Microplastics and microfibers in surface waters of Monterey Bay National Marine Sanctuary, California

Spatio-temporal distribution of microplastic abundances in Izmir Bay (eastern Aegean Sea)

Microplastics (MPs) and their impacts have been extensively studied in the Mediterranean region. However, more research has yet to be conducted on assessing the extent of microplastic (MP) pollution in the eastern Aegean Sea, specifically in Izmir Bay. This study aims to evaluate the current state of MP pollution in surface water and sediment samples collected from Izmir Bay. Ten sampling stations were specifically selected, including locations near stream discharge points, maritime transportation piers, and port areas. Surface water samples were collected using a manta trawl net, while sediment samples were obtained using a Van Veen grab. The mean MP abundances in surface water ranged from 1,083,882 to 8,091,684 items/km2. Fragment type MPs were dominant. In terms of size category, it was found that MP s of 500µm size were dominant. The dominant color of MPs was white. ATR-FTIR analyses revealed that polyethylene and polypropylene were the dominant polymer types. MP concentrations in sediment ranged from 2,125 to 4,925 items/m2, with fiber-type MPs being the most abundant. Black-colored MPs were found to dominate in sediment samples. Overall, the MP levels in Izmir Bay were higher than previous studies findings. Therefore, it is crucial to conduct long-term monitoring studies to obtain more consistent and reliable data on MP pollution levels in Izmir Bay.

Estimation of the age of polyethylene microplastics collected from oceans: Application to the western North Pacific Ocean

The knowledge of microplastic (MP) age could aid the deduction of the origin and fate of a fragment carried by ocean currents over long time periods and distances. The present study developed a novel method to estimate the age of MPs (i.e., UV radiation exposure time) using the oxidation level of polyethylene (i.e., carbonyl index) from infrared spectrometry, ultraviolet erythemal radiation (UVER) data, and ambient seawater temperatures. Accelerated and outdoor exposure experiments were conducted to establish relationships among the temporally integrated UVER, ambient temperature, and carbonyl index. Thereafter, the age of MPs was computed, with Miyakojima Island serving as the reference location. The estimated ages of MPs collected from the western North Pacific Ocean ranged from 1 to 3 years, and those MPs from nearshore waters ranged from 0 to 5 years.

Prevalence and characterisation of microfibres along the Kenyan and Tanzanian coast

Microplastic pollution is ubiquitous, with textiles being a major source of one of the dominant microplastic types—microfibres. Microfibres have been discovered in the aquatic environment and marine biota, demonstrating direct infiltration in the environment. However, the impact of non-plastic microfibres has been overlooked until recently despite their prevalence and the ecotoxicological risk posed by chemical dyes and finishes used during processing. During an expedition from Lamu to Zanzibar (East Africa), a citizen science strategy was employed to innovate, educate and influence microfibre pollution reform through the Flipflopi project, a circular economy effort to stop the use of single-use plastic. Simple sampling methods were developed to replace costly equipment, which local citizens could use to partake in the collection and sampling of surface water samples from the previously understudied Kenyan and Tanzanian coast. To maintain the reliability of samples and to minimise contamination, a forensic science strategy was embedded throughout the methodology of the study, collection and analysis of the samples. A total of 2,403 microfibres from 37 sites were recovered and fully characterised with 55% found to be of natural origin, 8% regenerated cellulosic and 37% synthetic microfibres. Natural microfibres were in higher abundance in 33 of the 37 sampled sites. Congruent with recent studies, these findings further support the need for greater understanding of the anthropogenic impact of natural microfibres.

Field measurements reveal exposure risk to microplastic ingestion by filter-feeding megafauna

Microparticles, such as microplastics and microfibers, are ubiquitous in marine food webs. Filter-feeding megafauna may be at extreme risk of exposure to microplastics, but neither the amount nor pathway of microplastic ingestion are well understood. Here, we combine depth-integrated microplastic data from the California Current Ecosystem with high-resolution foraging measurements from 191 tag deployments on blue, fin, and humpback whales to quantify plastic ingestion rates and routes of exposure. We find that baleen whales predominantly feed at depths of 50-250 m, coinciding with the highest measured microplastic concentrations in the pelagic ecosystem. Nearly all (99%) microplastic ingestion is predicted to occur via trophic transfer. We predict that fish-feeding whales are less exposed to microplastic ingestion than krill-feeding whales. Per day, a krill-obligate blue whale may ingest 10 million pieces of microplastic, while a fish-feeding humpback whale likely ingests 200,000 pieces of microplastic. For species struggling to recover from historical whaling alongside other anthropogenic pressures, our findings suggest that the cumulative impacts of multiple stressors require further attention.

Floating microplastics pollution in the Central Atlantic Ocean of Morocco: Insights into the occurrence, characterization, and fate

This work presents preliminary results about abundance, distribution, characteristics, sources, and fate of microplastics (MPs) in the Central Atlantic Ocean (CAO) of Morocco. The investigation was conducted into three subsections, each characterized by different types of human activities and covering rural, village, and urban areas. MPs were detected in 100 % of the sampling sites. The abundances varied from 0.048 to 3.305 items/m³, with a mean abundance of 0.987 ± 1.081 items/m³. MPs abundance was higher in surface seawater linked to urban areas compared to village and rural areas. The dominant polymer type was polyester (PET-53.8 %) followed by polypropylene (PP-24.36 %), polyamide (PA-7.56 %), polystyrene (PS-6.88 %), polyvinyl chloride (PVC-2.64 %), ethylene vinyl acetate (EVA-2.60 %), polyetherurethane (PUR-1.36 %), and acrylic (AC-0.8 %). Fibers were the most dominant shapes accounting for over 50 %. MPs were mainly smaller than 2 mm in size (71 %) and characterized by colorful aspects. These findings suggested that wastewater treatment plant (WWTP) effluents and anthropogenic activities (industry, tourism, sanitation, and fishing) are the major pollution sources of MPs in the study area. SEM/EDX micrographs showed different weathering degrees and chemical elements adhered to the MPs surface.

An assessment workflow to recover microplastics from complex biological matrices

A criteria-guided workflow was applied to assess the effectiveness of microplastic separation methods on complex marine biological matrices. Efficacy of four methods (nitric acid, HNO₃, and potassium hydroxide, KOH, digestions, and sodium chloride, NaCl, and potassium iodide, KI, density flotations) was evaluated on four taxa (hard coral, sponge, sea squirt, sea cucumber) using five microplastics (polyethylene, polystyrene, polyethylene terephthalate, PET, polyvinylchloride, rayon). Matrix clarification was only unacceptably low for KOH. PET discoloured regardless of reagent. Rayon threads unravelled into monofilaments after exposure to all reagents, with discolouration also occurring with HNO₃. Recovery rates were overall high, except for dense microplastics treated with NaCl and only KI yielded high rayon recovery efficiency. All polymers were accurately assigned, with subtle spectral changes observed. These results demonstrate specific limitations to separation methods applied to different biological matrices and microplastics and highlight the need to assess their suitability to provide estimates of microplastic contamination.

Temporal Variability of Microparticles Under the Seattle Aquarium, Washington State: Documenting the Global Covid-19 Pandemic

Anthropogenic debris including microparticles (<5 mm) are ubiquitous in marine environments. The Salish Sea experiences seasonal fluctuations in precipitation, river discharge, sewage overflow events, and tourism-all variables previously thought to have an impact on microparticle transport and concentrations. Our goals are two-fold: 1) describe long-term microparticle contamination data including concentration, type, and size; and 2) determine if seasonal microparticle concentrations are dependent on environmental or tourism variables in Elliott Bay, Salish Sea. We sampled 100 L of seawater at a depth of approximately 9 m at the Seattle Aquarium, Seattle, Washington State, United States, approximately every two weeks from 2019 through 2020 and used an oil extraction protocol to separate microparticles. We found that microparticle concentrations ranged from 0 to 0.64 particles L^-1 and fibers were the most common type observed. Microparticle concentrations exhibited a breakpoint on 10 April 2020, where estimated slope and associated microparticle concentration significantly declined. Further, when considering both environmental as well as tourism variables, temporal microparticle concentration was best described by a mixed-effects model, with tourism as the fixed effect and the person counting microparticles as the random effect. Although monitoring efforts presented set out to identify effects of seasonality and interannual differences in microparticle concentrations, it instead captured an effect of decreased tourism due to the global Covid-19 pandemic. Long-term monitoring is critical to establish temporal microparticle concentrations and to help researchers understand if there are certain events, both seasonal and sporadic (e.g., rain events, tourism, or global pandemics), when the marine environment is more at risk from anthropogenic pollution. Environ Toxicol Chem 2022;41:917-930. © 2021 Seattle Aquarium. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Current status of microplastics pollution in the aquatic environment, interaction with other pollutants, and effects on aquatic organisms

Microplastics, as emerging pollutants, have received great attention in the past few decades due to its adverse effects on the environment. Microplastics are ubiquitous in the atmosphere, soil, and water bodies, and mostly reported in aqueous environment. This paper summarizes the abundance and types of microplastics in different aqueous environments and discusses the interactions of microplastics with other contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), antibiotics, and heavy metals. The toxicity of microplastics to aquatic organisms and microorganisms is addressed. Particularly, the combined toxic effects of microplastics and other pollutants are discussed, demonstrating either synergetic or antagonistic effects. Future prospectives should be focused on the characterization of different types and shapes of microplastics, the standardization of microplastic units, exploring the interaction and toxicity of microplastics with other pollutants, and the degradation of microplastics, for a better understanding of the ecological risks of microplastics.

Occurrence and characterization of microplastic and mesoplastic pollution in the Migliarino San Rossore, Massaciuccoli Nature Park (Italy)

Microplastics pollution is progressively threatening natural parks across the world. In the framework of monitoring this concerning trend, the present study focuses on the occurrence and identification of mesoplastics (MEPs) and microplastics (MPs) in sand samples collected before and after the summer season from the beach of the Nature Park of Migliarino San Rossore Massaciuccoli (Pisa, Italy). Meso- and microplastics were identified using Fourier transform infrared spectroscopy 2D Imaging, and detected in all samples with average concentrations of 207 ± 30 MPs/kg d.w., and 100 ± 44 MEPs/kg d.w., respectively. Seasonal changes of flow of the Arno River, industrial activities, and urban footprint were considered as the major sources of plastic pollution. Our results showed the occurrence of both natural and synthetic polymers including cellulose, polyethylene, polypropylene, polyamides, polyethylene terephthalate, and acrylonitrile.

Spatiotemporal variations of surface water microplastics near Kyushu, Japan: A quali-quantitative analysis

Microplastics in the ocean are threatening marine ecosystems. Although plastic contaminants are ubiquitous, their distribution is thought to be heterogeneous. Here, we elucidate the spatial and temporal variations in the quanti-qualitative characteristics of microplastics near Kyushu, Japan in the East China Sea. Six surveys across nine stations were conducted over a 14-month period, and a total of 6131 plastic items were identified. The average microplastic abundance and size were 0.49 ± 0.92 (items·m^-3 ± S.D.), and 1.71 ± 0.93 (mm ± S.D.), respectively. Differences between the highest and lowest abundances were 50-fold among monthly means, and 550-fold across all net tows. With respect to colour, polymer type, and shape, white and transparent polyethylene fragments were the dominant composition. There were significant differences for each of the analytical microplastic parameters among the survey months. Our results provide baseline data and lead to a more comprehensive understanding of the spatiotemporal characteristics of microplastic pollution.

Plastic microfibre pollution: how important is clothes' laundering?

Plastic microfibre pollution produced by domestic and commercial laundering of synthetic textiles has recently been incriminated in the press and the scientific literature as the main source (up to 90%) of primary microplastics in the oceans. Polyethylene terephthalate (PET) is the most common microfibre encountered. This review aims to provide updated information on worldwide plastic microfibre pollution caused by textile laundering and some possibilities for its control. Release of microfibres during domestic washing and tumble drying, their fate in wastewater treatment plants (WWTPs) and the oceans, and their environmental effects on the aquatic biota are discussed, as well as potential control methods at the levels of textile modification and laundry procedures. Environmental effects on aquatic biota are important; as a result of their small size and length-to-diameter ratio, microfibers are more effectively incorporated by organisms than other plastic particle groups. Simulation laundering studies may be useful in the development of a Standard Test Method and modification of WWTPs may reduce microfibre release into aquatic systems. However, improvements will be necessary in textile design and appliance design, and recommendations should be made to consumers about reducing their personal impact on the environment through their laundering choices, which can include appliances, fabric care products and washing conditions. Official regulation, such as that introduced recently by the French government, may be necessary to reduce plastic microfibre release from clothes' laundering.