Amount Of Plastic Debris Research Articles

A Combination of Machine Learning Algorithms for Marine Plastic Litter Detection Exploiting Hyperspectral PRISMA Data

A significant amount of the produced solid waste reaching the oceans is made of plastics. The amount of plastic debris in the ocean and coastal areas is steadily increasing and is now a major global environmental issue. The monitoring of marine plastic litter, ground-based monitoring systems and/or field campaigns are time-consuming, expensive, require great organisational efforts, and provide very limited information in terms of the spatial and temporal dynamics of marine debris. Earth Observation (EO) by satellite can contribute significantly to marine plastic litter detection. In 2019, a new hyperspectral satellite, called PRISMA, was launched by the Italian Space Agency. The high spectral resolution of PRISMA may allow for better detection of floating plastic materials. At the same time, Machine Learning (ML) algorithms have the potential to find hidden patterns and identify complex relations among data and are increasingly employed in EO. This paper presents the development of a new method of identifying floating plastic objects in coastal areas by exploiting pan-sharpened hyperspectral PRISMA data, based on the combination of unsupervised and supervised ML algorithms. The study consisted of a configuration phase, during which the algorithms were trained in a fully controlled test, and a validation phase, in which the pre-trained algorithms were applied to satellite data collected at different sites and in different periods of the year. Despite the limited input data, results suggest that the tested ML approach, applied to pan-sharpened PRISMA data, can effectively recognise floating objects and plastic targets. The study indicates that increasing input datasets can help achieve higher-quality results.

An effect factor approach for quantifying the impact of plastic additives on aquatic biota in life cycle assessment

PurposePlastic 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.MethodsA 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 discussionEFs 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.ConclusionsThis 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.

First evidence of plastic fallout from the North Pacific Garbage Patch

The infamous garbage patches on the surface of subtropical oceanic gyres are proof that plastic is polluting the ocean on an unprecedented scale. The fate of floating plastic debris ‘trapped’ in these gyres, however, remains largely unknown. Here, we provide the first evidence for the vertical transfer of plastic debris from the North Pacific Garbage Patch (NPGP) into the underlying deep sea. The numerical and mass concentrations of plastic fragments (500 µm to 5 cm in size) suspended in the water column below the NPGP follow a power law decline with water depth, reaching values <0.001 pieces/m3 and <0.1 µg/m3 in the deep sea. The plastic particles in the NPGP water column are mostly in the size range of particles that are apparently missing from the ocean surface and the polymer composition of plastic in the NPGP water column is similar to that of floating debris circulating in its surface waters (i.e. dominated by polyethylene and polypropylene). Our results further reveal a positive correlation between the amount of plastic debris at the sea surface and the depth-integrated concentrations of plastic fragments in the water column. We therefore conclude that the presence of plastics in the water column below the NPGP is the result of ‘fallout’ of small plastic fragments from its surface waters.

Microplastic ingestion: Are seabirds more affected than other marine species?

In recent times, plastic production has increased due to the convenience and multipurpose use. As plastic may make lifeeasier on humans, the amount of plastic debris has increased as well as the effect on marine life. Since it is a relatively new topic,the effects on marine species are trying to be modeled in laboratories and observed in the field. The effects of plastic marine debrisinclude but are not limited to entanglement, ingestion, possible bioaccumulation, chemical exposures, and even death. Larger plasticscan become smaller particles, microplastics, which are difficult to study the effects on marine life due to the small size. Microplasticsare a global issue that effect species. Some of the factors that are considered of why different organisms ingest plastics include:method of feeding, color, age, and accidental/secondary ingestion. The focus of this research article is the ingestion of averagepercentage of microplastics of seabird species compared to other marine species throughout the world.

Spatial and temporal variation of macro-, meso- and microplastic abundance on a remote coral island of the Maldives, Indian Ocean

Plastic debris is ubiquitous in the marine environment and the world's shores represent a major sink. However, knowledge about plastic abundance in remote areas is scarce. Therefore, plastic abundance was investigated on a small island of the Maldives. Plastic debris (>1mm) was sampled once in natural long-term accumulation zones at the north shore and at the high tide drift line of the south shore on seven consecutive days to quantify daily plastic accumulation. Reliable identification of plastic debris was ensured by FTIR spectroscopy. Despite the remoteness of the island a considerable amount of plastic debris was present. At both sites a high variability in plastic abundance on a spatial and temporal scale was observed, which may be best explained by environmental factors. In addition, our results show that snapshot sampling may deliver biased results and indicate that future monitoring programs should consider spatial and temporal variation of plastic deposition.

Characterization of small plastic debris on tourism beaches around the South China Sea

Small plastic debris (1–20 mm) pollution levels are investigated for the first time in China. Small plastics from six tourism beaches around the South China Sea, which were divided into two groups to examine the influence of riverine inputs, were quantified and sorted into several categories. Representative plastics were identified using Raman spectroscopy. Vast amounts of plastic remain in beaches after beach cleaning. Spatial discrepancies in the amounts of plastics were observed, with the greatest quantity observed at Zhuhai and Weizhou Island. Small plastics accounted for 63.4% of plastic debris quantified by number. Larger plastics (>20mm) made up 74.7% of the total plastic weight. An exponential damping relationship between the size and amount of plastic debris was determined, although it is only of borderline significance (α=0.05). Plastic shapes were heterogeneous among the beaches. Polypropylene (59.7%) and polyethylene (31.9%) were the most common polymer compositions in the selected samples. Coloured and white plastics were more prevalent than black and transparent ones. This study provides baseline information of small plastic debris pollution for effective and comprehensive management actions.

Marine plastic pollution: using community science to address a global problem

It was once thought oceans were so vast they could not be affected by humans, but unfortunately rapid globalisation now threatens marine biodiversity. The negative effects of marine debris were recognised in the 1970s, and more recently globally acknowledged in scientific literature. We revisited the Greater Sydney region in New South Wales Australia, to research whether plastic waste on coastal beaches has reduced in recent years. This was achieved by designing a community science project in collaboration with local schools and volunteers. We discovered that plastic debris differed between beaches and strata, but was similar to Australian beaches that were sampled over a decade ago. The high correlations we found between plastic debris and both the frequency of storm-water drains and local population sizes suggested that storm-water drains may be responsible for delivering plastic waste to coastal ecosystems, and the amount of plastic debris was proportional to the size of the surrounding population. Involving local communities has the potential to rapidly raise awareness about key conservation issues to large and broad demographic audiences. Ultimately, this may inspire public and political change.

The amount and accumulation rate of plastic debris on marshes and beaches on the Georgia coast

The amount and accumulation rate of plastic debris at 20 sites along the Georgia coast were prepared using data reported by a number of volunteer organizations. The amount of plastic debris at highly visited barrier island beaches and estuarine marshes ranged from 300 to >1000kg. Relatively large amount of plastics (180–500kg) were found on less visited barrier island beaches, i.e. Blackbeard, Ossabaw and Cumberland Islands. A follow up monthly or quarterly collection study was carried out on two of the sites, a barrier beach and estuarine marsh, to determine accumulation rate in 8000m2 areas. Accumulation rates ranged from 0.18 to 1.28kg/30days–8000m2 on the barrier island beach and from 0.6 to 1.61kg/30days–8000m2 at the estuarine marsh site. The major type of plastics, e.g. bottles, food wrappers, plastic fragments, was highly variable at different seasons and sites. The authors recommend consideration of a standardization in reporting plastic debris, with respect to quantitation of debris and sample area.

Monitoring the abundance of plastic debris in the marine environment

Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and by our limited understanding of the pathways followed by plastic debris and its long-term fate. To date, most monitoring has focused on beach surveys of stranded plastics and other litter. Infrequent surveys of the standing stock of litter on beaches provide crude estimates of debris types and abundance, but are biased by differential removal of litter items by beachcombing, cleanups and beach dynamics. Monitoring the accumulation of stranded debris provides an index of debris trends in adjacent waters, but is costly to undertake. At-sea sampling requires large sample sizes for statistical power to detect changes in abundance, given the high spatial and temporal heterogeneity. Another approach is to monitor the impacts of plastics. Seabirds and other marine organisms that accumulate plastics in their stomachs offer a cost-effective way to monitor the abundance and composition of small plastic litter. Changes in entanglement rates are harder to interpret, as they are sensitive to changes in population sizes of affected species. Monitoring waste disposal on ships and plastic debris levels in rivers and storm-water runoff is useful because it identifies the main sources of plastic debris entering the sea and can direct mitigation efforts. Different monitoring approaches are required to answer different questions, but attempts should be made to standardize approaches internationally.