Seasonal variation of total and biochemically available concentrations of PAHs in a floodplain lake sediment has no effect on the benthic invertebrate community

• Published in: Chemosphere (Oxford) 2009-04, Vol.75 (3), p.319-326
• Main Authors: De Lange, H.J., Peeters, E.T.H.M., Harmsen, J., Maas, H., De Jonge, J.
• Format: Article
• Language: English
• Subjects: abundance; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Benthos; bioavailability; Biodiversity; Biological and medical sciences; contaminated sediments; Ecosystem; Ecotoxicology, biological effects of pollution; Environmental Monitoring; estuary; extraction; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Geologic Sediments - chemistry; Hydrophobic organic contaminants; Invertebrata; Invertebrates - drug effects; netherlands; organic-compounds; phase; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - isolation & purification; rhine; Risk Assessment; Seasonal dynamics; Seasons; Sediment contamination; Soil Pollutants - analysis; Soil Pollutants - isolation & purification; Synecology; Tenax extraction; toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2008.12.046

Floodplain areas in the Netherlands are moderately to heavily contaminated with trace metals and organic contaminants. The impact of this sediment pollution on benthic invertebrates is best described with so-called ‘bioavailable’ concentrations instead of total concentrations. Studies into the effect of contaminants on biota are usually a snapshot in time, with one or two samples in a year. In such studies, effect of seasonal variation cannot be detected. Objective of this study was to investigate the temporal variation of sediment PAH contamination in one floodplain lake, and possible consequences for the benthic invertebrate community. This was done by sampling biota, abiotic variables and sediment contaminants every four weeks during one year. We observed a limited seasonal variation in total and bioavailable concentrations of PAHs. Multivariate analysis revealed that the PAH contamination is not a significant factor for the benthic invertebrate community in this floodplain lake. Bioavailable concentrations of PAHs were low and no effects could be expected based on the measured values. No increase of available PAHs was observed in periods where conditions for degradation were absent (low temperature, anaerobic). These results also indicate that in such floodplain lake systems, with historical pollution, the timing of sampling to assess sediment contamination with organic pollutants is of limited importance. This can be useful for planning sampling in risk assessment studies.