BASIN-WIDE RIVER ENVIRONMENTAL EVALUATION BASED ON ENVIRONMENTAL DNA AND STABLE ISOTOPE

Abstract

 We conducted the eDNA and stable isotope samplings in order to evaluate the environmental conditions of two river basins (Takatsu and Takahashi rivers) with different land use in Japan in October of 2022.We used the quantitative eDNA metabarcoding to estimate the eDNA concentrations of fishes in the study sites. In addition, we used nitrogen stable isotope ratio of attached algae as the indicators of nutrient loads from the catchments. Our results showed that the river segments with higher restoration priority (e.g., river segments with higher species diversity and higher nutrient loads) were identified based on eDNA concentrations and nutrient stable isotope ratios.