title: Responses of earthworms to repeated exposure to three biocides applied singly and as a mixture in an agricultural field.
abstract: The study aimed at investigating effects of three differently acting biocides; the insecticide esfenvalerate, the fungicide picoxystrobin and the bactericide triclosan, applied individually and as a mixture, on an earthworm community in the field. A concentration-response design was chosen and results were analyzed using univariate and multivariate approaches. Effects on juvenile proportions were less pronounced and more variable than effects on abundance, but effects in general were species- and chemical-specific, and temporal variations distinct. Esfenvalerate and picoxystrobin appeared to elicit stronger effects than triclosan at laboratory-based ECx values, which is in accordance with our previous laboratory study on Eisenia fetida. The mixture affected abundance and juvenile proportions, but the latter only at high mixture concentrations. Esfenvalerate and picoxystrobin appeared to be the main drivers for the mixture's toxicity. Species-specific toxicity patterns question the reliability of mixture toxicity predictions derived on E. fetida for field earthworms. Biocide concentrations equaling EC50s (reproduction) for E. fetida provoked effects on the field earthworms mainly exceeding 50%, indicating effect intensification from the laboratory to field as well as the influence of indirect effects produced by species interactions. The differing results of the present field study and the previous laboratory study imply that lower- and higher-tier studies may not be mutually exclusive, but to be used in complementary.
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahls Vei 20, 1430 Ås, Norway. Electronic address: Lisbeth.Schnug@bioforsk.no.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Schnug
authors.affiliation: University of Oslo, Centre for Ecological and Evolutionary Synthesis, Blindernveien 31, 0316 Oslo, Norway. Electronic address: t.h.ergon@ibv.uio.no.
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Ergon
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahls Vei 20, 1430 Ås, Norway. Electronic address: Lena.Jakob@awi.de.
authors.forename: Lena
authors.initials: L
authors.lastname: Jakob
authors.affiliation: University of Aarhus, Department of Bioscience - Soil Fauna Ecology and Ecotoxicology, Vejlsøvej 25, 8600 Silkeborg, Denmark. Electronic address: jsf@dmu.dk.
authors.forename: Janeck J
authors.initials: JJ
authors.lastname: Scott-Fordsmand
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahls Vei 20, 1430 Ås, Norway. Electronic address: Erik.Joner@bioforsk.no.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Joner
authors.affiliation: University of Oslo, Department of Biosciences, Blindernveien 31, 0316 Oslo, Norway. Electronic address: h.p.leinaas@ibv.uio.no.
authors.forename: Hans Petter
authors.initials: HP
authors.lastname: Leinaas
mesh_terms: D000383:Agriculture; D000818:Animals; D004202:Disinfectants / Q000633:toxicity*; D004784:Environmental Monitoring; D009835:Oligochaeta; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D004202:Disinfectants; D012989:Soil Pollutants
keywords: Antimicrobial; Community; Mixture; Pyrethroid; Soil; Strobilurin