About
31
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Introduction
Christoph Schür is an ecotoxicologist working at the Swiss Federal Institute of Aquatic Science and Technology. Christoph does research on applying machine learning methods to ecotoxicology and the effects of Microplastics on freshwater invertebrates.
Current institution
Additional affiliations
October 2016 - September 2021
May 2014 - February 2015
Position
- Master's Student
Description
- Master thesis working on the impact of microplastic particles on Daphnia magna doi:10.1371/journal.pone.0155063
August 2012 - November 2012
Position
- Research Internship
Description
- Worked with PAH extraction using HDPE membrane devices and GC-MS
Education
October 2016 - November 2021
November 2012 - September 2015
October 2009 - August 2012
Publications
Publications (31)
Concerns are being raised that microplastic pollution can have detrimental effects on the feeding of aquatic invertebrates, including zooplankton. Both small plastic fragments (microplastics, MPs) produced by degradation of larger plastic waste (secondary MPs; SMPs) and microscopic plastic spheres used in cosmetic products and industry (primary MPs...
The current paper critically reviews the state-of-the-science on (1) microplastics (MP) types and particle concentrations in freshwater ecosystems, (2) MP and nanoplastics (NP) uptake and tissue translocation, (3) MP/NP-induced effects in freshwater organisms, and (4) capabilities of MP/NP to modulate the toxicity of environmental chemicals. The re...
Previous research reported the translocation of nano‐ and microplastics from the gastrointestinal tract to tissues in Daphnia magna , most prominently of fluorescent polystyrene beads to lipid droplets. For particles >300 nm, such transfer is biologically implausible as the peritrophic membrane retains these in the daphnid gut. We used confocal las...
Several studies have investigated the effects of nano- and microplastics on daphnids as key freshwater species. However, while information is abundant on the acute toxicity of plastic beads, little is known regarding the multigenerational effects of irregular microplastics. In addition, a comparison of microplastics to naturally occurring particles...
The aging of microplastics in the environment changes their physicochemical properties. While this may affect their toxicity, comparative data on the effects of aged compared to pristine microplastics are scarce. One of those aging processes is the sorption of chemicals, which has mainly been studied for individual pollutants present in marine ecos...
We address several comparability issues in chemical hazard assessment through in silico models. We review the recent literature and show that studies predicting fish acute toxicity are not comparable based on the following criteria:
(i) The datasets are different, representing different chemical and/or taxonomic spaces;
(ii) Even if the dataset wer...
Assessment of potential impacts of chemicals on the environment traditionally involves regulatory standard data requirements for acute aquatic toxicity testing using algae, daphnids and fish (e.g., OECD test guidelines (TG) 201, 202, and 203, respectively), representing different trophic levels. In line with the societal goal to replace or reduce v...
Assessment of potential impacts of chemicals on the environment traditionally involves regulatory standard data requirements for acute aquatic toxicity testing using algae, daphnids and fish (e.g., OECD test guidelines (TG) 201, 202, and 203, respectively), representing different trophic levels. In line with the societal goal to replace or reduce v...
Regulation of chemicals requires knowledge of their toxicological effects on a large number of species, which has traditionally been acquired through in vivo testing. The recent effort to find alternatives based on machine learning, however, has not focused on guaranteeing transparency, comparability and reproducibility, which makes it difficult to...
Regulation of chemicals requires knowledge of their toxicological effects on a large number of species, which has traditionally been acquired through in vivo testing. The recent effort to find alternatives based on machine learning, however, has not focused on guaranteeing transparency, comparability and reproducibility, which makes it difficult to...
The use of machine learning for predicting ecotoxicological outcomes is promising, but underutilized. The curation of data with informative features requires both expertise in machine learning as well as a strong biological and ecotoxicological background, which we consider a barrier of entry for this kind of research. Additionally, model performan...
The toxicity of microplastics on Daphnia magna as a key model for freshwater zooplankton is well described. While several studies predict population-level effects based on short-term, individual-level responses, only very few have validated these predictions experimentally. Thus, we exposed D. magna populations to irregular polystyrene microplastic...
The use of machine learning for predicting ecotoxicological outcomes is promising, but underutilized. The curation of data with informative features requires both expertise in machine learning as well as a strong biological and ecotoxicological background, which we consider a barrier of entry for this kind of research. Additionally, model performan...
The toxicity of microplastics on Daphnia magna as a key model for freshwater zooplankton is well described. While several studies predict population-level effects based on short-term, individual-level responses, only very few have validated these predictions experimentally. Thus, we exposed D. magna populations to irregular polystyrene microplastic...
Das interdisziplinäre Forschungsprojekt MiWa widmete sich grundlegenden Fragestellungen zur Analytik und Wirkung von Mikroplastik-Partikeln im Wasserkreislauf. Es wurden Methoden der Umweltprobennahme, der Probenaufbereitung und verschiedene Detektionsverfahren zur Charakterisierung und Quantifizierung von Mikroplastik intensiv untersucht, miteinan...
The toxicity and environmental risk of chemicals, such as the antiepileptic drug carbamazepine (CBZ), is commonly assessed using standardized laboratory tests and laboratory-to-field extrapolation. To investigate the toxicity of CBZ to aquatic key organisms in a more complex and environmentally relevant scenario, we conducted a 32-day multiple-stre...
Interact o Translocation of nano-and microplastics across biological barriers has toxicological relevance. Earlier studies reported translocation of fluorescent nano- and microplastic (20 nm and 1000 nm) particles to the lipid droplets of Daphnia magna [2]. A plausible biological mechanism is currently lacking. We could not replicate the findings o...
Descriptive statistics.
Descriptive statistics for life-history parameters obtained from Exp. I. Values are reported as mean ± standard deviation. Offspring = cumulative reproductive output, Surv.days = number of survived days, Broods = number of broods per female, AFR = Age at first reproduction, TBB = time between broods and DW = dry weight (μg)....
GLM results–maternal effects.
GLM results for maternal effects (Exp. V). Survival, size at birth and algal consumption in Daphnia neonates was modeled as a function of exposure concentration and particle type (primary, secondary MPs, kaolin and control). Daphnid dry weight (DW) was used as a covariate to test for differences in algal consumption. I...
Fluorescence measurements, carbon to particle number conversions and image analysis.
(DOCX)
EC50 values.
EC50 ± 95% confidence intervals for the number of produced offspring standardized by the number of individual survived days (NID) for primary and secondary MPs (PMP and SMP) and kaolin. * EC50 is significantly lower for SMP compared to kaolin.
(DOCX)
Secondary microplastic-aggregates in the gut.
Density plot showing the size distribution of secondary microplastic-aggregates (SMPs) formed in the gut (Exp. IV) at two test concentrations: 104 (low conc.) and 3 × 104 (high conc.) MPs mL-1.
(EPS)
Statistical outline for Exp. I.
Summary of the generalized linear models used for the data analysis. Explanations: Treatment refers to the test particles used (kaolin, PMP and SMP) and the control; Concentration—the test particle concentrations used; Algal concentration (0.4 and 9 μg C mL-1); Time –the time range within which gut passage time was m...
GLM results for Exp. I.
GLM results for the life-history parameters measured in Exp. I as a function of concentration and treatment. The estimate, shows the difference from the control. Significant effects are in bold face. Abbreviations: NID = Number of produced offspring standardized by the number of individual survived days, BID = number of broo...
GLM results for growth at high vs. low food.
GLM table for the comparison of body size (μg DW) between high (9 μg C mL-1) and low (0.4 μg C mL-1) algal concentration. The estimate shows the deviation from the control. Significant results are in bold face.
(DOCX)
Gut evacuation rates of primary and secondary microplastics.
Rate constants (K), half-lives and their 95% confidence intervals (CI) established in Exp. IV for the primary and secondary MPs (PMP and SMP, respectively) at different particle concentrations.
(DOCX)
MP ingestion by D. magna.
Microphotographs of primary and secondary microplastics (PMP and SMP respectively) used in the experiment and Daphnia magna after the feeding trials: (A) PMP particles; no visible agglomeration; (B) SMP particles; substantial MP/MP-aggregate formation is observed in the feeding suspension (encircled); (C) Daphnia fed PMP p...
Questions
Question (1)
Hi!
I'm looking to understand changes in the Daphnia magna microbiome related to feeding conditions. Currently I have my individuals stored in NAP buffer. Does anyone have input on isolation kits suitible for daphnids? Experiences about sample size, is one adult individual enough or do I have to pool them? What about chloroplast-rich algae food? Does that pose a problem?
Cheers,
Christoph
