JPI Oceans - Mikroplast - PLASTOX - SINTEF, NTNU, NPI, NILU - Dir and indir ecotoxicological impacts of microplastics on marine organisms

The PLASTOX project was coordinated through the European Joint Programming Initiative for Healthy and Productive Seas and Oceans (JPI Oceans) and comprises 15 partners from 11 European countries. PLASTOX investigated the ingestion (uptake), excretion and ecotoxicity of microplastic particles (MPs) on key European marine species and ecosystems. The influence of MP physical and chemical properties (e.g. size, shape, surface area and polymer composition) on these processes was evaluated. The role of existing environmental persistent organic pollutants (POPs) and plastic additive chemicals associated with MPs is also studied. Key research contributions from Norwegian partners included: A range of MP reference materials were used, representing different polymer types (e.g. polyethylene (PE), polystyrene (PS) and polypropylene (PP)) and size ranges. Large plastic marine litter was collected, identified and catalogued, and cryo-milled to create an environmentally relevant MP reference material in different size fractions. All reference materials were subjected to a basic physical and chemical characterisation and marine litter-derived MPs have undergone detailed characterisation. These techniques have also been developed and optimised for use in monitoring MP properties in field studies and in laboratory studies investigating MP aquatic environmental fate and effects. NILU coordinated the deployment of virgin plastic pellets at 6 European locations across the Baltic, North, Norwegian and Mediterranean Seas, and the Atlantic Ocean. Samples were taken after 1 w, 4 w, 3 m, 6 m, 9 m and 12 m at urban and remote locations. Common test materials were deployed in a harmonised manner, enabling a direct comparison of data. Post-industry plastics were deployed in both France and Norway to compare POP sorption at different latitudes. Chemical analysis is ongoing, and biofilm formation on the pellets was also investigated over time. An additional deployment of a subset of pellets was conducted at Ny Ålesund, Svalbard to widen the spatial scope to the North. Inter-seasonal changes of POP adsorption will be investigated to assess the effect of Arctic conditions with a lack of sunlight and low water temperatures. So far, results indicate that Arctic conditions cause a slower and lower absorption of POPs, as observed in temperate regions. Analysis showed winter conditions cause stronger disruption of the plastic surface due to direct contact with sea ice and wave action. The formation of small particles emphasises the impact of physical stress on plastic surfaces. Uptake, accumulation, excretion and toxicity were studied with ~10 µm PS, 1-5 µm PE MPs and a fluorescently labelled MP using microalgae (Rhodomonas baltica), dinoflagellates (Oxyrrhis marina) and copepods (Calanus finmarchicus). New rotating exposure systems were designed and built specifically for these studies. Results from the first studies indicate that MPs may affect algal growth at relatively high concentrations. Rapid ingestion of MPs was observed in O. marina, and there is indication of accumulation. Rapid ingestion of MPs was also observed in C. finmarchicus, and whilst MPs were excreted a small number of MPs were retained for a period of days. No acute toxicity was observed for either O. marina or C. finmarchicus. In June 2017, visiting researchers from the University of Exeter (UK) and personnel from SINTEF/NTNU/BioTrix undertook a comprehensive uptake and sublethal toxicity study of microplastic fibres with C. finmarchicus. In addition, a full generation exposure of C. finmarchicus to different concentrations of PS MPs was carried out to study the impact on development and reproduction. Data analysis is pending. As microplastic can interact with persistent organic pollutants (POPs) present in the environment, we studied the adsorption of two model polycyclic aromatic hydrocarbons (PAHs; phenanthrene and fluoranthene) to a suite of MP particles with different polymer compositions and sizes under different temperatures. The data were fitted to a range of adsorption isotherms and the best fitting isotherm identified for each polymer, size, PAH and temperature combination. In addition, we have developed and implemented a novel approach for investigating the effect of MP adsorption on PAH bioavailability and toxicity to lipid-rich and lipid-poor marine copepods (Calanus finmarchicus and Acartia tonsa, respectively). Studies were conducted using ingestible (10 µm) and non-ingestible (100 µm) PE microplastic particles at different temperatures. The results show that limited amounts of adsorbed PAHs are bioavailable to marine copepods. Finally, a series of plastic additive leachates were produced from the MP reference materials and subjected to a range of toxicity studies with algae and mussels (cells and larvae). Results indicated toxicity from all leachates, but with significant differences in the degree of toxicity depending on the source polymer.

PLASTOX has made a significant contribution to research on the environmental fate and effects of MPs on marine organisms. Through public outreach and media dissemination, PLASTOX communicated key findings and general knowledge about the environmental fate and effects of MP to the public. Contributions to regulations, policies and management practices: Andy Booth was appointed co-chair of the ICES Working Group on Marine Litter to develop MP monitoring. Dorte Herzke and Andy Booth were invited into the AMAP Litter and Microplastics Expert Group. Innovation: PLASTOX was responsible for the development of novel exposure systems, items of scientific equipment and methodologies. Education & career development: PLASTOX has co-funded 8 PhD students and 5 Post Docs, as well as supporting ~40 BSc and MSc students. New cooperation & collaboration: PLASTOX has established a strong network of European research centres studying the environmental fate and effects of MPs on marine ecosystems.

The PLASTOX project will investigate the ingestion and ecotoxicological impact of microplastics (MPs), together with the persistent organic pollutants (POPs), metals and plastic additive chemicals associated with them, on key European marine species and ecosystems. The influence of MP physicochemical properties (e.g. size, shape, surface area and composition) on these processes will be evaluated. PLASTOX aims to bridge the current gap between laboratory assessment using commercially available feedstock MPs and the additive-loaded and degrading MPs which dominate the marine environment. Macro-sized plastic debris collected from the marine environment will be used to generate fully characterized MPs derived from real marine litter. PLASTOX seeks to generate a clearer understanding of the adsorption and desorption of organic and inorganic pollutants to MPs using a range of common POP and metal contaminants, as well as common plastic additives. PLASTOX will investigate MP uptake through ingestion and other routes following controlled exposures. The potential for MP accumulation in tissues of marine organisms through transport across the gut and cell boundaries will be studied and attempts made to quantify MP accumulation using state of the art analytical approaches. MP accumulation will be linked to the physicochemical properties of MPs and comparisons drawn between different species. The acute and sublethal ecotoxicological effects of MPs will be assessed on marine phyto- and zooplankton. Using data and competence generated in these studies, a more detailed understanding of the potential for MP transfer between trophic levels, and the subsequent impacts this may have, will be obtained. The knowledge generated about MPs in the marine environment will be summarized in a guidance document and serve as a strong evidence base for development of future legislation and remedial efforts.