Ahead of World Fish Migration Day this Saturday, the paper highlights that since 1970 there has been an 81% decline in migratory fish populations, with the steepest declines in Latin America (91%), the Caribbean (91%) and Europe (75%).

However, the decline in freshwater fish is happening worldwide, threatening the food security and livelihoods of millions of people, the survival of many other species, and the health and resilience of rivers, lakes and wetlands.

The warnings are part of a new Living Planet Index report on freshwater migratory fish, published by the World Fish Migration Foundation and partners including the International Union for Conservation of Nature (IUCN) and WWF.

The Living Planet Index is a global indicator of the state of biodiversity, managed by the Zoological Society of London in partnership with WWF.

The paper explains that half of the threats to migratory fish are related to habitat degradation, including the construction of dams and other barriers on rivers, and the conversion of wetlands to agriculture. Overexploitation, increased pollution and the worsening impacts of climate change are also decimating migratory fish species.

"The catastrophic decline in migratory fish populations is a wake-up call for the world. We must act now to save these vital species and the rivers they depend on," said Herman Wanningen of the World Fish Migration Foundation, in a statement about the report.

He said migratory fish "are central to the cultures of many indigenous peoples, feed millions of people around the world and support a vast web of species and ecosystems", warning that we "cannot afford to let them slip away silently".

The paper's authors also highlight that freshwater migratory fish are vital for food for millions of people, especially in Asia, Africa and Latin America, and support the livelihoods of tens of millions more through local fisheries, trade, industry and recreational fishing.

And they highlight that on a positive note, a third of the species monitored have increased, thanks to better management of resources, habitat restoration and dam removals.

Thousands of dams, weirs and other river barriers have been removed in Europe and the United States. Last year Europe removed a record 487 barriers, a 50% increase on the previous record set in 2022.

Decision-makers worldwide must accelerate efforts to protect and restore river flows, investing in sustainable alternatives to planned hydropower dams. And they recall the targets agreed at the Kunming-Montreal global biodiversity summit in Canada in late 2022 to restore 300,000 kilometres of degraded rivers.

The World Fish Migration Foundation has been promoting World Fish Migration Day since 2014 to raise awareness of migratory fish. This year it is celebrating free-flowing rivers and already has over 65 countries taking part.

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