Vous êtes


Réduire la taille texte Rétablir la taille du texte par défaut Agrandir la taille du texte Partager cette page Favoris Email Imprimer

Diadromous migratory fish

Amphihaline migratory fish move between fresh-water and salt-water during their biological cycle.

While most of these fish breed in rivers and grow in the sea, some do the exact opposite, for example, the eel that reproduces in the Sargasso Sea.

In France, the best known amphihaline migratory fish are Atlantic salmon, shads, lampreys, eels and European sturgeon. Unmanaged fishing, habitat destruction, marine pollution, the inaccessibility of some waterways blocked by dams and the presence of hydroelectric turbines causing high mortality rates among migrating fish are the cause of stock decreases and, in some cases, species extinction.
Migrating shads, eels, sturgeons, lampreys and salmon are carefully monitored. Their populations are fragile because of the threats they face during their long journey from river to estuary to sea, or back again.
At Cemagref (French National Centre of Agricultural Machinery, Agricultural Engineering, and Water and Forests), a team of scientists is dedicated to studying the ecology of amphihaline migratory fish in European rivers and estuaries. They are studying the way in which these species use space during their migration. These scientists are developing methods and tools adapted to the restoration of the most threatened species.
They are also developing decision making tools for sustainable management of these species.

Find out more about the research into these migrating fish.