(v.li.) BOKU-Rektorin Eva Schulev-Steindl, Innovationsstadträtin Ulli Sima, Landwirtschaftsminister Norbert Totschnig und Klimaministerin Leonore Gewessler. © BML

Continuation of a success story: Austria's contribution to the protection of sturgeon in the Danube

Climate Minister Leonore Gewessler, Agriculture Minister Norbert Totschnig, Innovation City Councillor Ulli Sima and BOKU Rector Eva Schulev-Steindl today jointly released sturgeon into the Danube. The project follows the "LIFE-Sterlet" project, successfully completed in 2022, in which the University of Natural Resources and Applied Life Sciences built a sterlet breeding station on the Danube Island in Vienna and released a total of 240,000 sterlets into the Danube. This supported the highly endangered population of this last naturally occurring sturgeon species in Austria so that a self-reproducing population can develop again.

The now extended goal is to continue the know-how built up in the construction of a floating breeding station on the Danube in Vienna. The vessel is provided by the project partner viadonau, the mooring on the Danube Island by the City of Vienna. The focus is now on a total of four sturgeon species - in addition to the sterlet in the Upper and Middle Danube, the species Waxdick, Sternhausen and Hausen in the Lower Danube are now to be saved from extinction. The planned measures include keeping and breeding parent animals, releasing young fish into the wild, gene databases, scientific support, monitoring and extensive public relations work. The project is led by the University of Natural Resources and Applied Life Sciences in Vienna, with the participation of several institutions in Hungary, Slovenia, Romania, Bulgaria, Slovakia and Ukraine. In Austria, the Federal Office for Water Management (IGF Scharfling) is also involved.

The project will run from autumn 2022 to the end of 2029, with a total project volume of 11.8 million euros (67% LIFE funding). The majority of the co-financing will be provided by BML and viadonau with 1 million euros each and the City of Vienna with 500,000 euros. Further support comes, among others, from the regional fisheries associations of Lower Austria, Upper Austria and Vienna, as well as from the Danube Floodplains National Park.

"Our common goal for many years has been to preserve and protect the unique habitat along the Danube. When we see that animal species are on the brink of extinction, our decisive action is needed. I am therefore all the more pleased that in the course of this broad-based project everything is being done to ensure the survival of four sturgeon species," said Federal Minister Gewessler, expressing her delight at the joint efforts.

"My ministry invests in the renaturation of water spaces every year. The quality of the Danube and its creatures is also constantly monitored and improved with proven projects. Sturgeons react very sensitively to environmental influences and are therefore indicators of a healthy river system. At the same time, they are among the most endangered animals in the world. I am all the more pleased about the continuation of the successful initiative. At the same time, it is also very important to me that the public is informed about the results and can actively follow the progress," emphasises Federal Minister Norbert Totschnig.

"The project to protect the sterlet in the Danube is a real success story. More than 240,000 were reared in a rearing container on the island info of our Vienna Waters Department and finally released into the wild; since then, adult fish have also been sighted in the Danube again. I am very pleased that this exciting work is now being continued and even extended to other endangered sturgeon species - because we see that the effort is worthwhile and that biodiversity and water quality benefit. The City of Vienna is happy to be involved again as a project partner!" emphasises Ulli Sima, the city councillor responsible for Vienna's water bodies.

"The conservation and protection of habitat and biodiversity is a core mission of BOKU. For more than 40 years, the Institute of Hydrobiology has been researching and teaching on the sustainable use and conservation of stream ecosystems. Sturgeons are the perfect ambassadors for careful management of the lifelines of our landscape. We at BOKU are pleased to be able to show intensive commitment here in the Danube region and beyond," says Rector Eva Schulev-Steindl.

Sturgeons are highly endangered

Sturgeons are excellent indicators of ecologically healthy rivers and seas due to their size, high life expectancy and late sexual maturity, their diverse habitat requirements and migratory life cycle, and thus require a holistic approach to their conservation. The IUCN classifies sturgeon as the most threatened animal family in the world, due to past overfishing for meat and caviar, as well as migration barriers and habitat loss.

Successful conservation of sturgeon requires a comprehensive consideration of international river systems and coastal areas, as well as a wide range of measures, from protection of remaining genetic diversity, habitat restoration, passage of migration barriers to support of remnant populations through release of adapted juvenile fish. The "Pan-European Sturgeon Action Plan" emphasises in particular the need to keep genetically diverse dams in captivity in very small remnant populations and to release offspring into the wild to stabilise populations until conditions in the wild allow recovery through natural reproduction.

In the Danube, two out of six species are already extinct. Three species are currently still found sporadically in the lower Danube; natural reproduction is only sporadic. The extremely small populations cannot recover on their own, but need support through the release of genetically healthy and diverse juvenile fish that are adapted to their home waters through rearing in river water and are suitable for survival in the wild.

The overall objective of the project is to secure the gene pool of the four surviving Danube sturgeon species, Waxdick, Sterlet, Sternhausen and Hausen, from extinction through mothering and release of juvenile fish.

Key points on the project plan:

The following measures are planned:

- Construction of the "LIFE-Boat 4 Sturgeons", a floating breeding station, anchored on the Danube Island in the Danube in Vienna, for keeping mother fish and rearing juveniles.

- Facility for keeping mother fish at the Koros in Hungary

- Rearing container on the banks of the Mur in Slovenia

- Keeping of Danube mother stocks at several locations

- Reproduction, rearing and release of juvenile fish using state-of-the-art technology

- Establishment of a genetics database to preserve the greatest possible diversity in the long term

- Release of 1.6 million juveniles of the various species into different stretches of the Danube

- Modern and comprehensive monitoring programme in cooperation with environmental DNA and mark-recapture studies

- Extensive public relations and awareness raising through social media, events and guided tours for school classes

- Research activities to increase knowledge for the successful conservation of aquatic biodiversity

"Sturgeons are 200 million year old living fossils. In just 200 years, we have brought them to the brink of extinction. It is our social duty to preserve these fascinating creatures for future generations. The interplay of preserving genetic diversity by keeping mother fish and releasing young fish into the wild, restoring migration routes and habitat, research and education, and creating awareness of the issue among the population is the key to success. " says project manager Thomas Friedrich.

Enquiry note for media:

Thomas Friedrich
University of Natural Resources and Applied Life Sciences Vienna
Institute for Hydrobiology & Water Management
Project Management LIFE Boat4Sturgeon
Phone: 0650 4507428
E-mail: thomas.friedrich@boku.ac.at