people they’re a daily necessity, often the most accessible source of protein available. When fish populations crash and fishing industries follow, the communities built around them have very little to fall back on.
That said, there are genuine reasons for cautious optimism. According to reports, Europe removed more than 480 river barriers in 2023, and the United States restored 420 miles of salmon and steelhead trout habitat in the Klamath River. A smaller but telling example is the Columbia Dam removal in New Jersey, completed in 2019, which has already shown measurable signs of recovery — a reminder that rivers can bounce back when given the chance. Researchers are warning, if these populations collapse, the knock-on effects for ecosystems and fishing-dependent economies could be severe. The report pushes for concrete steps: removing dams that no longer serve a purpose, restoring natural river connectivity, cleaning up water quality, cracking down on unsustainable fishing, and getting countries to work together on protecting the river systems they share.
Scientists also warn freshwater ecosystems consistently get far less conservation funding and attention than oceans or forests, even though they support an enormous amount of biodiversity and human life.
