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Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.
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The variability in the surface circulation hampers the formation
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... The high spatiotemporal variability of the currents in this basin causes that there are no known plastic retention areas. 20 In order to get a better picture of the flow field, the time-mean surface currents over 2006−2016 have been plotted as vectors in Figure 1. In the same figure, locations of the measurements used here are plotted for which references are shown in the legend. ...
... Correcting this missing variance leads to an estimate of 190−340 tonnes of floating plastics. This is somewhat lower than the estimate by Coźar et al., 20 where it was estimated to be 756−2969 tonnes. ...
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Estimates of plastic inputs into the ocean are orders of magnitude larger than what is found in the surface waters. This can be due to discrepancies in the sources of plastic released into the ocean, but can also be explained due to the fact that it is not well known what the most dominant sinks of marine plastics are, and on what time scales these operate. To get a better understanding on possible sources and sinks, an inverse modelling methodology is presented here for a Lagrangian ocean model, estimating floating plastic quantities in the Mediterranean Sea. Field measurements of plastic concentrations in the Mediterranean are used to inform parametrizations defining various sources of marine plastics, and removal of plastic particles due to beaching and sinking. The parameters of the model are found using inverse modelling, by comparison of model results and measurements of floating plastic concentrations. Time scales for the sinks are found, and likely sources of plastics can be ranked in importance. A new mass balance is made for floating plastics in the Mediterranean: for 2015 there is an estimated input of 2,100-3,400 tonnes, and of plastics released since 2006, about 170-420 tonnes remain afloat in the surface waters, 49-63% ended up on coastlines, and 37-51% have sunk down.
... As a result, there is widely increasing attention on the problems caused by the generation of plastic waste, with society trying to replace unsustainable habits. Plastic waste also severely causes marine pollution and has become a large-scale problem after only half a century of widespread plastic use [3]. The Ellen MacArthur Foundation (EMF) stated that most of the plastic packaging produced ends up in landfills or oceans: "With 8 million tons of plastic that reach the ocean every year, we urgently need to rethink the way we manufacture, use and reuse plastics." ...
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Every day, society's concern over pollution caused by plastic waste grows greater. One of the most intensive sectors for the use of plastic is the food industry. Companies in this sector face the challenge of transitioning to a more sustainable and less intensive model of plastic use, respecting the principles established for a circular economy. Accordingly, one of the questions that industries tend to ask is whether sustainability will influence the consumer's purchase decision. To respond to this, the factors that determine a consumer's sustainable purchase decision in relation to the plastic and food industry have been analyzed in this paper. For this, a regression analysis was performed on a sample of Dutch consumers. The results show that the decision of purchase of the consumer of the Food Industry is conditioned by factors such as age, sustainable behavior, knowledge of the Circular economy and the perception of usefulness of plastic.
... Also, fouling processes allow lowdensity plastics were available for benthic species (see, e.g. Andrady, 2011;Zettler et al., 2013;Cózar et al., 2015) Differences found in the ingestion of microplastics could be attributed to some specificities of the region under study. According to Gago et al. (2015), our study area is characterized by a medium-level of microplastic contamination in the neustonic layer of the water column. ...
We evaluated the incidence of microplastics in the digestive tract contents of four fish species: Engraulis en-crasicolus, Sardina pilchardus, Callionymus lyra and Mullus surmuletus. Alkaline digestion (10% KOH) was used to degrade the organic matter. The percentage of fish with microplastics was 78% (88% fibres, 12% fragments). The main types of polymers identified by Raman spectroscopy were polyethylene and polypropylene. The diet of the four species was also studied and two feeding types were determined: plankton-feeders and benthic-feeders. The effect of a set of biological variables (Length, Fullness index, Fulton's condition factor and Feeding type) on the number and size of microplastics ingested was studied using Generalised Additive Models (GAMs). A significant increase in the number of microplastics with increasing length was observed. No significant effect of trophic variables (fullness index and feeding type) on the number and size of microplastics was found.
... Although many studies on seawater MPs contamination were carried out along the northern Mediterranean coasts (e.g. Eriksen et al., 2014;Suaria et al., 2016;Kedzierski et al., 2019aKedzierski et al., , 2019b, similar studies remain very scarce in southern Mediterranean Sea (Cózar et al., 2015;Cincinelli et al., 2019). ...
Compared to open sea environments, there is still limited knowledge about microplastic levels in semi-enclosed systems such as coastal lagoons. This work aims to assess the levels of MPs in the waters of an urban lagoon (Bizerte lagoon, northern Tunisia) and to study the effects of environmental factors on their distribution and abundance. Average concentration of total MPs was found to be 453.0 ± 335.2 items m−3. The upper 25 cm water layer of the lagoon is most likely to contain ~16.99 × 109 MPs items (which correspond to a total mass of 42.47 t). Fibers were the primary MPs types encountered, and most of MPs particles identified were white and clear-colored. Polyethylene and polypropylene were the predominant polymer types in Bizerte lagoon. Among the various potential plastic sources of MPs, unmanaged domestic plastic wastes are likely to be the major source of plastic pollution in the lagoon. Several environmental factors appeared to influence the distribution and density of MPs in the lagoon waters. These information contribute to better understand the dynamics of MPs in lagoons and to develop environmental management actions.
... Our results showed substantial spatial differences in the risk of MP in the ocean surface layer (0e5 m depth), and we identified the Mediterranean and Yellow seas as current hotspots of risks. The Mediterranean Sea had been reported to contain high loads of plastics compared to other regional seas (Compa et al., 2019;C ozar et al., 2015). The high human pressure, together with the hydrodynamics of this semi-enclosed basin, makes it a plastic accumulation area with no outflow possibilities of marine litter except to greater depths. ...
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Despite the ubiquitous and persistent presence of microplastic (MP) in marine ecosystems, knowledge of its potential harmful ecological effects is low. In this work, we assessed the risk of floating MP (1 μm – 5 mm) to marine ecosystems by comparing ambient concentrations in the global ocean with available ecotoxicity data. The integration of twenty-three species-specific effect threshold concentration data in a species sensitivity distribution yielded a median unacceptable level of 1.21 * 10⁵ MP m⁻³ (95% CI: 7.99 * 10³ – 1.49 * 10⁶ MP m⁻³). We found that in 2010 for 0.17% of the surface layer (0 – 5 m) of the global ocean a threatening risk would occur. By 2050 and 2100, this fraction increases to 0.52% and 1.62%, respectively, according to the worst-case predicted future plastic discharge into the ocean. Our results reveal a spatial and multidecadal variability of MP-related risk at the global ocean surface. For example, we have identified the Mediterranean Sea and the Yellow Sea as hotspots of marine microplastic risks already now and even more pronounced in future decades.
... Those small plastic fragments were found to be approximately 1.5 cm in diameter. Currently, it is estimated that the average plastic concentration in Mediterranean surface waters is 243,853 items per km 2 (Cózar et al., 2015) with sizes between 0.2 and 500 mm, being the highest concentration of particles located between 0.5 and 2.5 mm. Some factors that contribute to the issue of marine litter are the intense coastal and maritime tourism, the great flow of navigation, the industrial and fishing activities and also the configuration of the Mediterranean sea as a closed basin with a particular system of currents (Cincinelli et al., 2019). ...
Microplastics became an unprecedented challenge and mapping their contamination all over the world is needed in order to establish baseline levels and identify the polymers in order to enhance adequate legislation and policy. The main objective of this study is to demonstrate the existence of microplastic pollution on three beaches on the coast of Granada (Spain), namely La Herradura, Motril Beach and La Rábita, characterizing the particles and the relationships in their distribution. This may contribute supporting the studies carried out at a national level in accordance with the Directive on Marine Strategy (2008/56/EC). The results showed a greater median concentration of particles/kg of dry sediment in La Herradura (45.0 ± 24.7) than in Motril (31.5 ± 21.5) and La Rábita (22.0 ± 23.2). These data revealed a higher contamination by microplastics in an enclosed bay-type beach (La Herradura) in comparison with open delta-type beaches. The predominant morphologies were microspheres and fragments, with maximum median concentrations of 38.0 ± 23.7 and 6.0 ± 0.7 particles/kg, respectively. The distribution and size of the particles is affected by the geomorphological and sedimentary characteristics of these beaches, which are different from any other in Spain and in the Mediterranean in general. The beaches of Granada showed more microplastic contamination than Greek or Slovenian beaches, but less than other Spanish beaches. In this area of the Mediterranean, the presence of microplastics can be affected by the wind, sea currents or methodological aspects such as the pore size of the filters used. All of these factors were analysed when comparing the beaches of Granada with other Mediterranean beaches. This study shows that there is contamination by microplastics on the beaches of Granada, which have been little explored until now due to the difficult geological and granulometric characteristics, and gives support to other national studies.
... Plastic bottles comprise most of the floating marine debris and accumulate on the bottom of the sea and wash up on the coastlines [62,84]. The International Coastal Cleanup (ICC) report [85] found that plastic bottles were the third most common type of beach litter, that 10% of the global marine debris is plastic bottles [86] and make up 14% of the Mediterranean debris [55]. In order to identify plastic litter in the water, a plastic litter "target" measuring 3 m × 10 m was created from water bottles of 0.5-liter and 1.5-liter size (Figure 1), to emulate marine plastic litter clusters floating in the sea. ...
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Plastic litter floating in the ocean is a significant problem on a global scale. This study examines whether Sentinel-2 satellite images can be used to identify plastic litter on the sea surface for monitoring, collection and disposal. A pilot study was conducted to determine if plastic targets on the sea surface can be detected using remote sensing techniques with Sentinel-2 data. A target made up of plastic water bottles with a surface measuring 3 m × 10 m was created, which was subsequently placed in the sea near the Old Port in Limassol, Cyprus. An unmanned aerial vehicle (UAV) was used to acquire multispectral aerial images of the area of interest during the same time as the Sentinel-2 satellite overpass. Spectral signatures of the water and the plastic litter after it was placed in the water were taken with an SVC HR1024 spectroradiometer. The study found that the plastic litter target was easiest to detect in the NIR wavelengths. Seven established indices for satellite image processing were examined to determine whether they can identify plastic litter in the water. Further, the authors examined two new indices, the Plastics Index (PI) and the Reversed Normalized Difference Vegetation Index (RNDVI) to be used in the processing of the satellite image. The newly developed Plastic Index (PI) was able to identify plastic objects floating on the water surface and was the most effective index in identifying the plastic litter target in the sea.
... The high plastic particle pollution concentration reported for the region is likely heavily influenced by the presence of these two key industries (e.g. plastics production (DalbergAdvisors, 2019) and tourism (CIESIN, 2012)). In addition, the Mediterranean Sea is an enclosed basin with a high rate of shipping and marine traffic, which also contributes to the high particle concentration found therein (Cózar et al., 2015). ...
Areas like the Mediterranean coastlines, which have high population density, represent locations of high pollution risk for surrounding environments. Thus, this study aims to compare data on the abundance, size, and composition of buoyant plastic particles collected during two weeks in 2019 in the Ligurian and Tyrrhenian Seas with data from 2018. The results from 2019 show average meso- and microplastic particle concentrations of 255,865 ± 841,221 particles km⁻², or 394.19 ± 760.87 g km⁻²; values which differ significantly from those reported in 2018. Microplastic particles accounted for 88.7% of the sample; the majority of which had a size range being between 1 and 2.5 mm. These data are an important milestone for long-term monitoring of the highly variable plastic pollution levels within this region; showing overlaps in zones of pollutant accumulation in addition to increased overall concentrations of plastic particles compared to previous data.
The underwater habitat complexity of the Aegean Sea renders it home to a diversity of cetacean species. From shallow-diving piscivores to teuthophagous deep divers, this sea hosts seven regular cetacean species (Delphinidae, Phocoenidae, Physeteridae, and Ziphiidae), while five more species have been reported as visitors. Despite this high biodiversity, little is known about this taxon, with most available information referring only to presence data. Due to an ever-increasing human development in the area, seven threats can be identified so far: interactions with fisheries and plastic debris, noise and chemical pollution, shipping, climate change, and epizootics. The concurrent absence of abundance data for these apex predators and the lack of protection areas and law enforcement undermine the survival of the cetaceans in the Aegean Sea. Based on these deficiencies and the scarce governmental funding, we propose that research effort should focus on three main topics: abundance, fine-scale distribution, and ecology. Only with this information available, the monitoring of anthropogenic threats will allow the assessment of the effectiveness of potential conservation measures.
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There is no doubt that plastic is polluting the environment. Much terrifying evidence has been provided to show how great the impact of plastic on the living environment has become. Some regions around the world have taken a lead in establishing regulation to combat further plastic pollution. But still, more eminent evidences are required to increase the awareness about this major global problem. This paper presents an intensive discussion related to the evidence of plastic pollution in the environment, some established policies and regulations about plastic pollution and the technology in providing and revealing more evidence of plastic pollution. Current technologies in plastic particles identification and the limitation of widely used technologies are comprehensively elaborated. In addition, a feasible and reliable technique of sequential separation through salt solutions to identify plastic type is discussed in this review paper. This paper also provides future approaches in the effort to increase awareness of current global plastic pollution.
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Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world’s oceans from 24 expeditions (2007–2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N5680) and visual survey transects of large plastic debris (N5891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic ,4.75 mm and meso- and macroplastic .4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove ,4.75 mm plastic particles from the ocean surface.
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Drifter observations in the Mediterranean Sea between 1986 and 2012 have allowed study of important aspects of the surface dynamics in most areas of this marginal sea, including: interannual and seasonal variabilities; basin, subbasin, and mesoscale circulation features; inertial and tidal currents; coastal circulation; and relative dispersion by surface waters. This paper reviews selected important studies, carried out in the last two decades or still in progress, that used or are using Mediterranean drifter observations and ancillary remotely sensed observations (satellite altimetry and high-frequency coastal radars).
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There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.
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When sea ice forms it scavenges and concentrates particulates from the water column, which then become trapped until the ice melts. In recent years, melting has led to record lows in Arctic sea ice extent, the most recent in September 2012. Global climate models, such as that of Gregory et al. [2002], suggest that the decline in Arctic sea ice volume (3.4% per decade), will actually exceed the decline in sea ice extent, something that Laxon et al. [2013] have shown supported by satellite data. The extent to which melting ice could release anthropogenic particulates back to the open ocean has not yet been examined. Here we show that Arctic sea ice from remote locations contains concentrations of microplastics at least two orders of magnitude greater than those that have been previously reported in highly contaminated surface waters, such as those of the Pacific Gyre. Our findings indicate that microplastics have accumulated far from population centers and that polar sea ice represents a major historic global sink of man-made particulates. The potential for substantial quantities of legacy microplastic contamination to be released to the ocean as the ice melts therefore needs to be evaluated, as do the physical and toxicological effects of plastics on marine life.
An expedition on the sailing vessel Sea Dragon was organized and carried out by the 5 Gyres Institute to explore the presence and distribution of plastic pollution in the eastern South Pacific. The first sample was taken at 33°05'S, 81°08'W, subsequent samples were collected approximately every 50 nautical miles until reaching Easter Island, and then again every 60 miles along the same transect in the direction of Pitcairn Island to 24°49'S, 126°61'W. The transect length and direction was determined by using a computer model developed at the University of Hawaii to estimate the accumulation zone for plastic pollution in the SPSG (South Pacific Subtropical Gyre). The samples were later rinsed in salt water, which floated most of the plastic to the surface for removal. Using a dissecting microscope, plastic was removed from preserved natural material, and then sorted by rinsing through Tyler sieves. Analogously, high counts and weights in samples 22 and 23 were obtained during a short period of weaker wind.
Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (<1mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research.