Migratory fish populations have fallen 81% since 1970, study says

Migratory fish populations have fallen 81% since 1970, study says

From 1970 to 2020, the average and constant decline in some populations of fish freshwater migration reached 81%, with sharp drops in Europe (75%) and Latin America and Caribbean (91%), according to a study published this Tuesday by international entities, which suggest conservation to obtain positive effects.

The study carried out by the World Fish Migration Foundation, Zoological Society of London (ZSL), the International Union for Conservation of Nature (IUCN), The Nature Conservancy (TNC), Wetlands International Europe and the NGO WWF is part of the Day World Fish Migration World Cup, which is celebrated on May 25.

The new Living Planet Index (LPI) report on migratory freshwater fish reveals that between 1970 and 2020, observed populations included catastrophic declines in 91% in Latin America and the Caribbean and 75% in Europe, a “constant loss” which continues to be produced throughout the world.

These population declines in migratory freshwater fish, the research says, endanger the food security and livelihoods of millions of people, especially in vulnerable communities in Latin America, Africa and Asia, as well as the survival of countless other species. and the health and resilience of rivers, lakes and wetlands.

Habitat loss and degradation – including fragmentation of rivers by dams and other barriers and conversion of wetlands for agriculture – account for half of the threats to migratory fish, followed by overexploitation.

Furthermore, the constant loss of populations, which has been going on for thirty years, is due to increased pollution and the worsening effects of climate change.

The founder of the World Foundation for Fish Migration, Herman Wanningen, says in a statement that “The catastrophic decline in migratory fish populations is a deafening wake-up call for the world,” and calls for “acting now to save these key species and their rivers.”.

According to Wanningen, “Migratory fish are fundamental to the cultures of many indigenous peoples, feeding millions of people around the planet and supporting a vast network of species and ecosystems.”

The study recalls that fish are “the livelihood of tens of millions of people”, from local fisheries to the global trade in migratory fish and fish by-products, to the multi-billion dollar recreational fishing industry.

And it opens a window of hope, noting that almost a third of the species studied have increased, thanks to conservation and improved management and/or focused on fishing species, habitat restoration, removal of prey, creation of conservation sanctuaries and legal protection.

The researchers emphasize that the removal of dams, dikes and other river barriers has been increasing in recent decades in Europe, with 487 barriers in 2023, which represents an increase in fifty% in relation to the previous year, a practice that has also increased in the United States.

The “Popular action to reconnect European rivers and improve fish mobility is on the rise”, said the director of Wetlands International Europe, Chris Baker, who explained that together with Wetlands International, the Trans-European Waterways Network “It is helping to identify and prioritize the most important rivers and species to pay attention to.”

For this to reach a larger scale, “European governments must commit to and implement the Nature Restoration Act to help accelerate the recovery of our rivers and migratory fish,” says Baker.

In addition, researchers call for investing in sustainable renewable alternatives to the thousands of new hydroelectric dams that are planned around the world, as well as implementing other measures that contribute to the objectives of the Kunming-Montreal Global Biodiversity Framework of protecting he 30% of continental waters and restore the 30% of degraded continental waters.

In particular, they point out, achieving the Freshwater Challenge goal of restoring 300,000 kilometers of degraded rivers “will contribute greatly to reversing the trend of migratory fish populations.”

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Source: Gestion

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