Impacts of Anthropogenic Activities on Invertebrate Communities in an Urban River Revealed by eDNA Metabarcoding

As environmental indicators, invertebrate communities are closely related to the changes in the water environment. Efficient and accurate monitoring of invertebrates is of great significance for providing references for water environment conservation. Environmental DNA (eDNA) metabarcoding permits a useful tool for biodiversity monitoring in aquatic ecosystems. Panlong River is a typical urban river suffering from various anthropogenic activities in Kunming, Yunnan, China, and the current characteristics of invertebrate communities are unclear. Therefore, this study investigated the spatial and seasonal patterns of invertebrates and the environmental stressors of Panlong River. Based on eDNA metabarcoding, 968 amplicon sequence variants (ASVs) of invertebrates belonging to Annelida, Arthropoda, Cnidaria, Gastrotricha, Mollusca, Platyhelminthes, Protozoa, Rotifera and Tardigrada were identified, with Arthropoda being the absolute dominant phylum. Distinct spatial and seasonal variations in the invertebrate communities (e.g., ASV numbers, dominant genera, relative abundances and Shannon–Wiener index) were observed. Macrothrix was the first dominant genus both during dry and wet periods, while the second abundant genus was different during dry ( Acanthamoeba ) and wet ( Cricotopus ) periods. A spatial–seasonal heterogeneity of the relation between the invertebrate communities and environmental factors was observed in Panlong River. C, COD andNH 4 + were deemed to be the crucial environmental stressors influencing the distributions of the invertebrate communities in Panlong River, which was consistent with the spatial and seasonal differences in pollution characteristics around Panlong River. This study provides insights on conserving the diversity of invertebrate communities and the management of Panlong River and similar urban rivers.