Plastic contamination is universal all through the marine condition, yet gauges of the worldwide plenitude and weight of coasting plastics have needed information, especially from the Southern Hemisphere and remote areas. Here we report a gauge of the all-out number of plastic particles and their weight gliding on the planet's seas from 24 endeavours (2007–2013) over every one of the five subtropical gyres, coastal Australia, Bay of Bengal and the Mediterranean Sea directing surface net tows (N = 680) and visual review transects of huge plastic flotsam and debris (N = 891). Utilizing an oceanographic model of coasting trash dispersal adjusted by our information, and rectifying for wind-driven vertical blending, we gauge at least 5.25 trillion particles weighing 268,940 tons. When looking at between four size classes, two micro plastic <4.75 mm and meso and micro plastic >4.75 mm, a huge loss of micro plastics is seen from the ocean surface contrasted with anticipated paces of discontinuity, recommending there are systems at play that expel <4.75 mm plastic particles from the sea surface. The focus on the life cycle assessment and the brief overview of the plastic waste management over the ocean surfaces with the various mathematical models has been studied. The impact of the ocean pollution is also being analysed.
Pollution and Marine Debris
Since the industrial revolution in the eighteenth to nineteenth centuries, humans have greatly increased the flux of lead (Pb) to the atmosphere and ocean, mainly through the combustion of coals and leaded gasoline. Although such anthropogenic Pb emissions gave little harmful consequences in the open ocean, there have been apparent changes in Pb concentration and its stable isotopic ratios in seawater. Time-series Pb records in the surface oceans have been and will be constructed by the measurement of not only seawaters but corals recording the past seawater Pb during their growth. The Pb concentrations in the North Atlantic surface water, which showed tenfold increase between 1880 and 1970 reflecting the anthropogenic Pb inputs, have decreased drastically since the middle of 1970s due to the prohibition of leaded gasoline in U.S. and European countries. On the other hand, surface waters of northern and tropical Indian Ocean as well as those in the western Pacific Ocean showed significantly higher Pb concentrations than those of the North Atlantic Ocean, implying recent rapid industrialization and a late phase-out of leaded gasoline in developing countries in Asia.
Most of cigarettes used in the world have filters. Following smoking, the cigarette butts (CBs) are often littered as wastes in the environment. CBs generally contain several toxic substances that are trapped in the cigarette filter. Filters are made of non-biodegradable materials and remain in the environment for a long time. Within this study, it is attempted to systematically review the articles on CBs and find out the answers to the problems associated with the factors including quantity, distribution, origin and toxicity of CBs in the environment. It is estimated that approximately 5.5 trillion cigarettes are being produced annually in the world and the CB wastes would reach 1.2 million tons and increase by 50% until 2025. CBs contain thousands of dangerous chemicals such as arsenic, benzene, hydrogen cyanide, PAHs, pyridine, heavy metals and so forth. It is also believed that eachCB can pollute 1000 liters of water. Given the inadequacy of mechanical equipment as well as the cost of collecting these wastes, there should be a special focus on these items as follows: producing cigarettes with degradable filters, reducing the rate of smoking in the world, reducing the toxic and chemical substances in the process of plant growth, processing and production of cigarettes, training people to discard CBs properly, putting legal and financial pressures on cigarettes production, and the last but not least, providing effective solutions for collecting CBs.
Identification of an oil spill is additionally essential to evaluate the potential spread and float from the source to the adjacent coastal terrains. In such manner, usage of Synthetic Aperture RADAR (SAR) information for the recognition and checking of oil spills has gotten extensive consideration as of late, because of their wide zone inclusion, day-night and all-weather capabilities. The present examination studies an oil spill occurred in the Al Khafji region by applying Sentinel 1 SAR-C images. Al Khafji is on the borderline between Saudi Arabia and Kuwait in the Persian Gulf and it is detected as an unbiased zone. Al Khafji region can possibly deliver in excess of 7472.403m³ barrels of oil for every day (m³/d). Approaches dependent on multi-sensor satellite images examination have been produced for distinguishing oil spills from referred to common leaks just as oil slick procedures. In this paper, one of these techniques is associated with Sentinel 1 images of a known region of natural oil leakage and of an ongoing oil slick incident in Al Khafji zone. The Synthetic Aperture Radar (SAR) is perceived as the most significant remote sensing apparatus for the ocean and ocean waters oil slick examination, recording, documentation and propagation. Specifically, this paper examines oil spills recognition in the Persian Gulf surveyed by utilizing Sentinel-1 (SAR-C) imageries. Results demonstrated the significance of the VV polarization of the Sentinel-1 for recognizing oil-spills just as the diminished utility of the VH polarization in this sole circumstance.
Only 1% of plastic entering the ocean is found floating on its surface, with high loads in ocean accumulation zones and semi-enclosed seas, except for the Red Sea, which supports one of the lowest floating plastic loads worldwide. Given the extension of reefs in the Red Sea, we hypothesize a major role of scleractinian corals as sinks, through suspension-feeding, and assessed microplastic removal rates by three Red Sea coral species. Experimental evidence showed removal rates ranging from 0.25 × 10−3 to 14.8 × 10−3 microplastic particles polyp−1 hour−1, among species. However, this was only 2.2 ± 0.6% of the total removal rate, with passive removal through adhesion to the coral surface being 40 times higher than active removal through suspension-feeding. These results point at adhesion of plastic to coral reef structures as a major sink for microplastics suspended in the water column after sinking, helping explain low concentrations in Red Sea surface waters.
Detection of microplastics (MPs) in biotic and abiotic matrices is relevant to evaluate how marine ecosystem’s exposure to these pollutants is of emerging environmental concern and at risk of loss of functionality and biodiversity. The presence of MPs was studied for the first time in the gut of benthic oysters (Crassostrea gigas) and in the water column in a eutrophic estuary under high anthropogenic pressure, in the southwestern Atlantic. Significant abundances of small plastic debris were found at all the sampling stations- mainly fibers, fragments, pellets, and beads. MPs were categorized and counted according to type, color, and size. Microfibers presented the highest percentage of abundance in the water column (98% with Van Dorn bottles and 72.73 % with a plankton net) as well as in oysters (91%). In water collected with Van Dorn bottles, the total MP concentrations ranged from 5900 to 782,000 particles/m3 and from 42.6 to 113.6 particles/m3 in samples collected with a plankton net. The widespread presence of fibers in all the assessed components could be related to the intense harbor activities in the area, such as the use of ropes for the mooring of boats and from fishing nets, as well as from domestic and industrial effluents. The presence of MPs in both the pelagic and benthic realms may imply risk for the animals that inhabit the estuary, and for human wellbeing, with respect to the potential transfer of MPs through the food web, affecting the provisioning of ecosystem services.
Marine biota is currently exposed to plastic pollution. The biological effects of plastics may vary according to polymer types (e.g. polystyrene, polyethylene, acrylate), size of particles (macro, micro or nanoparticles) and their shape. There is a considerable lack of knowledge in terms of effects of nanoplastics (NP) to marine biota particularly of polymers like polymethylmethacrylate (PMMA). Thus, this study aimed to assess its ecotoxicological effects using a battery of standard monospecific bioassays with four marine microalgae (Tetraselmis chuii, Nannochloropsis gaditana, Isochrysis galbana and Thalassiosira weissflogii) and a marine rotifer species (Brachionus plicatilis). The tested PMMA-NP concentrations allowed the estimation of median effect concentrations for all microalgae species. T. weissflogii and T. chuii were respectively the most sensitive (EC50,96h of 83.75 mg/L) and least sensitive species (EC50,96h of 132.52 mg/L). The PMMA-NP were also able to induce mortality in rotifers at concentrations higher than 4.69 mg/L with an estimated 48 h median lethal concentration of 13.27 mg/L. A species sensitivity distribution curve (SSD), constructed based on data available in the literature and the data obtained in this study, reveal that PMMA-NP appears as less harmful to marine biota than other polymers like polystyrene.
While plastic items like bottles, bags, and balloons are highly visible litter and well-known as ugly eyesores and hazards to wildlife, there is another form of plastic that is generally not visible but is far more numerous and may be equally or more hazardous in the environment. This is microplastic, small pieces ranging from 5 mm in size down to microscopic. Microplastics are categorized as primary microplastic – that which was always tiny, and secondary microplastic-which results from the fragmentation of larger pieces. As with larger pieces, microplastics represent a variety of different polymers, such as polyethylene, polystyrene, etc. They are found in a variety of shapes, including spheres, fragments, films, and fibers. In the past decade there has been a great amount of study on microplastics – where they come from, where they are found, how organisms interact with them, and what effects they may have on the organisms and the ecosystem. Most of these studies have focused on the marine environment since that is where they were initially detected, but they have subsequently been found to be abundant in freshwater and terrestrial environments as well. This review examines the research, emphasizing aquatic environments, and suggests avenues for improving future research.
Marine microplastic particles (MPs,<5 mm) exhibit wide ranges of densities,sizes, and shapes, so that the entire MPs“ensemble”at every time instant can be character-ized by continuous distributions of these parameters. Accordingly, this community ofparticles demonstrates distributions of dynamical properties, such as sinking or risingvelocity, critical shear stress, and the re-suspension threshold. Moreover, all the MPs’properties vary significantly with the time spent in marine environment and withparticular conditions experienced by the particle on its journey. A brief review of thepresent-day numerical efforts towards prediction of MPs transport shows the prevalenceof the Lagrangian particle tracking approach, especially for floating litter. In a broadercontext, the present practice of MPs transport modelling follows the“selective”strategy(e.g., only a certain sub-class of MPs, or specific processes, are considered, sometimes in onlyone- or two-dimensional setting). The heterogeneous nature of MPs, their enormous longevityand movability in marine environment, and the wide spectrum of the involved environ-mental processes suggest further integration (or coupling) of different models in future, aswell as application of other types of models (ensemble modeling, chaos theory approaches,machine learning, etc.) to the problems of MPs transport and fate in the marine environment.Key words:microplastics, transport, modelling.
Studies related to the evaluation of plastics in freshwaters have been increasing in recent years because approximately 80% of plastic items found in the sea are from inland waters. Despite the ecological relevance of these surveys, no information has been available until now about the hazard related to plastic mixtures in freshwaters. To fill this knowledge gap, we carried out a study aimed to assess the environmental risk associated with the “cocktail” of plastics and environmental pollutants adsorbed on their surface in one of the larger European freshwater basins. Plastic debris was collected by a manta trawl along one transect each in four of the Italian subalpine great lakes (Lake Maggiore, Como, Iseo and Garda) and administered to zebra mussels (Dreissena polymorpha), a useful freshwater biological model present in all these lakes. We estimated a plastic density from 4908 MPs/km2 (Lake Iseo) to 272,261 MPs/km2 (Lake Maggiore), while the most common polymers found were polyethylene and polypropylene, with percentages varying between 73% and 100%. A biomarkers suite consisting of 10 different endpoints was performed after 7 days of exposure to investigate the molecular and cellular effects of plastics and related adsorbed pollutants. The main results highlighted a diffuse but different toxicity due to plastics for each lake, and there were significant changes in the antioxidant and detoxifying enzyme activities in Lake Maggiore, Iseo and Garda, an increase in protein carbonylation in L. Como, and a cellular viability decrease of approximately 30% for zebra mussels from L. Iseo and Garda. Despite this variability in the endpoints' responses, the application of the biomarker response index showed a similar environmental hazard due to plastics for all the sampled lakes.