Release Beluga sturgeons in the Danube

Target reached

Unbelievable 100%! We are going over 100% for 15.000 sturgeons, the remainder will go to the next dam removal.

We just got Borislava's update:

The little fish are now 72 days old and about 10 cm  long. In a couple of days 2 staff members of WWF Bulgaria will start tagging them with coded wired tags, very small pieces of metal with a code, that is only readable with special devices. These tags are implanted in the fish and are not visible, thus they do not affect  them. But they will allow to identify the fish when they are caught again through a monitoring action. Tagging 15000 small, spiny, slipy, very active fishes with less than a millimeter big tag, exactly behind the first pectoral fin requires a lot of concentration and time from our colleagues.

But they sure will have finished their task for the time of the release which is now planned between 16 and 18th June. Due to Covid restrictions it can not be planned as a big public event, but  at least representatives from the most important authorities will be invited. The release event is also a great opportunity to show the fish in reality to stakeholders and increase their commitments to engage in conservation measures, crucial for the long-term protection of sturgeon.  

WWFs field experts will start following the young ones downstream and will wait for them in our monitoring station at Vetren about 200 km downstream. 

Last year we learned that the little fish take very different traveling speeds, some simply drift down with the current of the mighty Danube and will reach the Delta as soon as 10 days after the release. Others will choose to take it slowly and will reach the Delta in 2-3 months.  In early autumn they will enter the Black Sea and look for overwintering sites, such as one identified close to the Ukrainian Black Sea cost.  Unfortunately we know still very little about this time of their life-cycle, but Belugas will spend the next 10-15 years in the Black Sea and than will eventually return to the Danube River to lay their eggs for the first time.

So this is only the start of a hopefully very long story.


Worldwide Sturgeons are the most endangered group of species, according to the IUCN who regularly publishes the global red list assessments. So it is clear that sturgeon need our help! Although once widespread in many rivers in Europe such as the Rhine or the River Po, the only river where sturgeon still spawn (reproduce) naturally today is the Lower Danube River, where sturgeons can still migrate freely between the Black Sea and more than 800km upstream crossing borders of Ukraine, Romania, Bulgaria and Serbia. 

But also here sturgeon stocks have been depleted due to massive overfishing in the past and their survival is at threat. Today sturgeon fishing is banned and WWF is engaged along the Danube to work with authorities to enforce these bans.

Now we got a unique chance to support sturgeon in the Danube, and you can help. We are offered the unique opportunity to buy and release at least 15.000 Beluga sturgeon in Bulgaria, close to an island in the Danube, located almost in the middle between the Bulgarian capital Sofia, and the Romanian capital Bucharest. The little sturgeon (10-15cm in size) will be a couple of weeks old when they are leased, and they will start their journey downstream towards the Black Sea, where they will spend a couple of years until they grow large (around 1-2m) and old enough to come back to breed again.

The release of these endangered fish, can directly contribute to their survival but it is also an important event to raise awareness and engage stakeholders from politicians to local fishermen, from fisheries agencies to police, from Water and Environmental Authorities. All of them are needed to engage in sturgeon conservation. A joint activity of actually releasing little sturgeon with their own hands is a once-in-a-lifetime experience for everybody. All the fish will be tagged with CWT (coded wire tags), allowing identification of these fish if they are recaptured later by other institutions or in different countries.. Additionally the tagging of released sturgeon will eventually contribute to further information of migration patterns of these fish and informs further conservation actions such as protection of habitats and migration corridors.


WWF Nederland


Borislava Margaritova, Expert Freshwater and Wildlife Conservation at WWF Bulgaria

Borislava graduated from Sofia University with a degree in applied hydrobiology and aquacultures, where she demonstrated a particular interest in populational biology of fish, biodiversity and the protection of fish populations. After finishing her studies in Sofia, Borislava participated in various hydrobiology projects, including mapping and determining the nature conservation status of fish in Natura 2000 sites. In 2013, she joined WWF Bulgaria in their project work on protecting sturgeon in the Lower Danube and the Black Sea. Since then, she’s been devoted to saving the last of the Danube sturgeon and, by doing so, prioritised river monitoring activities and engagement with fishing communities and law enforcement agencies. This has been recognised as key to protecting the most critically endangered group of species in the world. Borislava has never forgotten when, during her first field season in 2013, she and her colleagues caught only one sturgeon despite the long hours spent in the river. Numbers of reported sturgeons have slightly increased since then, and this inspires Borislava to remain committed to the mission of improving the conservation of sturgeon, not only in Bulgaria, but in Europe as a whole."



Oskar de Roos, Expert Fresh Water WWF The Netherlands

After studying Economics and International Relations, followed by a consultancy career, Oskar decided to pursue his passion and dream job: protecting and restoring natural wonders. His current focus is fresh water; an essential resource for people and nature. Pressures from agriculture, dam building and climate change, together with poor governance, result in water becoming scarce. In Europe rivers are obstructed by dams and freshwater systems are heavily polluted. As a consequence biodiversity is declining rapidly and local human populations are suffering more and more. At WWF we are committing to restore natural wonders by removing dams, in regions such as the Carpathian, the Danube Delta and the Balkan.

General facts on the Beluga Sturgeon (Huso huso):
Beluga sturgeon is the largest freshwater fish in the world, with a historic record from the Volga river of 7,2m and their eggs, are considered to form the best caviar quality and fetch high prices, up to 14.000 € per kg. In the Danube Belugas have known to reach sizes of 4,5m, and even today individuals of more than 2m are found. Although natural spawning of Belugas still occurs in the Lower Danube, they are considered critically endangered by IUCN, with a decreasing population trend. Poaching of adult fish for their caviar and meat still threatens their survival.