Abstract

Fine particulate organic matter (FPOM) is an important basal resource in stream ecosystems for deposit- and filter-feeding macroinvertebrates (collectively 'particle feeders'). Microplastics (MP) share many characteristics with FPOM (e.g. size range, surface area to volume ratios) and are potentially consumed by particle feeders. Accordingly, MP contamination of natural FPOM pools might affect particle feeder growth and survival, particularly when background FPOM resource quality is low, or intraspecific competition is high. We conducted a microcosm experiment to evaluate how a realistic (1400 particles/kg sediment) polyethylene MP (o = 45-53 mu m) concentration interacts with FPOM (o = 63-250 mu m) resource quality (low versus high nutrient content) and consumer density (10 versus 20 individuals per microcosm) to affect growth and survival of larval Chironomus riparius (Diptera: Chironomidae), a model particle feeder. We additionally quantified community respiration, based on three hour measurements of oxygen consumption in the microcosms at the end of the experiment. MP exposure reduced larval body lengths by 26.7%, but only under the low consumer density treatment. MPs reduced community respiration by 26.2%, but only in the absence of chironomids, indicating an impact on microbial respiration. In comparison, low resource quality and high consumer density were associated with 53.5-70.2% reductions in community respiration, chironomid body length and/or body mass. These results suggest that effects of contamination of FPOM with MPs at environmentally realistic concentrations on the life histories of particle feeders such as C. riparius might be limited, especially relative to the effects of resource quality and consumer density. However, the reduction in microbial respiration when MPs were present highlights the need for further research addressing MP impacts on microbes, given their key roles in ecosystem functioning.

Keywords

Fine particulate organic matter; Microplastics; Chironomus riparius; Consumer density; Resource quality; Community respiration

Published in

Aquatic Sciences - Research Across Boundaries
2023, Volume: 85, number: 3, article number: 70
Publisher: SPRINGER BASEL AG

SLU Authors

• Kong, Ze Hui

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

• Burdon, Francis

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

• Truchy, Amélie

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • National Research Institute for Agriculture, Food and Environment (INRAE)

• Bundschuh, Mirco

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • University of Kaiserslautern-Landau (RPTU)

• Futter, Martyn

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

• Mckie, Brendan

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

UKÄ Subject classification

Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1007/s00027-023-00964-w

Permanent link to this page (URI)

https://res.slu.se/id/publ/122131