Marine litter is an ever-increasing problem that demands immediate reduction plans and mitigation actions that should act synergically to efficiently meet ambitious goals. Since the seafloor has been recognized as the major sink for marine debris, the study of litter accumulation dynamics represents a fundamental tool to evaluate future removal actions. We analysed a 7 years (2013–2019) standardized data series collected along Sardinian fishing grounds through MEDiterranean International Trawl Survey, for which estimates of density and weight of seafloor macro-litter were calculated over 707 hauls. Results show the absence of any temporal trend in seafloor macro-litter density and weight, but rather indicate a spatial and bathymetric segregation of different litter categories. Our data showed how different sources and physical features of macro-litter items (i.e., plastic and fishing gears, rubber, glass, metal and textile) led to spatially segregated accumulation hotspots. These hotspots often occurred at shallower depths and closer to coastlines, representing spots where future litter removal action could be prioritized. We also point out here how the identification of seafloor macro-litter hotspots using aggregated data that include plastic items could indeed hide the identification of hotspots of other less abundant but yet detrimental macro-litter categories accumulated in the marine environment.

海洋垃圾是一个日益严重的问题，需要立即制定减少计划和缓解行动，这些计划和缓解行动应协同行动，以有效实现雄心勃勃的目标。由于海底被认为是海洋垃圾的主要汇地，因此垃圾堆积动力学的研究成为评估未来清除行动的基本工具。我们分析了通过地中海国际拖网调查沿撒丁岛渔场收集的 7 年（2013 年至 2019 年）标准化数据系列，其中计算了 707 次拖捞的海底大型垃圾的密度和重量估计值。结果显示，海底大型垃圾密度和重量不存在任何时间趋势，而是表明不同垃圾类别的空间和水深隔离。我们的数据显示了宏观垃圾物品（即塑料和渔具、橡胶、玻璃、金属和纺织品）的不同来源和物理特征如何导致空间隔离的积累热点。这些热点通常发生在较浅的深度和靠近海岸线的地方，代表未来垃圾清除行动可以优先考虑的地点。我们还指出，使用包括塑料物品在内的聚合数据识别海底大型垃圾热点确实可以隐藏对海洋环境中积累的其他数量较少但有害的大型垃圾类别热点的识别。