25 June 2021 - For the first time in Ukraine, reintroduction was organised as a complex process that was not limited to just releasing fish into the river. WWF-Ukraine conducted preliminary studies of sturgeon habitats in the Ukrainian part of the Danube, as well as genetic analysis to ensure that the sterlets were of Danube origin.
One thousand sterlets were tagged. ‘Sterlet was tagged in the least traumatic way by injecting a blue pigment under its skin," says Inna Hoch. “This is the first attempt at long-term monitoring of released fish, which has not yet existed in our country’.
As pure freshwater species, the sterlet (Acipenser ruthenus) does not need to migrate to the Black Sea. The sterlet is the most common sturgeon in the Danube River Basin and the only one found above the Iron Gate Dams. But even their fate is not looking too prosperous, as according to the International Union for the Conservation of Nature (IUCN), the sterlet population fell by about 70 percent in the 20th century. 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 to migrate between important habitats like spawning grounds, feeding grounds and wintering habitats, but poaching is one of the significant causes of this negative trend.
Currently, all sturgeon species living in Ukrainian waters are rare and listed in the Red Book of Ukraine with different conservation statuses. ‘In Ukraine, there are 6 species of sturgeon, occurring most often in the Danube basin’, comments Inna Hoch, WWF-Ukraine Freshwater Manager. ‘The species that outlived the dinosaurs have almost become extinct due to human activity’.
WWF-Ukraine has been involved in sturgeon conservation activities for over five years. WWF Central and Eastern Europe’s (WWF-CEE) Life for Danube Sturgeon Project has significantly strengthened this work at the state level by proposing a framework for the National Action Plan for Sturgeon Conservation in Ukraine for 2021-2030. The Plan was created in cooperation with the Ministry of Environment and Natural Resources of Ukraine and leading scientists in December 2020 based on the Pan-European Action Plan for Sturgeons adopted at the 38th Standing Committee Meeting of Bern Convention (EU Habitats Directive). This most recent Danube sturgeon reintroduction was the first step towards the implementation of this Action Plan.
Stocks were raised thanks to cooperation between WWF Central and Eastern Europe and Rewilding Europe, and donations from Ukrainian donors during WWF-Ukraine's New Year's ‘Gift to Nature’ Campaign. In January 2021, more than a thousand Ukrainians donated about 262,000 UAH (approx. 8,000 EUR), to preserve this ancient fish in Ukraine.
For more information:
Communications Officer, WWF-Ukraine
Read Report: WWF’s Market Survey on Sturgeon Poaching
Sturgeons used to be present in almost all European rivers, but today seven out of the eight species of sturgeon on the European continent are threatened with extinction. Sturgeons have survived the dinosaurs, but now teeter on the brink of extinction. The Black Sea Region is crucial to the survival of these species in Europe. The Danube and the Rioni River in Georgia are the only two rivers remaining in Europe where migrating sturgeons reproduce naturally. The main reasons are overfishing and loss of habitat through dams that block migration routes or in-river constructions, facilitating navigation. These are often detrimental to the feeding and spawning habitats, necessary for sturgeon survival. Within the EU the only river with naturally reproducing sturgeon populations remains the Danube. Crucial but no longer reproductive stocks are left in the Po River in Italy and the Gironde in France. Restocking activities take place in Bulgaria, Hungary, Romania, France, Germany, Poland, Austria and the Netherlands. Our priority is to identify and protect the critical habitats of the remaining four sturgeon species (Huso huso, Acipenser stellatus, A. ruthenus, A. gueldenstaedtii) in the Lower Danube and north-western Black Sea, as well as to reduce pressure on their remaining populations by addressing poaching and ensuring protection.
Sturgeon and other migratory fish species represent the historical, economic and natural heritage of the Danube. Furthermore, they are indicators of the ecological status of the river’s watercourses, especially concerning the function of the river as an ecological corridor. Yet, according to the recently released World’s Forgotten Fishes Report, populations of migratory freshwater fish have fallen by 76 per cent since 1970, and mega-fish such as sturgeons by a catastrophic 94 percent.