Saving species on the very brink of extinction through conservation restocking

On the 18thof April 2019 two important sturgeon stocking events took place in Baja (Hungary) and Isaccea (Romania) in attempt to stabilise sturgeon populations in the Danube River. These events were part of the MEASURES Project (Managing and Restoring Aquatic Ecological Corridors for Migratory Fish Species in the Danube River Basin) and aim to save and strengthen two highly endangered Danube sturgeon populations by state-of-the-art conservational methods. Stocking of sterlet (Acipenser ruthenus) took place in Hungary, and stocking of Russian sturgeon (Acipenser gueldenstaedtii) in Romania. The fish were tagged to enable identification in case of recapture by in-situ surveys, and assist evaluation of survival rates for those released. This will provide valuable insight for larger stocking plans in the future.

Although the restocking actions are no in direct relation with the “LIFE FOR DANUBE STURGEONS” project, both projects have the same ultimate goal: to save sturgeon and other migratory fish species that represent the historical, economic and natural heritage of the Danube. Furthermore, sturgeons are indicators of the ecological status of the river’s watercourses, especially concerning the function of the river as an ecological corridor. The fragmentation of rivers by transversal structures like hydropower dams or flood protection measures poses a threat to natural fish populations if they are no longer able reach important habitats like spawning grounds, feeding grounds and wintering habitats. Transnational management and restoration actions to re-establish these corridors as migration routes, as well as stocking with indigenous species are essential until a self-sustaining population is achieved again.

“Conservational restocking is one of many necessary actions to save endangered fish. In conjunction with the provision and restoration of habitat, it is essential to increase the number of animals of species and populations on the very brink of extinction,” says Thomas Friedrich, University of Natural Resources and Life Sciences, Vienna.

The events were organised by the MEASURES Project, which is co-funded by the European Union (ERDF, IPA). For more information, please visit the project website: