We developed generalised additive mixed models (GAMMs) to infer spatiotemporal trends of environmental PCB concentrations from an extensive dataset (n=1219) of PCB concentrations measured between 1991 and 2010 in sediments of the Belgian Coastal Zone (BCZ) and the Western Scheldt estuary. A GAMM with time, geographical zone, periodicity and the organic carbon - water partition coefficient as covariates explained 49% of the variability in the log transformed PCB sediment concentrations. The time trends unraveled two to threefold PCB concentration decreases in the BCZ during the last 20 years. However, in the Western Scheldt estuary, time trends were spatially heterogeneous and not significantly decreasing. These results demonstrate that international efforts to cut down emissions of PCBs have been effective to reduce concentrations in open water ecosystems like the BCZ but had little effect in the urbanised and industrialised area of the Scheldt estuary.
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http://dx.doi.org/10.1016/j.marpolbul.2014.01.002 | DOI Listing |
Ecol Appl
January 2025
Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, Yerseke, The Netherlands.
Tidal marshes can contribute to nature-based shoreline protection by reducing the wave load onto the shore and reducing the erosion of the sediment bed. To implement such nature-based shoreline erosion protection requires the ability to quickly restore or create highly stable and erosion-resistant tidal marshes at places where they currently do not yet occur. Therefore, we aim to identify the drivers controlling the rate by which sediment stability builds up in young pioneer marshes.
View Article and Find Full Text PDFSci Total Environ
January 2025
ECOSPHERE, Department of Biology, University of Antwerp, Wilrijk, Belgium.
Tidal marshes are often restored on compact agricultural soil that limits tidally induced groundwater dynamics and soil aeration after restoration. We hypothesized that impaired soil aeration affects biogeochemical cycling and leads to altered porewater nutrient concentrations in restored tidal marshes. We studied soil hydraulic properties, groundwater dynamics and porewater nutrient concentrations (nitrogen, phosphorus and dissolved silica) over the course of one year in a natural and a restored freshwater tidal marsh in the Scheldt estuary, Belgium.
View Article and Find Full Text PDFSci Total Environ
December 2024
Archaeology, Environmental Changes & Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, Brussels 1050, Belgium. Electronic address:
Estrogens are contaminants in the Scheldt estuary due to a dense population and intense industrial and anthropogenic activities, but their levels and evolution in this estuary are not well studied. Here we investigated estrogenic activity (EA) in the dissolved, particulate and sediment compartments of the estuary using the Estrogen Receptor (ER)-Chemical Activated Luciferase Gene Expression (CALUX) bioassay, in recent and historical samples. EA ranges between 7-168, 2.
View Article and Find Full Text PDFJ Environ Radioact
December 2024
Institute of Mechanics, Material and Civil Engineering, Université Catholique de Louvain, Louvain-la-Neuve, Belgium; Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium. Electronic address:
Using the discontinuous Galerkin method in the SLIM modelling framework, we study the transport in the Scheldt basin and adjacent coastal area of radionuclides possibly emitted by Doel nuclear power plant in the aftermath of an accident. The contamination pathways taken into consideration are direct liquid releases into the water and deposition via the atmosphere. In past nuclear accidents, several radionuclides were released, among which, I and Cs were considered herein.
View Article and Find Full Text PDFWater Res
October 2023
Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium.
Estuaries are strong sources of NO to the atmosphere; yet we still lack insights into the impact of their biogeochemical dynamics on the emissions of this powerful greenhouse gas. Here, we investigated the spatiotemporal dynamics of the N cycle in an estuary with a focus on the emission mechanisms and pathways of NO. By coupling NO isotopocule analysis and substrate NO isotope analysis, we found that nutrient availability, oxygen level, salinity gradient and temperature variation were major drivers of the NO emissions from the Scheldt Estuary.
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