Spatial dynamics of anadromous sturgeon migration (Huso huso, A. gueldenstaedtii, A. stellatus) along the Danube Delta branches (2022-2024)
Full-length research papers → Ichthyology
Authors
1. Danube Delta National Institute for Research and Development, Str. Babadag nr. 165, CP 820112 Tulcea, Romania
* Corresponding author: Ş. Honț, E-mail: stefan.hont@ddni.ro
Keywords
sturgeon, Danube River, migration, telemetry, Danube Delta.
Abstract
Monitoring fish species in large rivers has progressed from traditional fishing methods to modern electronic telemetry, such as acoustic and satellite tagging. These technologies provide long-term and high-precision data on fish migration in both riverine and marine environments. In the Danube River, sturgeon migration was first monitored using telemetry in 1998-1999, with a focus on anadromous species. Since 2009, several telemetry projects have been implemented, during which an increasing number of adult sturgeons have been tagged with acoustic transmitters. With a battery life of up to seven years, these tags enable continuous monitoring of sturgeon migration over extended periods. In this study, 11 adult Stellate sturgeons (Acipenser stellatus) and 5 Russian sturgeons (Acipenser gueldenstaedtii) were tagged and tracked between 2022 and 2023. Results revealed repeated autumn upstream migrations by certain individuals that reached the Iron Gates II area in both 2019-2020 and 2022-2023 under similar environmental conditions (water temperature and water level). A notable shift in migration routes across the Danube Delta branches was also observed in 2023 compared to 2022 and previous years (2012-2015). This redistribution may be linked to recent environmental and anthropogenic changes in the area during 2022-2023, including increased navigation and dredging activities. These findings highlight the influence of human-induced factors on sturgeon migration behavior and emphasize the importance of continuous acoustic monitoring for the conservation and management of endangered sturgeon populations in the Danube River.
Article history
Received: 10 July 2025 / Accepted: 19 May 2026 / Published online: 15 June 2026 / Printed: 30 June 2026
Authors` ORCID IDs
I.M. Iani https://orcid.org/0000-0002-0484-1128
M. Paraschiv https://orcid.org/0000-0003-1254-4614
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