In a stark warning for global biodiversity, a recent United Nations report reveals that migratory fish populations have declined by a staggering 81% over the past fifty years. This alarming trend is driven by a combination of habitat destruction, pollution, and overfishing, jeopardising not only the species themselves but also the livelihoods of millions who depend on them. The UN has identified thirty flagship species, including the golden mahseer and goonch catfish, as urgent priorities for conservation efforts.
The State of Our Waters
Freshwater fish play a crucial role in ecosystems and human communities. According to Dr. Zeb Hogan, a biologist at the University of Nevada, Reno, these fish are vital for the sustenance of around 200 million people globally. “Freshwater fish support hundreds of millions of people around the world, so for humans, they’re very important,” he emphasised. The report highlights the immense diversity within migratory fish, showcasing species capable of immense journeys, such as the golden dorado of South America and tropical eels navigating thousands of miles across Oceania.
The UN’s assessment of over 15,000 freshwater migratory fish marks a significant expansion from a previous study conducted in 2011, which only evaluated about 3,000 species. This latest analysis reveals the critical condition of these fish and underscores the need for immediate action.
Key Species at Risk
Among the thirty fish species identified for urgent conservation are several that are culturally significant, such as the golden mahseer, known as the “tiger of the river” in the Himalayas. Michele Thieme, deputy lead for freshwater at the World Wildlife Fund US, highlighted the dual threats of overfishing and habitat loss these species face. “Habitat loss includes things like dams that fragment a river system, which results in fish not being able to connect to their spawning habitats,” she explained.
The report also underscores the challenges posed by barriers to migration, particularly in Europe, where fish often encounter obstacles at every turn. Dr. Janina Gray, head of science at WildFish, pointed out that even small barriers can exhaust migrating fish, making them more vulnerable to disease and predation, ultimately leading to suboptimal spawning.
A Call for International Cooperation
The migration patterns of these fish span international borders, necessitating collaborative efforts among governments to address their declining populations. The UN is advocating for the inclusion of these thirty species into the Convention on the Conservation of Migratory Species, a treaty designed to promote cross-border conservation initiatives. The next meeting of the convention is set for in three years, where the future of these fish could be determined.
The revival of other species, such as the saiga antelope, serves as a beacon of hope. After facing a devastating population crash in 2015, an international anti-poaching initiative helped the saiga population rebound to over a million. Amy Fraenkel, the UN Executive Secretary for the Convention on Migratory Species, noted that it’s now time for freshwater fish to receive similar attention and support.
Why it Matters
The dramatic decline of migratory fish represents not just an environmental crisis but a fundamental threat to human livelihoods worldwide. As these species dwindle, so too do the resources that countless communities rely on for sustenance and cultural identity. Protecting these fish is not merely about preserving biodiversity; it is about ensuring food security, maintaining ecological balance, and honouring the cultural significance these species hold across the globe. The time for action is now, as we face the impending consequences of inaction on our vital freshwater ecosystems.
