Abstract

Herbicides are well known for unintended effects on freshwater periphyton communities. Large knowledge gaps, however, exist regarding indirect herbicide impacts on primary consumers through changes in the quality of periphyton as a food source (i.e., diet-related effects). To address this gap, the grazer Physella acuta (Gastropoda) was fed for 21 days with periphyton that grew for 15 days in the presence or absence of the herbicide diuron (8 mu g/L) to quantify changes in the feeding rate, growth rate, and energy storage (neutral lipid fatty acids; NLFAs) of P. acuta. Periphyton biomass, cell viability, community structure, and FAs served as proxies for food quality that support a mechanistic interpretation of the grazers' responses. Diuron changed the algae periphyton community and fatty acid profiles, indicating alterations in the food quality, which could explain differences in the snails' feeding rate compared to the control. While the snails' growth rate was, despite an effect size of 55%, not statistically significantly changed, NLFA profiles of P. acuta were altered. These results indicate that herbicides can change the food quality of periphyton by shifts in the algae composition, which may affect the physiology of grazers.

Keywords

biofilms; bottom-up effects; diatoms; diuron; fatty acids

Published in

Environmental Science and Technology
2021, Volume: 55, number: 21, pages: 14699-14709
Publisher: AMER CHEMICAL SOC

SLU Authors

• Bundschuh, Mirco

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

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1021/acs.est.1c01819

Permanent link to this page (URI)

https://res.slu.se/id/publ/114548