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Trace elements in microplastics stranded on beaches of remote islands in the NE Atlantic
Abstract
The increased quantity of microplastics entering the oceans is threatening the health of marine ecosystems worldwide. Microplastics are of particular concern because they are available to a wide range of organisms and can possibly transfer potential toxic substances such as trace elements. Herein, we provide baseline information on the spatio-temporal variation of trace elements adsorbed to plastic fragments (1–5 mm) stranded in two beaches of oceanic islands of the Azores archipelago, North-East Atlantic. While trace elements such as Ca, Mg and Fe were found in high concentrations probably as a result of particular features of volcanic characteristics in the region, other elements were particularly low compared to other locations. Our results provide new information on the levels of trace elements associated with microplastics, necessary for the development of a risk assessment framework for plastic pollution in this remote region of the North-East Atlantic Ocean.
... (continued on next page) G. Kutralam-Muniasamy et al. studies either analyzed individually a certain set of microplastics with unique characteristics or mixed microplastics irrespective of their characteristics to achieve a certain mass to carry out further protocols. Also, at times, samples have been mixed together from different time periods to investigate the extent of metals contamination in microplastics (Martins et al., 2020). The summary of microplastic characteristics in studies reviewed is shown in Table 1. ...
... However, the studies reviewed have shown variations in the selection of microplastics based on colors. For instance, some studies analyzed only white and transparent microplastics (Martins et al., 2020), while others considered microplastics of various colors (Prunier et al., 2019). At the same time, it is understood from Table 1 that PE, PP, PS and polyethylene terephthalate (PET) were the major polymer types of microplastics investigated. ...
... The important factors leading to fragmentation and consequent changes in the physical and chemical properties of the plastic include weathering processes induced by fluctuating temperature, humidity or UV light (Vedolin et al., 2018;Naqash et al., 2020). In an attempt to figure out how the role of environmental factors (i.e., different seasonal conditions) determine the amounts of metals adsorbed onto microplastics, Martins et al. (2020) conducted a study on microplastics extracted from shoreline sediments of NE Atlantic. The authors noticed varying metal concentrations between seasons, especially an increasing trend during the warmer seasons as a result of changes in surface characteristics of microplastics in exposure to UV light at increased temperature and humidity, promoting the adsorption of metals from the G. Kutralam-Muniasamy et al. surrounding seawater. ...
The identification and quantification of metals in microplastics are necessary to determine their exposure levels as well as to understand their potential toxicity in the environment linked to the ubiquity of microplastics. The readiness of effective protocols and measurement techniques for accurate metal quantification is of utmost importance. This first review, based on 28 original articles, provides a systematic assessment of the current protocols for extraction, detection and quantification of metals in microplastics and the challenges associated with them. Quality assurance and quality control measures are also summarized. Great variations of microplastic samples in terms of characteristics, number, mass and unit were noted. Wet acid and microwave acid digestion methods were commonly employed for metal extraction from microplastics using a combination of acids such as HF, HCl, HNO3 and H2SO4 at different concentrations and reaction conditions. Adaptation of one or multiple characterization techniques including, inductively coupled plasma-optical emission spectroscopy, inductively coupled plasma mass-spectrometry, X-ray fluorescence and atomic absorption spectroscopy has been considered. The discrepancies in methodology and elements analyzed between studies produce variable results and troublesome comparison. Having considered the need for a standard procedure, this review highlighted several suggestions towards standardization and recommended perspectives for future research.
... The analyses were made on MPs sampled by the environment and on laboratory studies, showing their role as possible carriers of heavy metals. The highest absorption rates of metals were recorded on aged particles (Barus et al., 2021;Godoy et al., 2019;Martins et al., 2020;Tang et al., 2020); this suggests the importance of exploring the presence of metals on microplastics collected from real environmental matrices to have information and a better understanding of this complex interaction. A large number of variables makes it challenging to reproduce the environmental conditions in the laboratory . ...
... It is estimated that 10 million tons of plastics enter the marine environment annually (Boucher and Friot, 2017). Metals such as Pb, Cu, and Cd were found with greater abundance on the MPs collected by the Yellow Sea (Gao et al., 2019), while metals found on MPs sampled from a beach were As, Ba, Cd, Cr, Ni, Pb, Zn (Acosta-Coley et al., 2019;Martins et al., 2020). ...
Recently, microplastics (MPs) have been detected in almost all environmental matrices (water, soil, air, biota). Their presence is of concern due to high environmental persistence and their ability to release or bind pollutants. In light of this, the present work aimed to quantify a poorly studied pollutant category associated with MPs: metals. This analysis was conducted on virgin MPs, used as raw materials in the plastics' production process and on environmental MPs taken from the Ofanto river in Southern Italy. The MP samples were initially grouped for colour, shape and ageing and following mineralised by a microwave digestor. The metals and metalloids Pb, Ba, Sb, Sn, Cd, Mo, Se, Zn, Cu, Ni, Co, Cr, Fe, Mn, Ti, Al, V, Ca, K, Mg, Na were subsequently quantified with ICP-MS. All the analysed elements were found on both types of samples (virgin and environmental MPs), with higher concentrations detected on environmental samples (above 14,400 μg/g⁻¹) rather than on pristine ones (above 5000 μg/g⁻¹). Many of these inorganic compounds are probably adsorbed by the surrounding environment, and others are intentionally added during the plastic production process to improve their properties (e.g. additives). Noticeable differences were detected concerning the metal's distribution and amount observed in the two types of MP particles analysed.
Moreover, trace element concentrations were also linked to the colour and shape of the environmental particles analysed. Most abundant levels of metals were quantified on aged black fragments, followed by coloured and transparent fragments and black pellets. Our concluding remarks underline the role of MPs as a vehicle for the transport of metals, with significant differences between the high abundance of these pollutants examined in our particles collected in a freshwater environment and the significantly lower concentrations revealed previously in marine MPs.
... Once ingested, these microplastic particles will remain in organisms, sometimes directly blocking their digestive tracts and causing physical damage (Browne et al., 2010). In addition, due to their small size, these microplastic particles easily carry organic pollutants (Goldstein & Goodwin, 2013;Kaposi et al., 2014;Horn et al., 2019;Shi et al., 2020) and a large number of heavy metal contamination, trace elements (Brennecke et al., 2016;Isabel et al., 2019;Martins et al., 2020) that have potential toxic effects on some marine biological communities and humans. When people are relaxing on beaches, if the content of microplastics in beach sediment is high, the pollutants and trace elements carried by which may make people face greater risks to their health, including the more consumption of seafood (Vethaak & Leslie, 2016). ...
Microplastic pollution on bathing beaches threatens the health of human beings and coastal organisms. There is a lack of assessment on the level of microplastic pollution and the health risk associated with plastics. As one of the earliest open bathing beaches in China, Liandao is well known as the two high-quality beaches. However, little is known about the extent of microplastic pollution on these bathing beaches. Based on the analysis of microplastic pollution abundance, distribution, shape, size, color, and composition at the Liandao bathing beaches, this study puts forward a novel approach to comprehensively evaluate the microplastic pollution level and risk level by using the Nemerow pollution index (NPI) and polymer hazard index (PHI). The results show that the average abundance of microplastics on the Liandao bathing beaches is 135.42 ± 49.58 items/kg; the main shapes are fibers, fragments, and granules. Most of the microplastics are transparent, brown, and black, accounting for 71.54%, and they have an average particle size of 0.63 ± 0.43 mm. The main components are PE, PP, PS, PET, and nylon, of which nylon appears in the highest proportion (54.77%). The microplastic NPI and PHI values are 0.38 and 74.81, respectively, indicating that the pollution level and health risk index of microplastics on the Liandao bathing beaches are both low. With the increase in population and per cap-ita consumption, plastic waste generated on land will continue to increase. Finally, this study puts forward some suggestions regarding microplastic monitoring, plastic waste management, and environmental attitudes and behavior.
... Several factors affect the migration or transport of microplastics in freshwater, including the water body size, wind currents, and particle density (Eriksen et al., 2013;Fischer et al., 2016;Free et al., 2014). Some investigations verified the existence of microplastics even in remote areas such as Antarctica (Cincinelli et al., 2017) and the Arctic (Lusher et al., 2015), central Atlantic Islands (Martins et al., 2020), Arabian Gulf (Abayomi et al., 2017) even in deep-sea Arctic sediments (Kanhai et al., 2019) although the studies are limited. ...
The ever-increasing presence of microplastics in many environmental components has been a cause of worry for humanity due to their small size and potential health risk. Since the last decade, numerous studies have been conducted on the prevalence and dispersion of microplastics. However, at present, there aren't any systematic studies on fate and transport of microplastics that consider multimedia environmental systems and their mitigation measures. Also, there are limited studies on the routes through which humans are exposed to microplastics. In this review, about 380 articles were evaluated to uncover the extent of microplastic fate, transport, and pollution in different environmental components, including soil, freshwater, marine, and atmosphere, as well as its effect on different ecosystems. We gave special attention to understanding many routes and sources of microplastics intended for human consumption and their consequences on human health. Furthermore, we tried to emphasize on the different methods used for sampling, extraction, identification and characterization of microplastics, along with associated benefits and limitations. This study highlighted existing knowledge and gaps in the remediation of microplastics. On this basis, the bottleneck and current challenges have been proposed.
... For example, to date there are no ingestion indices for shorebirds on their Arctic breeding grounds. While we might predict lower exposure to plastics pollution than during other phases of their annual cycle (but see Martins et al. 2020;Rey et al. 2021), various studies have shown that microplastics are abundant in Arctic marine, freshwater, and terrestrial habitats (Bergmann et al. 2019;Huntington et al. 2020;Mallory et al. 2021). To address this gap, we encourage collaborative studies such as those coordinated as part of the Arctic Shorebird Demographic Net-Environ. ...
Concerns about the impact of plastics pollution on the environment have been growing since the 1970s. Marine debris has reportedly entangled and (or) been ingested by 914 marine species ranging from microinvertebrates to large marine mammals. Shorebirds have a high potential to be exposed to and ingest plastics pollution, as many species migrate long distances and periodically concentrate around shorelines, coastal areas, and estuaries that can have elevated levels of plastics pollution. Currently, little is understood about plastics exposure, frequency of occurrence (FO), and potential impacts relating to shorebirds. In this study, we catalogued and reviewed available studies across the globe that examined plastics pollution in shorebirds. We then quantified relevant traits of species and their environments to explore how shorebirds may be exposed to plastics pollution. Of 1106 samples from 26 shorebird species described within 16 studies that examined plastic ingestion, 53% of individuals contained some form of plastics pollution. Overall, Haematopodidae (oystercatchers) had the highest FO of plastics, followed by Recurvirostridae (avocets), Scolopacidae (sandpipers, phalaropes, godwits, and curlews), and Charadriidae (plovers). Plastics FO was much greater among species that migrated across marine areas (either oceanic or coastal) than those species that used continental flyways. Species that foraged at sea, on mudflats, or on beaches had higher average FO of plastic ingestion than species that foraged in upland or freshwater environments. Finally, species that used a sweeping foraging mode showed higher levels of ingested plastics and contained a far greater number of plastic pieces than all other techniques. These conclusions are based on a limited number of species and samples, with the distribution of samples skewed taxonomically and geographically. Using the combined knowledge of known shorebirds–plastics interactions and shorebird ecology, we present a hierarchical approach to identifying shorebirds that may be more vulnerable and susceptible to plastic ingestion. We provide recommendations on sampling protocols and future areas of research.
... In recent times, extensive studies of elemental compositions in microplastics (MPs) have revealed that MPs may contain varying concentrations of metal(loid)s and, due to the toxicity of heavy metals, may pose a significant risk to the environment, marine organisms, and human health (Kutralam-Muniasamy et al., 2021;Fred-Ahmadu et al., 2020a, 2020b. Several notable studies have been conducted into the contributions of MPs as toxic and geochemical metals vectors in aquatic ecosystems (Carbery et al., 2020;Li et al., 2020;Martins et al., 2020;Patterson et al., 2020;Dobaradaran et al., 2018;Godoy et al., 2019). Several studies have found that the type of plastic found in the environment, i.e., virgin or aged (weathered) plastics, has a significant influence on the adsorption of metal(loid)s from aquatic ecosystems by microplastics (Mohsen et al., 2019;Karthik et al., 2018;Wang et al., 2017;Holmes et al., 2012). ...
The pervasive existence of microplastics (MPs) and toxic metals is raising environmental and health concerns. Plastics are essentially a complex mixture of chemicals, but exposure to the aquatic environment increases their complexity through contaminant desorption/sorption. The aim of this study was to establish baseline data on the elemental occurrence and distribution of potentially toxic and geochemical metals/metalloids in microplastics 1–5 mm and mesoplastics (> 5 mm – 1 cm) along designated coastlines of the Gulf of Guinea (Nigeria) in addition to enabling more comprehensive ecotoxicological risk assessment. The concentrations of twenty-six metals: aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), selenium (Se), sodium (Na), silicon (Si), silver (Ag), strontium (Sr), thallium (Tl), titanium (Ti), vanadium (V), and zinc (Zn), associated with beach MPs, pristine, and lagoon plastics were determined after extraction in 10% nitric acid and analysis using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The distribution of MPs was variable, with 3680 particles identified along the drift and high waterlines across designated shoreline locations. The beach MPs were dominated by polyethylene (PE), polypropylene (PP), and polystyrene (PS), whereas lagoon-sourced plastics were characterized by polyethylene terephthalate (PET), polystyrene (PS), and polyurethane (PUR). Metal concentration was higher when associated with foam plastic (PS, PUR, PEVA) compared to hard plastic (PE, PP, PET) samples. The results showed that all samples had slightly elevated Al, Fe, Mn, and Zn concentrations, suggesting potential sorption interactions and plastic additive influences. Notably, foam MPs had a stronger affinity for metals. This study emphasizes the critical role of microplastics in serving as vectors for toxic metals. Except for Cd, pollution indices such as the potential contamination index (PCI), hazard quotient (HQ), and modified hazard quotient (mHQ) indicated low severity contamination of beach and lagoon MPs by heavy metals. However, considering long-term accumulation of sorbed metals, their potential toxicity to marine biota may be considerable.
... Regarding plastics adsorbing metals from the surrounding environment, most of the field data concerns beached pellets or beached plastic debris (Table 1). Martins et al. (2020) observed that Mn and Fe adsorbed on the plastic debris extracted from two beaches in the NE Atlantic presented higher concentration; they also noted the changes in the concentration of metals in different seasons, especially in warmer seasons, which was conducive to the adsorption of metals by MPs from the surrounding seawater. In comparison, the highest Fe and Mn concentrations detected in MPs collected from sandy beaches in Hong Kong were up to 302 mg kg − 1 and 18.6 mg kg − 1 , respectively . ...
Microplastics (MPs) have recently attracted much attention due to their widespread distribution in the aquatic environment. Microplastics can act as a vector of heavy metals in the aquatic environment, causing a potential threat to aquatic organisms and human health. This review mainly summarized the occurrence of microplastics in the aquatic environment and their interaction with heavy metals. Then, we considered the adsorption mechanisms of MPs and heavy metals, and further critically discussed the effects of microplastics properties and environmental factors (e.g., pH, DOM, and salinity) on the adsorption of heavy metals. Finally, the potential risks of combined exposure of MPs and heavy metals to aquatic biota were briefly evaluated. This work aims to provide a theoretical summary of the interaction between MPs and heavy metals, and is expected to serve as a reference for the accurate assessment of their potential risks in future studies.
... Note that while acquisition of metals from the environment is possible (through adsorption, for example), concentrations arising from this route are much lower than the detection limit of the XRF. [33][34][35] When PVC is mechanically recycled, functional additives are retained, an approach that is favoured during the controlled reconstitution of the same type of product. However, less controlled and more open mechanical recycling may result in additives being introduced into different types of product (such as Sb in non-electrical goods) or being dispersed at lower concentrations into more general, blended recyclates which are oen mixed with virgin PVC. ...
Polyvinyl chloride (PVC) is one of the most widely used thermoplastics but is also a material of concern because of the generation and release of harmful chemicals during its life cycle. Amongst the chemicals added to PVC are metal-based stabilisers and Sb-based halogenated flame retardant synergists. However, very little quantitative information exists on these additives, and in particular in PVC lost to the environment. In this study, the distribution of PVC amongst consumer plastics in societal circulation and plastics retrieved from marine and lacustrine beaches and agricultural soils are compared, along with the presence and concentrations of Ba, Cd, Pb, Sb, Sn and Zn as proxies for common metal-based additives and determined by X-ray fluorescence spectrometry. About 10% of consumer plastics and 2% of environmental plastics were constructed of PVC, with the discrepancy attributed to the long service lives and managed disposal of PVC used in the construction sector and the propensity of the plastic to sink in aquatic systems and evade detection. Metal-based additives, defined as having a metal concentration >1000 mg kg-1, were present in about 75% of consumer and environmental PVC, with Ba and Pb most abundant and Cd and Zn least abundant in both types of sample, and median concentrations statistically different only for Ba. Metals also appeared to be present as contaminants (defined as concentrations <1000 mg kg-1) arising from manufacturing or recycling. Metals in PVC are believed to pose little risk when the material is in use, but experimental evidence in the literature suggests that significant mobilisation and exposure may occur from PVC microplastics when ingested by wildlife.
... Plastic pollutants abundantly accumulate in coastal zones due to high buoyancy in water, allowing transportation even by weak currents. De Souza Petersen et al. (2016), Kaviarasan et al. (2020), Krishnakumar et al. (2020), and Martins et al. (2020) found plastic on remote beaches of Brazil, India, Arabian Sea islands, and Northeast Atlantic islands, respectively. Smallsized plastic, in the form of microplastics (<0.05 mm), was not evaluated in this study; however, the large amount of fragmented plastics provides a continuous source of microplastics (Monteiro et al., 2020). ...
Intense human use and high construction density in coastal areas are stressors to sandy beaches. Pollution by marine debris is a major problem on beaches worldwide. This study pioneered an assessment of marine debris characterization over time on beaches with different levels of access. In two periods and seasons, marine debris was sampled on nine sandy beaches of Rio de Janeiro, grouped by levels of access. The general marine debris density has decreased over time, accompanied by an improvement in public cleaning mechanisms. The most important predictor for the majority of marine debris items is related to accessibility; beaches with restricted access showed a reduction in the abundance of most items. High marine debris densities, even on beaches with restricted access, showed that all evaluated beaches can be sinks for marine debris circulating in marine waters. Beach cleaning strategy improvements will be inefficient unless integrated marine debris management is implemented.
... Plastics typically enter the ocean from land as mismanaged waste transported via rivers or wind (Kershaw and Rochman, 2015), though local human deposition in coastal areas also contributes (Hardesty et al., 2016). While debris on land is found ubiquitously and has been reported from the most remote to the most densely populated corners of the earth, it is not equally distributed (Barnes et al., 2009;Martins et al., 2020;Napper et al., 2020). ...
There have been a variety of attempts to model and quantify the amount of land-based waste entering the world’s oceans, most of which rely heavily on global estimates of population density as the key driving factor. Using empirical data collected in seven different countries/territories (China, Kenya, South Africa, South Korea, Sri Lanka, Taiwan and Vietnam), we assessed a variety of different factors that may drive plastic leakage to the environment. These factors included both globally available GIS data as well as observations made at a site level. While the driving factors that appear in the best models varied from country to country, it is clear from our analyses that population density is not the best predictor of plastic leakage to the environment. Factors such as land use, infrastructure and socio-economics, as well as local site-level variables (e.g., visible humans, vegetation height, site type) were more strongly correlated with plastic in the environment than was population density. This work highlights the importance of gathering empirical data and establishing regular monitoring programs not only to form accurate estimates of land-based waste entering the ocean, but also to be able to evaluate the effectiveness of land-based interventions.
... Sources of these plastics are for example wear and tear during their use phase, littering of plastic products or mismanagement of waste (Jambeck et al., 2015;SAPEA, 2018;ter Halle et al., 2016). As a consequence, plastic debris has been detected in even the most remote and pristine locations such as in arctic deep-sea sediments (Bergmann et al., 2017), mountain lakes (Free et al., 2014) or remote islands (Martins et al., 2020). ...
Plastic items from urban, freshwater and marine environments as well as from household items and electric supplies were analyzed for their metals and metalloids arsenic, barium, bismuth, cadmium, cobalt, chromium, copper, manganese, nickel, iron, lead, antimony, tin and zinc. Total metal contents ranged from 3 μg/kg (5th percentile) up to 7 g/kg (95th percentile). The median content of most metals was below 1 mg/kg and did not exceed legal limits. Iron and zinc were the metals with the highest contents, with medians of approximately 50 mg/kg. Multivariate statistics (k-means clustering and principal component analysis) did not reveal a polymer specific metal composition except for samples of tire tread rubber that was obtained from passenger car tires. Investigation on the potential origin of the metals in plastics revealed that pigments were the most likely source. In comparison to natural and anthropogenic materials in rivers, oceans and air, the metal content of plastic items was within the same order of magnitude, except for antimony and zinc contents. Literature data on the adsorption capacities of plastics suggested that the inherent content of barium, iron, antimony and zinc was dominating the total content in the studied samples. Compared to suspended sediments in rivers, the metal flux into marine environment transported with plastic items was found to be negligible due to the three orders of magnitude lower masses. The different properties, however, may consequently lead to the transport of plastics and their constituents into pristine and remote environments which natural particulate matter may not reach.
Long-term microplastics (MPs) environmental pollution trends cannot be understood only by investigating their presence on beaches. Without estimating MPs for the entire beach, comparisons between multiple beaches cannot be made. In this study, Nagasaki Prefecture was selected as the study site, we measured MPs accumulation rate to express the MPs pollution trend and weighted the measurement results to enable comparison of MPs content among multiple sandy beaches. The MPs accumulation rate in the study site was measured by periodic investigation at fixed spots. The average in the supratidal zone was 1.5 ± 0.9 mg-MPs/(m ² -sand⋅ d) ( n = 15). The weighting of the MPs content in hot spots and non-hot spots by their respective areas enabled us to obtain the representative value and the dispersion of the MPs content in the entire study site. The MPs contents in the three beaches were 298 ± 144, 1,115 ± 518, and 4,084 ± 2,243 mg-MPs/(m ² -sand), respectively. Using these values, it is possible to compare the MPs contents of multiple beaches.
Microplastic pollution, or commonly known as “White Pollution,” has been drawing great interest as a new omnipresent environmental pollution. Plastic is potentially used in all kinds of industries, and their irresponsible waste disposal is the reason behind both aquatic and terrestrial pollution. The degradation period of plastic is a long-term process and occurs due to solar radiation, thermal oxidation, thermolysis, photo-oxidation, etc. The end result is tiny particles known as “microplastics” (diameter less than 5 mm) and “nanoplastics” (diameter less than 100 nm). MPs and NPs act as carriers for various chemical and biological toxins and are ingested by zooplankton, bivalves, echinoderms—these move through the food web and damage the internal digestive system of living organisms. To eliminate the ecological threats, a bioremediation system is urgently required. Microorganisms like Ideonella sakaiensis are known to have enzymes that degrade plastic and can be useful as remediators. This chapter discusses the sources and transports routes of microplastics in the aquatic environment and their ecotoxicological effects on living organisms. Moreover, it highlights the bioremediation of environmental microplastics, its mechanism, and some necessary environmental policies to prevent it.
Plastics are an emerging class of environmental contaminants whose impacts are not yet fully understood. Trace elements, another class of environmental contaminant and commonly associated with plastics, have been widely researched and are known to be toxic to organisms. However, the combined impacts of these two contaminants on the environment remain unclear. Here, we reviewed the current knowledge of the types and concentrations of trace elements associated with plastics, the role of plastics in creating new exposure routes, the processes involved in the release of trace elements from plastics, and the transport of plastics through environmental compartments. Trace elements inherent in plastics, due to addition during manufacture for formation or functional properties, are typically present at higher concentrations than those that are acquired from the environment, and consequently are likely to have greater impacts. Trace elements are continuously released into environmental matrices from plastics but may be released at higher concentrations when exposed to rapid changes in environmental conditions (pH, ionic strength, redox potential, salinity, UV levels). Plastics potentially provide additional exposure routes for organisms to trace elements. For example, exposure to trace elements may occur when organisms ingest plastics, use them for shelter and nest building or as a surface to attach onto. Further research to improve our understanding of this complex contaminant should focus on environmentally relevant studies on trace element release and their effects.
This is the first study that investigated the presence, distribution, and composition of microplastics, MPs (1-5 mm) on beaches in the Yasawa Islands, Fiji. A temporal assessment over three years on six beaches was undertaken to investigate different beach traits on MP abundance. Average MP concentration was 4.5 ± 11.1 MPs·m-2 with significantly higher concentrations were found on east-facing beaches than west (p < 0.001), and higher on the storm line compared to the high tide line (p < 0.001). No difference was found between tourist and local beaches (p = 0.21). These results demonstrate the role of current-driven ocean transport of plastic pollution in this part of The South Pacific. ATR FT-IR analysis showed that across all sites 34 % of MPs were polypropylene (PP), 33 % polystyrene (PS), 25 % polyethylene (PE), and 8 % other polymer types. Further studies are needed to assess the potential impacts of MPs on Fiji's coral reefs and marine life.
The polar plastics research community have recommended the spatial coverage of microplastic investigations in Antarctica and the Southern Ocean be increased. Presented here is a baseline estimate of microplastics in the nearshore waters of South Georgia, the first in situ study of the north-east coast of the island. Our results show that the microplastic concentration in seawater at twelve stations in proximity to King Edward Point Research Station ranged from 1.75 ± 5.17 MP/L (mean ± SD), approximately one order of magnitude higher than similar studies of sea surface waters south of the Polar Front. Levels of microplastics in freshwater (sampled from Gull Lake) and precipitation (collected adjacent to the research station) were 2.67 ± 3.05 MP/L, and 4.67 ± 3.21 MP/L respectively. There was no significant difference in the microplastic concentration between seawater sites, and no significant bilateral relationship between concentration and distance from the research station outlets. We report an average concentration of 1.66 ± 3.00 MP/L in wastewater collected from the research station but overall, the counts of microplastics were too low to attach any statistical significance to the similarity in the microplastic assemblages of seawater and wastewater, or assemblages retrieved from penguin species in the region in other studies. Using a calculation described in contemporary literature we estimate the number of microfibres potentially being released from ships and stations annually in the region but acknowledge that further samples are needed to support the figures generated. More extensive research into microplastic distribution, characteristics, and transport in the region is recommended to fully compute the level of risk which this pollutant represents to the ecosystem health of this remote region.
Marine debris, which is often called microplastics, is widespread in marine environments, particularly in sediments, and is recognized as an environmental hazard because it concentrates contaminants, forms biofilms, and sinks into marine sediments. In sediments, it may be ingested by benthos and have a negative impact on higher food chain levels. In this study, a new protocol was developed to identify microplastics in various sediment fractions. This protocol combined sieving and staining based on ordinal geotechnical/geological testing methods. The sieving process was derived from the conventional particle size distribution test, and nontoxic dyes were employed in the staining process. The protocol is safe and easy to perform as it merely involves the use of conventional geological/geotechnical testing equipment. The new protocol was successfully employed to stain and categorize different types and sizes of microplastic particles from contaminated sediments. This safe, easy-to-use, and efficient protocol can serve as the basis for a new alternative approach to study microplastics present in sediments, which can be performed using basic materials familiar to geotechnical/geological engineers.
The increasing presence of microplastics in marine environment is a critical issue and the plastic-metal contamination has received much attention. However, conventional methods for heavy metal determination are time-consuming, need sample pretreatments, require a strict operation environment, or have high limits of detection. In this study, heavy metals contaminated microplastics samples collected from a remote coral island were quantified and analyzed by using Laser-Induced Breakdown Spectroscopy (LIBS). The characters of the trace metals in microplastics were used to determine the sources of the contaminants, and the potential origins of the metals were demonstrated from the statistical analysis. LIBS is a facile and non-destructive trace analysis technique and the strategy led to rapid and multi-metals detection of individual samples. Heavy metals such as copper (Cu), lead (Pb), iron (Fe), cadmium (Cd), zinc (Zn), manganese (Mn), chromium (Cr) were detected and quantified in the individual microplastics samples. The findings showed that LIBS is a promising strategy for the characterization of microplastics and for the analysis of the source of heavy metals contaminants present in the microplastics particles.
Historically, many additives and catalysts used in plastics were based on compounds of toxic metals (and metalloids), like arsenic, cadmium, chromium(VI), and lead. Despite subsequent restrictions, hazardous additives remain in plastics in societal circulation because of the pervasiveness of many products and the more general contamination of recycled goods. However, little is understood about their presence and impacts in the environment, with most studies focusing on the role of plastics in acquiring metals from their surroundings through, for example, adsorption. Accordingly, this paper provides a review of the uses of hazardous, metal-based additives in plastics, the relevant European regulations that have been introduced to restrict or prohibit usage in various sectors, and the likely environmental impacts of hazardous additives once plastics are lost in nature. Examination of the literature reveals widespread occurrence of hazardous metals in environmental plastics, with impacts ranging from contamination of the waste stream to increasing the density and settling rates of material in aquatic systems. A potential concern from an ecotoxicological perspective is the diffusion of metals from the matrix of micro- and nanoplastics under certain physico-chemical conditions, and especially favorable here are the acidic environments encountered in the digestive tract of many animals (birds, fish, mammals) that inadvertently consume plastics. For instance, in vitro studies have shown that the mobilization of Cd and Pb from historical microplastics can greatly exceed concentrations deemed to be safe according to migration limits specified by the current European Toy Safety Directive (17 mg kg⁻¹ and 23 mg kg⁻¹, respectively). When compared with concentrations of metals typically adsorbed to plastics from the environment, the risks from pervasive, historical additives are far more significant.
Microplastics from the North Atlantic Gyre deposited on Guadeloupe beaches were sampled and characterized. A new method is developed to identify which elements were present as additives in these microplastics. The method used both acidic leaching and acidic digestion. Several elements (Al, Zn, Ba, Cu, Pb, Cd, Mn, Cr) were identified as pigments. Furthermore, some elements used as additives to plastics (especially the non-essential elements) seem to contribute to most of the acidic leaching, suggesting that these additives can leach and adsorb onto the surface microplastics, becoming bioavailable. Based on the acidic leaching element content, only Cd should represent a danger for fish when ingested. However, further studies are needed to determine the potential synergetic effect on health caused by the ingestion of several elements and microplastics.
Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P < 0.05. Polymers identified in field samples in order of abundance were; PVC (39), LDPE (28), PS (18), polyethylene (PE, 9), PP (8), nylon (8), high density polyethylene (HDPE, 7), polycarbonate (PC, 6), PET (6), polyurethane (PUR, 3) and polyoxymethylene (POM, 2). PVC and LDPE accounted for 46% of all samples. Field samples of PVC, HDPE and LDPE had significantly greater amounts of acid extracted copper and HDPE, LDPE and PUR significantly greater amounts of acid extracted zinc. PVC and LDPE had significantly greater amounts of acid extracted cadmium and PVC tended to have greater levels of acid extracted lead, significantly so for HDPE. Five of the collected items demonstrated extreme levels of acid extracted metal; greatest concentrations were 188, 6667, 698,000 and 930 μgg⁻¹ of copper, zinc, lead and cadmium respectively recovered from an unidentified object comprised of PVC. Comparison of recently manufactured versus field samples indicated that recently manufactured samples had significantly greater amounts of acid extracted cadmium and zinc and field samples significantly greater amounts of acid extracted copper and lead which was primarily attributed to metal extracted from field samples of PVC. Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the “inherent” load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.
A vulnerable species group, such as, the elasmobranchs, in a data-deficient context presents a complicated management problem. Evidence suggests that the Azores islands, a remote archipelago on the Mid-Atlantic Ridge, serve essential functions in the life-history of species across taxa. The diversity of marine resources within its EEZ are exploited by local to international fleets, and the full extent of fishing pressure can often be underestimated. Although sharks and rays appear to be of minor importance in the fishery, the possibilities of illegal, unreported, and unregulated fishing raises concerns about these threatened species. However, this group has failed to attract management attention, visible in the lack of regional studies focused on biodiversity, ecology, or threats of elasmobranchs. Our work attempts to review and update the information on elasmobranchs of the Azores and identify potential threats, mainly by the local fisheries. We aim to highlight knowledge gaps that require further research and conservation actions. We (1) update the annotated checklist of elasmobranch species, (2) compare species distribution across a biogeographically similar section of the North Atlantic, and (3) analyze the interaction of elasmobranch species with local fisheries. We confirm 61 chondrichthyan species for the Azores (39 sharks, 17 rays, and 5 chimaeras), adding 19 species to the previous annotated checklist of 1997. The Azores elasmobranch species assemblage most resembles Madeira, the neighboring Macaronesian archipelago. Biogeographic affinities between the chosen regions of the North Atlantic are reflected in the taxonomic structure of families. Although underestimated in the local fisheries, elasmobranchs constitute a regular but highly variable portion of total landings. Misreporting and misidentification is perhaps the greatest concern in the local fisheries records, further aggravated by few existing catch regulations for elasmobranchs. Local knowledge indicates that the Azores serves as essential habitat for at least a few species in coastal areas and shallow seamounts, and potentially so for a number of deep-sea elasmobranchs. The intersection of fishery threats and local essential habitat functions around the archipelago warrants greater research effort and studies.
Plastic in the global oceans fulfills two of the three conditions for pollution to pose a planetary boundary threat because it is causing planetary-scale exposure that is not readily reversible. Plastic is a planetary boundary threat if it is having a currently unrecognized disruptive effect on a vital Earth system process. Discovering possible unknown effects is likely to be aided by achieving a fuller understanding of the environmental fate of plastic. Weathering of plastic generates microplastic, releases chemical additives, and likely also produces nanoplastic and chemical fragments cleaved from the polymer backbone. However, weathering of plastic in the marine environment is not well understood in terms of time scales for fragmentation and degradation, the evolution of particle morphology and properties, and hazards of the chemical mixture liberated by weathering. Biofilms that form and grow on plastic affect weathering, vertical transport, toxicity, and uptake of plastic by marine organisms and have been underinvestigated. Laboratory studies, field monitoring, and models of the impact of weathering on plastic debris are needed to reduce uncertainty in hazard and risk assessments for known and suspected adverse effects. However, scientists and decision makers must also recognize that plastic in the oceans may have unanticipated effects about which we are currently ignorant. Possible impacts that are currently unknown can be confronted by vigilant monitoring of plastic in the oceans and discovery-oriented research related to the possible effects of weathering plastic.
Deep-sea hydrothermal sediments are known to support remarkably diverse microbial consortia. Culture-independent sequence-based technologies have extensively been used to disclose the associated microbial diversity as most of the microorganisms inhabiting these ecosystems remain uncultured. Here we provide the first description of the microbial community diversity found on sediments from Menez Gwen vent system. We compared hydrothermally influenced sediments, retrieved from an active vent chimney at 812 m depth, with non-hydrothermally influenced sediments, from a 1400 m depth bathyal plain. Considering the enriched methane and sulfur composition of Menez Gwen vent fluids, and the sediment physicochemical properties in each sampled area, we hypothesized that the site-associated microbes would be different. To address this question, taxonomic profiles of bacterial, archaeal and micro-eukaryotic representatives were studied by rRNA gene tag pyrosequencing. Communities were shown to be significantly different and segregated by sediment geographical area. Specific mesophilic, thermophilic and hyperthermophilic archaeal (e.g., Archaeoglobus, ANME-1) and bacterial (e.g., Caldithrix, Thermodesulfobacteria) taxa were highly abundant near the vent chimney. In contrast, bathyal-associated members affiliated to more ubiquitous phylogroups from deep-ocean sediments (e.g., Thaumarchaeota MGI, Gamma- and Alphaproteobacteria).
This study provides a broader picture of the biological diversity and microbial biogeography, and represents a preliminary approach to the microbial ecology associated with the deep-sea sediments from the Menez Gwen hydrothermal vent field.
Microplastics are an emerging marine pollutant. It is important to understand their distribution in the marine environment and their implications on marine habitats and marine biota. Microplastics have been found in almost every marine habitat around the world, with plastic composition and environmental conditions significantly affecting their distribution. Marine biota interact with microplastics including birds, fish, turtles, mammals and invertebrates. The biological repercussions depend on to the size of microplastics encountered, with smaller sizes having greater effects on organisms at the cellular level. In the micrometre range plastics are readily ingested and egested, whereas nanometre-sized plastics can pass through cell membranes. Despite concerns raised by ingestion, the effects of microplastic ingestion in natural populations and the implications for food webs are not understood. Without knowledge of retention and egestion rates of field populations, it is difficult to deduce ecological consequences. There is evidence to suggest that microplastics enter food chains and there is trophic transfer between predators and prey. What is clear is that further research on a variety of marine organisms is required to understand the environmental implications of microplastics in more detail and to establish effects in natural populations.
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.
An updated checklist of manta and devil rays (family Mobulidae) occurring in waters of the Azores archipelago is given based on new data from underwater images and on the re-evaluation of previous citations for the region. There are, at least, three species of mobulids occurring in the region, possibly four: giant manta Manta birostris; Chilean devil ray Mobula tarapacana; and one or both of the giant devil ray Mobula mobular/spinetail devil ray Mobula japanica species complex. These findings have direct implications for the known ranges of all these species and for the conservation of their North Atlantic populations.
Cetaceans living in offshore waters are under increasing pressure from anthropogenic activities. Yet, due to the lack of survey effort, relatively little is known about the demography or ecology of these populations. Spatial and temporal distribution of cetaceans in mid-Atlantic waters were investigated using a long term dataset collected from boat surveys and land-based observations around the Azores. From 1999 to 2009, 7307 cetacean schools were sighted during 271,717 km of survey effort. In 4944 h of land-based observations, 2,968 cetacean groups were detected. Twenty-four species were recorded: seven baleen whales, six beaked whales, eight dolphin species, Physeter macrocephalus, Kogia breviceps and Kogia
sima. Overall, Delphinus delphis was the most frequently sighted species but its encounter rate decreased in June�November, coinciding with the presence of Stenella frontalis in the region. Tursiops truncatus, P. macrocephalus and Grampus griseus were frequently encountered year-round, whereas large baleen whales showed a distinct peak in encounter rates in March/�May. Mesoplodonts were fairly common and appear to be present throughout the year. These findings fill in a significant gap in the knowledge of cetaceans occurring in a poorly studied region of the North Atlantic, providing much needed data to
inform management initiatives.
Small plastic detritus, termed 'microplastics', are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bio-imaging techniques to document ingestion, egestion and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7 - 30.6 µm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 µm microplastics (>4000 ml-1) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.
Plastics have become an indispensable ingredient of human life. Their enormous use is a matter of great environmental and economic concern, which has motivated the researchers and the technologists to induce different degrees of degradations in the plastic. These degradations can be induced in a better way if their mechanistic implications are properly understood. A better understanding of the mechanism for these degradations is also advocated in order to facilitate the proper use of the alternative waste disposal strategies. In view of the facts concerning the plastic degradation, in this review article, we have discussed various types of polymeric degradations along with their mechanisms, which include photo-oxidative degradation, thermal degradation, ozone-induced degradation, mechanochemical degradation, catalytic degradation and biodegradation. This article also discusses the different methods used to study these degradations and the factors that affect these degradations.
Hydrothermal vents emit sulphur and metals to the ocean1. Particular attention has been paid to hydrothermal fluxes of iron2, 3, 4, a limiting micronutrient of marine primary production5. Vent-derived iron was previously thought to rapidly oxidize and precipitate around vents6. However, organic matter can bind to and stabilize dissolved and particulate iron in hydrothermal plumes7, 8, 9, facilitating its dispersion into the open ocean10. Here, we report measurements of the chemical speciation of sulphide and iron in high-temperature fluids emanating from vents in the East Pacific Rise and the Eastern Lau Spreading Center. We show that pyrite nanoparticles—composed of iron and sulphur—account for up to 10% of the filterable iron (less than 200 nm in size) in these fluids. We suggest that these particles form before the discharge of the vent fluid. We estimate that pyrite nanoparticles sink more slowly than larger plume particles, and are more resistant to oxidation than dissolved Fe(II) and FeS. We suggest that the discharge of iron in the form of pyrite nanoparticles increases the probability that vent-derived iron will be transported over long distances in the deep ocean.
Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.
One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics. Within just a few decades since mass production of plastic products commenced in the 1950s, plastic debris has accumulated in terrestrial environments, in the open ocean, on shorelines of even the most remote islands and in the deep sea. Annual clean-up operations, costing millions of pounds sterling, are now organized in many countries and on every continent. Here we document global plastics production and the accumulation of plastic waste. While plastics typically constitute approximately 10 per cent of discarded waste, they represent a much greater proportion of the debris accumulating on shorelines. Mega- and macro-plastics have accumulated in the highest densities in the Northern Hemisphere, adjacent to urban centres, in enclosed seas and at water convergences (fronts). We report lower densities on remote island shores, on the continental shelf seabed and the lowest densities (but still a documented presence) in the deep sea and Southern Ocean. The longevity of plastic is estimated to be hundreds to thousands of years, but is likely to be far longer in deep sea and non-surface polar environments. Plastic debris poses considerable threat by choking and starving wildlife, distributing non-native and potentially harmful organisms, absorbing toxic chemicals and degrading to micro-plastics that may subsequently be ingested. Well-established annual surveys on coasts and at sea have shown that trends in mega- and macro-plastic accumulation rates are no longer uniformly increasing: rather stable, increasing and decreasing trends have all been reported. The average size of plastic particles in the environment seems to be decreasing, and the abundance and global distribution of micro-plastic fragments have increased over the last few decades. However, the environmental consequences of such microscopic debris are still poorly understood.
Plastic pollution is among the most pervasive stressors currently influencing the marine environment and affecting even the most remote areas. To date, there are still fundamental gaps in our understanding of the major pathways and fate of plastic debris in the oceans. Here we show that oceanic insular environments are important transitory repositories of small plastic items floating in the open ocean. Monthly monitoring of seven beaches over a three-year period demonstrate that beaches of the Azores islands with particular characteristics can capture significant quantities of fragments between 2 and 5 mm in length. The beach with the highest plastic loading rates was found to occasionally accumulate densities exceeding 15,000 fragments m⁻² on part of the backshore. However, a large portion of these fragments can be rapidly washed back into the marine environment. Detailed characterization of those plastic items revealed the typology and size distribution to be similar throughout the seven beaches and through the 33 months surveyed, suggesting a same and unique source. Our results show that these oceanic islands of the North-East Atlantic are under pressure of high quantities of fragmented plastic debris that probably entered the ocean many years ago.
Plastic pollution in the marine environment poses threats to wildlife and habitats through varied mechanisms, among which are the transport and transfer to the food web of hazardous substances. Still, very little is known about the metal content of plastic debris and about sorption/desorption processes, especially with respect to weathering. In this study, plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals; as a comparison, new packaging materials were also analyzed. Both the new items and plastic debris showed very scattered concentrations. The new items contained significant amounts of trace metals introduced as additives, but globally, metal concentrations were higher in the plastic debris. The results provide evidence that enhanced metal concentrations increase with the plastic state of oxidation for some elements, such as As, Ti, Ni, and Cd. Transmission electron microscopy showed the presence of mineral particles on the surface of the plastic debris. This work demonstrates that marine plastic debris carries complex mixtures of heavy metals. Such materials not only behave as a source of metals resulting from intrinsic plastic additives but also are able to concentrate metals from ocean water as mineral nanoparticles or adsorbed species. Plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals. Marine plastic debris carry complex mixtures of heavy metals but it is evidence that plastic oxidation favors their adsorption.
Marine litter has been identified as one of the major environmental problems that oceans are currently facing. Worldwide efforts are being made to reduce the input of litter into the oceans, and projects aimed at monitoring their quantities are key to evaluate their success. This study, provide baseline information on the quantities of marine litter found on 42 beaches spread throughout the nine islands of the Azores archipelago, North Atlantic Ocean. A total of 31,439 items were collected throughout the archipelago with an average density of 0.62 ± 0.15 macro-litter items m −2. Of this litter 87% were plastic and its majority (67%) plastic fragments. Six beaches were further monitored every three months for two years. Substrate type and wind exposure were important factors for explaining patterns of litter deposition. Our results highlight that marine litter have the tendency to accumulate in remote islands of the North Atlantic Ocean.
Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1–5 mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83 ± 6.09 (± SE) per individual, corresponding to a mean dry mass of 1.07 ± 0.41 g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic.
Samples of microplastic (n = 924) from two beaches in south west England have been analysed by field-portable-x-ray fluorescence (FP-XRF) spectrometry, configured in a low-density mode and with a small-spot facility, for the heavy metals, Cd and Pb, and the halogen, Br. Primary plastics in the form of pre-production pellets were the principal type of microplastic (>70%) on both beaches, with secondary, irregularly-shaped fragments representing the remainder of samples. Cadmium and Pb were detected in 6.9% and 7.5% of all microplastics, respectively, with concentrations of either metal that exceeded 10³ μg g⁻¹ usually encountered in red and yellow pellets or fragments. Respective correlations of Cd and Pb with Se and Cr were attributed to the presence of the coloured, inorganic pigments, cadmium sulphoselenide and lead chromate. Bromine, detected in 10.4% of microplastics and up to concentrations of about 13,000 μg g⁻¹, was mainly encountered in neutrally-coloured pellets. Its strong correlation with Sb, whose oxides are effective fire suppressant synergists, suggests the presence of a variety of brominated flame retardants arising from the recycling of plastics originally used in casings for heat-generating electrical equipment. The maximum bioaccessible concentrations of Cd and Pb, evaluated using a physiological extraction based on the chemical characteristics of the proventriculus-gizzard of the northern fulmar, were about 50 μg g⁻¹ and 8 μg g⁻¹, respectively. These concentrations exceed those estimated for the diet of local seabirds by factors of about 50 and 4, respectively.
The permanent presence of microplastics in the marine environment is considered a global threat to
several marine animals. Heavy metals and microplastics are typically included in two different classes
of pollutants but the interaction between these two stressors is poorly understood. During 14 days of experimental manipulation, we examined the adsorption of two heavy metals, copper (Cu) and zinc (Zn), leached from an antifouling paint to virgin polystyrene (PS) beads and aged polyvinyl chloride (PVC) fragments in seawater. We demonstrated that heavy metals were released from the antifouling paint to the water and both microplastic types adsorbed the two heavy metals. This adsorption kinetics was described using partition coefficients and mathematical models. Partition coefficients between pellets and water ranged between 650 and 850 for Cu on PS and PVC, respectively. The adsorption of Cu was significantly greater in PVC fragments than in PS, probably due to higher surface area and polarity of PVC. Concentrations of Cu and Zn increased significantly on PVC and PS over the course of the experiment with the exception of Zn on PS. As a result, we show a significant interaction between these types of microplastics and heavy metals, which can have implications for marine life and the environment. These results strongly support recent findings where plastics can play a key role as vectors for heavy metal ions in the marine system. Finally, our findings highlight the importance of monitoring marine litter and heavy metals, mainly associated with antifouling paints, particularly in the framework of the Marine Strategy Framework Directive (MSFD).
The well-constrained hydrology of the Furnas caldera permits the quantification of the precipitation, evapotranspiration, runoff and the groundwater discharge out of the volcanic structure. Chemical composition of the discharge in Furnas has been stable for at least a century. A hydrogeochemical survey and discharge measurement of the springs and runoff in Furnas allow estimates of chemical fluxes from the volcanic structure. A tectonically controlled lineament of high carbon dioxide flux has been identified across the caldera floor. Three water types are encountered in Furnas: hydrothermal, carbonated and cold waters. The hydrothermal waters originate from shallow aquifers which derive their heat from local intrusions at shallow depth (100–200 m) at about 160°C. The carbonated waters, some of which are steam heated by discharge from underlying thermal aquifers occurs above the carbon dioxide anomaly across the caldera floor. Extensive leaching, in some cases stoichiometric, of glassy volcanic rocks by these mildly acid carbonated waters supplies most of the dissolved solids in Furnas waters. Chemical flux estimates for the volcano show that carbon dioxide (9358 tons/yr), leached silica (3994 tons/yr) and leached sodium (2628 tons/yr) are the dominating mobile components of the system.
Plastic production pellets collected from beaches of south west England contain variable concentrations of trace metals (Cr, Co, Ni, Cu, Zn, Cd and Pb) that, in some cases, exceed concentrations reported for local estuarine sediments. The rates and mechanisms by which metals associate with virgin and beached polyethylene pellets were studied by adding a cocktail of 5 μg L(-1) of trace metals to 10 g L(-1) pellet suspensions in filtered seawater. Kinetic profiles were modelled using a pseudo-first-order equation and yielded response times of less than about 100 h and equilibrium partition coefficients of up to about 225 ml g(-1) that were consistently higher for beached pellets than virgin pellets. Adsorption isotherms conformed to both the Langmuir and Freundlich equations and adsorption capacities were greater for beached pellets than for virgin pellets. Results suggest that plastics may represent an important vehicle for the transport of metals in the marine environment.
Global set of trajectories of satellite-tracked Lagrangian drifters is used to study the dynamics of marine debris. A probabilistic model is developed to eliminate the bias in spatial distribution of drifter data due to heterogeneous deployments. Model experiments, simulating long-term evolution of initially homogeneous drifter array, reveal five main sites of drifter aggregation, located in the subtropics and maintained by converging Ekman currents. The paper characterizes the geography and structure of the collection regions and discusses factors that determine their dynamics. A new scale R(c)=(4k/|D|)(½) is introduced to characterize tracer distribution under competing effects of horizontal divergence D and diffusion k. Existence and locations of all five accumulation zones have been recently confirmed by direct measurements of microplastic at the sea surface.
Plastic waste disposal is one of the serious environmental issues being tackled by our society today. Polyethylene, particularly in packaging films, has received criticism as it tends to accumulate over a period of time, leaving behind an undesirable visual footprint. Degradable polyethylene, which would enter the eco-cycle harmlessly through biodegradation would be a desirable solution to this problem. However, the "degradable polyethylene" which is presently being promoted as an environmentally friendly alternative to the nondegradable counterpart, does not seem to meet this criterion. This article reviews the state of the art on the aspect of degradability of polyethylene containing pro-oxidants, and more importantly the effect these polymers could have on the environment in the long run. On exposure to heat, light, and oxygen, these polymers disintegrate into small fragments, thereby reducing or increasing the visual presence. However, these fragments can remain in the environment for prolonged time periods. This article also outlines important questions, particularly in terms of time scale of complete degradation, environmental fate of the polymer residues, and possible accumulation of toxins, the answers to which need to be established prior to accepting these polymers as environmentally benign alternatives to their nondegradable equivalents. It appears from the existing literature that our search for biodegradable polyethylene has not yet been realized.
Plastic production pellets sampled from four beaches along a stretch of coastline (south Devon, SW England) and accompanying, loosely adhered and entrapped material removed ultrasonically have been analysed for major metals (Al, Fe, Mn) and trace metals (Cu, Zn, Pb, Ag, Cd, Co, Cr, Mo, Sb, Sn, U) following acid digestion. In most cases, metal concentrations in composite pellet samples from each site were less than but within an order of magnitude of corresponding concentrations in the pooled extraneous materials. However, normalisation of data with respect to Al revealed enrichment of Cd and Pb in plastic pellets at two sites. These observations are not wholly due to the association of pellets with fine material that is resistant to ultrasonication since new polyethylene pellets suspended in a harbour for 8 weeks accumulated metals from sea water through adsorption and precipitation. The environmental implications and potential applications of these findings are discussed.
Selected Analytical Methods for Environmental Remediation and Recovery (SAM) 2017
- R Campisano
- K Hall
- J Griggs
- S Willison
- S Reimer
- H Mash
- M Magnuson
- L Boczek
- E Rhodes
Campisano, R., Hall, K., Griggs, J., Willison, S., Reimer, S., Mash, H., Magnuson, M.,
Boczek, L., Rhodes, E., 2017. Selected Analytical Methods for Environmental
Remediation and Recovery (SAM) 2017. U.S. Environmental Protection Agency,
Washington, DC, pp. 420.
Hazardous Substances in Plastic Materials. COWI and the Danish Technological Institute on Behalf of the Norwegian Climate and Pollution Agency
- E Hansen
- N H Nilsson
- D Lithner
- C Lassen
Hansen, E., Nilsson, N.H., Lithner, D., Lassen, C., 2013. Hazardous Substances in Plastic
Materials. COWI and the Danish Technological Institute on Behalf of the Norwegian
Climate and Pollution Agency, Oslo, pp. 150.