Understanding litter dynamics on riversides is challenging due to the need for extensive data. A seven-year citizen science study with schoolchildren showed no major changes in litter density, composition, and sources on German riversides. The study categorized 26,757 macrolitter items (> 2.5 cm in size), mainly consisting of plastic and cigarette butts, with a median litter density of 0.28 items m−2. We found that wide rivers (> 51 m) had significantly higher median litter densities (0.42 items m−2) than narrow rivers (< 10 m, 0.14 items m−2), indicating greater litter accumulation in downstream areas. A zero-inflated binomial hurdle model showed that litter density variations were influenced by the interaction of the river system with sampling campaign and river width. Schoolchildren identified visitors as the most likely source of riverine litter. These findings highlight the value of citizen science in understanding long-term trends and show the urgent need for political measures.

中文翻译：

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德国河流垃圾污染的时间可变性 – 作为公民科学家的中小学生的长期评估


由于需要大量数据，了解河边的垃圾动态具有挑战性。一项针对学童的为期 7 年的公民科学研究表明，德国河滨的垃圾密度、成分和来源没有重大变化。该研究对 26,757 个大型垃圾物品（> 2.5 厘米大小）进行分类，主要由塑料和烟头组成，垃圾密度中位数为 0.28 个 m-2。我们发现，宽河（x3E 51 m）的凋落物密度中位数（0.42 items m-2）明显高于狭窄河流（< 10 m，0.14 items m-2），表明下游地区的凋落物积累量更大。零膨胀二项式障碍模型显示，凋落物密度变化受河流系统与采样活动和河流宽度相互作用的影响。学童认为游客是最有可能的河流垃圾来源。这些发现突出了公民科学在理解长期趋势方面的价值，并表明迫切需要采取政治措施。