Silver Eel migration behaviour in the Mediterranean Sea
Although Mediterranean ecosystems such as coastal lagoons are known to be productive habitats providing numerous silver eels in short generation time, migration routes used by silver eels in the Mediterranean Sea have been poorly studied. Using pop-up satellite during escapement from coastal waters, Elsa Amilhat, of the Université de Perpignan, and her team, determined 3 migratory behaviours: on the continental shelf, on the deeper water (>200 m) and on the Gibraltar Strait. Tagged silver eels exhibited similar behaviour on the continental shelf, following continuously deeper water. Once in deeper water, they quickly established diel vertical migration (DVM).
Crossing the Atlantic
A high percentage of tagged eels were taken by predators within the Mediterranean, but four eels reached the Atlantic Ocean and three at distances greater than 2000 km from release. These eels ceased their DVM while they negotiated the Gibraltar Strait, and remained in deep water until they reached the Atlantic Ocean, when they recommenced DVM. Their results are the first to show that eels from Mediterranean can cross the Strait of Gibraltar and continue their migration into the Atlantic Ocean. This finding suggests that Mediterranean countries, as for other EU states, have an important role to play in the conservation and the recovery of the European eel stock.
© photo Université Perpignan