Community structure of zooplankton and its response to aquatic environmental changes based on eDNA metabarcoding

Environmental DNA (eDNA), as a tool for rapid, non-invasive biodiversity monitoring and ecological assessment, is pivotal to the understanding of aquatic biodiversity. In this study, eDNA metabarcoding technology was compared with conventional microscopical approaches to identify the variability characteristics of Weihe River community structure under changing environment. The number of species identified by molecular method was 3 times that by traditional method, which significantly improved the identification ability of species. There was a positive correlation between sequence abundances and microscopical individual counts (r = 0.84, p < 0.05;r = 0.97, p < 0.05). COI gene markers were more discriminative for the biological communities' heterogeneity, and their first two principal components (PC1 and PC2) explained 55.54% of the variance of the total variables. Moreover, molecular methods elucidated the interaction between eco-hydrological variables and zooplankton community structure. The variation of land-use types led to significant differences in zooplankton abundance. Total nitrogen, Water temperature, river width and altitudewere the key impact factors of zooplankton community change (p < 0.01). We believe that our research would provide meaningful demos on the application of eDNA technology in river ecosystem monitoring and assessment.