Populations of migratory freshwater fish, crucial to the health of rivers and the livelihoods of millions of people, are in free fall and risk collapsing, a major UN assessment warned on Tuesday.
Habitat destruction, overfishing and water pollution from the Amazon to the Danube threaten the very survival of hundreds of species whose epic journeys along the world’s great rivers go largely unnoticed.
Freshwater fish face multiple threats, according to the report published at the opening of the COP15 summit on migratory species in Brazil, making them “among the most endangered vertebrates.”
Populations of Mekong giant catfish, European eel and several sturgeon species are among those that have been decimated in recent decades due to human-caused pressures including dam construction and caviar harvesting.
Some, including the Chinese paddlefish, have already been declared extinct, while others are functionally dependent on captive breeding populations and reintroductions to sustain their wild populations.
According to the conservation group WWF, the number of migratory freshwater fish has plummeted about 81% since 1970.
These fish, a vital source of protein for people and animals around the world, require unobstructed passage to move between spawning and feeding grounds, which can cross borders.
This means international cooperation is needed to stop its decline.
The report, from the Convention on the Conservation of Migratory Species of Wild Animals (CMS), identifies nearly 350 species of migratory fish that could benefit from greater protection in the international framework.
Species such as salmon, eel and lamprey are among those to be considered during the March 23-29 meeting in Campo Verde.
Of these, the vast majority are found in Asia, followed by South America and Europe.
The river basins considered priority are the Amazon and La Plata-Paraná in South America, the Danube in Europe, the Mekong and the Ganges-Brahmaputra in Asia and the Nile in Africa.
“This assessment shows that migratory freshwater fish are in serious trouble and that protecting them will require countries working together to keep rivers connected, productive and full of life,” Zeb Hogan, lead author of the assessment, said in a statement.
