Description: In 1999 the AWI established the HAUSGARTEN observatory, to assess the impact of climate change on Arctic ecosystems in Fram Strait (Arctic), which included repeated camera transects to assess changes on the deep Arctic seafloor. A first analysis of the footage highlighted that marine debris increased over time. Plastic debris was also sighted during sea surface observations for seabird surveys. This prompted us to add a pollution observatory to the ongoing research programme FRAM, aiming to quantify plastic pollution in different ecosystem compartments to identify hidden sinks. Here, we summarise the results of this work encompassing matrices such as snow, sea ice, surface waters, water column, deep seafloor, biota and Arctic beaches. Images from the deep seafloor taken since 2002 showed a marine debris concentration of 4,571 ± 1,628 items km-2, which is in range with polluted oceanic regions. Visual surveys of floating debris from the same region revealed 500 times lower concentrations (9 items km-2), showing that the deep Arctic seafloor constitutes a sink for marine debris. Quantities of 9–483 g m-2 were reported from 15 beach surveys on Svalbard by citizen scientists. Plastics accounted for 〉80% of the mass, primarily from fisheries. Microplastics in samples from the sea surface, water column, sediment, sea ice and snow were analysed by combining state-of–the-art sampling technology with µFT-IR analyses. Using the same analysis for samples from different ecosystem compartments enabled us to determine the vertical distribution of microplastics, as sea ice entrains extremely high microplastic concentrations, which are released to the underlying waters during ice melts. In-situ pump-filtrations throughout the water column revealed that microplastics prevail at all depths in Fram Strait (0–1,287 items m–3). Microplastic concentrations in sediments ranged from 239–13,331 N kg–1. Highest microplastics concentrations in sediments and the water column were measured close to the marginal ice zone and polymer compositions indicated a sea ice origin for most particles found in the deep waters of East Greenland, indicating sea ice as a temporal sink. Indeed, the highest concentration (1.2 ± 1.4) ×107 items m-3) was recorded in an ice core from pack ice of Fram Strait. The presence of microplastic in snow samples from ice floes indicates atmospheric deposition of microplastics. Recent research shows that resident zooplankton ingests microplastics, which were also found in the ice algae Melosira arctica. The data indicate that the seafloor and sea ice constitute (temporal) sinks of plastic pollution and that pollution levels are high, despite of the distance to sources. The receding sea ice has already led to increased anthropogenic pressure in the Fram Strait, which is likely to become a major shipping lane during summer. The number of fishers operating around Svalbard and of ship calls to Longyearbyen has already increased significantly. In addition, the prevailing hydrography promotes the transport of plastic pollutants from distant sources, mostly from the Atlantic Ocean, but also from the Central Arctic via the Transpolar Drift. Long-range atmospheric transport and deposition likely adds to this.

Description: Die Be­las­tung un­se­rer Mee­re und Ozea­ne mit Müll ist ein Um­welt­pro­blem glo­ba­len Aus­ma­ßes. Es wird pro­gnos­ti­ziert, dass der jähr­li­che glo­ba­le Ein­trag von land­ba­sier­tem Kunst­stoff­müll von rund 8 Mil­lio­nen Ton­nen im Jahr 2010 auf bis zu 100–250 Mil­lio­nen Ton­nen im Jahr 2025 an­stei­gen wird. 99% al­ler See­vo­gel-Ar­ten sol­len bis 2050 Plas­tik­müll ver­zeh­ren, heute sind es bereits ca. 90%. Wir wis­sen mitt­ler­wei­le, dass hier ein Um­welt­pro­blem glo­ba­len Aus­ma­ßes ent­stan­den ist, das nicht nur die Na­tur be­droht, son­dern auch Aus­wir­kun­gen auf den Men­schen ha­ben wird. Zu den bio­lo­gi­schen Ef­fek­ten kom­men so­zio-öko­no­mi­sche Aus­wir­kun­gen, wie Ein­bu­ßen im Tou­ris­mus, aber auch die un­mit­tel­ba­re Be­schä­di­gung in­dus­tri­el­ler An­la­gen und Kos­ten durch See­notret­tung. Seit 1999 be­treibt das Al­fred-We­ge­ner-In­sti­tut Lang­zeit­un­ter­su­chun­gen am Tief­see-Ob­ser­va­to­ri­um HAUS­GAR­TEN in der Ark­tis. Re­gel­mä­ßig wie­der­hol­te Auf­nah­men mit ei­ner ge­schlepp­ten Ka­me­ra zei­gen, dass der Mee­res­grund der ark­ti­schen Tief­see seit 2002 im­mer mehr Müll be­her­bergt. Auch an den Strän­den Spitz­ber­gens wird mitt­ler­wei­le an­ge­schwemm­ter Müll ein­ge­sam­melt. Un­se­re Un­ter­su­chun­gen zei­gen, dass gro­ße Men­gen von Mi­kro­plas­tik in das Meer­eis, Schnee und die Se­di­men­te der Tief­see ge­langt sind. In die­sem Vor­trag wird ein Aus­blick über die Er­geb­nis­se ge­zeigt und die Ur­sa­chen dis­ku­tiert.

Description: Floating marine debris is ubiquitous in marine environments but knowledge about quantities in remote regions is still limited. Here, we present the results of an extensive survey of floating marine debris by experts, trained scientists from fields other than pollution or non-professional citizen scientists. A total of 276 visual ship-based surveys were conducted between 2015 and 2020 in the Northeast (NE) Atlantic from waters off the Iberian Peninsula to the Central Arctic, however, with a focus on Arctic waters. Spatiotemporal variations among regional seas (Central Arctic, Barents Sea, Greenland Sea, Norwegian Sea, North Sea) and oceanic regions (Arctic waters and the temperate NE Atlantic) were explored. The overall median debris concentration was 11 items km-2, with considerable variability. The median concentration was highest in the North Sea with 19 items km-2. The Nordic seas, except the Central Arctic showed median concentrations ranging from 9 to 13 items km-2. Plastic accounted for 91% of all floating items. Miscellaneous fragments, films, ropes and nets, packaging materials, expanded polystyrene and straps were the most frequently observed plastic types. Although the median debris concentration in the Central Arctic was zero, this region was not entirely free of floating debris. The variations between regional seas and oceanic regions were statistically not significant indicating a continuous supply by a northward transportation of floating debris. The data show a slight annual decrease and clear seasonal differences in debris concentrations with higher levels observed during summer. A correlation between debris concentrations and environmental and spatial variables was found, explaining partly the variability in the observations. Pollution levels were 500 times lower than those recorded on the seafloor indicating the seafloor as a sink for marine debris. The Arctic was characterised by similar pollution levels as regions in temperate latitudes highlighting that Arctic ecosystems face threats from plastic pollution, which add to the effects of rapid climate change.