Click the link to read the article on The Guardian website (Phoebe Weston). Here’s an excerpt:
May 21, 2024
Migratory fish populations have crashed by more than 80% since 1970, new findings show. Populations are declining in all regions of the world, but it is happening fastest in South America and the Caribbean, where abundance of these species has dropped by 91% over the past 50 years. This region has the world’s largest freshwater migrations, but dams, mining and humans diverting water are destroying river ecosystems. In Europe, populations of migratory freshwater fishes have fallen by 75%, according to the latest update to the Living Planet Index.
Migratory freshwater fish partially or exclusively rely on freshwater systems – some are born at sea and migrate back into fresh water, or vice versa. They can in some cases swim the width of entire continents and then return to the stream in which they were born. They form the basis for the diets and livelihoods of millions of people globally. Many rivers, however, are no longer flowing freely due to the construction of dams and other barriers, which block species’ migrations. There are an estimated 1.2m barriers across European rivers. Other causes of decline include pollution from urban and industrial wastewater, and runoff from roads and farming. Climate breakdown is also changing habitats and the availability of freshwater. Unsustainable fishing is another threat.
Herman Wanningen, founder of the World Fish Migration Foundation, one of the organisations involved in the study, said: “The catastrophic decline in migratory fish populations is a deafening wake-up call for the world. We must act now to save these keystone species and their rivers.
“Migratory fish are central to the cultures of many Indigenous peoples, nourish millions of people across the globe, and sustain a vast web of species and ecosystems. We cannot continue to let them slip silently away.”