View in EDS

Complete exhaustion of dissolved nutrients in a large lowland river

Saved in:
Bibliographic Details
Title: Complete exhaustion of dissolved nutrients in a large lowland river
Authors: Kamjunke, Norbert, Sanders, Tina
Source: Environ Monit Assess
Publisher Information: Springer Science and Business Media LLC, 2024.
Publication Year: 2024
Subject Terms: 0106 biological sciences, Nitrates, Nitrogen, Research, Silicates, Phosphorus, Nutrients, 01 natural sciences, Phosphates, Phosphates/analysis [MeSH], Water Pollutants, Chemical/analysis [MeSH], Phytoplankton, Biomass [MeSH], Rivers/chemistry [MeSH], Denitrification, Nutrients/analysis [MeSH], Environmental Monitoring [MeSH], Phytoplankton [MeSH], Phosphorus/analysis [MeSH], Silicates/analysis [MeSH], Silicate, Nitrate, Nitrate stable isotopes, Nitrates/analysis [MeSH], Nitrogen/analysis [MeSH], Rivers, Biomass, Water Pollutants, Chemical, Environmental Monitoring, 0105 earth and related environmental sciences
Description: 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.
Document Type: Article
Other literature type
Language: English
ISSN: 1573-2959
0167-6369
DOI: 10.1007/s10661-024-12834-5
Access URL: https://pubmed.ncbi.nlm.nih.gov/38916758
https://repository.publisso.de/resource/frl:6509055
Rights: CC BY
Accession Number: edsair.doi.dedup.....1f51cd20b7ea974b56ece4b29047c28b
Database: OpenAIRE
Description
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.
ISSN:15732959
01676369
DOI:10.1007/s10661-024-12834-5