1. Anthropogenic litter (solid manufactured waste) is an understudied but pervasive element of river systems worldwide. Its physical structure generally differs from natural substrates, such as gravel and cobbles (hereafter rocks). Consequently, anthropogenic litter could influence ecological communities in urban rivers by providing novel habitats.
2. This study compares the macroinvertebrates recorded on anthropogenic litter with those on rocks to test whether the different substrates support distinct communities. Macroinvertebrates were collected from individual rocks and anthropogenic litter, predominantly plastic, metal, and glass, in three U.K. rivers.
3. Macroinvertebrate communities on anthropogenic litter were consistently more diverse than those found on rocks, reflecting its greater surface complexity, but the density of macroinvertebrates was similar among substrates. The community composition also varied between substrates, with five taxa only recorded on anthropogenic litter. Community differences largely reflected greater abundances of common taxa on anthropogenic litter, which were relatively insensitive to environmental quality. Plastic and fabric anthropogenic litter communities were the most dissimilar to those on rocks, probably due to their flexibility, which could replicate the physical structure of aquatic macrophytes.
4. Our findings indicate that anthropogenic litter supports a distinct and diverse community of macroinvertebrates in urban rivers, which are otherwise relatively homogenous in habitat structure.
5. Removal of anthropogenic litter from urban rivers may not be beneficial for local biodiversity. Understanding the functional habitats provided by anthropogenic litter could help better manage urban rivers to replace habitat lost through urbanisation.

中文翻译：

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人为垃圾是城市河流中水生无脊椎动物的新栖息地

1. 人为垃圾（固体废物）是世界范围内河道系统研究不足但普遍的要素。其物理结构通常不同于天然基质，例如砾石和鹅卵石（以下称岩石）。因此，人为垃圾可以通过提供新颖的栖息地来影响城市河流的生态群落。
2. 这项研究比较了人为凋落物和岩石上记录的大型无脊椎动物，以测试不同基质是否支持不同的群落。在英国的三条河流中，从单个岩石和人为垃圾（主要是塑料，金属和玻璃）中收集了无脊椎动物。
3. 人为凋落物上的大型无脊椎动物群落比岩石上的群落更加多样化，这反映出其更大的表面复杂性，但基质之间大型无脊椎动物的密度相似。底物之间的群落组成也有所不同，仅在人为凋落物上记录了五个分类单元。社区差异在很大程度上反映出人为凋落物上的常见分类单元数量增加，这对环境质量相对不敏感。塑料和织物人为凋落物群落与岩石上最相似，可能是由于它们的柔韧性，它们可以复制水生植物的物理结构。
4. 我们的研究结果表明，人为乱扔垃圾支持城市河流中一个独特而多样的大型无脊椎动物群落，否则它们在生境结构上相对同质。
5. 从城市河流清除人为垃圾可能对当地生物多样性没有好处。了解人为垃圾提供的功能性栖息地有助于更好地管理城市河流，以替代因城市化而丧失的栖息地。