27 Jul 2021
Science for Environment Policy: Marine microplastics from ship coatings are the main polluter of waters
The most recent issue of Science for Environment Policy news and information services has published an article about a recent study by Dibke, C., et al. which assesses the distribution, variation, composition, concentration and sources of microplastics in the North Sea and German Bight.
The researchers in the study explored 24 locations in the North Sea and the German Bight with different potential impacts and sources of microplastic. They used the analytical methodology of ‘pyrolysis-gas chromatography coupled to mass spectrometry’ (Py-GC/MS). The study aimed to map particle distributions, properties, trends and concentrations; and to identify possible land and marine-based sources of 10 commonly used plastic polymers. The microplastics detected were almost exclusively under 1 mm in size.
Microplastic concentrations were elevated in coastal areas, in particular in the Elbe estuary, reflecting the many terrestrial plastic sources that find their way into the ocean. On the other hand, areas far away from the coastline revealed raised loads. Fishing activity was identified as a key source of anthropogenic floating debris in the North Sea, with high amounts of plastics commonly used for fishing nets, ropes, twines, and boxes used to transport seafood.
Notably, a cluster of polymers predominantly used in long-lasting applications (e.g. construction) and antifouling ship coatings dominated in the cross-section slicing from south-east to north-west, aligning closely with major commercial shipping lanes.
The findings invert the assumption that most marine microplastics come from land-based sources, instead indicating that in parts of the German Bight and attached estuaries, marine sources (shipping) far outweigh those based on land (packaging).
Microplastics are a complex class of contaminants that are currently receiving much attention from policymakers worldwide, including via the EU’s strategy on plastics and the European Chemicals Agency’s assessment for a wide-ranging restriction on intentionally-added microplastics in products.
The CLAIM project is also on the mission to monitor the pollution in seas and oceans. One of CLAIM’s technologies, the FerryBox, is an automated seawater sampling device and passive flow-through filtering system. It assists the collection of data on the distribution of microplastics and helps understand their impact on marine ecosystems. This autonomous system is used in the Mediterranean and Baltic Seas. The overall scope of CLAIM’s technological innovations are the six case study areas: Saronikos gulf (Greece), Ligurian Sea (Italy), Gulf of Lion (France), Gulf of Gabes (Tunisia), Baltic Sea: Gulf of Finland (Estonia), and the Belt Sea (Denmark – Germany).
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Source: Dibke, C., Fischer, M., Scholz-Böttcher, B. M. (2021) Microplastic Mass Concentrations and Distribution in German Bight Waters by Pyrolysis–Gas Chromatography–Mass Spectrometry/Thermochemolysis Reveal Potential Impact of Marine Coatings: Do Ships Leave Skid Marks? Environmental Science and Technology, 55 (4): 2285–2295.