TY - JOUR A1 - Cole, Matthew A1 - Liddle, Corin A1 - Consolandi, Giulia A1 - Drago, Claudia A1 - Hird, Cameron A1 - Lindeque, Penelope Kate A1 - Galloway, Tamara S. T1 - Microplastics, microfibres and nanoplastics cause variable sub-lethal responses in mussels (Mytilus spp.) JF - Marine pollution bulletin : the international journal for marine environmental scientists, engineers, administrators, politicians and lawyers N2 - 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. KW - Plastic KW - Litter KW - Debris KW - Pollution KW - Shellfish KW - Bivalve KW - Fibres KW - Exposure KW - Ecotoxicology Y1 - 2020 U6 - https://doi.org/10.1016/j.marpolbul.2020.111552 SN - 0025-326X SN - 1879-3363 VL - 160 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Spijkerman, Elly A1 - Behrend, Hella A1 - Fach, Bettina A1 - Gaedke, Ursula T1 - Decreased phosphorus incorporation explains the negative effect of high iron concentrations in the green microalga Chlamydomonas acidophila JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - The green microalga Chlamydomonas acidophila is an important primary producer in very acidic lakes (pH 2.0-3.5), characterized by high concentrations of ferric iron (up to 1 g total Fe L-1) and low rates of primary production. It was previously suggested that these high iron concentrations result in high iron accumulation and inhibit photosynthesis in C. acidophila. To test this, the alga was grown in sterilized lake water and in medium with varying total iron concentrations under limiting and sufficient inorganic phosphorus (Pi) supply, because Pi is an important growth limiting nutrient in acidic waters. Photosynthesis and growth of C. acidophila as measured over 5 days were largely unaffected by high total iron concentrations and only decreased if free ionic Fe3+ concentrations exceeded 100 mg Fe3+ L-1. Although C. acidophila was relatively rich in iron (up to 5 mmol Fe: mol C), we found no evidence of iron toxicity. In contrast, a concentration of 260 mg total Fe L-1 (i.e. 15 mg free ionic Fe3+ L-1), which is common in many acidic lakes, reduced Pi-incorporation by 50% and will result in Pi-limited photosynthesis. The resulting Pi-limitation present at high iron and Pi concentrations was illustrated by elevated maximum Pi-uptake rates. No direct toxic effects of high iron were found, but unfavourable chemical Pi-speciation reduced growth of the acidophile alga. KW - Chlamydomonas KW - Ecotoxicology KW - Extreme environment KW - Iron toxicity KW - Phosphate limitation KW - Phytoplankton Y1 - 2018 U6 - https://doi.org/10.1016/j.scitotenv.2018.01.188 SN - 0048-9697 SN - 1879-1026 VL - 626 SP - 1342 EP - 1349 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Reeg, Jette A1 - Heine, Simon A1 - Mihan, Christine A1 - Preuss, Thomas G. A1 - McGee, Sean A1 - Jeltsch, Florian T1 - Potential impact of effects on reproductive attributes induced by herbicides on a plant community JF - Environmental Toxicology and Chemistry N2 - Current herbicide risk assessment guidelines for nontarget terrestrial plants require testing effects on young, vulnerable life stages (i.e., seedling emergence [and subsequent growth] and vegetative vigor [growth and dry wt]) but not directly on the reproduction of plants. However, the European Food Safety Authority (EFSA) has proposed that effects on reproduction might be considered when evaluating the potential effects on plants. We adapted the plant community model for grassland (IBC-grass) to give insight into the current debate on the sensitivity of reproductive versus vegetative endpoints in ecological risk assessment. In an extensive sensitivity analysis of this model, we compared plant attributes potentially affected by herbicides and the consequences for long-term plant population dynamics and plant diversity. This evaluation was implemented by reducing reproductive as well as vegetative endpoints by certain percentages (e.g., 10-90%) as a theoretical assumption. Plant mortality and seed sterility (i.e., inability of seeds to germinate) were the most sensitive attributes. Our results indicated that effects on seed production at off-field exposure rates must be very strong to have an impact on the risk assessment. Otherwise, effects on seed production are compensated for by the soil seed bank. The present study highlights the usefulness of community level modeling studies to support regulators in their decisions on the appropriate risk assessment endpoints and provides confidence in their assessments. Environ Toxicol Chem 2018;37:1707-1722. (c) 2018 SETAC KW - Ecological risk assessment KW - Ecotoxicology KW - Herbicide KW - Plant reproduction KW - Plant community model KW - Nontarget terrestrial plants Y1 - 2018 U6 - https://doi.org/10.1002/etc.4122 SN - 0730-7268 SN - 1552-8618 VL - 37 IS - 6 SP - 1707 EP - 1722 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Meli, Mattia A1 - Palmqvist, Annemette A1 - Forbes, Valery E. A1 - Groeneveld, Jürgen A1 - Grimm, Volker T1 - Two pairs of eyes are better than one: Combining individual-based and matrix models for ecological risk assessment of chemicals JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Current chemical risk assessment procedures may result in imprecise estimates of risk due to sometimes arbitrary simplifying assumptions. As a way to incorporate ecological complexity and improve risk estimates, mechanistic effect models have been recommended. However, effect modeling has not yet been extensively used for regulatory purposes, one of the main reasons being uncertainty about which model type to use to answer specific regulatory questions. We took an individual-based model (IBM), which was developed for risk assessment of soil invertebrates and includes avoidance of highly contaminated areas, and contrasted it with a simpler, more standardized model, based on the generic metapopulation matrix model RAMAS. In the latter the individuals within a sub-population are not treated as separate entities anymore and the spatial resolution is lower. We explored consequences of model aggregation in terms of assessing population-level effects for different spatial distributions of a toxic chemical. For homogeneous contamination of the soil, we found good agreement between the two models, whereas for heterogeneous contamination, at different concentrations and percentages of contaminated area, RAMAS results were alternatively similar to IBM results with and without avoidance, and different food levels. This inconsistency is explained on the basis of behavioral responses that are included in the IBM but not in RAMAS. Overall, RAMAS was less sensitive than the IBM in detecting population-level effects of different spatial patterns of exposure. We conclude that choosing the right model type for risk assessment of chemicals depends on whether or not population-level effects of small-scale heterogeneity in exposure need to be detected. We recommend that if in doubt, both model types should be used and compared. Describing both models following the same standard format, the ODD protocol, makes them equally transparent and understandable. The simpler model helps to build up trust for the more complex model and can be used for more homogeneous exposure patterns. The more complex model helps detecting and understanding the limitations of the simpler model and is needed to ensure ecological realism for more complex exposure scenarios. (C) 2013 Elsevier B.V. All rights reserved. KW - Ecotoxicology KW - Folsomia candida KW - Mechanistic effect models KW - Soil invertebrates Y1 - 2014 U6 - https://doi.org/10.1016/j.ecolmodel.2013.07.027 SN - 0304-3800 SN - 1872-7026 VL - 280 SP - 40 EP - 52 PB - Elsevier CY - Amsterdam ER -