Preface. A third of freshwater fish are under threat from pollution, over fishing, dams, non-native species, climate change, disruption of river ecology and more. 

Alice Friedemann  www.energyskeptic.com  Author of Life After Fossil Fuels: A Reality Check on Alternative Energy; When Trucks Stop Running: Energy and the Future of Transportation”, Barriers to Making Algal Biofuels, & “Crunch! Whole Grain Artisan Chips and Crackers”.  Women in ecology  Podcasts: WGBH, Planet: Critical, Crazy Town, Collapse Chronicles, Derrick Jensen, Practical Prepping, Kunstler 253 &278, Peak Prosperity,  Index of best energyskeptic posts

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Harvey F (2021) Global freshwater fish populations at risk of extinction, study finds. World’s Forgotten Fishes report lists pollution, overfishing and climate change as dangers. The Guardian.

Rivers and lakes are vital ecosystems. They cover less than 1% of the planet’s surface, but their nearly 18,000 fish species represent a quarter of all vertebrates, as well as providing food for many millions of people. Healthy rivers are also needed to supply clean water.

Freshwater fish are under threat, with as many as a third of global populations in danger of extinction, according to an assessment.

Populations of migratory freshwater fish have plummeted by 76% since 1970, and large fish – those weighing more than 66 pounds (30 kg) – have been all but wiped out in most rivers. The global population of megafish down by 94%, and 16 freshwater fish species were declared extinct last year.

Only 14% of the world’s river basin areas have fish populations escaping serious damage from humans activities.

The worst-hit regions are western Europe and North America, where large and affluent populations mean humans’ impact on rivers is highest, such as with the Thames in the UK and the Mississippi in the US.

The report by 16 global conservation organizations, called The World’s Forgotten Fishes, said that global populations of freshwater fish were in freefall. The problems are diverse and include pollution, overfishing and destructive fishing practices, the introduction of invasive non-native species, climate change and the disruption of river ecologies. Most of the world’s rivers are now dammed in parts, have water extracted for irrigation or have their natural flows disrupted, making life difficult for freshwater fish. Only a third of the world’s great rivers are still free flowing without dams on them.

The report found that biodiversity in freshwater ecosystems was being lost at twice the rate of oceans and forests. There are more than 18,000 species of freshwater fish known, and more are still being discovered. The International Union for Conservation of Nature (IUCN), which compiles the global red list of species in danger, has assessed more than 10,000 species and found that about 30% were at risk of extinction.

The 16 organizations behind the report were: Alliance for Freshwater Life, Alliance for Inland Fisheries, Conservation International, Fisheries Conservation Foundation, Freshwaters Illustrated, Global Wildlife Conservation, InFish, the IUCN, the Sustainable Seafood Coalition, Mahseer Trust, Shoal, Synchronicity Earth, the Nature Conservancy, World Fish Migration Foundation, the WWF and Zoological Society of London.