Marine Debris Floating in Arctic and Temperate Northeast Atlantic Waters

Abstract

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.

Where does Arctic beach debris come from? Analyzing debris composition and provenance on Svalbard aided by citizen scientists

“…Small, unidentifiable plastic debris and foam particles were also most abundant on the Western Black Sea coast (Topcu et al, 2013). Strapping bands (15 -20%) came second highest in abundance, similar to observations in the Russian Far East (Jaskoĺski et al, 2018) and the Siberian Arctic (Vesman et al, 2020) and floating debris surveys in the Arctic and Northeast Atlantic (Tekman et al, 2022a).…”

“…(Thompson et al, 2004). If the mean count is converted to items km -2 to enable a magnitudescale comparison with data from the nearby Fram Strait obtained during the same time period, it is obvious that mean quantities are highest on beaches (370,000 items km -2 ) followed by the seafloor (3,485 items km -2 (Parga Martıńez et al, 2020)) and the sea surface (11 items km -2 , (Tekman et al, 2022a)). The two and five orders of magnitude differences support the realization that beaches are important accumulation areas of marine debris (Onink et al, 2021;Haarr et al, 2022;Isobe and Iwasaki, 2022;Tekman et al, 2022c).…”

“…Although research has recently highlighted the presence of plastic debris in some compartments of the Fram Strait such as the sea surface, water column and the deep seafloor (Bergmann et al, 2016;Tekman et al, 2017;Grøsvik et al, 2018;Parga Martıńez et al, 2020;Tekman et al, 2022a), such observations rarely allow identification of the provenance of debris. Modeling patterns indicate that a large part of debris drifts northwards with the Atlantic or originates from local sources (Pogojeva et al, 2021;Strand et al, 2021), however, empirical evidence is still limited.…”

“…We quantified the debris mass and abundance per m 2 to determine current pollution levels and composition of Arctic beaches. These data were compared with those from the seafloor (Parga Martıńez et al, 2020) and sea surface (Tekman et al, 2022a) in the region to delineate potential sinks of marine debris. The provenance of debris was determined to assess if items come from local or distant sources.…”

Status and future recommendations for recording and monitoring litter on the Arctic seafloor

“…In addition to time series of litter on the seafloor, the HAUSGARTEN observatory work also includes regular sampling of deep-sea sediments for microplastic analyses (Bergmann et al, 2017a;Tekman et al, 2020). It also includes occasional surveys of the water column, sea ice, snow (Bergmann et al, 2019;Tekman et al, 2020), and zooplankton (Botterell et al, 2022), as well as macrolitter surveys at the sea surface and on the beaches of Svalbard (Bergmann et al, 2016(Bergmann et al, , 2017bTekman et al 2022). Recommendations For monitoring purposes, it is recommended that seafloor litter is documented both from imagery recording or through trawling if part of an ongoing fisheries stock assessment.…”