Heading south or north : novel insights on European silver eel Anguilla anguilla migration in the North Sea

The European eel Anguilla anguilla L. is a critically endangered fish species that migrates from coastal and freshwater habitats to the Sargasso Sea to spawn. However, the exact migration routes and destination of European eel are still unknown. We are the first to observe southward migrating silver eels in the North Sea. Eels were tagged with acoustic transmitters in 3 different river catchments in Western Europe and swam to the Dutch-Belgian coastal zone during their spawning migration. Therefore, at least part of the Western European population of eels migrates towards the English Channel, in contrast with the Nordic migration route hypothesis. This different migratory route may affect the energy reserve available for spawning and therefore the contribution of these eels to the population. As such, increasing our knowledge of marine eel migrations contributes to the goal of achieving sustainable eel stock management