Species traits as predictors for intrinsic sensitivity of aquatic invertebrates to the insecticide chlorpyrifos

Abstract

Ecological risk assessment (ERA) has followed a taxonomy-based approach, making the assumption that related species will show similar sensitivity to toxicants, and using safety factors or species sensitivity distributions to extrapolate from tested to untested species. In ecology it has become apparent that taxonomic approaches may have limitations for the description and understanding of species assemblages in nature. Therefore it has been proposed that the inclusion of species traits in ERA could provide a useful and alternative description of the systems under investigation. At the same time, there is a growing recognition that the use of mechanistic approaches in ERA, including conceptual and quantitative models, may improve predictive and extrapolative power. Purposefully linking traits with mechanistic effect models could add value to taxonomy-based ERA by improving our understanding of how structural and functional system facets may facilitate inter-species extrapolation. Here, we explore whether and in what ways traits can be linked purposefully to mechanistic effect models to predict intrinsic sensitivity using available data on the acute sensitivity and toxicokinetics of a range of freshwater arthropods exposed to chlorpyrifos. The results of a quantitative linking of seven different endpoints and twelve traits demonstrate that while quantitative links between traits and/or trait combinations and process based (toxicokinetic) model parameters can be established, the use of simple traits to predict classical sensitivity endpoints yields little insight. Remarkably, neither of the standard sensitivity values, i.e. the LC50 or EC50, showed a strong correlation with traits. Future research in this area should include a quantitative linking of toxicodynamic parameter estimations and physiological traits, and requires further consideration of how mechanistic trait-process/parameter links can be used for prediction of intrinsic sensitivity across species for different substances in ERA.Electronic supplementary materialThe online version of this article (doi:10.1007/s10646-012-0962-8) contains supplementary material, which is available to authorized users.

Evaluating aquatic invertebrate vulnerability to insecticides based on intrinsic sensitivity, biological traits, and toxic mode of action

“…The percentage of the variance explained by these models is lower than that reported in previous studies (e.g. [15,16,30,49]), probably because of the reduced number of traits included here and because of the characteristics of the dataset, including toxicity data from thousands of different sources. The majority of the traits included in the present study are somehow related to the processes involved in chemical uptake, and the inclusion of other traits related to bioaccumulation (e.g.…”

“…In a follow-up study, Rubach et al [16] demonstrated that differences in toxicokinetic parameters and sensitivity of aquatic organisms to the insecticide chlorpyrifos can be largely explained by a combination of few biological traits (e.g. respiration type, body surface area).…”

Phytotoxicity of chlorpyrifos to white mustard (Sinapis alba L.) and maize (Zea mays L.): Potential indicators of insecticide presence in water

“…Biological assays have been used for several decades in risk assessment and detection of water contamination with chlorpyrifos, but they have mainly involved aquatic invertebrates (chironomid larvae, mosquitoes, dragon flies, prawns, shells and hydras), aquatic vertebrates such as fish and algae, and aquatic plants such as Lemna minor (Montagna and Collins 2007, Palma et al, 2008, Sperone et al 2011, Rubach et al 2012Shafiq-ur-Rehman et al 2012, Tongbai et al 2012. Based on these facts, it is obvious that the use of plants as indicators of contamination has been generally underestimated and rarely used in toxicological studies, compared to animal organisms (Moor and Kroege, 2010).…”

Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge‐of‐field surface waters

“…Many fungicides, however, have general biocidal properties in that representatives of different taxonomic groups may be categorised as potentially sensitive (Maltby et al, 2009). Recently efforts are being made to mechanistically link biological traits with intrinsic sensitivity of individual species of concern (Rubach et al, 2012). Experimental results indicate that this approach has promise, but, according to Baird and Van den Brink (2007) effort is needed to compile the trait information of species to increase the power, precision and taxonomic representativeness of this approach.…”