Seafloor Litter - Composition of litter according to material categories in percent per trawl 2007/2021 v2021

This visualization product displays the marine litter material categories percentage per trawl per year.<br><br>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). <br>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.<br><br>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.<br>Only surveys with an unknown number of items were excluded from this product.<br><br>Harmonization of the material categories between ICES and MEDITS lists has been performed and the following calculation has been applied: <br>Material % = (∑Number of items of each material category*100)/(∑Number of items of all material categories)<br><br>More information on data processing and calculation are detailed in the document attached.