Indirect effects ecotoxicology

DeAngelis DL. 1996. Indirect effects concepts and approaches from ecological theory. In Baird DJ, Maltby L, Greig-Smith PW, Douben PET, editors. ECOtoxicology ecological dimensions. London (UK) Chapman Hall, p 25-41. 

Preston BL. 2001. Indirect effects in aquatic ecotoxicology implications for ecological risk assessment. Environ Managment 29 311-323. 

Successful implementation of a Triad approach is dependent on the availability of a suitable set of instruments chemical, toxicological (bioassays) and ecological. Without doubt, substance-oriented approaches have received a lot of attention in ecotoxicology and the available techniques are relatively mature (Posthuma et al., 2002). The current focus in this field of research is on improvement of bioavailability considerations, the effect of mixtures and the indirect effects of substances. 

Assessment tools used in ecotoxicology range from toxicity tests (link the response of damaged biological systems to a particular substance), chemical analyses of substances (proof of the presence of a toxicant), and field surveys (characteristics of the damaged ecosystem). These three tools help in the assessment of risk. Indirect effects of toxicants are more difficult to predict. For example, an organism s response to a toxicant depends on the presence of other organisms in the community and also on the environmental conditions. Most of the relationships between environmental conditions and toxicity have yet to be established. 

Here we will describe the methods that are used to derive critical limits for soil, based on direct ecotoxicological effects on microorganisms and plants. The indirect approaches (food web models) to derive critical limits for soil based on critical limits for terrestrial fauna such as MPC values for target organisms will be also considered. 

Belanger SE, Meiers EM, Bausch RG. 1995. Direct and indirect ecotoxicological effects of alkyl sulfate and alkyl ethoxysulfate on macroinvertebrates in stream mesocosms. Aquat Toxicol 33 65-87. 

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