砂河川に生息する底生魚カマツカの河床環境劣化抑制機能の評価

抄録

Pseudogobio esocinus is a common benthic fish in Japanese rivers, which has powerful effects on sand particle motions by its feeding and submerging in sand bed. In the present study, the indoor flume experiments with these fish were conducted to examine the preference of substratum condition for their staying and submerging, and furthermore to evaluate their impacts on pick up rate and step length of bed load particles which adapted to the conventional probability model for bed load developed by Einstein (1942). The results of our experiments, especially in comparison of the pick up rates of bed load with the conventional hydraulic knowledge, have clarified that the individuals of P. esocinus could have increased 20-30 % of the dimensionless tractive force without these fishes on sand bed channels.