Matter budget of microplastics in limnic ecosystems: sources, flow paths and sinks of microplastic particles in the model catchment area of Lake Tollense, Mecklenburg Western-Pomerania
Final Report Abstract
The MICROLIM project aimed to record and analyze the occurring concentrations of microplastics in the different ecosystem compartments water - sediment and atmosphere in a lake catchment area of Mecklenburg-Vorpommern. The analysis of the shoreline sediments in spatial and temporal resolution was carried out by semi-annual measurement campaigns over two years, during which at the four sand dominated beach sections of the lake in three different littoral positions along the waterline and 3-5 parallels. In addition, sediment samples were collected from the lake bottom along the longitudinal extent of Tollensesee. The mean microplastic concentration was 1,410 particles/kg dry weight (TG) for lakeshore sediments and 10,476 particles/kg TG for lake bottom sediments. Fragments were more abundant compared to fibers in both sediment compartments. Elevated microplastic levels were detected on the beach with the lowest anthropogenic influence, but near a tributary whose watershed consists primarily of agricultural land that acts as a potential pathway for microplastics to enter Lake Tollense. To investigate microplastics in the lake's water body, both net-based near-surface samples and pump-based samples were collected in the water column. For this purpose, sampling was carried out in three measurement campaigns using manta trawls and pump-based at three depths (surface, 7 m and 10 m) along a transect with eight sampling points. The vertical distribution of MP particles in Lake Tollens differed considerably between the particle morphologies (fragments and fibers). In contrast to fibers, fragments showed a significant pattern in the depth profile with decreasing concentrations with increasing depth. Fragments were dominated by buoyant polymers (mainly polyethylene and polypropylene) while fibers consisted mainly of polyethylene terephthalate and polypropylene. In addition to the inherent properties of the particles, the spatial distribution patterns indicate wind-induced mixing, which also affects the intensity of the vertical concentration gradients. The detection of potential atmospheric MP inputs was performed within the MICROLIM project over a period of one year at four sites in each of three parallels with exposure north, south, west and east of Lake Tollensee analyzed. The obtained results compare very well to rural sites in northern Germany and are significantly different to urban sites in terms of concentration and dominant particle morphologies.
Publications
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Anthropogenic litter in freshwater environments – Study on lake beaches evaluating marine guidelines and aerial imaging. Environmental Research, 189, 109945.
Hengstmann, Elena & Fischer, Elke Kerstin
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Microplastics in a deep, dimictic lake of the North German Plain with special regard to vertical distribution patterns. Environmental Pollution, 267, 115507.
Tamminga, Matthias & Fischer, Elke Kerstin
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Microplastics in atmospheric deposition in Northern Germany Micro2020
Klein & M. Fischer, E.K.
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Microplastic concentrations, characteristics, and fluxes in water bodies of the Tollense catchment, Germany, with regard to different sampling systems. Environmental Science and Pollution Research, 29(8), 11345-11358.
Tamminga, Matthias; Hengstmann, Elena; Deuke, Ann-Kristin & Fischer, Elke Kerstin
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Microplastics in lakeshore and lakebed sediments – External influences and temporal and spatial variabilities of concentrations. Environmental Research, 197, 111141.
Hengstmann, Elena; Weil, Esther; Wallbott, Paul Christian; Tamminga, Matthias & Fischer, Elke Kerstin
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Spatial distribution of atmospheric microplastics in bulk deposition of urban and rural environments of Northern Germany, Micro 2022
Klein, M. & Fischer, E.K.
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Anthropogenic litter and microplastics in freshwater sediments – A case study at Lake Tollense, Germany, Micro2020, Lanzarote
Hengstmann, E. & Fischer, E.K.
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Microplastics in a deep, dimictic lake with special regard to vertical distribution patterns, Micro2020, Lanzarote
Tamminga, M. & Fischer, E.K.
