This work was carried out for the Danish Environment Protection Agency (EPA) targeting microplastics (MP) in Danish marine sediments. It addresses the geographical distribution of MP in sediments from 23 stations, among which, 19 were analysed in 2022 (https://www.emodnet-ingestion.eu/submissions/submissions_details.php?menu=39&tpd=1185&step=001Denmark), and four were analysed in 2023. One of these four samples were collected from Skagerrak, and three were from the North Sea. It attempts to map the level and geographical distribution of MP in sediments from the North Sea and Skagerrak. The monitoring should furthermore create a baseline for future efforts to assess temporal changes of MP in Danish marine sediments.

In relation to Danish MSFD monitoring the data maps microplastics content in sediments in Danish waters. Data covers 13 sediment samples from the Belt Sea and its fjords, Kattegat and Limfjord. The samples were taken in 2018-2021 and analyzed in 2020-2021. A study of variation of microplastics over short distances, consisting of 13 sediment samples taken in a grid in Odense Fjord in 2021. The survey showed that microplastic could be found in all sediment samples in concentrations ranging from 22 to 7402 µg kg-1 (microgram microplastic per kg sediment dry matter). As number of microplastic particles, this corresponded to between 508 and 23340 N kg-1 (number of microplastics per kg of sediment dry matter) Odense Fjord showed that the microplastic content at this locality varied greatly. The average mass concentration was 4683 µg kg-1 with a range from 250 to 24848 µg kg-1 . Measured as a number, the concentration averaged 18671 N kg-1 with a range from 7266 to 34141 N kg-1 .