Abstract
Environmental DNA (eDNA) analysis, which has developed remarkably in recent years, has reached the stage where relatively large evaluation of the biomass of ayu (Plecoglossus altivelis) at the water sampling point is possible, in addition to the fact that the work at the site is only water sampling and the burden is small. In this research, using this eDNA analysis, we clarified the habitat of ayu during river life in wide area including Tama River and its branch, grasp the distribution of the population density of ayu, and especially in Tama River We identified areas with high population density. In addition, it was confirmed that the high range of the specified habitat density and the range where the confirmed population was large in the census of riparian waters nearly coincided, and the estimation of the population density of ayu by eDNA is consistent with the capture survey.
Furthermore, from the results of concentration comparison with Saba and Takatsu River which quantified eDNA of Ayu by the same method as this research, the eDNA concentration of Tamagawa obtained this time is extremely high, and the Ayu resource amount of Tama River is It was suggested that there was a lot.
