The national monitoring program is financed by the Swedish Agency for Marine and Water Management. Monitoring is performed by the Swedish Museum of Natural History. Data are stored in the Swedish Ocean Archive (SHARK) by the Swedish Meteorological and Hydrological Institute (SMHI). Information about the program and the methods are available in Swedish at the website of Swedish Agency for Marine and Water Management, https://www.havochvatten.se/overvakning-och-uppfoljning/miljoovervakning/marin-miljoovervakning/tumlare.html

Contents and composition of microplastic-like particles have been analysed in ten sediment samples from the Danish part of the open North Sea and in the Inner Danish waters in 2015. The contents of microplastic-like particles in the size range 100-5000 µm were determined to be in the range of 192-3511 particles per kg dry weight sediment, dominated by blue and black coloured particles, mainly as fibres, and particle sizes < 300 µm were dominating.

This study is a first attempt in Denmark on assessing the presence of microplastics in our open & coastal waters from Baltic to North Sea. The occurrence and impact of microplastics have in the Danish initial assessment for EU’s Marine Strategy Framework Directive (MSFD) been identified as a relevant indicator for describing “Good Environmental Status” (GES) for descriptor 10 on Marine Litter. Microplastic particles in marine waters, which consist of synthetic polymer materials, origin mainly from secondary microplastics, i.e. fragments of litter like solid waste, fishing gear, paint flakes etc. from either sea- or land based sources. Primary microplastics (engineered) are not expected to be as common as secondary microplastics. Microplastics can origin from both local sources and from long-range transport with ocean or air currents.