Evaluation of bioassays versus contaminant concentrations in explaining the macroinvertebrate community structure in the Rhine‐Meuse delta, The Netherlands

Abstract

It is often assumed that bioassays are better descriptors of sediment toxicity than toxicant concentrations and that ecological factors are more important than toxicants in structuring macroinvertebrate communities. In the period 1992 to 1995, data were collected in the enclosed Rhine-Meuse delta, The Netherlands, on macroinvertebrates, sediment toxicity, sediment contaminant concentrations, and ecological factors. The effect of various groups of pollutants (polycyclic aromatic hydrocarbons, trace metals, oil, polychlorinated biphenyls) and of ecological variables on the structure of the macroinvertebrate community were quantified. Ecological factors explained 17.3% of the macroinvertebrate variation, while contaminants explained 13.8%. Another 14.7% was explained by the covariation between ecological variables and contaminants. Polycyclic aromatic hydrocarbons explained a larger part of the variation than trace metals. The contributions of oil and polychlorinated biphenyls were small but significant. Elevated contaminant concentrations were significantly associated with differences in the macroinvertebrate food web structure. The response in bioassays (Vibrio fischeri, Daphnia magna, Chironomus riparius) was susceptible to certain contaminants but also to certain ecological factors. There was a weak correlation between in situ species composition and bioassays; 1.9% of in situ macroinvertebrate variation was explained by the bioassay responses. This seems to contradict the validity of using bioassays for a system-oriented risk assessment. Possible reasons for this discrepancy might be the manipulations of the sediment before the test and a higher pollutant tolerance of the in situ macroinvertebrates. Thus, macroinvertebrate field surveys and laboratory bioassays yield different types of information on ecotoxicological effects, and both are recommended in sediment risk assessment procedures.

Impact of triphenyltin acetate in microcosms simulating floodplain lakes. I. Influence of sediment quality

“…Differences in the dominance of phytoplankton and invertebrate populations between microcosm types may have been caused directly by differences in sediment quality, or indirectly by differences in macrophyte biomass. Several field studies have revealed that both sediment-bound toxicants (Peeters et al 1999;Reinhold-Dudok van Heel and Den Besten 1999; Tables 4 and 5 Ecotoxicology (2006) Peeters et al 2001) and beds of aquatic vascular plants (LaLonde and Downing 1992;Brock and Van der Velde 1996;Scheffer 1998) have a significant effect on invertebrate communities.…”

Trace metal availability and effects on benthic community structure in floodplain lakes

“…Furthermore, mixtures of pollutants make it difficult to ascribe observed effects to one or more substances. Recently, a specific multivariate statistical approach has been used to quantify the impact of pollutants on benthic communities in relation to the effects of other factors [13–15]. This approach, the variance partitioning method, can be applied to assess the contribution of pollutants relative to the effect of other variables, for example, water, sediment, and other habitat characteristics.…”

Sediment Contamination and Faunal Communities in Two Subwatersheds of Mona Lake, Michigan

“…Since baetids can rapidly colonize these environments (Richards and Minshall, 1988), they may have been able to avoid exposure to the fine sediment that likely contained the heavy metals and PAHs. The ability of physical habitat or environmental factors to override or confound the influence of toxicants on benthic communities has been noted by others as well (Peeters et al, 2001; Carew et al, 2007). Alternatively, some species of the genus baetidae are tolerant of heavy metals (Aoki et al, 1989; Cain et al, 2004) which may have allowed them to proliferate at LBC 4, even in the presence of high toxicant concentrations.…”