Emerging and Established Diseases of Sturgeons (Acipenseridae) in the Pontic-Danubian Region and Aquaculture: Etiology and Geographic Distribution

The Ponto-Danubian Basin Acipenseridae family includes species of fish with high economic value, as well as some of the most vulnerable taxonomic groups in terms of biodiversity conservation worldwide. Viral diseases have been documented considerably less frequently than bacterial and parasitic diseases. However, the European sturgeon iridovirus (AcIV-E) and herpes viruses have recently emerged as epizootic pathogens, raising concerns about their potential impact on sturgeon populations in the Black Sea basin. Bacterial pathogens were the main cause of the diseases reported in the reviewed literature. Many of these pathogens belonged to the Genera Aeromonas, Vibrio, Pseudomonas, and Citrobacter. These pathogens were particularly implicated in the etiology of septicemic and hemorrhagic symptoms, which significantly impacted the mortality of affected populations. Ecto- and endoparasitic infestations were primarily caused by protozoa, monogeneans, trematodes, and nematodes, resulting in tissue lesions of varying severity, depending on the parasite and the host’s immune status. Temporal analysis revealed a significant increase in reports of bacterial diseases after 2000, coinciding with the growth of sturgeon aquaculture in Turkey and Romania. Outbreaks of disease exhibited pronounced geographical clustering in the northwestern Black Sea Region and the Danube River. These areas are characterized by intensive aquaculture activity and ecological vulnerability. These findings highlight the importance of coordinated regional surveillance, wider adoption of molecular diagnostics, and incorporation of health management strategies into conservation planning for Acipenseridae populations in the Black Sea Region.