Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1007/s10661-024-12834-5
Licence creative commons licence
Title (Primary) Complete exhaustion of dissolved nutrients in a large lowland river
Author Kamjunke, N.; Sanders, T.
Source Titel Environmental Monitoring and Assessment
Year 2024
Department FLOEK
Volume 196
Issue 7
Page From art. 660
Language englisch
Topic T5 Future Landscapes
T4 Coastal System
Data and Software links https://doi.org/10.1594/PANGAEA.963359
Keywords Phytoplankton; Phosphorus; Nitrate; Silicate; Denitrification; Nitrate stable isotopes
Abstract Riverine phytoplankton takes up phosphate, dissolved silicate, and nitrate. We investigated which nutrients are depleted during a Lagrangian sampling in the free-flowing part of the River Elbe in 2023. As part of this study, we tested the hypotheses that nutrient depletion might be caused by (1) above-average phytoplankton biomass or by (2) decreased nutrient load of the river during previous years. Phytoplankton biomass increased up to 350 km in rivers and stopped increasing exactly when soluble reactive phosphorus had been completely consumed, and molar carbon to phosphorus ratios of seston indicated the beginning phosphorus limitation. The concentrations of dissolved silicate and nitrate dropped below the detection limit as well. In contrast to the results from eight previous longitudinal samplings taken in 2018–2022, nitrate exhaustion was detected for the first time in 2023 within the transect. This was caused neither by an above-average phytoplankton biomass nor by a declined overall nutrient load of the river in 2018–2023. Instead, denitrification appears to be the most plausible explanation for the downstream decrease of nitrate and the loss of total nitrogen which was supported by enrichment of nitrate stable isotopes and a decreasing ratio of nitrate 15N/18O.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=29223
Kamjunke, N., Sanders, T. (2024):
Complete exhaustion of dissolved nutrients in a large lowland river
Environ. Monit. Assess. 196 (7), art. 660 10.1007/s10661-024-12834-5