Historically, three long migratory / anadromous species of sturgeons, used to migrate as far as Regensburg, Germany (at rKm 2375) for spawning of adults and nursery of young sturgeons.Spawning grounds of sturgeons located on the gravely bottom branches of the Schüttinsel / Szigetköz inner delta, downstream of Bratislava, and fishing sites for sturgeons upstream of Komárom, in Hungary (rKm 1767), were famous during the Middle Ages. Iron Gate (IG) gorges were very famous for their fishing sites for sturgeons. Longitudinal continuity of the Danube River at IG (roughly 950 Km from the Black Sea) has been successively blocked by construction of hydropower (HP) dams IG I (completed in year 1974) (rKm 943) and IG II (completed in year 1984) (rKm 863). None of the dams was foreseen with fish passage facilities. The project aims to identify it the sturgeons are still migrating up to IG II dam and their behavior close to the dam using acoustic telemetry equipments.