Work

Flocculation regulates suspended sediment transport in estuarine fronts

Year: 2025

Type: article

Abstract: This study examines suspended sediment transport affected by flocculation settling in a highly stratified tidal estuary. In situ observation recorded two estuarine front passages during strong‐ebb and flood‐slack tides, respectively. The strong‐ebb front enhanced turbulence, increasing sediment concentrations (~ 5 ppm), macrofloc size (~ 300 μm) and settling efficiency. The surface plume combined with middle layer together thickened from 1.5 to 2.5 m, facilitating particles mixing. The plankton and organic debris were transported into bottom water, forming fluffy, porous macroflocs. In contrast, the flood‐slack front developed stable middle barrier layer (~ 2 m) that restricted mixing and organic input, leading to denser, compact flocs (~ 150 μm) in bottom waters. Floc size distributions shifted from microfloc‐dominated to macrofloc‐dominated during strong‐ebb front passing, then returned to smaller, denser flocs. Dissolved‐oxygen changes due to sediment oxygen depletion varying. These findings help to improve predictive models for sediment transport and hypoxia dynamics in estuarine systems.

Source: Limnology and Oceanography Letters

DOI: 10.1002/lol2.70016

Authors: Leiping Ye, Jiayao Zhang, Jie Ren, Huan Liu, Jiaxue Wu

Institutions: Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Life below water

Open Access status: gold

Estimated APC paid: $3,700