Impact of seasonal vertical stratification on the dispersion patterns of dredging plumes off the south coast of Korea

Seo, Jun Young; Ha, Ho Kyung; Im, Jungho; Hwang, Jin Hwan; Choi, Sun Min; Won, Nam‐Il; Kim, Young-Sung

doi:10.1016/j.margeo.2017.09.005

Cited by 11 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Environmental impact assessments on the marine environment are a common practice in European Member States (Peduzzi, 2014). Impacts are well inventoried (ICES, 2022) with direct and indirect consequences including morphological changes due to seabed removal (e.g., Bellec et al, 2010;Degrendele et al, 2010;Gonçalves et al, 2014;Mielck et al, 2019) and changes in suspended matter due to increased turbidity (e.g., Roman-Sierra et al, 2011;Caballero et al, 2018) resulting from "active"-overflow and "passive"-sediment plumes (e.g., Duclos et al, 2013; that are dispersed over long distances (e.g., Kim et al, 2018;Seo et al, 2018). Near-to far-field effects are described (e.g., Becker et al, 2015; with deposition from sediment plumes potentially leading to smothering (e.g., Smith and Friedrichs, 2011;Spearman, 2015).…”

Section: Introductionmentioning

confidence: 99%

Sediment variability in intermittently extracted sandbanks in the Belgian part of the North Sea

Kint,

Barette,

Degrendele

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

Introduction: In the Belgian part of the North Sea, sand for beach and foreshore nourishments is extracted from the Hinder Banks, about 40 km offshore. The extraction is not screened for shells and other very coarse material, as is the case for sand extraction for industrial use. Intermittent but intensive sand extraction took place from 2012 to 2019 on the Oosthinder, and since 2019 on the Noordhinder.Methods: To better understand sediment variability during human-induced disturbance of the seabed, both sandbanks have been monitored using multibeam bathymetry and backscatter, and Reineck box cores on board of the Research Vessel Belgica A962. Acoustic and sediment data were preferably jointly collected within a one-week period to substantiate the interrelationships.Result: Very well-sorted medium sands with low backscatter values (−28 to −33 dB) are detected near the top of the sandbank, while (moderately) well-sorted coarser sands and shell fragments with high backscatter values (−20 to −24 dB) are detected in the deeper parts of the sandbank slope. Although natural conditions such as sandwave movement and storms may mask early sediment changes, 7 years of intermittent and intensive sand extraction on the upper parts of a gentle sandbank slope caused a seabed deepening of at least 2 m, a backscatter decrease between 5 and 8 dB, a reduction in carbonate content by 1%–5% and an increase in organic matter content by 1%–2%. Two years after the cessation of the operations, the carbonate content increased and organic matter content decreased by 1%–2%.Discussion: Natural variability of sediments remains dependent on depth and geomorphology in both undisturbed, as well as recently and longer disturbed sandbank systems. However, a spreading of the more homogeneous, very well-sorted medium sands with limited carbonate content from the sandbank crest to the upper parts of the sandbank slope was observed, as sand extraction progressed. Subsequently, possible first signs of a slow return to the original sediment characteristics were detected.

show abstract

Section: Introductionmentioning

confidence: 99%

Sediment variability in intermittently extracted sandbanks in the Belgian part of the North Sea

Kint,

Barette,

Degrendele

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…Sediment plumes caused by dredging operations can travel along currents and expand over large areas before settling on the seafloor (Barnes et al, 2015). Furthermore, environmental characteristics can also play an important role in the persistence and spread of turbid plumes, such as water column stratification (Seo et al, 2018) or the nature of the suspended matter (Smith and Friedrichs, 2011).…”

Section: Introductionmentioning

confidence: 99%

Dredging-induced turbid plumes affect bio-irrigation and biogeochemistry in sediments inhabited by Lanice conchilega (Pallas, 1766)

Mestdagh

Ysebaert

Moens

et al. 2018

ICES Journal of Marine Science

View full text Add to dashboard Cite

Building man-made structures in coastal seas are often preceded by dredging operations, inducing turbid plumes of suspended sediment. To study the effects of such high-concentration sediment plumes on the suspension-feeding polychaete Lanice conchilega, a laboratory experiment was performed, in which individuals of L. conchilega were exposed to natural seawater with a suspended sediment concentration (SSC) of ∼ 0.3 g l−1 and treatments with elevated SSC of 5 and 1 g l−1, representing concentrations in a dredging plume at the moment of sediment release and after initial dilution, respectively. We measured clearance rates of sediment particles, biogeochemical fluxes, and bio-irrigation. While clearance rates and nitrite efflux significantly increased in both treatments with elevated SSC compared with the control, bio-irrigation increased at 1 g l−1 but was lowest at 5 g l−1. It is suggested that piston pumping is intensified under intermediate concentrations to remove sediment, but ceases under high concentrations are due to sediment ingestion. By transporting oxygen into the sediment, bio-irrigation enhances aerobic microbial processes, among which nitrification. We conclude that short-term extreme suspended sediment concentrations can have a significant impact on the biogeochemistry of the seabed through changes in behaviour of L. conchilega.

show abstract

Assessment of the physical impact of a short-term dredging operation on a semi-enclosed environment: South Euboean Gulf, Greece

Kanellopoulos

Karageorgis

Kikaki

et al. 2019

Environ Monit Assess

View full text Add to dashboard Cite

Impact of seasonal vertical stratification on the dispersion patterns of dredging plumes off the south coast of Korea

Cited by 11 publications

References 43 publications

Sediment variability in intermittently extracted sandbanks in the Belgian part of the North Sea

Sediment variability in intermittently extracted sandbanks in the Belgian part of the North Sea

Dredging-induced turbid plumes affect bio-irrigation and biogeochemistry in sediments inhabited by Lanice conchilega (Pallas, 1766)

Assessment of the physical impact of a short-term dredging operation on a semi-enclosed environment: South Euboean Gulf, Greece

Contact Info

Product

Resources

About