環境DNAを用いたダクタイル鋳鉄かご工法「鋳田籠」の魚類・甲殻類の生息場としての機能評価

抄録

Recent years, “nature-oriented river works” taking riverine landscape and biota into consideration have been conducted on river management. One of the techniques in the nature-oriented river works is “ductile iron net method”. This study has evaluated the function of the ductile iron net method named “Chutaro” for habitats of fishes and decapods, using environmental DNA (eDNA) methods. On the eDNA quantification of Japanese eel (Anguilla japonica) by the real-time qPCR, the eDNA concentrations of Japanese eel at the sites with Chutaro tended to be higher than those of Japanese eel in the sites with concrete revetment. On the other hand, there were not significant differences in species richness and compositions of fishes and decapods regardless of the presence and absence of Chutaro. These results suggest that Chutaro could provide A. japonica with their habitats and could be useful for the nature-oriented river works.