The St. Lawrence River, one of the world\'s largest estuaries, drains >25 % of the world\'s freshwater reserves and is affected by various anthropogenic effluents. Although previous studies reported micro- and nanoplastics contamination in the Estuary and Gulf of St. Lawrence (EGSL), this study provides a first evaluation of macroplastic pollution along the north and south shores of the EGSL. Plastic debris categorization was performed according to the OSPAR protocol completed by polymer identification using Fourier-transform infrared spectroscopy. The EGSL appeared ubiquitously contaminated by plastic debris, dominated by single-use plastics primarily made of polypropylene (28 %), polyethylene (25 %) and polystyrene (17 %). The EGSL shores exhibited a mean contamination level of 0.17 ± 0.11 items/m2 and distance to Montreal significantly influenced the distribution of plastic debris. This study provides an essential baseline for implementing local waste reduction and management actions in the St. Lawrence watershed to reduce plastic pollution.

Plastic pollution is ubiquitous in the marine environment. Beach cleanups are considered a cost-effective mitigative measure with generally few negative environmental impacts. Beached litter is not static, however, and may wash back out to sea or be buried, meaning it is only temporarily available for cleanup. We studied deposition and turnover of litter on three Arctic beaches in Lofoten, Norway, biweekly for 31 months. The mean estimated daily deposition rate was 10 items/100 m, with a median residence time of 99 days. Both processes were impacted by seasons and weather and varied both spatially and temporally. Strong winds during the fall increased litter influx and onshore winds contributed to its loss. Heavier objects and those higher on the beach persisted longer yet were still subject to turnover. Snow temporarily buries litter but protects it in the long run. Given the turnover of litter, frequent (albeit smaller) cleanups can readily remove 3-4 times more litter from circulation in the environment than larger, infrequent cleanups. With limited resources, it is recommended to prioritise late fall cleanups.

Bio-ingestion of microplastics poses a global threat to ecosystems, yet studies within nature reserves, crucial habitats for birds, remain scarce despite the well-documented ingestion of microplastics by avian species. Located in Jiangsu Province, China, the Yancheng Wetland Rare Birds Nature Reserve is home to diverse bird species, including many rare ones. This study aimed to assess the abundance and characteristics of microplastics in common bird species within the reserve, investigate microplastic enrichment across different species, and establish links between birds\' habitat types and microplastic ingestion. Microplastics were extracted from the feces of 110 birds, with 84 particles identified from 37.27% of samples. Among 8 species studied, the average microplastic abundance ranged from 0.97 ± 0.47 to 43.43 ± 61.98 items per gram of feces, or 1.5 ± 0.87 to 3.4 ± 1.50 items per individual. The Swan goose (Anser cygnoides) exhibited the highest microplastic abundance per gram of feces, while the black-billed gull (Larus saundersi) had the highest abundance per individual. The predominant form of ingested microplastics among birds in the reserve was fibers, with polyethylene being the most common polymer type. Significant variations in plastic exposure were observed among species and between aquatic and terrestrial birds. This study represents the first quantitative assessment of microplastic concentrations in birds within the reserve, filling a crucial gap in research and providing insights for assessing microplastic pollution and guiding bird conservation efforts in aquatic and terrestrial environments.

The growing environmental consequences caused by plastic pollution highlight the need for a better understanding of plastic polymer cycles and their associated additives. We present a novel, comprehensive top-down method using inflow-driven dynamic probabilistic material flow analysis (DPMFA) to map the plastic cycle in coastal countries. For the first time, we covered the progressive leaching of microplastics to the environment during the use phase of products and modeled the presence of 232 plastic additives. We applied this methodology to Norway and proposed initial release pathways to different environmental compartments. 758 kt of plastics distributed among 13 different polymers was introduced to the Norwegian economy in 2020, 4.4 Mt was present in in-use stocks, and 632 kt was wasted, of which 15.2 kt (2.4%) was released to the environment with a similar share of macro- and microplastics and 4.8 kt ended up in the ocean. Our study shows tire wear rubber as a highly pollutive microplastic source, while most macroplastics originated from consumer packaging with LDPE, PP, and PET as dominant polymers. Additionally, 75 kt of plastic additives was potentially released to the environment alongside these polymers. We emphasize that upstream measures, such as consumption reduction and changes in product design, would result in the most positive impact for limiting plastic pollution.

Poor waste management and unsustainable institutional and individual behaviors, have led to the accumulation of plastic litter in many habitats worldwide. Assessment of plastic pollution in Kenyan marine environment was conducted focusing on the impact of banning the single-use plastic carrier bags in Kenya. The quantification, composition, and distribution of plastics were determined at nine (9) beaches along Kenyan coastline using standing stock method. A total of 750 plastic items were collected and categorized with only 47 pieces being single-use plastic carrier bags. A great number of plastics (n = 383), were identified by their original use, with packaging plastics being the most common (n = 155). Macroplastics were the overall dominant plastics at 76%, mesoplastics, 21% and microplastics, 3%, which were altogether dominated by low-density polyethylene (LDPE) at (46%), followed by polypropylene (PP), 30%; polyethylene tetraphthalate (PET), 9%; polyvinyl chloride (PVC), 8%; and polystyrene (PS), 7%. The absence of identifiable single-use plastic carrier bags in 6 out of 9 beaches signified the effectiveness of the ban in Kenya. Monitoring of trends and sources of plastic debris is encouraged to help enhance the science-policy linkage aimed at reducing marine plastic pollution.

This paper presents the first assessment of marine litter in the Mogadishu coastal area of Somalia. Samples were collected monthly using 100 m × 40 m transect and classified following OSPAR Marine Litter Survey Guide while litter sources were identified using Ocean Conservancy Marine Debris Index. The results showed a total of 119873 items consisting of plastics (89.47%), clothing items (7.53%), and others (3.00%) recovered from Liido Beach. Litter density ranged from 2.19 items/m2 to 14.18 items/m2 with a mean of 6.25 items/m2 and Clean Coast Index (CCI) suggesting that Liido Beach is extremely dirty (>20 items/m2). In addition, the primary sources of marine litter at the beach are local recreational and shoreline activities (54.12%), and dumping (36.61%). The dominance of plastic litter on the beach poses potential threats to marine biodiversity in the Somalia coastal area and the West Indian Ocean. It is recommended that effective strategies and solutions to mitigate litter on the beach and other coastal areas in Somalia should be developed and compensated with public education and awareness campaigns across the country.

Emerging contaminants can act as contributing factors to the decline of amphibian populations worldwide. Recently, scientists have drawn attention to the potential ecotoxicity of microplastics and nanomaterials in amphibians, however, their possible effects on embryonic developmental stages are still absent. Thus, the present study analyzed the developmental toxicity of environmentally relevant concentrations of polyethylene microplastics (PE MPs; 60 mg/L) and titanium dioxide nanoparticles (TiO2 NPs; 10 μg/L), isolated or in combination (Mix group) on bullfrog embryos, Aquarana catesbeiana, adapting the Frog Embryo Teratogenesis Assay (FETAX, 96h). Allied to the FETAX protocol, we also analyzed the heart rate and morphometric data. The exposure reduced the survival and hatching rates in groups exposed to TiO2 NPs, and to a lesser extent, also affected the Mix group. TiO2 NPs possibly interacted with the hatching enzymes of the embryos, preventing hatching, and reducing their survival. The reduced effects in the Mix group are due to the agglomeration of both toxicants, making the NPs less available for the embryos. PE MPs got attached to the gelatinous capsule of the chorion (confirmed by fluorescence microscopy), which protected the embryos from eventual direct effects of the microplastics on the hatching and survival rates. Although there were no cardiotoxic effects nor morphometric alterations, there was a significant increase in abdominal edemas in the hatched embryos of the PE MPs group, which indicates that osmoregulation might have been affected by the attachment of the microplastics on the embryos\' gelatinous capsule. This study presents the first evidence of developmental toxicity of environmental mixtures of microplastics and nanoparticles on amphibians and reinforces the need for more studies with other amphibian species, especially neotropical specimens that could present bigger sensibility. Our study also highlighted several features of the FETAX protocol as useful tools to evaluate the embryotoxicity of several pollutants on amphibians.

During wet weather events, combined sewer overflows (CSOs) transfer large amount of particulate matter and associated pollutants into surrounding water bodies, thereby deteriorating the recipients\' ecological health. Resuspension of sewer sediments during these events contributes significantly to pollution level of these discharges. However, how much this in-sewer process contributes to CSOs\' quality regarding microplastic (MP) pollution is little known. Therefore, an investigation on sewer deposits inside the Parisian combined sewer network was carried out. The study found high MP concentrations stored in this matrix, ranging from 5 × 103 to 178 × 103 particle/kg dry weight. Polymer composition is similar to what found in raw wastewater, containing a high proportion of polyethylene and polypropylene. Thus, the results indicated the persistence of MPs in sewer network during transport during dry weather periods to treatment facilities. Once resuspension of sewer deposits happens, MPs can be released into water flow and get discharged along with CSOs. This highlights another potential pathway of MPs into freshwater environment.

This study provides with evidence of the presence of sea surface microplastics in a UNESCO marine biosphere reserve: the island of Menorca in the north-western Mediterranean Sea. From a total of 90 samples, in 100% of the samples, microplastics were observed with a mean value of 0.18 ± 0.01 items/m2. According to data, no significant differences were observed for sampling period with very similar values between 2021 (0.17 ± 0.02 items/m2) and 2022 (0.18 ± 0.02 items/m2). However, significant differences were observed regarding sampling area (both site and locality) suggesting that sea surface plastics in the study area might be more dependent of the spatial scale rather than on the temporal scale. Fibre type microplastics predominated over fragments, films, pellets, and foams, but in the commercial Port de Maó, almost 50% of the identified items were foams which could be related to the transportation of packed goods to this port. Results from the model applied to study the relation between waste management indicators and microplastic abundance indicate that when considering all marine litter categories, the explanatory variables are plastic waste generated by residents population (tonnes/year/km2) and waste collection rate (%), whereas if only plastics are considered, the indicator regarding waste per capita (kg/hab/year) is also included. Data in this study is obtained through a harmonized protocol which can be used to define baseline and threshold values to evaluate good environmental status regarding descriptor 10 of the Marine Strategy Framework Directive.

Identifying sources is crucial for proposing effective actions to combat marine litter pollution. Here, we used an innovative approach to identify hotspots of mismanaged plastic waste (MPW) within Brazil and subsequent leakage to the ocean, based on population density, socio-economic conditions, municipal solid waste management and environmental parameters. We estimated plastic waste generation and MPW for each of the 5570 Brazilian municipalities, which totaled 3.44 million metric tons per year. Then, we estimated the probability of litter mobilization and transport (P) and the relative risk of leakage to the ocean (MPW × P). The Guanabara Bay and La Plata River comprised the main oceanic entry hotspots of litter produced in Brazil. The use of national databases allowed us to increase spatial and temporal granularity, offering a detailed baseline for the application of prevention and mitigation actions. However, overcoming data limitations is still a challenge in Brazil as in other Global South countries.