97% of migratory fish are going extinct. Swimways are a critical solution.

Silver salmon jump out of rushing white water in Katmai National Park

A staggering 97% of migratory fish on the Convention of Migratory Species (CMS) face extinction. A recent United Nations report takes a close look at the status of migratory species listed by the CMS; fish species are the most threatened, and freshwater fish species, in particular, are the most underrepresented. But amidst this alarming decline of migratory fish worldwide, emerges a promising solution. Swimways, a concept akin to 'flyways' but tailored for aquatic habitats, introduce a fresh perspective to conservation efforts. It underscores the critical significance of preserving free-flowing rivers as indispensable migratory pathways for a myriad of aquatic species.

Since 1935, when Frederick Lincoln first introduced the concept of 'flyways' to protect the migratory paths of birds by conserving wetlands along their routes, we’ve made significant progress.

But birds are not the only animals that migrate extreme distances and require protection to ensure the continuity of their migration path. Aquatic animals—including fish, turtles, and freshwater dolphins— depend on long stretches of free-flowing rivers to find food, reach historic mating or nursing grounds, or move between habitats in response to seasonal variations in water levels.

Aquatic animals need protection. Populations of freshwater species have already declined by 84% on average since 1970, with the degradation of rivers a leading cause of this decline. And nearly 1/3 of all freshwater fish face extinction. Protecting free-flowing rivers as Swimways allows populations to rebound without the pressure of habitat fragmentation.

What are swimways?

Swimways are rivers and their associated ecosystems that support the entire migration routes of biologically and/or socioeconomically important freshwater fish.

As the climate crisis alters temperature and weather patterns globally, ensuring the viability of migration routes is increasingly critical for species survival. With over 1,000 migratory fish species relying on unimpeded access along their routes, maintaining swimways protections is essential for both ecological integrity and human livelihoods.

The importance of migratory fish

Migratory fish provide a key food source for communities and help move critical nutrients that maintain the richness of the freshwater environments they call home. Their movements can provide key ecosystem functions and values for the people and species with which they interact along their route. Connected rivers allow the gilded catfish (dorado) to migrate from the Andes mountains to the Amazon River to feed and grow over six feet long. They’re critical for the movement of the sockeye salmon from the Pacific Ocean into the rivers of the Pacific Northwest, where Indigenous peoples have relied on them for food for generations.

Swimways are critical to conservation

Just as 'flyways' have successfully safeguarded avian migration for decades, it's also imperative to extend similar protections to aquatic species. Implementing and evaluating swimways can pave the way for scalable global conservation efforts aimed at preserving these vital aquatic lifelines.

Learn more about WWF's work on freshwater