A newly released UN report highlights a startling decline in migratory fish populations, revealing that these vital species have suffered an alarming 81% drop in numbers over the past fifty years. The findings underscore the urgent need for conservation efforts, as numerous fish species essential to both ecosystems and human livelihoods face unprecedented threats from habitat destruction, pollution, and overfishing.
A Global Crisis for Migratory Fish
Migratory fish, which traverse vast distances through rivers, lakes, and oceans, are increasingly at risk. The Atlantic tarpon, a species known for its long coastal migrations along the US shore, is just one example of the many fish whose populations are declining due to the degradation of their habitats. The report, produced by a team of international scientists, assessed over 15,000 species of freshwater migratory fish, highlighting that these creatures, which constitute half of all fish species, require immediate attention.
Dr. Zeb Hogan, a co-author of the report and a professor of biology at the University of Nevada, Reno, emphasized the critical role of these fish in global food security, stating, “Freshwater fish support hundreds of millions of people around the world, so for humans, they’re very important.” He pointed out that migratory species, such as the giant catfish, can weigh over 650 pounds and travel more than 7,000 miles, showcasing the remarkable diversity that must be preserved.
Priority Species for Conservation
The report identifies 325 fish species that warrant inclusion in a global framework aimed at monitoring and conserving threatened migratory animals. Among them, 30 species have been singled out as priorities, with several found in the UK, including the Allis Shad, River Lamprey, Brook Lamprey, and Atlantic Salmon. Michele Thieme, deputy lead for freshwater at the World Wildlife Fund US, explained the cultural importance of species like the golden mahseer, stating, “It’s called the tiger of the river, and many of the people in that region value that fish for cultural and spiritual practices that go far beyond the economic values.”
The threats these species face are twofold: overfishing and habitat loss. Dams and other developments disrupt river systems, altering the natural flow and preventing access to spawning grounds. Dr. Janina Gray, head of science at the charity WildFish, noted that barriers to migration are particularly prevalent in Europe, where fish encounter obstacles every kilometre on average. This disruption not only drains fish energy reserves but also increases their susceptibility to disease and predation.
A Call for International Cooperation
Migratory fish do not adhere to national borders, necessitating coordinated global efforts to address the multifaceted challenges they face. The UN’s Convention on the Conservation of Migratory Species, established in 1979, aims to unite countries in protecting a range of migratory species, including fish. The organisation is now advocating for the inclusion of the 30 priority fish species in the treaty during its annual meeting set for three years from now.
Past successes in conservation, such as the remarkable recovery of the saiga antelope, serve as a beacon of hope. Once facing extinction due to mass die-offs, international conservation initiatives have helped the saiga population rebound to over a million. Amy Fraenkel, the UN Executive Secretary for the Convention on Migratory Species, acknowledged that while major attention has traditionally focused on more visible species like big cats and whales, it is time for migratory freshwater fish to benefit from similar coordinated efforts.
Why it Matters
The drastic decline of migratory fish populations poses a significant threat not only to biodiversity but also to the millions of people who rely on these species for their livelihoods. The urgent call for action highlights the need for collective global responsibility in safeguarding these vital creatures. Without immediate interventions, we risk losing not only the ecological balance but also a crucial source of food and cultural heritage for countless communities worldwide. The time to act is now.
