EXAMINING ENVIRONMENTAL FACTORS AFFECTING FISH ASSEMBLAGE PATTERNS IN THE TRIBUTARIES USING QUANTITATIVE EDNA METABARCODING

Abstract

 In this study, we examined the fish assemblage patterns on different tributary habitat types (natural and artificial tributaries) and relationships between the fish assemblages and environmental factors in the Gonokawa River in Japan using quantitative environmental DNA (eDNA) metabarcoding. The analysis results indicate that the species richness in the natural tributary streams was higher than that in the irrigation channels. In addition, the eDNA concentrations of fishes that tend to prefer sand/gravel substrates or aquatic vegetation in the natural tributary streams were higher than those in the irrigation channels. Further, stream discharge was positively related to certain fishes. This study indicates that quantitative eDNA metabarcoding is an efficient monitoring tool, elucidating that artificial stream modifications would affect fish assemblage compositions in the tributaries.