Fram pollution observatory anthropogenic debris pollution in the Arctic

The exponential increase in plastic production is reflected in the amount of waste produced, yet the waste management infrastructures and practices have been insufficient to regulate and govern the extensive plastic waste entering the environment, which was estimated as 19 – 23 million metric tons in 2016 for aquatic systems. Disturbing footage of pervasive pollution or an increasing number of sightings of encounters with charismatic species not only draw public attention but also boosted an interest within the scientific community. Soon enough, it was realized that anthropogenic debris pollution has even reached uninhabited remote islands and polar regions. Globally, there are thousands of studies on regional or large-scale anthropogenic debris pollution, yet a holistic approach to identify the distribution patterns is mostly lacking. In this regard, with the aim of measuring anthropogenic debris and microplastic pollution levels in all ecosystem compartments in the Arctic, the FRAM Pollution Observatory represents a rare case. The comparison of findings from different ecosystem compartments allowed us to explore and identify the sources, transportation pathways and sinks of anthropogenic debris in the Arctic. In this dissertation, I summarise the findings obtained by the studies of the FRAM Pollution Observatory. The main chapters deal with the distribution of macro-debris floating in Arctic surface waters (Chapter 2.1) and on the deep seafloor (Chapter 2.2) and with the distribution of microplastic throughout the water column and in deep-sea sediments (Chapter 3). However, in the general discussion (Chapter 4), I focused on the findings from all ecosystem compartments including sea ice, snow, Svalbard beaches and biota. Overall, the majority of anthropogenic macro-debris in the Arctic is plastic. In all ecosystem compartments, high levels of pollution were detected, which are comparable to those reported from more densely populated regions of the world. Quantities of floating macro-debris in Arctic waters were not different to those in the North Sea. Higher concentrations of floating macro-debris measured in summer than in autumn and spring highlighted the indirect effect of decreasing sea ice extent, which has opened new passages for maritime activities. Between 2002 and 2014, a significant increase in macro-debris concentrations on the deep seafloor was identified. Deep-sea sediments are an ultimate sink for microplastic pollution. Throughout the water column, highest microplastic concentrations were observed in the ocean surface layer and decreased towards greater depths as did organic matter distribution, too. Microplastic particles between 10 and 100 µm accounted for 99.9% of the microplastics detected in the water column, raising concerns about their bioavailability. A different vertical profile at the Molloy Deep suggested that local oceanographic conditions and bathymetry affect microplastic distribution. The simulation of drift trajectories indicated the North Atlantic Current as the main carrier of anthropogenic debris to the Fram Strait, yet with a contribution of the Transpolar Drift carrying debris from the Siberian Arctic. Sea ice drift trajectories identified the Kara and Laptev Seas as another source of pollution in the Fram Strait. As for the other studies of the FRAM Pollution Observatory, Arctic sea ice is a temporary sink of microplastic, scavenging particles from surrounding waters during ice formation and releasing them upon melting. Microplastic concentrations in Arctic snow, as an indicator of atmospheric microplastic pollution, showed considerable concentrations, which are comparable to those from urban areas. A preliminary analysis of microplastic distribution in the water column, sediment and snow showed significant differences in concentrations between sediment and other ecosystem compartments, but not between those obtained from the water column and snow. This finding points out a turnover at the sea-air interface. Last but not least, zooplankton organisms in the Fram Strait were found to have ingested microplastic, confirming the bioavailability of these anthropogenic pollutants. Although, a substantial number of findings helped me to understand the pollution levels and trends of anthropogenic debris in the Arctic, they raised a lot more questions to be answered. We still do not know, how and when such a pervasive pollutant will affect the biodiversity, biogeochemical cycles in the Arctic and eventually global climate patterns. I hope, we will be able to regulate our plastic production, consumption and waste management before such destructive impacts occur

Litter trends at three stations of the HAUSGARTEN observatory

The deep sea is considered a major sink for debris even in regions as secluded as the Arctic Ocean. Here, we assess the variability of litter over a latitudinal gradient at the HAUSGARTEN observatory by adding imagery from the southernmost station S3 to previously published data from the northernmost station N3 and the central station HG-IV. The analysis includes footage of the seafloor from 2002 to 2017. Photographic surveys were analyzed to determine litter density, material composition, size and interactions with epibenthic fauna. Litter density clearly increased over time ranging between 813 ± 525 (SEM) and 6,717 ± 2,044 (SEM) items km-². The dominant material was plastic and small-sized items accounted for 63% of the litter in the observatory. N3 experienced the strongest increase in litter dominated by dark pieces of glass (41%). Interactions between litter and epibenthic megafauna were frequently observed (45% of items) in the form of entanglement with sponges or colonization by sea anemones

Hotspots of Floating Plastic Particles across the North Pacific Ocean

The pollution of the marine environment with plastic debris is expected to increase, where ocean currents and winds cause their accumulation in convergence zones like the North Pacific Subtropical Gyre (NPSG). Surface-floating plastic (>330 μm) was collected in the North Pacific Ocean between Vancouver (Canada) and Singapore using a neuston catamaran and identified by Fourier-transform infrared spectroscopy (FT-IR). Baseline concentrations of 41,600–102,700 items km–2 were found, dominated by polyethylene and polypropylene. Higher concentrations (factors 4–10) of plastic items occurred not only in the NPSG (452,800 items km–2) but also in a second area, the Papaha̅naumokua̅kea Marine National Monument (PMNM, 285,200 items km–2). This second maximum was neither reported previously nor predicted by the applied ocean current model. Visual observations of floating debris (>5 cm; 8–2565 items km–2 and 34–4941 items km–2 including smaller “white bits”) yielded similar patterns of baseline pollution (34–3265 items km–2) and elevated concentrations of plastic debris in the NPSG (67–4941 items km–2) and the PMNM (295–3748 items km–2). These findings suggest that ocean currents are not the only factor provoking plastic debris accumulation in the ocean. Visual observations may be useful to increase our knowledge of large-scale (micro)plastic pollution in the global oceans

Plastic pollution in the Arctic

Plastic pollution is now pervasive in the Arctic, even in areas with no apparent human activity, such as the deep seafloor. In this Review, we describe the sources and impacts of Arctic plastic pollution, including plastic debris and microplastics, which have infiltrated terrestrial and aquatic systems, the cryosphere and the atmosphere. Although some pollution is from local sources — fisheries, landfills, wastewater and offshore industrial activity — distant regions are a substantial source, as plastic is carried from lower latitudes to the Arctic by ocean currents, atmospheric transport and rivers. Once in the Arctic, plastic pollution accumulates in certain areas and affects local ecosystems. Population-level information is sparse, but interactions such as entanglements and ingestion of marine debris have been recorded for mammals, seabirds, fish and invertebrates. Early evidence also suggests interactions between climate change and plastic pollution. Even if plastic emissions are halted today, fragmentation of legacy plastic will lead to an increasing microplastic burden in Arctic ecosystems, which are already under pressure from anthropogenic warming. Mitigation is urgently needed at both regional and international levels to decrease plastic production and utilization, achieve circularity and optimize solid waste management and wastewater treatment

Hotspots of Floating Plastic Particles across the North Pacific Ocean

The pollution of the marine environment with plastic debris is expected to increase, where ocean currents and winds cause their accumulation in convergence zones like the North Pacific Subtropical Gyre (NPSG). Surface-floating plastic (>330 μm) was collected in the North Pacific Ocean between Vancouver (Canada) and Singapore using a neuston catamaran and identified by Fourier-transform infrared spectroscopy (FT-IR). Baseline concentrations of 41,600–102,700 items km–2 were found, dominated by polyethylene and polypropylene. Higher concentrations (factors 4–10) of plastic items occurred not only in the NPSG (452,800 items km–2) but also in a second area, the Papaha̅naumokua̅kea Marine National Monument (PMNM, 285,200 items km–2). This second maximum was neither reported previously nor predicted by the applied ocean current model. Visual observations of floating debris (>5 cm; 8–2565 items km–2 and 34–4941 items km–2 including smaller “white bits”) yielded similar patterns of baseline pollution (34–3265 items km–2) and elevated concentrations of plastic debris in the NPSG (67–4941 items km–2) and the PMNM (295–3748 items km–2). These findings suggest that ocean currents are not the only factor provoking plastic debris accumulation in the ocean. Visual observations may be useful to increase our knowledge of large-scale (micro)plastic pollution in the global oceans

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

Publisher Correction: Plastic pollution in the Arctic

Correction to: Nature Reviews Earth & Environment https://doi-org.proxy.library.uu.nl/10.1038/s43017-022-00279-8, published online 5 April 2022. The credit line for Figure 5 was inadvertently omitted in the original version of this article. Figure 5 was adapted from an image courtesy of Julia Baak. This error has been corrected in the HTML and PDF versions of the article