Sessions

In my thesis, the emergence and epidemiological relevance of the Siberian sturgeon herpesvirus (SbSHV) in Hungary was examined in Russian (Acipenser gueldenstaedtii) and Siberian sturgeons (Acipenser baerii). The family Acipenseridae represents one of the most ancient groups of fish, several species of which have become critically endangered due to overfishing, loss of spawning grounds, and environmental pollution. Therefore, artificial propagation and aquaculture have gained increasing importance worldwide, serving not only as a major sector of meat and caviar production but also as a key tool for species conservation.

Among the various health risks occurring in farmed stocks, viral diseases require particular attention. In addition to several bacterial and parasitic infections, the Siberian sturgeon herpesvirus (SbSHV) can cause severe losses. First isolated in Russia, SbSHV has been detected recently in Europe and also in Hungary, associated with significant mortality events. A major concern is that the virus can persist in a latent form within carrier fish and is able to spread horizontally and presumably also vertically, thereby potentially threatening the long-term stability of broodstock populations.

In Hungary, the virus was first detected in 2023 in Russian sturgeon and Siberian sturgeon populations, where high mortality rates were observed among juvenile fish. Laboratory investigations confirmed the presence of SbSHV. Sampling of fry, six-year-old fish, and broodstock from different facilities, followed by PCR and sequencing, demonstrated the occurrence of the virus in certain cases. Results indicated that although the infections were localized, fish transfers between farms and connections to open waters may pose a risk of further spread. The study highlights that regular veterinary monitoring, strict quarantine procedures, and the implementation of strict biosecurity measures are indispensable in Hungarian aquaculture. The application of early diagnostic techniques enables rapid identification and selection of infected stocks, thereby reducing economic losses and mitigating the risk of epidemic outbreaks.

Based on our findings, further research and sample analysis are essential to ensure that the culture of Russian sturgeon, Siberian sturgeon, and other sturgeon species remains sustainable and economically viable in the long term, while at the same time contributing to the conservation of these endangered species.