2024 Volume 80 Issue 16 Article ID: 23-16103
In this study, we used quantitative environmental DNA metabarcoding to estimate basin-wide fish species diversity in the Takatsu River in Japan. We calculated fish diversity indices at each sampling point and used generalized linear model (GLM) to examine the relationships between the fish diversity indices and environmental factors. Using the GLM, we created fish diversity potential maps of the river. Our results showed that water temperature and river slope were correlated with species richness, while the water depth, river discharge, proportion of paddy fields, and water temperature were correlated with the Simpson diversity index. Species richness had a significant positive relationship with water temperature, and the Simpson diversity index had a significant negative correlation with the river discharge. Additionally, we observed higher species richness in the downstream and higher Simpson diversity index in both upstream and downstream areas. These results indicate that it is possible to estimate the basin-wide spatial distribution of fish diversity.
