In 2018, during a circumnavigation of Antarctica below 62° S by the sailing boat Katharsis II, the presence of plastics was investigated with surface sampling nets at ten evenly spaced locations (every 36° of longitude). Although fibres that appeared to be plastic (particles up to 2 cm) were found in numbers ranging from 1 particle (0.002 particles per m3) to 171 particles (1.366 particles per m3) per station, a Fourier-transform infrared spectroscopy (FT-IR) analysis indicated that these particles were not composed of plastic. The fibres which superficially reminded plastic were composed of silica and are of biological origin most likely generated by phytoplankton (diatoms). Therefore, the offshore Antarctic locations were proven to be free of floating microplastics.
Pollution and Marine Debris
Plastic debris and marine microplastics are being discharged into the ocean at an alarming scale and have been observed throughout the marine environment. Here we report microplastic in sediments of the Challenger Deep, the deepest known region on the planet, abyssal plains and hadal trenches located in the Pacific Ocean (4900 m–10,890 m). Microplastic abundance reached 71.1 items per kg dry weight sediment. That high concentrations are found at such remote depths, knowing the very slow sinking speed of microplastics, suggests that supporting mechanisms must be at-play. We discuss cascading processes that transport microplastics on their journey from land and oceanic gyres through intermediate waters to the deepest corners of the ocean. We propose that hadal trenches will be the ultimate sink for a significant proportion of the microplastics disposed in the ocean. The build-up of microplastics in hadal trenches could have large consequences for fragile deep-sea ecosystems.
The mitigation of microplastic pollution in the environment calls for a better understanding of the sources and transportation, especially from land sources to the open ocean. We conducted a large-scale investigation of microplastic pollution across the Greater Melbourne Area and the Western Port area, Australia, spanning gradients of land-use from un-developed catchments in conservation areas to more heavily-developed areas. Microplastics were detected in 94% of water samples and 96% of sediment samples, with abundances ranging from 0.06 to 2.5 items/L in water and 0.9 to 298.1 items/kg in sediment. The variation of microplastic abundance in sediments was closely related to that of the overlying waters. Fiber was the most abundant (89.1% and 68.6% of microplastics in water and sediment respectively), and polyester was the dominant polymer in water and sediment. The size of more than 40% of all total microplastics observed was less than 1 mm. Both light and dense polymers of different shapes were more abundant in sediments than those in water, indicating that there is microplastic accumulation in sediments. The abundance of microplastics was higher near coastal cities than at less densely-populated inland areas. A spatial analysis of the data suggests that the abundance of microplastics increases downstream in rivers and accumulates in estuaries and the lentic reaches of these rivers. Correlation and redundancy analysis were used to explore the associations between microplastic pollution and different land-use types. More microplastics and polymer types were found at areas with large amounts of commercial, industrial and transport activities. Microplastic abundances were also correlated with mean particle size. Microplastic hotspots within a coastal metropolis might be caused by a combination of natural accumulation via hydrological dynamics and contribution from increasing anthropogenic influences. Our results strongly suggest that coastal metropolis superimposed on increasing microplastic levels in waterbodies from inland areas to the estuaries and open oceans.
Marine fauna in the California Current System is susceptible to entanglement in anthropogenic debris. We examined beach survey data from six California counties to describe trends of entangled marine birds and mammals (1997–2017). Surveyors reported 357 cases of entanglements among 65,604 carcasses. Monterey County had the greatest average entanglement rate (0.007) of surveyed counties, however, was not statistically different from Santa Cruz (p > 0.05). Twenty-six seabird species (97%) and three marine mammal species (3%), and three non-marine birds were affected. Numerically, Common Murre (23%), Brandt's Cormorant (13%), Western Gull (9.6%), Sooty Shearwater (8%) and Brown Pelican (7%) were the most affected due to abundance, but their entanglement rates were not statistically different (p > 0.05). The most vulnerable species were those frequently documented as entanglement despite low deposition numbers (Merganser spp. 25%). Entangling material consisted primarily of monofilament line (some hooks/lures), but other entanglement items were reported.
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.
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.