Sturgeons have inhabited the Earth for 200 million years and are therefore rightfully referred to as “living fossils”. However, sturgeons have become the world’s most endangered animal family due to habitat loss, blocked migratory routes, overfishing, water pollution and hybridisation. All sturgeon species live long lives and a known for migrating long distances. Large species, such as the beluga sturgeon (Huso huso), may travel up to 2,500 km to reach their spawning grounds. In the Danube, migratory routes ranging from the Black Sea to Ulm (Germany) have been documented. The sterlet (Acipenser ruthenus), one of the smallest sturgeon species, only lives in freshwater and rarely migrates more than 200 km. Such long migrations are barely possible these days because most of the rivers sturgeons live in have been fragmented by power stations. Therefore, the beluga sturgeon and the Russian sturgeon can now only inhabit the Danube’s lower river.
Size: up to 2.3 m & 120 kg
Habitat: Black Sea, Sea of Azov, Caspian Sea
Migration habits: anadromous
Austria’s Red List: regionally extinct
Global Red List: critically endangered
Fun fact: Individual fish with very light-coloured noticeable patterns are called diamond sturgeons.
Size: up to 1.2 m & 16 kg
Habitat: Ponto-Caspian and Siberian Region
Migration habits: potamodrous
Austria’s Red List: critically endangered
Global Red List: endangered
Fun fact: This is the smallest sturgeon species in Austria. It only lives in freshwater.
Size: up to 2.2 m & 60 kg
Habitat: Black Sea, Sea of Azov, Caspian Sea
Migration habits: anadromous
Austria’s Red List: regionally extinct
Global Red List: critically endangered
Fun fact: The Latin word stellatus means “covered with stars”.
Size: up to 7 m & 2000 kg
Habitat: Black Sea, Sea of Azov, Caspian Sea
Migration habits: anadromous
Austria’s Red List: regionally extinct
Global Red List: critically endangered
Fun fact: The beluga sturgeon is the largest freshwater fish, and its eggs, Beluga caviar, are the most expensive food in the world.