Evaluating the properties, fate and individual-to-ecosystem level impacts of contrasting microplastics in freshwatersShow others and affiliations
2023 (English)Report (Other academic)
Abstract [en]
- Microplastic particles (MPs) are fragments, fibres and other shapes derived fromplastic polymers in the size range of 1–5 000 μm. Concern about the environmentalimpacts of MPs and their implications for human wellbeing has never been higher.Unfortunately, growth in the empirical understanding of the dynamics and impactsof MPs lags behind. This hinders the capacity of scientists, managers and policymakers to address public concerns about the true level of risk posed by MPs, andto develop effective management, policy and governance strategies for eliminatingor reducing those risks.
- Research on the behaviour and impacts of MPs in freshwater ecosystems is especiallydeficient, despite their vulnerability to inputs of plastic waste (e.g. via storm waterand other terrestrial runoff), and their capacity to act as key transport pathwaysthrough the landscape. This represents a substantial black box in our understandingof the dynamics of MPs from inland to the ocean.
- In seven research activities (5 mesocosm experiments, 1 field study and 1 literaturereview) we addressed two broad research questions:a) Initial fate and environmental interactions of MP particles in streams, includingbiofilm formation and sorption of chemical stressorsb) Ecological impacts of MPs on resource consumption, growth and survival oforganisms, and on key ecosystem processes.
- Among our key results addressing the initial fate and biofilm formation of MPparticles, we found that (i) biofilm formation generally made denser particles morebuoyant and caused more buoyant particles to sink faster, (ii) biofilms on polystyreneMPs supported more cyanobacteria than other polymers, and (iii) aquatic macrophytesincrease MP retention by up to 94 %.
- Among our key results addressing the ecological impacts of MPs, we found that almostall MP shapes and polymers studied had one or more effects on stream microbialorganisms and associated ecosystem processes (e.g. microbial respiration, detritusbreakdown), and/or on the life history of a model macroinvertebrate detritivore.
- We also provide evidence that effects of MPs on microbial organisms can propagateup food-chains to affect consumer growth and fat storage.
- Some MP impacts were similar to those of naturally occurring organic and inorganicparticles, whilst others represented a risk over and above that associated with naturalparticles.
- The number of MP impacts detected in our experiments provides sufficient basis for“moving beyond the precautionary principle” when motivating a need for monitoringand management – there is now sufficient evidence that MPs alter key aspects of thefunctioning of stream benthic food webs to motivate a need for action.
- Based on our results, we further provide a series of recommendations formonitoring,policy and management targeting MPs, and for future research.
Place, publisher, year, edition, pages
Stockholm: Naturvårdsverket, 2023. , p. 62
Series
Rapport / Naturvårdsverket, ISSN 0282-7298 ; 7100
National Category
Environmental Sciences
Identifiers
URN: urn:nbn:se:naturvardsverket:diva-10606ISBN: 978-91-620-7100-4 (print)OAI: oai:DiVA.org:naturvardsverket-10606DiVA, id: diva2:1779554
2023-07-042023-07-042023-07-04Bibliographically approved