Hydrodynamic and primary production effects on seasonal DO variability in the Danube River

Maier, Jan; Visser, Anna-Neva; Schubert, Christina M.; Wander, Simon T.; Barth, Johannes A. C.

doi:https://doi.org/10.5194/bg-22-5123-2025

Articles | Volume 22, issue 18

https://doi.org/10.5194/bg-22-5123-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-22-5123-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 22, issue 18

Research article

|

29 Sep 2025

Research article |

| 29 Sep 2025

Hydrodynamic and primary production effects on seasonal DO variability in the Danube River

Jan Maier, Anna-Neva Visser, Christina M. Schubert, Simon T. Wander, and Johannes A. C. Barth

Supplement

https://doi.org/10.5194/bg-22-5123-2025-supplement

Data sets

Seasonal Dataset of DO, δ¹⁸ODO and Biogeochemical Parameters in the Danube River (2023–2024) Jan Maier et al. https://doi.org/10.1594/PANGAEA.983395

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Short summary

We present the first large-scale assessment of the dissolved oxygen (DO) budget and δ¹⁸ODO across the Danube to distinguish DO sources and sinks, key for biogeochemical cycles. Two highly productive areas in the warm season showed large deviations (+12.1 ‰) from atmospheric equilibrium (+24.6 ‰ ± 0.4 ‰), unusual for large rivers. Critically low DO in the Sava (0.16 mmol/L) and lower Danube (0.2 mmol/L) in late summer resulted from intensified respiration.