Additive modelling reveals spatiotemporal PCBs trends in marine sediments.
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.
Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, B-9000 Ghent, Belgium. Electronic address: Gert.Everaert@UGent.be.
Gert
G
Everaert
Université de Namur, Biology Department, Research Unit in Environmental and Evolutionary Biology, Rue de Bruxelles, 61, B5000 Namur, Belgium.
Frederik
F
De Laender
Flanders Marine Institute VLIZ, InnovOcean Site, Wandelaarkaai 7, B-8400 Ostend, Belgium.
Klaas
K
Deneudt
Royal Belgian Institute of Natural Sciences, Management Unit, 3de en 23ste Linieregimentsplein, B-8400 Ostend, Belgium.
Patrick
P
Roose
Flanders Marine Institute VLIZ, InnovOcean Site, Wandelaarkaai 7, B-8400 Ostend, Belgium.
Jan
J
Mees
Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, B-9000 Ghent, Belgium.
Peter L M
PL
Goethals
Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, B-9000 Ghent, Belgium.
Colin R
CR
Janssen
D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D008956:Models, Chemical; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls
Additive modelling; Marine environment; Polychlorinated biphenyl (PCB); Sediment concentration; Time trend