Catastrophic decline in migratory fish is a wake-up call

Global populations of migratory freshwater fish species – including salmon, trout, eel, and sturgeon – are facing severe decline. This alarming trend endangers the food security and livelihoods of millions of people and threatens the health and resilience of vital freshwater ecosystems.

A new study by the World Fish Migration Foundation, ZSL, IUCN, The Nature Conservancy, Wetlands International, and WWF has revealed the extent of this crisis.

According to the Living Planet Index (LPI) report on freshwater migratory fishes, monitored populations experienced an average decline of 81% from 1970 to 2020.

The situation is especially dire in Latin America and the Caribbean, with a 91% decline in freshwater fish populations.

Causes of freshwater fish decline

Habitat loss and degradation are the primary threats, accounting for half of the overall decline in freshwater fish numbers. These threats include the fragmentation of rivers by dams and other barriers and the conversion of wetlands for agriculture.

Over-exploitation, increasing pollution, and the worsening impacts of climate change also contribute to the decline of these species, which have been steadily diminishing over the past 30 years.

“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,” warned Herman Wanningen, founder of the World Fish Migration Foundation.

“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,” Wanningen told The Guardian.

Importance of migratory freshwater fish

Migratory freshwater fishes are crucial for the food security and nutritional needs of hundreds of millions of people, particularly in vulnerable communities across Asia, Africa, and Latin America.

They also support the livelihoods of tens of millions – from local fisheries to global trade – as well as the multi-billion dollar recreational fishing industry.

“In the face of declining migratory freshwater fish populations, urgent collective action is imperative. Prioritizing river protection, restoration, and connectivity is key to safeguarding these species, which provide food and livelihoods for millions of people around the world,” said Michele Thieme, Deputy Director of Freshwater at WWF-US.

“Let’s unite in this crucial endeavor, guided by science and shared commitment, to ensure abundance for generations to come.”

Successful conservation efforts

Despite the grim statistics, the report offers a glimmer of hope. Nearly one-third of monitored species have shown increases, indicating that conservation efforts and improved management can make a positive impact.

Effective strategies include species-focused fisheries management, habitat restoration, dam removals, the creation of conservation sanctuaries, and legal protections.

In Europe and the United States, thousands of dams, levees, weirs, and other river barriers have been removed in recent decades, with momentum growing.

In 2023, Europe set a record by removing 487 barriers – a 50% increase from 2022. In the United States, the largest dam removals in history are underway along the Klamath River in California and Oregon.

These actions are cost-effective, create jobs, and help reverse the disturbing trend of biodiversity loss in freshwater systems, improving river health and resilience for people as well.

Protecting and restoring free-flowing rivers

Beyond scaling up dam removals, decision-makers must urgently accelerate efforts to protect and restore free-flowing rivers through basin-wide planning.

Investing in sustainable renewable alternatives to the numerous planned hydropower dams and implementing other measures will help meet the ambitious goals of the Kunming-Montreal Global Biodiversity Framework to protect 30% of inland waters and restore 30% of degraded inland waters.

Furthermore, achieving the Freshwater Challenge’s goal of restoring 300,000 kilometers of degraded rivers will significantly contribute to reversing the decline in migratory fish populations.

WWF-US recently joined as an inaugural member of the White House’s America the Beautiful Freshwater Challenge Partnership, the largest freshwater restoration and protection initiative in history.

Strengthening monitoring efforts for migratory fish

Along with protecting and restoring healthy rivers, strengthening monitoring efforts is a crucial step forward. Understanding the life histories, movements, and behaviors of migratory fish; expanding international cooperation; and adding more freshwater fish to the Convention on Migratory Species (CMS) are also essential steps.

Since 2014, the World Fish Migration Foundation has organized World Fish Migration Day every two years to raise awareness about migratory fish, with over 68 countries participating this year.

By uniting in this global effort, we can ensure the survival of migratory fish species and the health of our freshwater ecosystems for future generations.

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