First Results from Sterlet Monitoring in the Danube Show Encouraging Signs

The first results from sterlet monitoring activities carried out by IMSI – the University of Belgrade’s Institute for Multidisciplinary Research (Department of Biology and Inland Water Protection) in a protected section of the Danube in Serbia, along the border with Croatia, are providing valuable new insights into the behavior of this endangered sturgeon species and represent an important step forward in understanding its movements in the Danube. 

During a recent field survey, the IMSI research team retrieved data from receivers and tested detection efficiency of transmitters underwater acoustic signals at varying distances. The results were encouraging: signals from sterlet tagged on the 3^rd of December were recorded not only at the initial release location, but also by receivers installed near the localities of Marin Prut and Purina Jama. 

These findings confirm both the effective functioning of the monitoring equipment and the movement of tagged individuals across the investigated area. Such information is particularly valuable during the winter period, when data on sterlet behavior and habitat use are traditionally scarce. 

Tracking movement to support conservation 

By monitoring the movement of tagged sterlet, the researchers aim to better understand migration patterns, habitat use, and seasonal behavior. The collected data will support further analyses in the coming months, with monitoring activities continuing throughout spring and summer. 

Hydroacoustic receivers have been installed beneath white buoys placed in the Danube riverbed, allowing for regular data collection and analysis. Selected sterlet individuals were fitted with transmitters using careful surgical procedures and were safely released back into the river after recovery. 

Cooperation with local stakeholders 

The implementation of these monitoring activities is supported through cooperation with local stakeholders, including the Serbian public enterprise JP Vojvodinašume, which participates in the project as an Associated Strategic Partner. Anglers in the Danube sections near Bogojevo, Staklara, and Bakulja have been informed about the presence of monitoring equipment and asked not to disturb the white buoys placed in the river. 

They have also been advised to immediately release any sterlet showing visible surgical scars and to report such catches to the designated contact persons. Each safely released, tagged individual provides important data for ongoing research. 

From signals to solutions 

Every registered signal contributes to a clearer understanding of sterlet movement and habitat use in the Danube. These first results demonstrate the value of fieldwork and coordinated monitoring efforts, as well as the importance of cooperation between researchers, water managers, and local river users.