We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Comparing effects of microplastic exposure, FPOM resource quality, and consumer density on the response of a freshwater particle feeder and associated ecosystem processes
AI summary Read the abstract
Researchers found that realistic microplastic concentrations had minimal direct effects on freshwater particle feeders compared to the much stronger influences of food resource quality and consumer density on growth, survival, and ecosystem processes in stream microcosms.
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 ( ø = 45–53 µm) concentration interacts with FPOM ( ø = 63–250 µm) 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.
More Papers Like This
Microplastic loads within riverine fishes and macroinvertebrates are not predictable from ecological or morphological characteristics
AI summary Read the abstract
Researchers measured microplastic loads in riverine fish and macroinvertebrates and found that particle counts were not reliably predicted by species ecology or morphology, suggesting that individual variation and local environmental factors play a larger role in microplastic ingestion than feeding guild or habitat alone.
Microplastics in freshwaters: Comparing effects of particle properties and an invertebrate consumer on microbial communities and ecosystem functions
AI summary Read the abstract
Researchers tested how different microplastic properties, including concentration, shape, and polymer type, affect microbial communities and ecosystem functions in freshwater environments. They found that the presence of an invertebrate consumer had a stronger influence on microbial activity than the microplastics themselves, though high concentrations of certain particle shapes did alter community composition. The study suggests that the ecological effects of microplastics in freshwater depend heavily on the broader biological context.
Microplastics in freshwater sediments: Effects on benthic invertebrate communities and ecosystem functioning assessed in artificial streams
AI summary Read the abstract
Researchers tested the effects of polyethylene microplastics on freshwater invertebrate communities in artificial streams using environmentally relevant concentrations. They found that microplastics significantly reduced the abundance of deposit-feeding and grazing organisms by 31-50%, with chironomids and mayflies showing the highest ingestion of plastic particles.
Microplastics have lethal and sublethal effects on stream invertebrates and affect stream ecosystem functioning
AI summary Read the abstract
Using a mesocosm experiment, researchers showed that microplastics at environmentally relevant concentrations caused lethal and sublethal effects on freshwater invertebrates and reduced key ecosystem functions including leaf litter decomposition and algal colonization of streambed substrates.
Increased food availability reducing the harmful effects of microplastics strongly depends on the size of microplastics
AI summary Read the abstract
Researchers found that increased food availability reduced microplastic toxicity in the waterflea Daphnia magna, but this protective effect depended strongly on particle size, with the smallest nanoplastics remaining harmful even when food was plentiful.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.