水理模型実験によるトミヨのための小規模魚道の開発

抄録

  In order to develop a small-scale fishway for Amur stickleback, 25 experiments were conducted using hydraulic models of (1) pool-and-weir fishway with orifices, (2) pool-and-weir fishway without orifices, (3) Chidori-X type fishway with orifices, and (4) Ice-Harbor type fishway with orifices. The results of the experiments showed that (i) Amur sticklebacks had a tendency of passing through orifices in the experiments with orifices and the ascending speeds of Amur sticklebacks were faster in the experiments with orifices than without orifices, (ii) the ascending ratios of Amur sticklebacks were higher and the low-speed region of the pool was wider in the pool-and-weir fishway with orifices than other fishways, (iii) the ascending ratios of Amur sticklebacks were affected by the water temperature, (iv) Amur sticklebacks had a tendency of migrating in the daytime, not in the nighttime, and (v) the small-scale fishway for Amur sticklebacks was successfully developed to deal with higher difference in water level, by increasing the number of pools and setting 0.025m for the difference in design water level between adjacent pools.