Global Assessment Identifies 325 Migratory Freshwater Fish Species Requiring International Protection

The study identified species that cross international borders. These species require deliberate international action for their survival due to population declines or risks of extinction.

Migratory freshwater fish encounter obstacles including dams, habitat degradation, and overfishing. The report calls for international cooperation.

Dams prevent upstream migration and downstream return after spawning. Habitat degradation includes conversion of spawning grounds to gravel or sand mines and use of floodplains for agriculture.

Species The American eel reproduces in the Sargasso Sea near Bermuda, with larvae traveling to the St. Lawrence River and into the Great Lakes. Returning to mating grounds presents difficulties. The species faces high mortality at hydropower facilities.

Concerns remain due to these migration challenges. Overfishing and habitat issues affect the species similarly to others in the assessment.

Value Migratory freshwater fish provide nutrients from oceans to freshwater systems, supporting forest growth in some areas.

They contribute to food security in regions where access to store-bought fish is limited. These fish serve as a seasonal resource supporting low-income communities. In Canada, species such as salmon, sturgeon, and American eels connect to Indigenous communities.

These species have iconic status due to epic migrations, including Pacific salmon, Atlantic salmon, and sturgeon. These connections highlight cultural significance alongside ecological roles.

Conservation Measures Conservation efforts can address these threats.

Solutions include modifications to dams for fish passage and sustainable fishing practices. International cooperation is necessary given the cross-border nature of migrations. The assessment emphasizes the need for coordinated management to prevent further declines.