Published

Annual biogeochemical dynamics in the Western Scheldt Version 22

Karline Soetaert (Royal Netherlands Institute for Sea Research) Royal Netherlands Institute for Sea Research https://doi.org/10.25850/nioz/7b.b.qf

Estuarine intertidal sediments are important centres for organic matter remineralization and nutrients recycling. Nevertheless, there is limited understanding regarding how these processes occur along the salinity gradient and their seasonality. Here, we report on the seasonal biogeochemical cycles from three types of intertidal sedimentary habitats (freshwater, brackish and marine) located in the Western Scheldt estuary (The Netherlands and Belgium). A full year of solute fluxes, porewater nutrient and sediment pigment concentrations at a monthly resolution revealed clear differences in the biogeochemistry of the three sites, indicating that environmental conditions determined the local nutrient dynamics. Temperature controlled sediment oxygen consumption rates and nutrient fluxes, but also affected pore water nutrient concentrations up to 14 cm deep. Fresh and brackish sediments had a net influx of dissolved inorganic nitrogen (DIN) (􀀀 1.62 mmol m􀀀 2 d􀀀 1 and -2.84 mmol m􀀀 2 d􀀀 1, respectively), while only the freshwater sediments showed a net influx of phosphate (􀀀 0.07 mmol m􀀀 2 d􀀀 1). We estimated that intertidal sediments remineralized a total of 10,000 t C y􀀀 1, with 97% of mineralization occurring in the brackish and marine parts. Overall, sediments removed 11% (1500 t N y􀀀 1) and 15% (~200 t P y􀀀 1) of the total nitrogen and phosphorus entering the estuary from riverine input. Moreover, observations revealed the historical improvement of water quality resulting from water treatment policies. This spatiotemporal study of OM remineralization and early diagenesis in estuarine systems highlights the importance of intertidal sediments for estuarine systems. Our observations can be used in models to predict estuarine biogeochemistry or assess climate change scenarios.

Data and Resources

Additional Info

Field Value
Subject Earth and Environmental Sciences
DAS Code 7b.b.qf
Source https://doi.org/10.25850/nioz/7b.b.qf
Version 22
Creator(s)
Soetaert, Karline (Royal Netherlands Institute for Sea Research)
ORCID
Contact the corresponding author

Rios Yunes, Dunia (Royal Netherlands Institute for Sea Research)
ORCID
Depositor Dunia Rios Yunes (dunia.rios.yunes@nioz.nl)
Publication Date 2023-08-04T10:22:00.3812029
Deposit Date 2023-08-04
Dataset Persistent Identifier DOI:10.25850/nioz/7b.b.qf
Alternate identifier
Related identifier https://doi.org/10.1016/j.ecss.2023.108227
Contributor Royal Netherlands Institute for Sea Research (NIOZ)
Distributor Research Data Management(NIOZ Royal Netherlands Institute for Sea Research)
Distribution Date 2023-08-04
Production Date 2023-08-04
Dates
Collected
2019-03-01 until 2020-02-29
Monthly samples of sediment and water from three sites, appels, groot buitenshoor and paulina polder in the western scheldt
Funding References
Royal Netherlands Academy of Arts and Sciences (KNAW) (PSA-SAE- 02)
Geographic Coverage