Abstract

Agricultural land-use frequently results in short pulse exposures of insecticides such as pyrethroids in river systems, adversely affecting local invertebrate communities. In order to assess insecticide-induced effects, stream mesocosms are used within higher tier aquatic risk assessment. Regulatory acceptable concentrations (RACs) derived from those studies are often higher compared with tier 1 RACs. Hence, the present mesocosm study evaluates this aspect using a pulse exposure scenario typical for streams and the pyrethroid insecticide etofenprox. A 6-h pulse exposure with measured concentrations of 0.04, 0.3 and 5.3 mu g L-1 etofenprox was used. We considered abundance, drift and emergence of invertebrates as structural endpoints and the in situ-measured feeding rates of the isopod Asellus aquaticus as functional endpoint. Most prominent effects were visible at 5.3 mu g L-1 etofenprox which caused adverse effects of up to 100% at the individual and population level, as well as community structure alterations. Transient effects were observed for invertebrate drift (effect duration <= 24 h) and for the invertebrate community (9 days after exposure) at 0.3 mu g L-1 etofenprox. Furthermore, 0.04 mu g L-1 etofenprox affected the abundance of the mayfly Cloeon simile (decrease by 66%) and the feeding rate of A. aquaticus (decrease by 44%). Thus, implications for the functional endpoint leaf litter breakdown in heterotrophic ecosystems may be expected. A hypothetical RAC derived from the present mesocosm study (0.004 mu g L-1) is in line with the official tier 1 RAC (0.0044 mu g L-1) and thus shows that the present mesocosm study did not result in a higher RAC. (C) 2017 Elsevier B.V. All rights reserved.

Keywords

Functional endpoint; Aquatic guidance document; Community; Drift; Emergence

Published in

Science of the Total Environment
2018, Volume: 610-611, pages: 810-819

SLU Authors

• Bundschuh, Mirco

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Other Natural Sciences not elsewhere specified


Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2017.08.048

Permanent link to this page (URI)

https://res.slu.se/id/publ/86680