This visualization product displays the marine litter material categories percentage per trawl.
EMODnet Chemistry included the collection of marine litter in its 3rd phase. Since the beginning of 2018, data of seafloor litter collected by international fish-trawl surveys have been gathered and processed in the EMODnet Chemistry Marine Litter Database (MLDB).
The harmonization of all the data has been the most challenging task considering the heterogeneity of the data sources, sampling protocols (OSPAR and MEDITS protocols) and reference lists used on a European scale. Moreover, within the same protocol, different gear types are deployed during fishing bottom trawl surveys.
Unlike other EMODnet seafloor litter products, all trawls surveyed since 2007 are included in this map even if the wingspread and/or the distance are unknown.
Only surveys with an unknown number of items were excluded from this product.
Harmonization of the material categories between ICES and MEDITS lists has been performed and the following calculation has been applied:
Material % = (?Number of items of each material category*100)/(?Number of items of all material categories)
More information on data processing and calculation are detailed in the document attached.
Warning: the absence of data on the map doesn't necessarily mean that they don't exist, but that no information has been entered in the Marine Litter Database for this area.