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The Arctic and Antarctica represent two of the most inhospitable and poorly investigated biomes in the world. Although polar regions are still perceived as some of the most pristine places still in existence, these remote places are no longer immune to anthropogenic pollution, in particular, micro- and nanoplastics. Seabirds, avian species feeding mainly at sea, are indicators of change in the environment and represent an early study group of ecological indicators for plastic pollution. The goal of this bibliometric overview is to evaluate international research trends on the impacts of microplastics (MPs) and nanoplastics (NPs) on seabirds inhabiting polar regions. A total of at least 13 seabird species were reported to have ingested MPs from 1983-2023. Overall, 1130 samples were investigated, including stomach content, pouch content, guano, and pellets. Pellets were the most investigated substrate (699), followed by stomach contents (309), guano (101), and pouch contents (21). A median of 31.5 MPs per sample was found in the Arctic, with an average of 7.2 MPs per sample. A median of 35 MPs per sample was found in Antarctica, with an average of 1.1 MPs per sample. Overall, MPs were most frequently found in fragment form. A total of 3526 MPs were retrieved from stomachs (3013), pellets (398), guano (75), and pouch contents (40). Polyethylene was the dominant plastic polymer found, followed by polypropylene and polystyrene. The monitoring of MP ingestion is crucial to mitigating the impacts on marine and terrestrial organisms. Standardized protocols could boost the safeguarding of seabirds and reduce the impacts of MPs on polar regions. [ABSTRACT FROM AUTHOR]

Polystyrene (PS) and microplastic production pose persistent threats to the ecosystem. Even the pristine Antarctic, which is widely believed to be pollution-free, was also affected by the presence of microplastics. Therefore, it is important to comprehend the extent to which biological agents such as bacteria utilise PS microplastics as a carbon source. In this study, four soil bacteria from Greenwich Island, Antarctica, were isolated. A preliminary screening of the isolates for PS microplastics utilisation in the Bushnell Haas broth was conducted with the shake-flask method. The isolate AYDL1 identified as Brevundimonas sp. was found to be the most efficient in utilising PS microplastics. An assay on PS microplastics utilisation showed that the strain AYDL1 tolerated PS microplastics well under prolonged exposure with a weight loss percentage of 19.3% after the first interval (10 days of incubation). Infrared spectroscopy showed that the bacteria altered the chemical structure of PS while a deformation of the surface morphology of PS microplastics was observed via scanning electron microscopy after being incubated for 40 days. The obtained results may essentially indicate the utilisation of liable polymer additives or "leachates" and thus, validate the mechanistic approach for a typical initiation process of PS microplastics biodeterioration by the bacteria (AYDL1)—the biotic process. [ABSTRACT FROM AUTHOR]

Nanoplastics and engineering nanomaterials (ENMs) are contaminants of emerging concern (CECs), increasingly being detected in the marine environment and recognized as a potential threat for marine biota at the global level including in polar areas. Few studies have assessed the impact of these anthropogenic nanoparticles in the microbiome of marine invertebrates, however combined exposure resembling natural scenarios has been overlooked. The present study aimed to evaluate the single and combined effects of polystyrene nanoparticles (PS NP) as proxy for nanoplastics and nanoscale titanium dioxide (nano-TiO 2) on the prokaryotic communities associated with the gill tissue of the Antarctic soft-shell clam Laternula elliptica , a keystone species of marine benthos Wild-caught specimens were exposed to two environmentally relevant concentrations of carboxylated PS NP (PS–COOH NP, ∼62 nm size) and nano-TiO 2 (Aeroxide P25, ∼25 nm) as 5 and 50 μg/L either single and combined for 96h in a semi-static condition.Our findings show a shift in microbiome composition in gills of soft-shell clams exposed to PS NP and nano-TiO 2 either alone and in combination with a decrease in the relative abundance of OTU1 (Spirochaetaceae). In addition, an increase of gammaproteobacterial OTUs affiliated to MBAE14 and Methylophagaceae (involved in ammonia denitrification and associated with low-quality water), and the OTU Colwellia rossensis (previously recorded in polluted waters) was observed. Our results suggest that nanoplastics and nano-TiO 2 alone and in combination induce alterations in microbiome composition by promoting the increase of negative taxa over beneficial ones in the gills of the Antarctic soft-shell clam. An increase of two low abundance OTUs in PS-COOH NPs exposed clams was also observed. A predicted gene function analysis revealed that sugar, lipid, protein and DNA metabolism were the main functions affected by either PS-COOH NP and nano-TiO 2 exposure. The molecular functions involved in the altered affiliated OTUs are novel for nano-CEC exposures. [Display omitted] • Antarctic soft-shell clam microbiome affected by nanoplastic and nanoscale titanium dioxide exposure. • The main predicted gene functions affected were implicated in gill's metabolism • Single and combined exposure to nano-TiO 2 affect prokaryotic symbiosis • An increase of two low abundance OTUs in PS-COOH NPs exposed clams was observed • A decrease in relative abundances of Spirochaetia occurred upon exposure to nano-TiO 2 [ABSTRACT FROM AUTHOR]

It is generally acknowledged that microplastic pollutants are prevalent in ocean waters and sediments across a range of tropical, temperate, subpolar, and polar regions. The waters surrounding King George Island are significantly impacted by human activities, particularly those related to scientific stations, fishing, and tourism. Organisms, such as Laternula elliptica, can be used as environmental monitors due to the likelihood that they will bioaccumulate pollutants. The goal of this study was to quantify and identify plastic and cellulosic micro-fragments and microfibers present in the soft body of clams (n = 21), collected from Fildes Bay near sewage and wastewater discharges. Plastic and cellulose microfragments and microfibers were counted, and their compositions were determined using FT-IR. All 21 individuals sampled contained fragments and fibers, with a total of 900 items detected (42.86 ± 25.36 mean ± SD items per individual), or 1.82 items g.wet mass−1. 58 % of items were cellulose and 22 % plastic. Considering the plastic polymer compositions, 28.57 % were polyethylene terephthalate (PET), 21.43 % acrylic, 14.29 % high-density polyethylene (HDPE), 14.29 % Polypropylene (PP), 7.14 % ultra-high drawn polyethylene filament (UHMWPE), 7.14 % polyester and 7.14 % Polyethylene. The quantities and prevalence of MP in L. elliptica were higher than those found in other Antarctic marine species, and even in bivalves from populated regions of the world. Our work assessed the pollution status of L. elliptica near an effluent of wastewater plants and found that 95 % of individuals displayed MP and 100 % microfibers that could impact their population. [Display omitted] • L. elliptica is a bioindicator to MPs footprint of human presence in Antarctica. • 95 % of individuals had plastic and cellulosic micro-fragments and 100 % microfibers. • 900 total items were recorded from 21Antarctic clams. • The micro-plastics found in L. elliptica were higher than other bivalve species. [ABSTRACT FROM AUTHOR]

Plastic packaging accounts for 36% of all plastics made, but amounts to 47% of all plastic waste; 90% of all plastic items are used once and then discarded, which corresponds to around 50% of the total mass of plastics manufactured. Evidence for the ubiquity of microplastic pollution is accumulating rapidly, and wherever such material is sought, it seems to be found. Thus, microplastics have been identified in Arctic ice, the air, food and drinking water, soils, rivers, aquifers, remote maintain regions, glaciers, the oceans and ocean sediments, including waters and deep sea sediments around Antarctica, and within the deepest marine trenches of the Earth. They have also been detected in the bodies of animals, including humans, and as being passed along the hierarchy of food chains, up to marine top predators. Evidence has also been presented that microplastics are able to cross different life stages of mosquito that use different habitats – larva (feeding) to pupa (non-feeding) to adult terrestrial (flying) – and therefore can be spread from aquatic systems by flying insects. The so-called 'missing plastic problem' appears to be, in part, due to limitations in sampling methods, that is, many of the very small microplastic particles may simply escape capture in the trawl nets that are typically employed to collect them, but have been evidenced in grab-sampling experiments. Moreover, it is simply not possible to measure entirely through the vast, oceanic volumes of the oceans. It can, however, be concluded with some confidence that the majority of the plastic is not located at the sea surface, and indeed, several different sinks have been proposed for microplastics, including the sea floor and sediments, the ocean column itself, ice sheets, glaciers and soils. The treatment of land with sewage sludge is also thought to make a significant contribution of microplastics to soil. A substantial amount of airborne microparticulate pollution is created by the abrasion of tyres on road surfaces (and other 'non-exhaust' sources), meaning that even electric vehicles are not 'clean' in this regard, despite their elimination of tailpipe PM2.5 and PM10 emissions. The emergence of nanoplastics in the environment poses a new set of potential threats, although any impacts on human health are not yet known, save, as indicated from model studies. While improved design, manufacture, collection, reuse, repurposing and reprocessing/recycling of plastic items are necessary, overwhelmingly, a curbing in the use of plastic materials in the first place is demanded, particularly from single-use packaging. However, plastic pollution is just one element in the overall matrix of a changing climate ('the world's woes') and must be addressed as part of an integrated consideration of how we use all resources, fossil and otherwise, and the need to change our expectations, goals and lifestyles. In this effort, the role of deglobalisation/relocalisation may prove critical: thus, food and other necessities might be produced more on the local than the global scale, with smaller inputs of fossil fuels for transportation and other purposes, water and fertilisers, along with a marked reduction in the need for plastic packaging. [ABSTRACT FROM AUTHOR]

Human settlements within the Antarctic continent have caused significant coastal pollution by littering plastic. The present study assessed the potential presence of microplastics in the gastrointestinal tract of the Antarctic fish Harpagifer antarcticus , endemic to the polar region, and in the sub-Antarctic fish Harpagifer bispinis. H. antarcticus. A total of 358 microfibers of multiple colors were found in 89 % of H. antarcticus and 73 % of H. bispinis gastrointestinal track. A Micro-FTIR analysis characterized a sub-group (n = 42) of microfibers. It revealed that most of the fibers were cellulose (69 %). Manmade fibers such as microplastics polyethylene terephtalate, acrylics, and semisynthetic/natural cellulosic fibers were present in the fish samples. All the microfibers extracted were textile fibers of blue, black, red, green, and violet color. Our results suggest that laundry greywater discharges of human settlements near coastal waters in Antarctica are a major source of these pollutants in the Antarctic fish. [Display omitted] • 358 microfibers of multiple colors were found in the gastrointestinal tract of fish. • 69 % of microfibers were characterized as cellulose, followed by PET and acrylic microfibers. • 89 % of Harpagifer antarcticus gastrointestinal tract presented a high abundance of microfibers. [ABSTRACT FROM AUTHOR]

Enzyme-catalyzed degradation of poly(trimethylene carbonate) homo-polymer (PTMC) and poly(trimethy-lene carbonate-co-glycolide) co-polymer (PTGA) was investigated in the presence of lipases from Candida antarctica and Hog pancreas. Degradation was monitored by gravimetry, size-exclusion chromatography (SEC), nuclear magnetic resonance (NMR), tensiometry and environmental scanning electron microscopy (ESEM). PTMC can be rapidly degraded by Candida antarctica lipase with 98% mass loss after 9 days, while degradation by Hog pancreas lipase leads to 27% mass loss. Introduction of 16% glycolide units in PTMC chains strongly affects the enzymatic degradation. Hog pancreas lipase becomes more effective to PTGA co-polymer with a mass loss of 58% after 9 days, while Candida antarctica lipase seems not able to degrade PTGA. Bimodal molecular weight distributions are observed during enzymatic degradation of both PTMC and PTGA, which can be assigned to the fact that the surface is largely degraded while the internal part remains intact. The composition of the PTGA co-polymer remains constant, and ESEM shows that the polymers are homogeneously eroded during enzymatic degradation. Contact angle measurements confirm the enzymatic degradation mechanism, i.e., enzyme adsorption on the polymer surface followed by enzyme-catalyzed chain cleavage. [ABSTRACT FROM AUTHOR]

• Very low concentrations of floating macro and microplastics found around Antarctica. • Mean densities of 0.03 macrolitter items·km−2 and 187.6 microplastics·km−2. • Plastic densities are one order of magnitude lower than in adjacent temperate waters. • The Subtropical Front seems to be a barrier to the dispersal of drifting plastics. While macroplastics have been washing up on Southern Ocean islands for decades and microplastics have been found in seabirds from the region since 1960, there are still relatively few quantitative data on the amount of plastic pollution, especially with regard to floating plastics, at high southern latitudes. We present a baseline estimate of the abundance of floating plastics around the Southern Ocean from a survey of floating macro-, meso- and microplastic pollution conducted during the Antarctic Circumnavigation Expedition in 2016/17. A total of 40 net trawls and 626 h of observation were performed during this survey. Of these, 33 net samples and 552 h of observation were made in polar waters south of the Subtropical Front (STF). Only 5 microplastics and 17 macrolitter items were observed south of the STF, confirming the Southern Ocean as the region with the lowest concentrations of plastic pollution globally. The mean concentrations of floating macrolitter (0.02–0.03 items·km−2) and small plastic fragments (188 ± 589 particles·km−2) south of the STF were one order of magnitude lower than in adjacent temperate waters north of the STF, which suggests that the STF acts as a barrier to the southward transport of floating debris. Despite their much lower density, the mass of macroplastics was similar to that of floating microplastics in the Southern Ocean. [ABSTRACT FROM AUTHOR]