Search publications of the members of the Royal Belgian institute of natural Sciences
-
4DEMON: Integrating 40 Years of Data on PCB and Metal Contamination in Marine Sediments of the Belgian Part of the North Sea
- The assessment of historical data is important to understand long-term changes in the marine environment. Whereas time series analyses based on monitoring data typically span one or two decades, this work aimed to integrate 40 years of monitoring and research data on polychlorinated biphenyls (PCBs) and metals in the Belgian Part of the North Sea (BPNS). Multiple challenges were encountered: sampling locations changed over time, different analytical methods were applied, different grain size fractions were analyzed, appropriate co-factors were not always analyzed, and measurement uncertainties were not always indicated. These issues hampered the use of readily available, highly standardized trend modeling approaches like those proposed by regional sea conventions such as OSPAR, named after the Oslo and Paris conventions.Therefore, we applied alternative approaches, allowing us to include most older historical data that have been obtained during the nineteen seventies and eighties. Our approach included reproducible and quality controlled procedures from data collection up to data assessment. It included spatial clustering, data normalization and parametric linear mixed effect modeling. A Ward hierarchical clustering was applied on recently obtained contaminant data, as the basis for a spatial division of the BPNS into five distinct areas with different contamination profiles. To minimize the risk of normalization errors for the metal data analyses, four normalization approaches were applied and mutually compared: granulometric and nickel (Ni) normalization, next to two hybrid normalization methods combining aluminum (Al) and iron (Fe) normalization. The long-term models revealed decreasing trends for most metals, except zinc (Zn) for which three out of four models showed increasing concentrations in all five zones of the BPNS. Offshore sediments contained the lowest normalized mercury (Hg) and cadmium (Cd) concentrations but high arsenic (As) concentrations. Trend analysis revealed a strong decrease in PCB concentrations in the nineteen eighties and nineties, followed by a slight increase over the last decade. The extended timeframe for contaminant assessment, as applied in this study, is of added value for scientists and policy makers, as the approach allows to detect trends and effects of anthropogenic activities within the marine environment within a broad perspective.
-
Latest Cretaceous hadrosaurid dinosaurs from Eastern Asia
-
A new basal neoceratopsian dinosaur from the ‘middle’ Cretaceous of Jilin Province, China
-
Cranial endocasts of the two hadrosaurids from Blagoveschensk, Amur Region (Russia)
-
A new latest Cretaceous dinosaur locality in northeastern China
-
Taphonomy and age profile of a latest Cretaceous bonebed in Far Eastern Russia
-
The latest Cretaceous hadrosaurid dinosaurs from Heilongjiang Province (China) and Amur Region (Russia)
-
A reappraisal of Aralosaurus tuberiferus (Dinosauria, Hadrosauridae) from the Upper Cretaceous of Kazakhstan
-
Sondages exploratoires dans le ‘Cran aux Iguanodons’ de Bernissart
-
Une occupation rurale du Haut Moyen Âge au lieu-dit a Lohincou à Villers-le-Bouillet (Province de Liège, Belgique)
-
Endocasts of ornithopod dinosaurs: comparative anatomy
-
Extreme reduction of morphological characters: a type of brachidial development found in several Late Cretaceous and Recent brachiopod species—new relationships between taxa previously listed as incertae sedis
-
Recent thecideide brachiopods (Thecideida, Thecideoidea) from northern Sulawesi (Indonesia) with discovery of a new Thecidellina species (Thecidellinidae)
-
A reappraisal of the genus Tethyrhynchia Logan, 1994 (Rhynchonellida, Brachiopoda): a conflict between phylogenies obtained from morphological characters and molecular data
-
Restudy of the Lower Carboniferous Scaphopoda described by de Koninck (1843, 1883)
-
Givetian brachiopods from the Trois-Fontaines Formation at Marenne (Belgium, Dinant Synclinorium)
-
Revision of the brachiopod Cyrtina rigauxi Maillieux, 1909 and description of a new ambocoeliid genus (Dionacoelia n. gen.) from the Frasnian of southern Belgium
-
The genus Iowatrypa Copper, 1973 (Brachiopoda) in the Les Valisettes Formation (late Frasnian of the Philippeville Anticlinorium, southern Belgium)
-
The genus Biernatella Baliński, 1977 (Brachiopoda) from the late Frasnian of Belgium
-
Two new atrypid brachiopod species from the late Frasnian of Belgium
