Published

How Shells of Different Shapes Affect Current-driven Sand Transport [data and code] Version 9

Tjeerd Bouma (Royal Netherlands Institute for Sea Research) Royal Netherlands Institute for Sea Research https://doi.org/10.25850/nioz/7b.b.0j

This dataset and code belongs to the manuscript "How Shells of Different Shapes Affect Current-driven Sand Transport".

The seabed rarely consists solely of bare sand: often other materials, such as shells are present. They can influence sand transport by armouring the bed and modifying its roughness. Biogenic shells come in different shapes and sizes, depending on the mollusc species that produce them. To understand how changes in bivalve species composition affect sediment transport, we need a mechanistic understanding of how shell content and shell shape influence the near-bed flow and sand transport. We performed experiments in a racetrack flume, testing the effect of elongated (Ensis leei) versus rounded (Spisula subtruncata) shells on unidirectional current-driven sand transport. For both types of shells, a higher depth-averaged flow velocity was needed for initiation of motion and a decrease in bedload transport of sand was found. At a shell content of 20%, the threshold of motion of sand increased up to 75%, and bedload transport was reduced by up to 50%. These effects are explained by a balance between roughness-induced turbulence and bed armouring. Compared to a bare bed, shells decreased bed roughness by reducing ripple formation; rounded shells lowered roughness more than elongated shells, which formed roughness elements themselves, but also covered a larger fraction of the bed. However, there was no clear difference between round versus elongated shells on the overall sand transport; only shell content was key for the overall effect. Our results imply that sediment transport is likely overpredicted when a high number of shells is present in the seabed.

Data and Resources

Additional Info

Field Value
Subject Earth and Environmental Sciences
DAS Code 7b.b.0j
Source https://doi.org/10.25850/nioz/7b.b.0j
Version 9
Creator(s)
Kooistra, Tjitske (Royal Netherlands Institute for Sea Research)
ORCID

Haarbosch, Steven H. (Delft University of Technology)
ORCID

Bosma, Jorn W. (Utrecht University)
ORCID

Bouma, Tjeerd (Royal Netherlands Institute for Sea Research)
ORCID
Contact the corresponding author

van Prooijen, Bram C. (Delft University of Technology)
ORCID

Soetaert, Karline (Royal Netherlands Institute for Sea Research)
ORCID

Pearson, Stuart (Royal Netherlands Institute for Sea Research)
ORCID
Depositor Tjitske Kooistra (tjitske.kooistra@nioz.nl)
Publication Date 2025-11-13T11:04:43
Deposit Date 2025-08-21
Dataset Persistent Identifier DOI:10.25850/nioz/7b.b.0j
Alternate identifier
Related identifier
Contributor Royal Netherlands Institute for Sea Research (NIOZ)
Distributor Research Data Management(NIOZ Royal Netherlands Institute for Sea Research)
Distribution Date 2025-08-21
Production Date 2025-11-13
Dates
Collected
2022-08-15 until 2025-08-15
Funding References
NWO (17600)
Tracking Ameland Inlet Living Lab Sediment (TRAILS)

NWO (18035)
Effective Upgrades and REtrofits for Coastal Climate Adaptation (EURECCA)

NWO (21026)
Revealing Hidden Networks of Coastal Sediment Pathways
Geographic Coverage