Identifying hidden sinks of Arctic plastic pollution: Fram Pollution Observatory

• Main Authors: Bergmann, Melanie, Tekman, Mine Banu, Allen, Deonie, Gerdts, Gunnar, Gutow, Lars, Meyer, Anna Natalie, Peeken, Ilka, Primpke, Sebastian
• Format: Conference Object
• Language: unknown
• Published: 2022
• Subjects: Arctic; Climate change; Fram Strait; Sea ice; Svalbard
• Online Access: https://epic.awi.de/id/eprint/57160/; https://hdl.handle.net/10013/epic.bef8823e-465f-486c-9573-f513306e9b2d

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 ...