Abstract

Shredders play a central role in the breakdown of leaf material in aquatic systems. These organisms and the ecological function they provide may, however, be affected by chemical stressors either as a consequence of direct waterborne exposure or through alterations in food-quality (indirect pathway). To unravel the biological relevance of these effect pathways, we applied a 2 x 2-factorial test design. Leaf material was microbially colonized for 10 days in absence or presence of the fungicide epoxiconazole (15 mu g/L) and subsequently fed to the shredder Asellus aquaticus under exposure to epoxiconazole (15 mu g/L) or in fungicide-free medium over a 28-day period (n = 40). Both effect pathways caused alterations in asselids' food processing, physiological fitness, and growth, although not always statistically significantly: assimilation either increased or remained at a similar level relative to the control suggesting compensatory behavior of A. aquaticus to cope with the enhanced energy demand for detoxification processes and decreased nutritional quality of the food. The latter was driven by lowered microbial biomasses and the altered composition of fatty acids associated with the leaf material. Even with increased assimilation, direct and indirect effects caused decreases in the growth and lipid (fatty acid) content of A. aquaticus with relative effect sizes between 10 and 40%. Moreover, the concentrations of two essential polyunsaturated fatty acids (i.e., arachidonic acid and eicosapentaenoic acid) were non-significantly reduced (up to similar to 15%) in asselids. This effect was, however, independent of the exposure pathway. Although waterborne effects were generally stronger than the diet-related effects, results suggest impaired functioning of A. aquaticus via both effect pathways. (C) 2016 Elsevier B.V. All rights reserved.

Keywords

Asellus aquaticus; Biofilm; Fatty acid composition; Food quality; Leaf litter breakdown; Shredder

Published in

Science of the Total Environment
2016, Volume: 571, pages: 992-1000
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Feckler, Alexander

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

• Goedkoop, Willem

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

• Bundschuh, Mirco

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • University of Koblenz-Landau

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all
SDG3 Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Other Natural Sciences not elsewhere specified


Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2016.07.088

Permanent link to this page (URI)

https://res.slu.se/id/publ/80849