A study reveals that global migratory freshwater fish populations have dropped over 80% in the past 50 years, primarily due to human activities like dam construction, mining, water diversion, and pollution.
Phoebe Weston reports for The Guardian.
In short:
- Migratory fish populations have decreased by over 80% globally, with a 91% drop in South America and the Caribbean.
- Human activities such as dam building, pollution, and unsustainable fishing are major causes of the decline.
- Climate change and habitat disruption further threaten these fish, which are vital to ecosystems and human livelihoods.
Key quote:
“The catastrophic decline in migratory fish populations is a deafening wake-up call for the world.”
— Herman Wanningen, founder of the World Fish Migration Foundation
Why this matters:
Dams and water diversion projects, while providing benefits like hydroelectric power and irrigation, can obstruct migratory routes and alter the natural flow of rivers. Mining operations introduce harmful pollutants, and water pollution from agricultural runoff and industrial waste further degrades habitats. The decline in migratory freshwater fish populations threatens the ecosystems they support and the millions of people who rely on them for food and income.














