Description: 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.

Description: Although recent research indicates that microplastic (MP) has spread to all marine ecosystem compartments from the sea surface to the deep sea, our knowledge about the distribution through the water column is still limited and largely based on model runs. To fill this gap, we deployed WTS-LV large volume pumps at four different depths (sea surface, ~300m, ~1000m, near seafloor) at five stations of the HAUSGARTEN observatory (west of Svalbard). These pumps filtered 218–560 litres of seawater during each deployment with 10 µm mesh metal filters. Additionally, sediment was sampled at the same stations to understand accumulation mechanisms of MP in the sediment. Our analyses of water column samples using µFTIR spectroscopy resulted in 0–1373 MP m-3, comprising 15 different polymer types. MP concentrations in the sediment were found 1,200-33,000 times higher than in the water column. The northernmost station, which is located in the transition zone between the open ocean and sea ice, harboured the highest mean concentration (416 MP m-3) through the water column, and polyamide accounted for the largest proportion. The surface waters had the highest MP concentrations at all stations with a decrease towards the sediment. Our results will be compared with trends in the vertical distribution of organic particles and discussed in the context of prevailing water masses and sea ice coverage. Still, our preliminary results highlight that noticeable amounts of MP are present throughout the water column, Earth’s largest biome, which has been largely neglected in previous estimates of plastic in the world’s oceans.

Description: There is a 99% mismatch between plastic debris estimated to enter the oceans and empirical evidence pointing to yet unaccounted sinks. The FRAM pollution observatory was installed to quantify plastic pollution in different ecosystem compartments to identify hidden sinks and pathways in an area of increasing pollution. Indeed, our first analyses showed enormous quan- tities of microplastics ≤ 25 im in both Arctic sea ice and sediments from the deep sea posing the question: How is all this plastic transported so far to the North? The importance of atmospheric transport was recently stressed by reports of microplastic in the atmosphere of Paris and Dongguan city. Here, we analysed snow samples from ice floes in the Fram Strait (2016/17) and from snow collected on Spitsbergen, Helgoland, Bremen and the Swiss Alps (2018) to assess the role of this potential pathway of microplastic to the North. Identification of particles was carried out by i-Raman and FTIR imaging. Microplastic particles appeared to be in all samples analysed but polymer composition varied. As with previous data, the sizes of particles were mostly in the smallest size range. The results are discussed in the context of data from other ecosystem compartments.

Description: Plastic pollution of the oceans is a global problem, which currently receives increasing attention by policy makers, public authorities, media and the general public. Although this field of has recently seen a marked increase in research efforts, there is a level of uncertainty, misinformation and worry in the general public indicating that scientific knowledge is currently insufficiently channelled back to society. To bridge this gap, we devised an online portal, LITTERBASE (litterbase.org), which provides continuously updated information on the global distribution and composition of litter pollution and its impacts on biota to stakeholders based on data from peer-reviewed publications. To date, data from 1,725 studies (status April 2018) have been extracted, fed manually into a database and translated into understandable global maps and infographs to open scientific knowledge to the public. Bibliometric data of all publications were entered, as were metadata pertaining to litter type (e.g. plastic, glass, metal, fishing gear), size (i.e. nano, micro, macro), litter quantity unit (e.g. items km-2, items km-1, items m3), aquatic system (e.g. marine, freshwater, estuary), biome (e.g. beach, sea surface, water column, benthic) and total litter quantity. Litter quantities were standardised to the most frequently used units to achieve comparability. Data on biological interactions with litter were also extracted: location of field records, number of species affected, percentage of individuals affected, type of interaction incurred (e.g. entanglement, ingestion, coverage, rafting), effects on biota (e.g. injury, mortality, growth, behaviour), litter type, size, aquatic system and biome. Accordingly, 1,472 taxa (status April 2018) have been found affected by marine litter. Here, we will discuss the use of LITTERBASE with a focus on microplastic distribution, particularly in terms of unveiling our blind spots.

Description: Recent data indicate accumulation areas of marine litter in Arctic waters and significant increases on the seafloor 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, which participated in sailing cruises around Svalbard in 2016. Litter quantities on six beaches 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 including polar bears (Ursus maritimus), 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. Similar programmes could be adopted in other poorly sampled areas of the world to increase our knowledge base and to stimulate a sense of connectedness with the environment visited.

Description: Contamination of the oceans with anthropogenic litter is a global environmental problem which currently receives increasing attention by scientists, policy makers, public authorities, media and the general public. Although research efforts have been intensified, they often do not provide stakeholders with easily understandable information about the dimensions and the extent of the problem. We have developed an online portal to provide easily digestible and continuously updated information on marine litter and microplastics to stakeholders based on scientific literature on a global scale. LITTERBASE gives insight about the distribution of marine litter and its effects on marine biota. Data from 1,420 scientific studies (status 09/10/2017) have been compiled into global maps and real-time graphs to make scientific knowledge accessible to the public. Bibliometric data of all publications were entered, as were metadata pertaining to litter type, litter size, litter quantity unit, aquatic system, biome and total litter quantity. Litter quantities were standardised to the most frequently used units to achieve comparability. Data on biological interactions with litter were also extracted: location of field records, number of species affected, percentage of individuals affected, type of interaction, effects on biota, litter type, litter size, aquatic system and biome. Currently, 1,441 species (status 09/10/2017) have been found to interact with marine litter resulting in mortality in almost 20% of the cases. Web statistics reveal that the information displayed in the LITTERBASE online portal is continuously being retrieved by users from all over the world.

Description: There is a multitude of pollutants that combine persistent and hydrophobic properties. In aquatic environments, they are largely deposited in sediments. The amount and characteristics of the organic carbon determine how strongly they are bound or if they are readily available for partitioning to biota and biouptake. These pollutants can be accumulated by aquatic organisms and biomagnified to higher trophic levels. Hence, it is important to explore the composition, activity and effects of environmental mixtures of pollutants in sediments of different origin, characteristics and pollution history. Sediments from Sweden, the European Arctic (coastal Svalbard vs. open sea), Queensland (Australia) and a French-German river were collected. The freely dissolved concentrations (Cfree) of the chemicals were determined using equilibration with thin coatings of silicone on the inner walls of glass jars with subsequent solvent extraction. Total sediment concentrations (Ctotal) were determined using accelerated solvent extraction. While there is a wide range of pollutants that have been detected in sediments world-wide, traditional chemical analysis cannot cover all compounds and their transformation products. Therefore, in this study, the extracts were dosed into seven cell-based bioassays covering cytotoxicity, activation of metabolic enzymes (binding to the arylhydrocarbon receptor, AhR), specific, receptor-mediated effects such as estrogenicity (ERa); and adaptive stress response (oxidative stress, AREc32). Cytotoxicity was assessed in all bioassays and occurred occasionally. Moreover, four of the seven bioassays were active in this study: AhR, AREc32, the peroxisome proliferator-activated receptor gamma (PPARg) and ERa. The activation of the AhR was by far most responsive and showed a distinct pattern across the sampling locations. The other three assays showed responses only at higher enrichment factors of the extracts, also revealing specific contamination patterns. A comparison between Cfree vs. Ctotal will enable assessing the actual risk (Cfree) vs. the potential hazard of those chemicals that might be released in future scenarios (Ctotal). The presented work calls for more detailed studies at specific sites and testing of additional endpoints with the aim of obtaining a complete picture of mixture effects caused by the freely dissolved and total concentrations of hydrophobic organic chemicals in sediments.