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The twenty‐first century is confronted with the consequences of enormous amounts of global emerging plastic waste resulting from an excessive use of plastic, which has been imparting several negative impacts on the environment and human health. Moreover, some novel variants have also been reported in some coastal environments, so far, as a result of mixing of plastic waste with various other matrices. As a result, the problem of various forms of plastic waste within the marine ecosystem has emerged as a major concern in recent years. The current review is focused on the detrimental implications of various emerging and novel plastic variants, with an emphasis on coastal and marine environments. This review highlights the fate and transportation patterns of plastic waste, along with the contemporary examples of its implications on marine biota. Additionally, this work also examines the impacts of marine plastic waste on the environment. The review further highlights the importance of circular economy of plastic waste for sustainability. Then in the end, the growing anxieties about the impacts of plastic waste on coastal as well as marine environment, along with the strategies for reducing its impacts on ecological sustainability are discussed. This article is categorized under: Climate and Environment > Circular Economy [ABSTRACT FROM AUTHOR]

Hundreds of studies have surveyed plastic debris in surface ocean gyre and convergence zones, however, comprehensive microplastics (MPs, ≤5 mm) assessments beneath these surface accumulation areas are lacking. Using in situ high‐volume filtration, Manta net and MultiNet sampling, combined with micro‐Fourier‐transform‐infrared imaging, we discovered a high abundance (up to 244.3 pieces per cubic meter [n m−3]) of small microplastics (SMPs, characteristically <100 μm) from the surface to near‐sea floor waters of the remote South Atlantic Subtropical Gyre. Large horizontal and vertical variations in the abundances of SMP were observed, displaying inverse vertical trends in some cases. SMP abundances in pump samples were more than two orders of magnitude higher than large microplastics (LMPs, >300 μm) concurrently collected in MultiNet samples. Higher‐density polymers (e.g., alkyd resins and polyamide) comprised >65% of the total pump sample count, highlighting a discrepancy between polymer compositions from previous ocean surface‐based surveys, typically dominated by buoyant polymers such as polyethylene and polypropylene. Contrary to previous reports stating LMP preferentially accumulated at density gradients, SMP with presumably slower sinking rates are much less influenced by density gradients, thus resulting in a more even vertical distribution in the water column, and potentially longer residence times. Overall, our findings suggest that SMP is a critical and largely underexplored constituent of the oceanic plastic inventory. Additionally, our data support that weak current systems contribute to the formation of SMP hotspots at depth, implying a higher encounter rate for subsurface particle feeders. Our study unveils the prevalence of plastics in the entire water column, highlighting the urgency for more quantification of the deep‐ocean MP, particularly the smaller size fraction, to better understand ecosystem exposure and to predict MP fate and impacts. [ABSTRACT FROM AUTHOR]

Microplastic pollution has been reported from coral reef systems all over the tropics. Exposure to microplastics has several negative impacts on coral health, such as bleaching, tissue necrosis, or an impairment of the coral's immune system. Despite this potential risk for reef systems, the controlling processes for microplastics dispersion and accumulation in reef sediments are still largely under‐studied. Presented here is a study of microplastics (125 µm to 5 mm) distribution in two tropic atoll reef platforms in Kepulauan Seribu, Indonesia. Sediment samples were collected in different facies zones within the reef platform. Microplastics were concentrated using density floatation and characterized by light and scanning electron microscopy. Some particles were identified as polypropylene using micro‐Fourier transform infrared spectroscopy. All recovered microplastics were classified as secondary microplastics, likely derived from marine and local sources, with fibres as the most abundant type. Microplastics are showing similar transport and accumulation behaviour as fine siliciclastic grains. The abundance of microplastic is controlled by the proximity to the source area of larger plastic debris and hydrodynamic processes. Microplastics are not only present in low energy environments but also high energy settings such as the reef crest. Processes that contribute to accumulation in reef sediments are biofouling, interlocking and the creation of compound grains. Microplastics are present in sediment close to the seafloor (0 to 3.5 cm) but also at depths between 3.5 cm and 7.0 cm. Microplastic particles from below 3.5 cm are unlikely to be remobilized under modal weather conditions in the studied equatorial reefs. Subtidal reef sediment therefore can be regarded as a permanent sink for microplastics. The study shows that microplastics in coral reef environments deserve careful consideration since microplastics pose an additional threat to corals and their ability as framework builders in reef systems. [ABSTRACT FROM AUTHOR]

Plastic pollution has pervaded almost every facet of the biosphere, yet we lack an understanding of consumption risk by marine species at the global scale. To address this, we compile data from research documenting plastic debris ingestion by marine fish, totaling 171,774 individuals of 555 species. Overall, 386 marine fish species have ingested plastic debris including 210 species of commercial importance. However, 148 species studied had no records of plastic consumption, suggesting that while this evolutionary trap is widespread, it is not yet universal. Across all studies that accounted for microplastics, the incidence rate of plastic ingested by fish was 26%. Over the last decade this incidence has doubled, increasing by 2.4 ± 0.4% per year. This is driven both by increasing detection of smaller sized particles as a result of improved methodologies, as well as an increase in fish consuming plastic. Further, we investigated the role of geographic, ecological, and behavioral factors in the ingestion of plastic across species. These analyses revealed that the abundance of plastic in surface waters was positively correlated to plastic ingestion. Demersal species are more likely to ingest plastic in shallow waters; in contrast, pelagic species were most likely to consume plastic below the mixed layer. Mobile predatory species had the highest likelihood to ingest plastic; similarly, we found a positive relationship between trophic level and plastic ingestion. We also find evidence that surface ingestion‐deep sea egestion of microplastics by mesopelagic myctophids is likely a key mechanism for the export of microplastics from the surface ocean to the seafloor, a sink for marine debris. These results elucidate the role of ecology and biogeography underlying plastic ingestion by marine fish and point toward species and regions in urgent need of study. [ABSTRACT FROM AUTHOR]

Plastic pollution is widespread throughout the marine environment representing a risk for ecosystems and human health when plastic enters the food chain. Understanding factors and processes controlling plastic distribution and accumulation is crucial to identify plastic hotspots. Gateways and straits can play an important role on transferring plastic debris at superficial and sea bottom level depending on the local water masses stratification. [ABSTRACT FROM AUTHOR]

The success of plastic as a material has shaped the development of modern society and challenged older materials in many of their established uses. However, plastic is now a major component of litter and is extensively reported within the marine environment. Impacts from plastic debris have been identified as a major global conservation issue with implications for maritime industries, tourism, marine life, and human health. Although there are many benefits of plastic, it is clear that society's relationship and reliance on plastics needs to be addressed. Conversely, alternative materials to replace plastic items, or solutions mitigating plastic release, also need to be critiqued to make sure their properties and environmental impacts are more beneficial. This review examines the history and impact of plastics in the marine environment. Current solutions that aim to mitigate plastics accumulation in the environment and the future challenges of plastic as a material are also discussed. [ABSTRACT FROM AUTHOR]

As a consequence of the global ubiquity of plastic pollution, scientists, decision‐makers, and the public often ask whether macroplastics (>5 mm) and microplastics (<5 mm) have a realized ecological threat. In 2016, we conducted a systematic review of the literature and made a call for further research testing hypotheses about ecological effects. In the subsequent years, the amount of relevant research has risen tremendously. Here, we reassess the literature to determine the current weight of evidence about the effects of plastic pollution across all levels of biological organization. Our data spans marine, freshwater, and terrestrial environments. We extracted data from 139 lab and field studies testing 577 independent effects across a variety of taxa and with various types, sizes, and shapes of plastic. Overall, 59% of the tested effects were detected. Of these, 58% were due to microplastics and 42% were due to macroplastics. Of the effects that were not detected, 94% were from microplastics and 6% were from macroplastics. We found evidence that whether or not an effect is detected, as well as the severity and direction of the effect, is driven by dose, particle shape, polymer type, and particle size. Based on our analyses, there is no doubt that macroplastics are causing ecological effects, however, the effects of microplastics are much more complex. We also assessed the environmental relevancy of experimental studies by comparing the doses used in each exposure to the concentrations and sizes of microplastics found in the environment. We determined that only 17% of the concentrations used in experimental studies have been found in nature, and that 80% of particle sizes used in experiments fall below the size range of the majority of environmental sampling. Based on our systematic review and meta‐analysis, we make a call for future work that recognizes the complexity of microplastics and designs tests to better understand how different types, sizes, shapes, doses, and exposure durations affect wildlife. We also call for more ecologically and environmentally relevant studies, particularly in freshwater and terrestrial environments. [ABSTRACT FROM AUTHOR]

Microplastics are ubiquitous in marine systems; however, knowledge of the effects of these particles on marine fauna is limited. Ocean‐borne plastic debris accumulates in littoral ecosystems worldwide, and invertebrate infauna inhabiting these systems can ingest small plastic particles and fibers, mistaking them for food. We examined the effect of microplastic fibers on physiological and reproductive outcomes in a nearshore organism by exposing Pacific mole crabs (Emerita analoga) to environmentally relevant concentrations of microsized polypropylene rope fibers. We compared adult gravid female crab mortality, reproductive success, and embryonic developmental rates between microfiber‐exposed and control crabs. Pacific mole crabs exposed to polypropylene rope had increased adult crab mortality, and decreased retention of egg clutches, causing variability in embryonic development rates. These effects of microplastic ingestion on a nearshore prey species have implications for predators such as surf perf and shore birds, as plastic use, and resultant microplastic presence in nearshore environments increases. Microplastics are ubiquitous in marine and sandy beach environments, posing a significant threat to the marine organisms that reside therein. The most predominant classification of microplastics found have been microfibers. Although a number of biological effects of microplastics have been measured, with documented effects on growth, little research has examined how microplastic fibers affect reproductive output and subsequent development of offspring. We examined the effects of exposure to microfibers on adult mortality, reproductive output, and embryonic development of the filter feeding Pacific mole crab (E. analoga), a dominant infaunal organism on sandy beaches. We demonstrate the effects of microplastic ingestion on mole crab mortality and embryonic development, filling a gap in the current knowledge on the impact of microplastics. [ABSTRACT FROM AUTHOR]

Microorganisms drive the biogeochemical cycles that link abiotic and biotic processes in the aqueous environment and are intricately associated with plastic debris. The presence of microplastics in water and sediment introduces new concerns as small particle size allows for increased pathways of microplastics in the food web and element cycles. In this review, we present the current state of knowledge on microbe‐plastic interactions and summarize the potential impact of biogeochemical processes on plastic distribution, cycling, transport, and sedimentation. We explore how microbe‐plastic interactions influence the exposure of consumers to microplastics and plastic degradation products. Key methods used to elucidate biofilm development, microbial biodegradation, and microplastic detection in the aqueous environment are discussed. Finally, we comment on potential future questions and research directions needed to further define the role of microorganisms in the environmental fate of microplastics. [ABSTRACT FROM AUTHOR]

Detailing the distribution of past and future plastic debris in the marine environment has become a pressing challenge. Plastic pollution poses a potential threat to marine organisms and the marine environment as a whole. Previous studies using Lagrangian particle models have identified five garbage patches within subtropical ocean gyres, with the possibility of a sixth garbage patch within the Barents Sea. We present the first coarse resolution three‐dimensional plastic distribution model to use an Eulerian approach. It considers seven plastic components, three of them buoyant and four nonbuoyant, based upon real world plastic types. Our control results support the observations of positively buoyant plastic accumulations within the five garbage patches. However, there is no evidence of a sixth garbage patch in the Barents Sea. Meanwhile, our simulations reveal a previously unreported accumulation of plastic in the Gulf of Guinea. The negatively buoyant plastic tends to accumulate within the deepest regions of the sea floor, loosely following the bathymetry. In two further experiments, we introduce idealized plastic removal rates to simulate the proportion of plastics that are sequestered within sediments once they reach the sea floor. The results of the simulations show that substantial quantities of plastic debris are subject to vertical transport in the ocean and are therefore present throughout the water column as well as on the sea floor. A final experiment, focusing on neutrally buoyant plastics, shows the potentially ubiquitous presence of small microplastics and nanoplastics in the water column. Plain Language Summary: Detailing the distribution of past and future plastic debris in the ocean has become a pressing challenge. Plastic pollution poses a potential threat to marine organisms and the marine environment as a whole. The use of numerical modeling has identified five garbage patches, with the possibility of a sixth garbage patch in the Arctic. However, these models have focused on plastics that float on or near the sea surface and do not consider the plastics which sink or are drawn down once they enter the ocean. We present the first plastic distribution model, which includes both floating and sinking plastics and looks at the distribution of these plastics throughout the water column. Both types of plastics are present throughout the water column, with the floating plastics mainly collecting within the five previously identified garbage patches and the sinking plastics gathering within the deepest areas of the seafloor. Simulations including a crude mechanism by which plastics are removed into the seafloor "sediments," reveal wide‐spread areas of the seafloor, which may host large amounts of plastic debris. An experiment with neutrally buoyant plastic tracers that mimics the behavior of microplastics and nanoplastics shows these plastics to be present at all depths globally. Key Points: An Eulerian, three‐dimensional marine microplastic distribution modelA microplastic plastic distribution model including negatively buoyant plasticsMicroplastic debris is present throughout water column and on sea floor [ABSTRACT FROM AUTHOR]