@article{PawlakNoetzelDragoetal.2022, author = {Pawlak, Julia and Noetzel, Dominique Christian and Drago, Claudia and Weithoff, Guntram}, title = {Assessing the toxicity of polystyrene beads and silica particles on the microconsumer Brachionus calyciflorus at different timescales}, series = {Frontiers in Environmental Science}, journal = {Frontiers in Environmental Science}, publisher = {Frontiers}, address = {Lausanne, Schweiz}, issn = {2296-665X}, doi = {10.3389/fenvs.2022.955425}, pages = {1 -- 11}, year = {2022}, abstract = {Environmental pollution by microplastics has become a severe problem in terrestrial and aquatic ecosystems and, according to actual prognoses, problems will further increase in the future. Therefore, assessing and quantifying the risk for the biota is crucial. Standardized short-term toxicological procedures as well as methods quantifying potential toxic effects over the whole life span of an animal are required. We studied the effect of the microplastic polystyrene on the survival and reproduction of a common freshwater invertebrate, the rotifer Brachionus calyciflorus, at different timescales. We used pristine polystyrene spheres of 1, 3, and 6 µm diameter and fed them to the animals together with food algae in different ratios ranging from 0 to 50\% nonfood particles. As a particle control, we used silica to distinguish between a pure particle effect and a plastic effect. After 24 h, no toxic effect was found, neither with polystyrene nor with silica. After 96 h, a toxic effect was detectable for both particle types. The size of the particles played a negligible role. Studying the long-term effect by using life table experiments, we found a reduced reproduction when the animals were fed with 3 µm spheres together with similar-sized food algae. We conclude that the fitness reduction is mainly driven by the dilution of food by the nonfood particles rather than by a direct toxic effect.}, language = {en} } @article{DragoWeithoff2021, author = {Drago, Claudia and Weithoff, Guntram}, title = {Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles}, series = {Toxics}, volume = {9}, journal = {Toxics}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {2305-6304}, doi = {10.3390/toxics9110305}, pages = {13}, year = {2021}, abstract = {Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5-25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs.}, language = {en} } @article{DragoPawlakWeithoff2020, author = {Drago, Claudia and Pawlak, Julia and Weithoff, Guntram}, title = {Biogenic aggregation of small microplastics alters their ingestion by a common freshwater micro-invertebrate}, series = {Frontiers in Environmental Science}, volume = {8}, journal = {Frontiers in Environmental Science}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-665X}, doi = {10.3389/fenvs.2020.574274}, pages = {11}, year = {2020}, abstract = {In recent years, increasing concerns have been raised about the environmental risk of microplastics in freshwater ecosystems. Small microplastics enter the water either directly or accumulate through disintegration of larger plastic particles. These particles might then be ingested by filter-feeding zooplankton, such as rotifers. Particles released into the water may also interact with the biota through the formation of aggregates, which might alter the uptake by zooplankton. In this study, we tested for size-specific aggregation of polystyrene microspheres and their ingestion by a common freshwater rotifer Brachionus calyciflorus. The ingestion of three sizes of polystyrene microspheres (MS) 1-, 3-, and 6-mu m was investigated. Each MS size was tested in combination with three different treatments: MS as the sole food intake, MS in association with food algae and MS aggregated with biogenic matter. After 72 h incubation in pre-filtered natural river water, the majority of the 1-mu m spheres occurred as aggregates. The larger the particles, the higher the relative number of single particles and the larger the aggregates. All particles were ingested by the rotifer following a Type-II functional response. The presence of algae did not influence the ingestion of the MS for all three sizes. The biogenic aggregation of microspheres led to a significant size-dependent alteration in their ingestion. Rotifers ingested more microspheres (MS) when exposed to aggregated 1- and 3-mu m MS as compared to single spheres, whereas fewer aggregated 6-mu m spheres were ingested. This indicates that the small particles when aggregated were in an effective size range for Brachionus, while the aggregated larger spheres became too large to be efficiently ingested. These observations provide the first evidence of a size- and aggregation-dependent feeding interaction between microplastics and rotifers. Microplastics when aggregated with biogenic particles in a natural environment can rapidly change their size-dependent availability. The aggregation properties of microplastics should be taken into account when performing experiments mimicking the natural environment.}, language = {en} } @article{ColeLiddleConsolandietal.2020, author = {Cole, Matthew and Liddle, Corin and Consolandi, Giulia and Drago, Claudia and Hird, Cameron and Lindeque, Penelope Kate and Galloway, Tamara S.}, title = {Microplastics, microfibres and nanoplastics cause variable sub-lethal responses in mussels (Mytilus spp.)}, series = {Marine pollution bulletin : the international journal for marine environmental scientists, engineers, administrators, politicians and lawyers}, volume = {160}, journal = {Marine pollution bulletin : the international journal for marine environmental scientists, engineers, administrators, politicians and lawyers}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0025-326X}, doi = {10.1016/j.marpolbul.2020.111552}, pages = {10}, year = {2020}, abstract = {We compare the toxicity of microplastics, microfibres and nanoplastics on mussels. Mussels (Mytilus spp.) were exposed to 500 ng mL(-1) of 20 mu m polystyrene microplastics, 10 x 30 mu m polyamide microfibres or 50 nm polystyrene nanoplastics for 24 h or 7 days. Biomarkers of immune response, oxidative stress response, lysosomal destabilisation and genotoxic damage were measured in haemolymph, digestive gland and gills. Microplastics and microfibres were observed in the digestive glands, with significantly higher plastic concentrations after 7-days exposure (ANOVA, P < 0.05). Nanoplastics had a significant effect on hyalinocytegranulocyte ratios (ANOVA, P < 0.05), indicative of a heightened immune response. SOD activity was significantly increased followed 24 h exposure to plastics (two-way ANOVA, P < 0.05), but returned to normal levels after 7-days exposure. No evidence of lysosomal destabilisation or genotoxic damage was observed from any form of plastic. The study highlights how particle size is a key factor in plastic particulate toxicity.}, language = {en} }