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The issue of plastic pollution is recognised as a pervasive and ubiquitous problem which can pose a threat to ecosystems worldwide and potentially affect human health. In this perspective, we selected the latest research that identifies potential impacts beyond individual species to draw attention on wider biogeochemical cycles and the most fundamental biological processes we all depend on, namely, breathing, feeding and carrying offspring. We highlight the need for uniform research methods, giving examples of protocols and indicator species that should be evaluated by the research community for their potential wide adoption. We stress the need for systemic changes and our role as scientific community to demand changes proportionate to the severity and implications of our findings. We further explore the push and pull mechanisms between researchers and policymakers in relation to the global environmental challenges such as plastic pollution. Finally, we recommend a path of action inspired by the global action taken to address the ozone layer depletion by banning chlorofluorocarbons (CFC).

Despite the increase in the documentation on, and interest in marine debris, there remains a gap between the analytic information available and the recommendations developed by policy and decision makers that could reduce this pollutant. Our paper summarizes some successful initiatives across policy, industry, infrastructure and education; and where they sit in the value chain of plastic products. We suggest that a multidisciplinary approach is required to most effectively address the marine plastic litter problem. This approach should emphasize (1) minimizing plastic production and consumption (where possible), and waste leakage; by (2) improving waste management (taking into consideration the informal sector) rather than focussing on clean-up activities. We then suggest some steps that once addressed would assist policy professionals, and a wide variety of entities and individuals with decision-making to reduce marine plastic litter. We suggest the creation of a user-friendly framework (tool) would facilitate transparency and democratization of the decision-making process across stakeholders and the wider community. This tool would be most useful if it comprised information on (i) defining appropriate metrics for quantifying plastic waste for the study/work case; (ii) providing a list of possible interventions with their key associated enabling and disabling factors, (iii) identifying the main influential factors specific to the situation/region; (iv) recognizing the risks associated with the selected interventions and the consequences of these interventions on the most influential factors; (v) objectively ranking solutions using the information gathered (metrics, targets, risks, factors) based on the regional, national, and/or international context. This tool then provides an opportunity for user groups to explore different suites of options for tackling marine plastic pollution and co-create a suite that is optimum for them.

Simple Summary: Plastic pollution presents a growing concern for marine biodiversity, and among these, anthropogenic particles (APs) are entering marine ecosystems at an alarming rate from land and sea sources. In this study, we quantify the ingestion of APs across fish, sea urchins, sea cucumbers (echinoderms), bivalves (molluscs), and jellyfish (cnidarians), identify biotic and abiotic factors that might influence the ingested items; and identify ingestion patterns based on taxonomic groups, trophic guilds, and habitats. Ingestion of APs was observed in the majority of the species analyses with occurrence ranging from 0% to 100%. The study results indicate that plastic pollution poses a threat to species found within the marine protected area of the Cabrera Marine-Terrestrial National Park despite their protection status. The multispecies approach provided a better understanding of the high level of AP exposure to species, highlighting the associated damage to marine biodiversity related to marine waste. We have applied a multispecies ecosystem approach to analyse the ingestion of anthropogenic particles (AP) in the gastrointestinal tract of 313 individuals (17 fish species and 8 invertebrate species) from pelagic, demersal and benthic habitats in a marine protected area off the Western Mediterranean (Cabrera National Park). We have quantified and characterized the ingestion at several taxonomic levels of fish, sea urchins, sea cucumbers, bivalves, and jellyfish in relation to biotic/abiotic factors based on taxonomic groups, trophic guilds (functional groups) and habitats. AP ingestion occurrence ranged from 26 to 100% with no significant differences among taxonomic groups. The fish within the MPA showed an overall ingestion occurrence ranging from 0 to 100%, the echinoderms from 29 to 100%, the bivalves from 72 to 96% and the jellyfish 36% ingestion. The ecosystem approach applied to evaluate overall AP ingestion within the species reported that for trophic guilds, the omnivorous species ingested the highest amounts of anthropogenic items, while herbivores ingested significantly fewer items than all other trophic guilds. Moreover, no significant differences were found amongst habitats, indicating a homogeneous spatial distribution of APs at all studied habitats. The multispecies approach provided insight into the high APs exposure to species within Cabrera MPA, highlighting the potential harm linked with marine litter that threatens marine biodiversity. [ABSTRACT FROM AUTHOR]

The global accumulation of plastic waste has reached crisis levels. The diverse and multilayered impacts of plastic on biological health prompts an evaluation of these effects from a One Health perspective, through which the complexity of these processes can be integrated and more clearly understood. Plastic particles ranging from nanometers to meters in size are found throughout every ecosystem on Earth, from the deepest marine trenches to the highest mountains. Plastic waste affects all layers of biological organization, from the molecular and cellular to the organismal, community, and ecosystem-levels. These effects are not only mediated by the physical properties of plastics, but also by the chemical properties of the plastic polymers, the thousands of additives combined with plastics during manufacturing, and the sorbed chemicals and microbes that are transported by the plastic waste. Using a One Health framework we provide an overview of the following themes: 1) ways in which plastic impacts global health across levels of biological organization, 2) how the effects of plastic interact between layers of biology, and 3) what knowledge gaps exist in understanding the effects of plastic within and between biological scales. We also propose potential solutions to address this growing crisis, with an emphasis on One Health perspectives that consider the oneness of animals, humans, and the environment.

Governments worldwide are increasingly adopting public policies, laws, and ordinances to reduce plastic pollution. To date, studies have not analyzed the content of, and trends in, these policies. Employing a content analysis and literature search, we set out to better understand: (i) governments responses to this problem over time, and (ii) the state of the available evidence on the effectiveness of policy responses. Our motivations were to: (i) expand evidence-based policy-making to reduce plastic pollution by identifying and classifying the policy instruments used by governments; (ii) compile evidence regarding policy effectiveness; and (iii) provide a global database in the form of a Plastics Policy Inventory (https://nicholasinstitute.duke.edu/plastics-policy-inventory) to track government responses, as requested by the United Nations Environment Assembly in Resolution 4/6. Policies that fell within our scope aimed to reduce plastic pollution beyond business-as-usual solid waste management schema. This Inventory and study have an English-language bias. International and national policies are fairly representative of plastic pollution policies and the subnational (e.g., states, cities) policies are examples. International governments most frequently used plans and commitments for future action. National and subnational governments most frequently used bans. Ten policies targeted only microplastics and one policy targeted tire wear particles, lagging reported pollution. The peer-reviewed literature reported plastic bag consumption reductions between 27% and 100% after policy adoption. This work lays a foundation for future evidence-based policymaking to reduce plastic pollution and provides a useful tool to track policies, analyze existing policies from new angles, and target gaps in the global plastics policy landscape. • 291 plastic pollution policies were compiled in a free, open-access inventory. • National and subnational policies most frequently banned macroplastics and bags. • International policies most frequently featured plans for future action. • Plastic bag policies were most commonly studied for effectiveness. • Policies on every level infrequently targeted microplastics or tire wear particles. [ABSTRACT FROM AUTHOR]

Entrepreneurs working to tackle marine challenges are contributing to the Blue Economy by developing new technologies, services and products that can simultaneously stimulate economic growth and deliver environmental benefits. We study a subset of these blue entrepreneurs focused on marine plastic pollution mitigation, since little is known about the business models deployed and their associated drivers and barriers in this emerging industry. We utilize a multiple case study approach to analyze the business models of 96 startups working to manage marine plastic and identify four business model categories: 1) consumer targeted solutions, 2) government and business solutions, 3) companies focused on value chain development, and 4) startups that generate revenue to fund plastic waste recovery. These four BMs differ in how they create environmental benefits, as well as their economic value capture or revenue models. We then conducted 19 interviews with entrepreneurs (20% of the sample) and six experts to understand the conditions that support or hinder business model development. We find that entrepreneurial challenges and motivations associated with starting a new business are experienced by all companies, regardless of the business model chosen. Other relevant drivers include the availability of financing early on in business development, a supportive culture and positive and constructive market response. Challenges include competition from less sustainable businesses that may negatively influence the legitimacy of the industry, as well as slow government responses. Finally, we propose recommendations for policy makers to encourage blue entrepreneurship and for practitioners to prepare for identified barriers and predict avenues of support.

Large masses of pelagic Sargassum occur in the Atlantic Ocean between the latitudes 5°S and 38°N. Since 2011, inundations have happened in the Gulf of Mexico, the Caribbean, and West Africa, affecting biological communities and economies. A series of severe weather events in the Azores led to a Sargassum inundation between mid-December 2023 and early April 2024, here reported for the first time. Although the sea reclaimed most of the stranded algae, 555 metric tons were removed. Periodic inundations may represent an introduction pathway for non-native species since massive amounts of organisms are deposited alive on the coast. Besides the ecological impact, the inundations can be harmful to human health and impact the tourism sector. Further studies on the expected changes in the frequency and severity of storms in the region are necessary to evaluate the probability of new inundations. Measures to attenuate possible impacts should also be searched. [Display omitted] • Sargassum inundation is reported for the first time for the Azores Archipelago. • 555 metric tons of stranded macroalgae collected from mid-January to early-April 2024. • Sargassum morphotypes, associated fauna, and plastic debris are illustrated. • Pelagic Sargassum may represent an introduction pathway for non-native species. • Possible impacts on the environment, human health, and local economy are presented. [ABSTRACT FROM AUTHOR]

Purpose: Plastic pervades now almost every aspect of our daily lives, but this prosperity has led to an increasing amount of plastic debris, which is now widespread in the oceans and represents a serious threat to biota. However, there is a general lack of consideration regarding marine plastic impacts in life cycle assessment (LCA). This paper presents a preliminary approach to facilitate the characterization of chemical impacts related to marine plastic within the LCA framework. Methods: A literature review was carried out first to summarize the current state of research on the impact assessment of marine plastic. In recent years, efforts have been made to develop LCA-compliant indicators and models that address the impact of marine littering, entanglement, and ingestion. The toxicity of plastic additives to marine biota is currently a less understood impact pathway and also the focus of this study. Relevant ecotoxicity data were collected from scientific literature for a subsequent additive-specific effect factor (EF) development, which was conducted based on the USEtox approach. Extrapolation factors used for the data conversion were also extracted from reliable sources. Results and discussion: EFs were calculated for six commonly used additives to quantify their toxicity impacts on aquatic species. Triclosan shows an extremely high level of toxicity, while bisphenol A and bisphenol F are considered less toxic according to the results. Apart from additive-specific EFs, a generic EF was also generated, along with the species sensitivity distribution (SSD) illustrating the gathered data used to calculate this EF. Further ecotoxicity data are expected to expand the coverage of additives and species for deriving more robust EFs. In addition, a better understanding of the interactive effect between polymers and additives needs to be developed. Conclusions: This preliminary work provides a first step towards including the impact of plastic-associated chemicals in LCA. Although the toxicity of different additives to aquatic biota may vary significantly, it is recommended to consider additives within the impact assessment of marine plastic. The generic EF can be used, together with a future EF for adsorbed environmental pollutants, to fill a gap in the characterization of plastic-related impacts in LCA. [ABSTRACT FROM AUTHOR]

The increasing global concern surrounding plastic marine pollution has placed a spotlight on the key items identified as major contributors. The subsequent public outcry has forced key value-chain actors – such as brand owners, retailers and restaurateurs – to be seen to be responding to the issue. However, are their responses motivated by a true desire for environmentalism or are actors engaging in greenwashing? In this case study on plastic straws, the brand owners and retailers interviewed are driven by a desire to meet consumer expectations. This desire has led to the substitution of plastic straws with glass, paper and polylactide alternatives. However, the broader environmental implications of the alternatives are rarely considered. This single-minded focus on marine pollution has the potential to result in inadvertent greenwashing as alternative products may result in more harm in other environmental compartments. Significance: • The increasing concern surrounding plastic pollution has placed a spotlight on key items, forcing plastic value-chain actors to respond. • The broader environmental impacts of the interventions are rarely considered, resulting in the potential for adoption of products which may result in increased harm in other environmental compartments.

Although several new technologies have promoted the development of modern oceanography, human activities have caused many environmental problems, such as ocean pollution. In this paper, we focus on three topics of environmental DNA, BGC Argo, and bio-logging as the new methods contributing to the future development in oceanography. Accidentally released radionuclides have been a severe concern since the accident of the Fukushima Dai-ichi nuclear power plant in 2011. In addition, plastic debris has recently attracted considerable attention as an international issue. We thus focus on these two topics as a problem in the current ocean environments. [ABSTRACT FROM AUTHOR]

The increasing global concern surrounding plastic marine pollution has placed a spotlight on the key items identified as major contributors. The subsequent public outcry has forced key value-chain actors - such as brand owners, retailers and restaurateurs - to be seen to be responding to the issue. However, are their responses motivated by a true desire for environmentalism or are actors engaging in greenwashing? In this case study on plastic straws, the brand owners and retailers interviewed are driven by a desire to meet consumer expectations. This desire has led to the substitution of plastic straws with glass, paper and polylactide alternatives. However, the broader environmental implications of the alternatives are rarely considered. This single-minded focus on marine pollution has the potential to result in inadvertent greenwashing as alternative products may result in more harm in other environmental compartments. Significance: The increasing concern surrounding plastic pollution has placed a spotlight on key items, forcing plastic value-chain actors to respond. The broader environmental impacts of the interventions are rarely considered, resulting in the potential for adoption of products which may result in increased harm in other environmental compartments. [ABSTRACT FROM AUTHOR]

We have applied a multispecies ecosystem approach to analyse the ingestion of anthropogenic particles (AP) in the gastrointestinal tract of 313 individuals (17 fish species and 8 invertebrate species) from pelagic, demersal and benthic habitats in a marine protected area off the Western Mediterranean (Cabrera National Park). We have quantified and characterized the ingestion at several taxonomic levels of fish, sea urchins, sea cucumbers, bivalves, and jellyfish in relation to biotic/abiotic factors based on taxonomic groups, trophic guilds (functional groups) and habitats. AP ingestion occurrence ranged from 26 to 100% with no significant differences among taxonomic groups. The fish within the MPA showed an overall ingestion occurrence ranging from 0 to 100%, the echinoderms from 29 to 100%, the bivalves from 72 to 96% and the jellyfish 36% ingestion. The ecosystem approach applied to evaluate overall AP ingestion within the species reported that for trophic guilds, the omnivorous species ingested the highest amounts of anthropogenic items, while herbivores ingested significantly fewer items than all other trophic guilds. Moreover, no significant differences were found amongst habitats, indicating a homogeneous spatial distribution of APs at all studied habitats. The multispecies approach provided insight into the high APs exposure to species within Cabrera MPA, highlighting the potential harm linked with marine litter that threatens marine biodiversity.

As plastic waste accumulates in the ocean at alarming rates, the need for efficient and sustainable remediation solutions is urgent. One solution is the development and mobilization of technologies that either 1) prevent plastics from entering waterways or 2) collect marine and riverine plastic pollution. To date, however, few reports have focused on these technologies, and information on various technological developments is scattered. This leaves policymakers, innovators, and researchers without a central, comprehensive, and reliable source of information on the status of available technology to target this global problem. The goal of this study was to address this gap by creating a comprehensive inventory of technologies currently used or in development to prevent the leakage of plastic pollution or collect existing plastic pollution. Our Plastic Pollution Prevention and Collection Technology Inventory (https://nicholasinstitute.duke.edu/plastics-technology-inventory) can be used as a roadmap for researchers and governments to 1) facilitate comparisons between the scope of solutions and the breadth and severity of the plastic pollution problem and 2) assist in identifying strengths and weaknesses of current technological approaches. We created this inventory from a systematic search and review of resources that identified technologies. Technologies were organized by the type of technology and target plastics (i.e., macroplastics, microplastic, or both). We identified 52 technologies that fall into the two categories of prevention or collection of plastic pollution. Of these, 59% focus specifically on collecting macroplastic waste already in waterways. While these efforts to collect plastic pollution are laudable, their current capacity and widespread implementation are limited in comparison to their potential and the vast extent of the plastic pollution problem. Similarly, few technologies attempt to prevent plastic pollution leakage, and those that do are limited in scope. A comprehensive approach is needed that combines technology, policymaking, and advocacy to prevent further plastic pollution and the subsequent damage to aquatic ecosystems and human health.

The transport of plastic particles from inland sources to the oceans garbage patches occurs trough coastal regions where the transport processes depend highly on wave‐induced motions. In this study, experimental measurements of the plastic particles wave‐induced Lagrangian drift in intermediate water depth are presented investigating the influence of the wave conditions, particle size and density on the motion of relatively large plastic particles. A large influence of the particle density is observed causing particles to float or sink for relative densities lower and larger than water respectively. The measured net drift of the floating particles correlates well with theoretical solutions for particle Stokes drift, where the net drift is proportional to the square of the wave steepness. Floating particles remain at the free water surface because of buoyancy and no evidence of any other influence of particle inertia on the net drift is observed. Nonfloating particles move close to the bed with lower velocity magnitudes than the floating particles' motion at the free surface. The drift of nonfloating particles reduces with decreasing wave number, and therefore wave steepness. Plain Language Summary: Marine plastic pollution attracts significant attention from scientists and the general public. Most focus is on the floating plastic that accumulates in the centers of the ocean basin. However, for plastic originating from land to end up in these open‐ocean regions, it first needs to be transported through the coastal zone. Little is known how coastal waves transport plastic. Here, we use a 16 m‐long wave‐flume to measure how waves transport both floating and nonfloating plastic particles in the laboratory. The floating particles move with the waves as predicted by the so‐called Stokes drift, while nonfloating particles feel the effect of the bottom shear. These results improve our understanding of how plastics move from the coast to the open ocean and vice versa, thereby supporting improvements in our modeling capacity of the transport of marine plastic litter. Key Points: A 16 m wave flume is used to measure wave transport of floating and non‐floating plasticFloating plastic transport correlates well with Stokes drift and buoyancy is the only non‐inertial effectNon‐floating particles experience shear forces. Transport varies with particle size and density [ABSTRACT FROM AUTHOR]

Plastic marine debris (PMD) affects spatial scales of life from microbes to whales. However, understanding interactions between plastic and microbes in the "Plastisphere"—the thin layer of life on the surface of PMD—has been technology‐limited. Research into microbe–microbe and microbe–substrate interactions requires knowledge of community phylogenetic composition but also tools to visualize spatial distributions of intact microbial biofilm communities. We developed a CLASI‐FISH (combinatorial labelling and spectral imaging – fluorescence in situ hybridization) method using confocal microscopy to study Plastisphere communities. We created a probe set consisting of three existing phylogenetic probes (targeting all Bacteria, Alpha‐, and Gammaproteobacteria) and four newly designed probes (targeting Bacteroidetes, Vibrionaceae, Rhodobacteraceae and Alteromonadaceae) labelled with a total of seven fluorophores and validated this probe set using pure cultures. Our nested probe set strategy increases confidence in taxonomic identification because targets are confirmed with two or more probes, reducing false positives. We simultaneously identified and visualized these taxa and their spatial distribution within the microbial biofilms on polyethylene samples in colonization time series experiments in coastal environments from three different biogeographical regions. Comparing the relative abundance of 16S rRNA gene amplicon sequencing data with cell‐count abundance data retrieved from the microscope images of the same samples showed a good agreement in bacterial composition. Microbial communities were heterogeneous, with direct spatial relationships between bacteria, cyanobacteria and eukaryotes such as diatoms but also micro‐metazoa. Our research provides a valuable resource to investigate biofilm development, succession and associations between specific microscopic taxa at micrometre scales. [ABSTRACT FROM AUTHOR]

Floating plastic debris is an increasing source of pollution in the world's oceans. Numerical simulations using models of ocean currents give insight into the transport and distribution of microplastics in the oceans, but most simulations do not account for the oscillating flow caused by global barotropic tides. Here, we investigate the influence of barotropic tidal currents on the transport and accumulation of floating microplastics, by numerically simulating the advection of virtual plastic particles released all over the world's oceans and tracking these for 13 years. We use geostrophic and surface Ekman currents from GlobCurrent and the currents caused by the four main tidal constituents (M 2, S 2, K 1, and O 1) from the FES model. We analyze the differences between the simulations with and without the barotropic tidal currents included, focusing on the open ocean. In each of the simulations, we see that microplastic accumulates in regions in the subtropical gyres, which is in agreement with observations. The formation and location of these accumulation regions remain unaffected by the barotropic tidal currents. However, there are a number of coastal regions where we see differences when the barotropic tidal currents are included. Due to uncertainties of the model in coastal regions, further investigation is required in order to draw conclusions in these areas. Our results suggest that, in the global open ocean, barotropic tidal currents have little impact on the transport and accumulation of floating microplastic and can thus be neglected in simulations aimed at studying microplastic transport in the open ocean. Plain Language Summary: Pollution of the world's oceans by plastic waste is a problem of increasing concern. Most of the floating plastic accumulates in regions often referred to as "garbage patches." In order to fully assess the problem and find solutions, it is important to have a good understanding of the processes influencing the transport and fate of plastic in the ocean. As it is hard to study floating plastic observationally, especially for so‐called microplastics (less than 5 mm in size), a widely used method to study marine plastic waste is through computer simulations. A group of ocean currents that are often not included in these models are currents caused by the tides. Here, we create a computer model for transport of microplastic particles by these tidal currents. By comparing the transport of microplastic with and without the tides, we can find out what their influence is. We focus on the open ocean (away from coasts). We find that the garbage patch regions are not affected by the tides. This can be considered good news for the scientific community using computer simulations to study microplastic in the open ocean, because it means that they do not have to take the tides into account. Key Points: Barotropic tidal currents have little impact on transport and accumulation of floating microplastic in the global open oceanSimulations of plastic dispersion in the open ocean do not need to take barotropic tides into accountA computationally efficient implementation for advecting virtual particles by tidal currents is provided [ABSTRACT FROM AUTHOR]

Pacific island countries are facing critical challenges in managing the growing amount of increasingly diverse wastes because of changing lifestyles and the concentration of populations in urban areas. Although marine plastic waste is an issue in the Pacific region, there have been almost no studies of the estimation and impacts of ocean plastic waste, and measures to control such waste, in these countries. Here, first we conducted a questionnaire survey about consumption and disposal of plastic products at households in Samoa as one of the examples of Pacific island countries to grasp the flow of plastic materials and awareness or behaviour for plastic waste. Then we quantified ocean plastic waste and discussed the effective and needed countermeasures in Pacific island countries. The total amount of mismanaged plastic waste was estimated to be 327,000 or 156,000 t y−1 (depending on the scenario) in Pacific island countries. The regional Pacific island countries contribution to the global total mismanaged plastic waste was estimated to range from 1.3% to 2.7%. The amount of mismanaged plastic waste per capita in some Pacific island countries, such as Solomon Islands and Micronesia, was also ranked highly globally. The main reasons seem to be that waste collection rates are relatively low in rural areas and rates of plastic waste generation are high. To implement solutions, including improving municipal solid waste collection, reducing plastic waste, improving the collection and recycling of plastics, and the integration of a number of policies is essential. [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]

Abstract The presence of marine litter is a complex, yet persistent, threat to the health and biodiversity of the marine environment, and plastic is the most abundant, and ubiquitous type of marine litter. To monitor the level of plastic waste in an area, and the prospect of it entering the food chain, bioindicator species are used extensively throughout Northern European Seas, however due to their distribution ranges many are not applicable to the Mediterranean Sea. Guidance published for the Marine Strategy Framework Directive suggests that the contents of fish stomachs may be analyzed to determine trends of marine plastic ingestion. In order to equate transnational trends in marine plastic ingestion, the use of standardized fish species that widely occur throughout the basin is favoured, however for the Mediterranean Sea, specific species are not listed. Here we propose a methodology to assess how effective Mediterranean fish species, that are known to have ingested marine plastic, are as bioindicators. A new Bioindicator Index (BI) was established by incorporating several parameters considered important for bioindicators. These parameters included species distribution throughout the Mediterranean basin, several life history traits, the commercial value of each species, and the occurrence of marine litter in their gut contents. By collecting existing data for Mediterranean fish, ranked scores were assigned to each trait and an average value (BI value) was calculated for each species. Based on their habitat preferences, Engraulis encrasicolus (pelagic), Boops boops (benthopelagic), three species of Myctophidae (Hygophum benoiti , Myctophum punctatum and Electrona risso) (mesopelagic), Mullus barbatus barbartus (demersal) and Chelidonichthys lucerna (benthic), were identified as currently, the most suitable fish for monitoring the ingestion of marine plastics throughout the Mediterranean basin. The use of standardized indicator species will ensure coherence in the reporting of marine litter ingestion trends throughout the Mediterranean Sea. Graphical abstract Image 1 Highlights • An index describes suitable marine plastic fish bioindicators in the Mediterranean. • European anchovy is well suited to monitor plastic trends in pelagic environments. • Boops boops appears the most adept plastic bioindicator for benthopelagic habitats. • For marine demersal habitats, Mullus barbatus barbatus is a suitable bioindicator. • The work contributes to standardization of Mediterranean monitoring protocols. Using a novel index, seven species of fish were identified as the most suitable to monitor marine plastic ingestion trends in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Despite concerns regarding the environmental impacts of microplastics, knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we utilize an optimized enzymatic digestion methodology, previously developed for zooplankton, to explore whether synthetic particles could be isolated from marine turtle ingesta. We report the presence of synthetic particles in every turtle subjected to investigation (n = 102) which included individuals from all seven species of marine turtle, sampled from three ocean basins (Atlantic [ATL]: n = 30, four species; Mediterranean (MED): n = 56, two species; Pacific (PAC): n = 16, five species). Most particles (n = 811) were fibres (ATL: 77.1% MED: 85.3% PAC: 64.8%) with blue and black being the dominant colours. In lesser quantities were fragments (ATL: 22.9%: MED: 14.7% PAC: 20.2%) and microbeads (4.8%; PAC only; to our knowledge the first isolation of microbeads from marine megavertebrates). Fourier transform infrared spectroscopy (FT‐IR) of a subsample of particles (n = 169) showed a range of synthetic materials such as elastomers (MED: 61.2%; PAC: 3.4%), thermoplastics (ATL: 36.8%: MED: 20.7% PAC: 27.7%) and synthetic regenerated cellulosic fibres (SRCF; ATL: 63.2%: MED: 5.8% PAC: 68.9%). Synthetic particles being isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. These include exposure from polluted seawater and sediments and/or additional trophic transfer from contaminated prey/forage items. We assess the likelihood that microplastic ingestion presents a significant conservation problem at current levels compared to other anthropogenic threats. Knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we explore whether synthetic particles could be isolated from marine turtle ingesta and report the presence in every turtle subjected to investigation including individuals from all the seven species of marine turtle, sampled from three ocean basins. Most particles were fibres in lesser quantities were fragments/microbeads and were a range of synthetic materials. Synthetic particles isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. We assess the likelihood this presents a significant conservation problem at current levels. [ABSTRACT FROM AUTHOR]

• DNA sequencing of marine organisms can be applied in marine plastic identification. • Light and humid rather than salts degraded marine PET most. • Salts penetrate into marine PET and cannot be totally removed by cleaning. The aging degradation behaviors of the most common PET plastics in the marine environment were investigated in different conditions, with the combination of "real-world sample/outdoor simulation/aging box accelerated simulation". By obtaining data on the morphology, biological and microbial distribution, mechanical properties, viscosity, color difference, thermal properties, and chemical composition of marine plastics after aging, the influence of typical environmental factors such as light, temperature, high pressure, salinity, moisture, and marine life on the aging degradation behavior of PET plastics were discussed. Among them, light, high pressure heat and humid environment have the most significant effects on degradation, while the high-salt environment has less effect on degradation. In addition, the Pressure Cooker Test (PCT) results showed that the ordinary cleaning process is not enough to remove the inorganic substances that penetrated into the interior of marine plastics, which will have a negative impact on the performance of marine plastics. Therefore, it is necessary to select appropriate recycling methods and processes. This study provides a new idea for the study of the aging degradation behavior of marine plastics, which is important for analyzing the environmental factors affecting the degradation behavior of marine plastics in the marine environment. [ABSTRACT FROM AUTHOR]

• The complex refractive indices of nine common marine plastics in the ultraviolet to infrared spectral ranges were measured. • The plastics with partially identical monomers are compared to analyze how the monomers can change the refractive index. • The refractive indices in the weak absorption wavebands were fitted using Cauchy's dispersion formula. Plastic litter is a pervasive issue in the ocean, posing threats to both marine ecosystems and human health. In the field of marine remote sensing detection, one common method for detecting and identifying marine plastics is by analyzing their optical characteristics, specifically their spectral remote sensing reflectance. This reflectance is dependent on the complex refractive index of plastics. Therefore, understanding the complex refractive index, which is an intrinsic optical property of plastics, holds significant importance in marine plastics research. In this study, we utilized spectroscopic ellipsometry to measure the complex refractive index of 9 common ploymers including polymethyl methacrylate (PMMA), methyl methacrylate–styrene copolymer (MS), polyethylene (PE), poly (ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), polybutylene terephthalate (PBT), polyoxymethylene (POM), perfluoroalkoxy (PFA), acrylonitrile butadiene styrene (ABS), and styrene-acrylonitrile copolymer (SAN). In addition, we have expanded the complex range of refractive index measurements to include UV and MIR bands with wavelengths up to 32 μm. To ensure the reliability and accuracy of the measurements, experimental results for polycarbonate (PC) were compared with data from the existing literature. The variation of refractive index with wavelength is studied and the causes of absorption peaks in the infrared range are discussed. Furthermore, Considering the dispersion relationship and monomer composition of PMMA, MS, ABS and SAN plastics, a comparative analysis of plastics with commonly used monomers is conducted, and the influence of monomers on refractive index is discussed. Our study indicates that the presence of styrene monomers leads to an increase in the refractive index of plastics in the visible to near-infrared band, while the presence of butadiene monomers results in a decrease.The findings from this study provide fundamental data for future research on marine plastic remote sensing detection applications. [ABSTRACT FROM AUTHOR]

Rivers are key pathways for transporting microplastics from land to the oceans, yet microplastic flux estimates remain uncertain. Remote sensing allows repeated broad-scale measurements and can be used to extrapolate limited in situ observations. This study investigated the relationship between suspended particulate matter (SPM), a satellite-observable water quality parameter, and microplastic concentration in a partially mixed estuary (Tamar, UK). Microplastic concentrations ranged from 0.04 to 0.99 microplastics/m3, decreasing downstream. A significant correlation was found between SPM and microplastic concentration over two seasons. This relationship was used to compute a multiyear timeseries of proxy microplastic concentration from satellite imagery and produce estimates of annual proxy microplastic flux. This approach could be applied to investigate microplastic flux in other major rivers worldwide where such a relationship between microplastics and SPM exists. To apply this workflow elsewhere, the establishment of local SPM-to-microplastic relationships from in situ observations and local validation of remote sensing SPM algorithms are essential. • Microplastics (>200 μm) and suspended particulate matter (SPM) were sampled in a UK estuary. • Microplastic concentrations were relatively low and decreased downstream. • A significant correlation between SPM and microplastic concentration was found. • Annual microplastic flux was estimated from satellite SPM using this relationship. [ABSTRACT FROM AUTHOR]

Abstract The exponential increase in the use of plastic in modern society and the inadequate management of the resulting waste have led to its accumulation in the marine environment. There is increasing evidence of numerous mechanisms by which marine plastic pollution is causing effects across successive levels of biological organization. This will unavoidably impact ecological communities and ecosystem functions. A remaining question to be answered is if the concentration of plastic in the ocean, today or in the future, will reach levels above a critical threshold leading to global effects in vital Earth-system processes, thus granting the consideration of marine plastic pollution as a key component of the planetary boundary threat associated with chemical pollutants. Possible answers to this question are explored by reviewing and evaluating existing knowledge of the effects of plastic pollution in marine ecosystems and the ‘core planetary boundaries’, biosphere integrity and climate change. The irreversibility and global ubiquity of marine plastic pollution mean that two essential conditions for a planetary boundary threat are already met. The Earth system consequences of plastic pollution are still uncertain, but pathways and mechanisms for thresholds and global systemic change are identified. Irrespective of the recognition of plastic as a novel entity in the planetary boundaries framework, it is certain that marine plastic pollution is closely intertwined with global processes to a point that deserves careful management and prevention. Highlights • Marine plastic pollution shows ecological, biogeochemical and physical thresholds. • Mounting evidence shows that MPP meets planetary boundary threat conditions. • Knowledge gaps prevent us from proposing a boundary control variable. • Precautionary policy should take planet-scale Earth system dynamics into account. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are becoming widely recognized as one of many global environmental issues. Although recently, it has been suggested that marine plastics may affect a ship's operation, the presence of MPs in a ship's cooling system has not received significant attention. In this study, samples of 40 L each were taken from each of the five main pipes (sea chest (SC), ejector pump (EP), main engine jacket freshwater pump (MJFP), main engine jacket freshwater cooler (MJFC), and expansion tank (ET)) in each season (February, May, July, October 2021) to identify and characterize MPs in the five main pipes of the ship cooling system from the training ship Hanbada, Korea Maritime and Ocean University. As a result of FTIR analysis, the total MP abundance was 24,100 particles/m3 in the cooling system of the ship. MP concentrations were observed to be higher (p < 0.05) in winter and spring (dry season: 1578 ± 604 particles/m3) than in summer and autumn (wet season: 990 ± 390 particles/m3). In addition, the MP concentration in the seawater cooling system (SCS) (1509 ± 553 particle/m3) was slightly higher (p > 0.05) than that in the freshwater cooling system (FCS) (1093 ± 546 particles/m3). Compared to previous studies, it was confirmed that the quantitative amount of MPs on board was similar to or slightly less than the concentration of MPs investigated along the coast of Korea (1736 particles/m3). To identify the chemical composition of MPs, an optical microscope and FTIR analysis was carried out, and PE (polyethylene), PP (polypropylene), and PET (polyethylene terephthalate) were identified as major chemicals in all samples. MPs in the form of fibers and fragments accounted for approximately 95% of the total. This study provided evidence of MP contamination in the main pipe in the cooling system of the ship. These findings confirm that marine MPs existing in seawater may have flowed into the ship's cooling system, and it is necessary to understand the effect of marine MPs on the ship's engine and cooling system through continuous monitoring. • Microplastic abundance and distribution in an engine cooling system of a ship was firstly investigated. • Quantification and polymer identification of microplastics via MicroFTIR • 475–2300 particles/m3 of microplastics were detected for each ship engine cooling system sample. • PE (polyethylene), PP (polypropylene), and PET (polyethylene terephthalate) were identified as major polymer types of microplastics. • Fibers and fragments were the most abundant in all of ship engine cooling samples. [ABSTRACT FROM AUTHOR]

Plastic debris has become an abundant pollutant in marine, coastal and riverine environments, posing a large threat to aquatic life. Effective measures to mitigate and prevent marine plastic pollution require a thorough understanding of its origin and eventual fate. Several models have estimated that land-based sources are the main source of marine plastic pollution, although field data to substantiate these estimates remain limited. Current methodologies to measure riverine plastic transport require the availability of infrastructure and accessible riverbanks, but, to obtain measurements on a higher spatial and temporal scale, new monitoring methods are required. This paper presents a new methodology for quantifying riverine plastic debris using Unmanned Aerial Vehicles (UAVs), including a first application on Klang River, Malaysia. Additional plastic measurements were done in parallel with the UAV-based approach to make comparisons between the two methods. The spatiotemporal distribution of the plastics obtained with both methods show similar patterns and variations. With this, we show that UAV-based monitoring methods are a promising alternative for currently available approaches for monitoring riverine plastic transport, especially in remote and inaccessible areas.

The leakage of large plastic litter (macroplastics) into the ocean is a major environmental problem. A significant fraction of this leakage originates from coastal cities, particularly during extreme rainfall events. As coastal cities continue to grow, finding ways to reduce this macroplastic leakage is extremely pertinent. Here, we explore why and how coastal cities can reduce macroplastic leakages during extreme rainfall events. Using nine global cities as a basis, we establish that while cities actively create policies that reduce plastic leakages, more needs to be done. Nonetheless, these policies are economically, socially and environmentally cobeneficial to the city environment. While the lack of political engagement and economic concerns limit these policies, lacking social motivation and engagement is the largest limitation towards implementing policy. We recommend cities to incentivize citizen and municipal engagement with responsible usage of plastics, cleaning the environment and preparing for future extreme rainfall events. [ABSTRACT FROM AUTHOR]

Microplastic pollutants occur in marine environments globally, however estimates of seafloor concentrations are rare. Here we apply a novel method to quantify size-graded (0.038–4.0 mm diam.) concentrations of plastics in marine sediments from 42 coastal and estuarine sites spanning pollution gradients across south-eastern Australia. Acid digestion/density separation revealed 9552 individual microplastics from 2.84 l of sediment across all samples; equating to a regional average of 3.4 microplastics·ml − 1 sediment. Microplastics occurred as filaments (84% of total) and particle forms (16% of total). Positive correlations between microplastic filaments and wave exposure, and microplastic particles with finer sediments, indicate hydrological/sediment-matrix properties are important for deposition/retention. Contrary to expectations, positive relationships were not evident between microplastics and other pollutants (heavy metals/sewage), nor were negative relationships with neighbouring reef biota detected. Rather, microplastics were ubiquitous across sampling sites. Positive associations with some faunal-elements (i.e. invertebrate species richness) nevertheless suggest high potential for microplastic ingestion. [ABSTRACT FROM AUTHOR]

Marine plastic floating on the sea surface is an extensive environmental problem. The present study investigated the transport patterns of marine litter and areas of its accumulation in the Baltic Sea by using a hydrodynamic model coupled with a particle-tracking model. We also studied the extent of marine litter from the main polluting rivers. Mapping of marine plastic debris distribution in 2017–2018 revealed that the largest plastic accumulation area is between latitude 59° N and 61° N, which includes the Northern Baltic Proper, Archipelago Sea, and the Gulf of Finland. The floating plastic spreads from the largest plastic pollution sites River Vistula, Oder and Neman to the waters of all the countries around the Baltic Sea. • Hydrodynamic and particle-tracking coupled model revealed the transport pattern of plastic • Homogeneous and quasi-realistic simulations showed the same plastic accumulation areas. • The largest plastic accumulation area lies between the latitudes 59° N and 61° N. • Plastic particles migrated over the Baltic Sea from the biggest sources of pollution, the Vistula, Oder, and Neman rivers. [ABSTRACT FROM AUTHOR]

Plastics, foams and ropes collected from beaches in SW England have been analysed for As, Ba, Br, Cd, Cl, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn and Zn by field-portable-x-ray fluorescence spectrometry. High concentrations of Cl in foams that were not PVC-based were attributed to the presence of chlorinated flame retardants. Likewise, high concentrations of Br among both foams and plastics were attributed to the presence of brominated flame retardants. Regarding heavy metals and metalloids, Cd and Pb were of greatest concern from an environmental perspective. Lead was encountered in plastics, foams and ropes and up to concentrations of 17,500 μg g − 1 due to its historical use in stabilisers, colourants and catalysts in the plastics industry. Detectable Cd was restricted to plastics, where its concentration often exceeded 1000 μg g − 1 ; its occurrence is attributed to the use of both Cd-based stabilisers and colourants in a variety of products. [ABSTRACT FROM AUTHOR]

Captain Charles Moore introduced the world to the 'Great Pacific Garbage Patch' in the mid-1990s, and images of plastic debris in the oceans began to sweep the media. Since then, there has been increasing interest from scientists, the public, and policy makers regarding plastic debris in the environment. Today, there remains no doubt that plastic debris contaminates aquatic (marine and freshwater) habitats and animals globally. The growing scientific evidence demonstrates widespread contamination from plastic debris, and researchers are beginning to understand the sources, fate, and effects of the material. As new scientific understanding breeds new questions, scientists are working to fill data gaps regarding the fate and effects of plastic debris and the mechanisms that drive these processes. In parallel, policy makers are working to mitigate this contamination. The authors focus on what is known about plastic debris that is relevant to policy by reviewing some of the weight of evidence regarding contamination, fate, and effects of the material. Moreover, they highlight some examples of how science has already been used to inform policy change and mitigation and discuss opportunities for future linkages between science and policy to continue the relationship and contribute to effective solutions for plastic debris. Environ Toxicol Chem 2016;35:1617-1626. © 2016 SETAC [ABSTRACT FROM AUTHOR]

A state-of-the-science review was conducted to examine the potential for microplastics to sorb hydrophobic organic chemicals (HOCs) from the marine environment, for aquatic organisms to take up these HOCs from the microplastics, and for this exposure to result in adverse effects to ecological and human health. Despite concentrations of HOCs associated with microplastics that can be orders of magnitude greater than surrounding seawater, the relative importance of microplastics as a route of exposure is difficult to quantify because aquatic organisms are typically exposed to HOCs from various compartments, including water, sediment, and food. Results of laboratory experiments and modeling studies indicate that HOCs can partition from microplastics to organisms or from organisms to microplastics, depending on experimental conditions. Very little information is available to evaluate ecological or human health effects from this exposure. Most of the available studies measured biomarkers that are more indicative of exposure than effects, and no studies showed effects to ecologically relevant endpoints. Therefore, evidence is weak to support the occurrence of ecologically significant adverse effects on aquatic life as a result of exposure to HOCs sorbed to microplastics or to wildlife populations and humans from secondary exposure via the food chain. More data are needed to fully understand the relative importance of exposure to HOCs from microplastics compared with other exposure pathways. Environ Toxicol Chem 2016;35:1667-1676. © 2016 SETAC [ABSTRACT FROM AUTHOR]

As part of the degradation process, it is believed that most plastic debris becomes brittle over time, fragmenting into progressively smaller particles. The smallest of these particles, known as microplastics, have been receiving increased attention because of the hazards they present to wildlife. To understand the process of plastic degradation in an intertidal salt marsh habitat, strips (15.2 cm × 2.5 cm) of high-density polyethylene, polypropylene, and extruded polystyrene were field-deployed in June 2014 and monitored for biological succession, weight, surface area, ultraviolet (UV) transmittance, and fragmentation. Subsets of strips were collected after 4 wk, 8 wk, 16 wk, and 32 wk. After 4 wk, biofilm had developed on all 3 polymers with evidence of grazing periwinkles ( Littoraria irrorata). The accreting biofilm resulted in an increased weight of the polypropylene and polystyrene strips at 32 wk by 33.5% and 167.0%, respectively, with a concomitant decrease in UV transmittance by approximately 99%. Beginning at 8 wk, microplastic fragments and fibers were produced from strips of all 3 polymers, and scanning electron microscopy revealed surface erosion of the strips characterized by extensive cracking and pitting. The results suggest that the degradation of plastic debris proceeds relatively quickly in salt marshes and that surface delamination is the primary mechanism by which microplastic particles are produced in the early stages of degradation. Environ Toxicol Chem 2016;35:1632-1640. © 2016 SETAC [ABSTRACT FROM AUTHOR]

Marine plastic has received significant attention as a spectacle of consumer waste and ecosystemic fragility, but there has been little discussion of its ethical implications. This essay argues that marine plastic poses a direct challenge to the basic frameworks of global ethics. These frameworks are dominated by the image of the ‘circle’, an abstract boundary intended to separate ‘humanity’ from the rest of the universe and insulate it against harm. However, this article argues that marine plastic undermines the ‘circle’ in two ways. First, it embodies conditions of ‘hyper-relationality’, including entanglement and the properties of toxicity, that penetrate the boundaries of ‘the circle’. Second, it exerts ‘forcefulness’, but at scales that radically exceed the dominant spatio-temporal dimensions of ‘the circle’. By virtue of these features, marine plastic thoroughly penetrates the boundaries of ‘the circle’, making it impossible to expel harm beyond its boundaries. Although this essay focuses on marine plastic, its core argument can also be fruitfully applied to other phenomena that share similar material, scalar, spatio-temporal and relational features (for instance, atmospheric particulate, nuclear waste and nitrate pollution). The essay concludes by exploring the alternative ethical possibilities that marine plastic and similar phenomena prompt: in particular, a responsive ethos based on a sense of shared vulnerability and exposure. [ABSTRACT FROM AUTHOR]