Arctic sea ice is an important temporal sink and means of transport for microplastic

Microplastics (MP) are recognized as a growing environmental hazard and have been identified as far as the remote Polar Regions, with particularly high concentrations of microplastics in sea ice. Little is known regarding the horizontal variability of MP within sea ice and how the underlying water body affects MP composition during sea ice growth. Here we show that sea ice MP has no uniform polymer composition and that, depending on the growth region and drift paths of the sea ice, unique MP patterns can be observed in different sea ice horizons. Thus even in remote regions such as the Arctic Ocean, certain MP indicate the presence of localized sources. Increasing exploitation of Arctic resources will likely lead to a higher MP load in the Arctic sea ice and will enhance the release of MP in the areas of strong seasonal sea ice melt and the outflow gateways.

Ilka Peeken, Sebastian Primpke, Birte Beyer, Julia Gütermann, Christian Katlein, Thomas Krumpen, Melanie Bergmann, Laura Hehemann,  Gunnar Gerdts, Nature Communications, volume 9, 24 April 2018

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Plastic ingestion by juvenile polar cod (Boreogadus saida) in the Arctic Ocean

One of the recently recognised stressors in Arctic ecosystems concerns plastic litter. In this study, juvenile polar cod (Boreogadus saida) were investigated for the presence of plastics in their stomachs. Polar cod is considered a key species in the Arctic ecosystem. The fish were collected both directly from underneath the sea ice in the Eurasian Basin and in open waters around Svalbard. We analysed the stomachs of 72 individuals under a stereo microscope. Two stomachs contained non-fibrous microplastic particles. According to µFTIR analysis, the particles consisted of epoxy resin and a mix of Kaolin with polymethylmethacrylate (PMMA). Fibrous objects were excluded from this analysis to avoid bias due to contamination with airborne micro-fibres. A systematic investigation of the risk for secondary micro-fibre contamination during analytical procedures showed that precautionary measures in all procedural steps are critical. Based on the two non-fibrous objects found in polar cod stomachs, our results show that ingestion of microplastic particles by this ecologically important fish species is possible. With increasing human activity, plastic ingestion may act as an increasing stressor on polar cod in combination with ocean warming and sea-ice decline in peripheral regions of the Arctic Ocean. To fully assess the significance of this stressor and its spatial and temporal variability, future studies must apply a rigorous approach to avoid secondary pollution.

Susanne Kühn, Fokje L. Schaafsma, Bernike van Werven, Hauke Flores, Melanie Bergmann, Marion Egelkraut-Holtus, Mine B. Tekman, Jan A. van Franeker, Polar Biology, pp 1–10,

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Plastic found in mussels from Arctic to China – enters human food

Tiny bits of plastic are contaminating mussels from the European Arctic to China in a sign of the global spread of ocean pollution that can end up on people’s dinner plates.

Mussels in apparently pristine Arctic waters had most plastic of any tested along the Norwegian coast, according to a study this month by the Norwegian Institute for Water Research (NIVA).

Plastics may be getting swept north by ocean currents and winds from Europe and America, ending up swirling around the Arctic Ocean, NIVA researcher Amy Lusher told Reuters.

“Microplastics have been found in mussels everywhere scientists have looked,” she said.

Past surveys have found microplastics off nations including China, Chile, Canada, Britain and Belgium. Off Norway, the molluscs contained on average 1.8 bits of microplastic – defined as smaller than 5 mm long (0.2 inch) – with 4.3 in the Arctic. (…) (reuters.com, 20/12/2017)

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Microplastics in Polar Regions: the role of long range transport

Microplastics (particles <5 mm) pose a threat to the marine ecosystem that is disproportionate to their tiny size. They have been found in high numbers in sea water and sediments, and are interacting with organisms and the environment in a variety of ways. Recently their presence has been confirmed in Polar water, sediment, and sea ice. We review the recent literature on microplastic distribution and transport in marine environments, primarily in the Northern Hemisphere, summarize current understanding, identify gaps in understanding, and suggest future research priorities.

Rachel W. Obbard, Current Opinion in Environmental Science & Health, Available online 13 December 2017, In Press

Citizen scientists reveal: Marine litter pollutes Arctic beaches and affects wild life

Recent data indicate accumulation areas of marine litter in Arctic waters and significant increases over time. Beaches on remote Arctic islands may be sinks for marine litter and reflect pollution levels of the surrounding waters particularly well. We provide the first quantitative data from surveys carried out by citizen scientists on six beaches of Svalbard. Litter quantities recorded by cruise tourists varied from 9–524 g m− 2 and were similar to those from densely populated areas. Plastics accounted for > 80% of the overall litter, most of which originated from fisheries. Photographs provided by citizens show deleterious effects of beach litter on Arctic wildlife, which is already under strong pressure from global climate change. Our study highlights the potential of citizen scientists to provide scientifically valuable data on the pollution of sensitive remote ecosystems. The results stress once more that current legislative frameworks are insufficient to tackle the pollution of Arctic ecosystems.

Melanie Bergmann, Birgit Lutz, Mine B. Tekman, Lars Gutow, Marine Pollution Bulletin, Volume 125, Issues 1–2, 15 December 2017, Pages 535-540

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High quantities of microplastic in Arctic deep-sea sediments from the HAUSGARTEN observatory

Although mounting evidence suggests the ubiquity of microplastic in aquatic ecosystems worldwide, our knowledge of its distribution in remote environments such as Polar Regions and the deep sea is scarce. Here, we analyzed nine sediment samples taken at the HAUSGARTEN observatory in the Arctic at 2,340 – 5,570 m depth. Density separation by MicroPlastic Sediment Separator and treatment with Fenton’s reagent enabled analysis via Attenuated Total Reflection FTIR and µFTIR spectroscopy. Our analyses indicate the wide spread of high numbers of microplastics (42 – 6,595 microplastics kg-1). The northernmost stations harbored the highest quantities, indicating sea ice as a transport vehicle. A positive correlation between microplastic abundance and chlorophyll a content suggests vertical export via incorporation in sinking (ice-) algal aggregates. Overall, 18 different polymers were detected. Chlorinated polyethylene accounted for the largest proportion (38 %), followed by polyamide (22 %) and polypropylene (16 %). Almost 80 % of the microplastics were ≤ 25 µm. The microplastic quantities are amongst the highest recorded from benthic sediments, which corroborates the deep sea as a major sink for microplastics and the presence of accumulation areas in this remote part of the world, fed by plastics transported to the North via the Thermohaline Circulation.

Melanie Bergmann, Vanessa Wirzberger, Thomas Krumpen, Claudia Lorenz, Sebastian Primpke, Mine B. Tekman, and Gunnar Gerdts, Environ. Sci. Technol., Volume 51, Issue 19, Page 11000-11010, October 3, 2017

The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation

The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources. In the present study, the Arctic Ocean was extensively sampled for floating plastic debris from the Tara Oceans circumpolar expedition. Although plastic debris was scarce or absent in most of the Arctic waters, it reached high concentrations (hundreds of thousands of pieces per square kilometer) in the northernmost and easternmost areas of the Greenland and Barents seas. The fragmentation and typology of the plastic suggested an abundant presence of aged debris that originated from distant sources. This hypothesis was corroborated by the relatively high ratios of marine surface plastic to local pollution sources. Surface circulation models and field data showed that the poleward branch of the Thermohaline Circulation transfers floating debris from the North Atlantic to the Greenland and Barents seas, which would be a dead end for this plastic conveyor belt. Given the limited surface transport of the plastic that accumulated here and the mechanisms acting for the downward transport, the seafloor beneath this Arctic sector is hypothesized as an important sink of plastic debris.

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