Ocean plastic pollution is a global issue, but many small island states lack relevant research studies and data. Microplastics are a major concern due to their persistence, entry into food chains and potential to transfer pollutants. Fish gastrointestinal tracts are easy to sample and provide a useful indicator of pollution levels. In 2024, we sampled 201 reef fish spanning 44 species from Funafuti Atoll, Tuvalu, to provide the first baseline microplastic data from this island nation. In total, 75 individuals (37.3%) contained microplastics. The mean occurrence was 0.72 ± 1.16 (mean ± SD) particles per fish, with a maximum of 5 particles per fish found in individuals of four species: Aphareus rutilans, Mulloidichthys flavolineatus, Mulloidichthys vanicolensis and Sargocentron spiniferum. When focusing analyses on seven species with 10 or more individual samples, generalized linear models found no significant differences among species, but revealed fish had significantly more microplastics close to the most populous islet Fongafale (0.95 ± 1.26 particles per individual), compared to rural islets Papaelise and Funafala (0.28 ± 0.77 particles per individual). Fibers were the most common microplastic, and polypropylene was the dominant polymer. This study confirms microplastic presence within the gastrointestinal tracts of key food fish from Funafuti lagoon, emphasizing the need for further research.

Rivers act as long-term plastic storage and a pathway for land-based plastic pollution into the ocean. Monitoring river plastic at a global scale remains challenging, with only limited large-scale and long-term monitoring efforts to date. Citizen science approaches may ensure a more continuous basic knowledge of plastic pollution in rivers, which can be used to assess the efficacy of reduction measures. We evaluated the suitability of several river plastic monitoring methods for citizen science, through field monitoring and a subsequent survey with citizen scientists in Accra, Ghana. Four measurement techniques (visual counting, macroplastic net sampling, microplastic net sampling and hydrometric measurements) were tested in the field and evaluated by citizen scientists. The visual counting method, used to estimate floating macroplastic transport, emerged as the most promising method for citizen science–based river plastic monitoring. Using the data collected by citizens, we quantify the variability in transport and concentration of both macroplastic and microplastic.

Microplastic fibres are found everywhere that researchers have looked for them, from remote mountains to human lungs. However, data are not yet available to facilitate the design of low-shedding textiles. Effective use of standard test methods could establish the impact of processing variables on textile’s propensity to fragment or shed fibres into the environment, allowing industry to design and select lower-polluting materials. Three new test methods are recommended using the widely accessible accelerated laundering equipment used for colour fastness to wash tests. However, the recommended gravimetric analysis of results takes over 8 h per specimen batch, in addition to specimen preparation, testing and effluent filtration, making analysing test results prohibitively time-consuming, and expensive, for many brands. Visual ‘grey scales’ are very commonly used to grade colour fastness test results, and this article proposes the use of an equivalent ‘fibre fragmentation scale’ to dramatically increase the throughput of fibre fragmentation testing and reduce its cost without compromising accuracy or reliability. Mean fibre fragmentation scale grades given by sets of three observers correlated with gravimetric results at 99% confidence. Subjective grades assigned to test specimens, and photographs of test specimens, had significantly lower variability than gravimetric methods at small, ‘more acceptable’, levels of fibre fragmentation.

Microplastics pollution is a widely recognized issue, although significant analytical challenges remain to be overcome in order to achieve a more comprehensive ecological understanding. The complex nature of this pollutant, with its variable physical and chemical properties, presents considerable challenges when it comes to establishing standardized methods for studying it. One crucial factor that influences its toxicity is particle size, yet even this parameter lacks a well-established framework, especially in the case of nanoplastics. Although the size range limits are already proposed in the literature, where the most acceptable values for microplastics are from 1 to 5,000 μm and for nanoplastics are from 1 to 1,000 nm, we propose narrowing these limits to 0.1–1,000 μm and 10–100 nm, respectively. We based our discussion on conceptual terminology, polymer structure and toxicity, highlighting the significance of accurately defining their size range. The standardization of these limits will allow the development of more efficient approaches to studying this pollutant, enabling a comprehensive understanding of its ecological consequences and potential risks.

Microplastics (MPs) are carbon-rich polymers that are ubiquitous in the environment. With the increase of plastic production, microplastic pollution may be exacerbated and result in significant changes in microbial communities and biogeochemical processes such as carbon cycling, eventually impacting greenhouse gas emission and carbon storage in terrestrial ecosystems. However, current research on the effect of MPs on soil carbon cycling is still limited, and there is a lack of systematic review of the scattered information obtained from previous studies. Accordingly, this review provides a systematic overview of the current knowledge on the effects of MPs on soil carbon cycling and gives future research suggestions. Emerging evidence indicates that MPs could affect soil carbon stability and CO2 and CH4 emission by modifying soil physicochemical and microbiological properties; though biodegradable MPs often exhibit a greater effect than nonbiodegradable ones, the specific effects are highly dependent on plastic type, size and concentration. The specific mechanisms of MPs’ impact on soil carbon cycles remain elusive, which are discussed mainly from the perspective of microbial changes, including microbial biomass, microbial community composition, and key enzymes and functional genes associated with carbon metabolism. Further research is needed to elucidate whether MPs have a positive priming effect on soil carbon decomposition and the biotic and abiotic mechanisms involved. This review paper helps researchers gain a clearer picture of how and through which way MPs impact carbon cycling in soil ecosystems.