Blocking of migration routes: a critical threat to sturgeons

Canva

Spawning migration is essential to the survival of sturgeon species. However, physical barriers such as dams can block their traditional routes, making key habitats unreachable and disrupting reproduction cycles.

In the Lower Danube, sturgeons once had access to a 2,000 km migratory corridor. Today, due to the Iron Gates dam system between Romania and Serbia, only 900 km remain accessible. This dramatic reduction affects not only spawning, but also wintering and nursery grounds.

Further hydropower development proposals along the Lower Danube, including near Turnu Măgurele–Nikopol and Silistra–Călărași, highlight the need for careful environmental assessment to ensure that remaining migration routes are preserved.

Similar challenges exist in the Rioni River in Georgia, where a cascade of hydropower dams has left only the lower 91 km of the river accessible to sturgeons. Flow fluctuations further disrupt spawning.

Maintaining free-flowing river sections is key to the survival of these ancient fish and the ecosystems they support.

The Pan-European Action Plan for Sturgeons, adopted in 2018 under the Bern Convention, serves as a vital framework for conserving Europe's eight native sturgeon species—many of which are critically endangered. The plan emphasizes habitat protection, restoration of migration routes, and coordinated conservation efforts across river basins and sea regions.

In 2025, the European Commission released updated reports assessing the implementation of the Action Plan in key regions, including the Lower Danube, Black Sea, and Baltic Sea basins. These reports highlight both progress and persistent challenges, such as habitat fragmentation and enforcement gaps.

As part of these continued efforts, the SCUTE project—a coordinated initiative under the EU Biodiversity Strategy—has published a comprehensive set of deliverables to support the conservation of Europe’s native sturgeon species. These materials, available via the European Commission, offer practical tools, scientific insights, and guidance for decision-makers, conservationists, and local communities.

Explore the SCUTE deliverables below:

·        Factsheet (in 18 languages): A plan to save sturgeons in Europe – link

 ·        Video: Join Us to Save Sturgeons from Extinction - link

 ·        Regional reports:

1.      State of implementation of the Pan-European Action Plan for Sturgeons – Baltic Sea region 2024 - link

2.      State of implementation of the Pan-European Action Plan for Sturgeons – Atlantic region 2024 - link

3.      State of implementation of the Pan-European Action Plan for Sturgeons – Lower Danube and Black Sea region 2024 - link

4.      State of implementation of the Pan-European Action Plan for Sturgeons – Upper and Middle Danube region 2024 - link

5.      State of Implementation of the Pan-European Action Plan for Sturgeons – Italy Mediterranean region 2024 - link

 ·        Report: Review of bycatch prevention and mitigation measures for sturgeons - link

 ·        Technical guidelines:

1. Technical guideline for sturgeon population monitoring – link  

2. Technical guideline for Ex situ conservation measures in sturgeons – link  

3. Technical guideline for sturgeon habitat monitoring - link

#Biodiversity #SturgeonConservation #Danube #BlackSea