Beach Litter - Composition of litter according to material categories in percent - Official monitoring

This visualization product displays marine litter material categories percentage per year per beach during monitoring surveys. EMODnet Chemistry included the gathering of marine litter in its 3rd phase. Since the beginning of 2018, data of beach litter 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 and reference lists used on a European scale. Preliminary processing were necessary to harmonize all the data : - Exclusion of OSPAR 1000 protocol, - Separation of monitoring surveys from research & cleaning operations - Exclusion of beaches with no coordinates - Normalization of survey lengths and survey numbers per year - Some categories & some litter types have been removed To calculate percentages, formula applied is : Material (%) = (total number of items (normalized at 100 m) of each material category)/(total number of items (normalized at 100 m) of all categories)*100 The material categories differ between reference lists (OSPAR, ITA, TSG_ML, UNEP, UNEP_MARLIN). In order to apply a common procedure for all the surveys, the material categories have been harmonized. Eleven material categories have taken into account for this product and information on data processing and calculation are detailed in the document attached p14.

本可视化产品展示了在监测调查期间，海滩上海洋垃圾材料类别按年度的百分比分布。在EMODnet Chemistry的第三阶段工作中，收集海洋垃圾已成为其中一项重要内容。自2018年初以来，海滩垃圾数据已在EMODnet Chemistry海洋垃圾数据库（MLDB）中进行收集和处理。鉴于数据来源、采样协议和参考列表在欧盟范围内的异质性，数据的一致性处理成为最具挑战性的任务。为使所有数据一致化，进行了初步处理：- 排除OSPAR 1000协议，- 将监测调查与研究和清洁操作分离，- 排除无坐标的海滩，- 规范化调查长度和每年调查次数，- 移除某些类别和某些垃圾类型。为计算百分比，应用的公式为：材料百分比（%）=（每种材料类别在100米范围内的物品总数）/（所有类别在100米范围内的物品总数）*100。参考列表（OSPAR、ITA、TSG_ML、UNEP、UNEP_MARLIN）中的材料类别有所不同。为了对所有调查应用统一程序，已对材料类别进行了协调。本产品考虑了十一类材料，数据处理的详细信息及计算方法详见附文第14页。