Comparing the effects of fludioxonil on non-target soil invertebrates using ecotoxicological methods from single-species bioassays to model ecosystems

Arne Haegerbaeumer; Ricarda Raschke; Nicola Reiff; Walter Traunspurger; Sebastian Höss

doi:10.1016/j.ecoenv.2019.109596

Comparing the effects of fludioxonil on non-target soil invertebrates using ecotoxicological methods from single-species bioassays to model ecosystems

Ecotoxicol Environ Saf. 2019 Nov 15:183:109596. doi: 10.1016/j.ecoenv.2019.109596. Epub 2019 Aug 24.

Authors

Arne Haegerbaeumer¹, Ricarda Raschke², Nicola Reiff³, Walter Traunspurger², Sebastian Höss⁴

Affiliations

¹ Bielefeld University, Department of Animal Ecology, Konsequenz 45, 33615, Bielefeld, Germany. Electronic address: a.haegerbaeumer@uni-bielefeld.de.
² Bielefeld University, Department of Animal Ecology, Konsequenz 45, 33615, Bielefeld, Germany.
³ Ecossa, Giselastr. 6, 82319, Starnberg, Germany.
⁴ Bielefeld University, Department of Animal Ecology, Konsequenz 45, 33615, Bielefeld, Germany; Ecossa, Giselastr. 6, 82319, Starnberg, Germany.

PMID: 31454750
DOI: 10.1016/j.ecoenv.2019.109596

Abstract

The lower tier toxicity tests used for risk assessment of plant protection products are conducted with single species, only regarding direct effects of the tested substances. However, it is not clear, if lower tier tests are able to protect in situ soil communities, as these tests are not able to account for direct and indirect effects of chemicals on multi-species systems in natural soil communities. This knowledge gap between single-species tests and field studies can be bridged using model ecosystems (microcosms), which allow for the assessment of direct and indirect effects of the compounds under evaluation. In the present study, single-species toxicity tests and soil-spiked microcosms were used to comparatively investigate the toxicity of the non-systemic fungicide fludioxonil (FDO) on non-target soil organisms, with nematodes being the test organisms of choice. The potential effects of FDO on nematodes were investigated in two different test systems: (i) standardized toxicity tests using Caenorhabditis elegans exposed to FDO-spiked soil (FDO concentrations 50-1207 mg/kg soil dry weight) and (ii) in situ nematode communities sampled from microcosms containing FDO-spiked soil (FDO concentrations 75-600 mg/kg soil dry weight). FDO dose-dependently inhibited the reproduction of C. elegans, with an effect concentration (EC50) of 209.9 mg FDO/kg soil dry weight and a no observed effect concentration (NOEC) of 63.0 mg FDO/kg soil dry weight. In the microcosms, FDO significantly affected trait-based indices, such as the Maturity Index (MI25) and the Enrichment Index (EI), which responded already at FDO concentrations of 14.3 and 62.4 mg/kg dry soil. Overall, this study provides new insights into the impact of the non-systemic fungicide FDO on non-target soil organisms and demonstrates the suitability of nematode-based tools, that allow for a quick and cost-effective lower and higher tier risk assessment of plant protection products.

Keywords: Caenorhabditis elegans; Nematodes; Plant protection products; Risk assessment; Soil.

Publication types

Comparative Study

MeSH terms

Animals
Caenorhabditis elegans / drug effects
Caenorhabditis elegans / physiology
Dioxoles / toxicity*
Dose-Response Relationship, Drug
Ecosystem*
Ecotoxicology / methods*
Fungicides, Industrial / toxicity*
Invertebrates / drug effects*
Nematoda / drug effects
Nematoda / physiology
Pyrroles / toxicity*
Risk Assessment
Soil Pollutants / toxicity*

Substances

Dioxoles
Fungicides, Industrial
Pyrroles
Soil Pollutants
fludioxonil